2.2. Using the pywbemcli command line general options
2.2.1. Overview of the general options
General options define:
The server definition (i.e. :term:connection definition) to the WBEM server or mock WBEM server against which the pywbemcli commands are targeted. See Defining the WBEM server for details.
Attributes of the WBEM server which is being targeted. This includes attributes such as the user/password, certificates, etc. pull operations. These attributes are attached to the current WBEM server connection definition and persisted with that connection definition.
Operation behavior of pywbemcli for requests; i.e. using the pull operations vs the traditional operations, the client side timeout, etc.. See Controlling operation behavior and monitoring operations for details.
Execution options to monitor the requests and responses (statistics keeping, and logging of operations) and to display the results. See Controlling operation behavior and monitoring operations and Controlling output formats for details.
General options to show the pywbemcli version, and display help for any of the command groups or commands.
General options must be entered on the command line before the command group or command.
For example the following enumerates qualifier declarations and outputs the
result in the simple
table format:
pywbemcli --output-format simple --server http://localhost qualifier enumerate
Qualifier Declarations
Name Type Value Array Scopes Flavors
----------- ------- ------- ------- ----------- ---------------
Description string False ANY EnableOverride
ToSubclass
Translatable
Key boolean False False PROPERTY DisableOverride
REFERENCE ToSubclass
In interactive mode, general options from the command line are defined once and retain their value throughout the execution of the interactive mode.
General options defined in the command line may be overwritten by specifying them on interactive mode commands. The resulting new value is used only for that one command, and is not retained for subsequent interactive mode commands.
In the following example, the --output-format general option is used on an interactive mode command to overwrite the default output format, and the --server general option is used to overwrite the server that was specified in the command line invocation:
$ pywbemcli --server http://myserver
pywbemcli> --output-format table --server http://localhost qualifier enumerate
Qualifier Declarations
+-------------+---------+---------+---------+-----------+-----------------+
| Name | Type | Value | Array | Scopes | Flavors |
+=============+=========+=========+=========+===========+=================+
| Description | string | | False | ANY | EnableOverride |
| | | | | | ToSubclass |
| | | | | | Translatable |
+-------------+---------+---------+---------+-----------+-----------------+
| Key | boolean | False | False | PROPERTY | DisableOverride |
| | | | | REFERENCE | ToSubclass |
+-------------+---------+---------+---------+-----------+-----------------+
The following table is an overview of all of the pywbemcli general options with a cross-reference to a detailed definition of each option.
Option Name |
Function(1) |
Description |
Type |
Default Value |
---|---|---|---|---|
Server Definition |
Define server URI |
String |
||
Sever Definition |
Get server definition by name |
String |
||
Server Definition |
Define mock server |
String |
||
Server Attribute |
Server user name |
String |
||
Server Attribute |
Server user password |
String |
||
Server attribute |
Use of pull Operations |
Choice |
either |
|
Server attribute |
Max pull response size |
Integer |
1000 |
|
Server attribute |
Server cert attribute |
String |
||
Server attribute |
Private key file attribute |
String |
||
Client attribute |
Control stats |
Boolean |
||
Client attribute |
Define log output |
String |
||
Client attribute |
Verify server cert |
Boolean |
True |
|
Client blah |
Define server ca certs |
String |
||
Client attribute |
Timeout server request |
Integer (sec) |
30 sec |
|
Client attribute |
Connection default namespace |
String |
root/cimv2 |
|
Client attribute |
Define Table format |
Choice |
MOF |
|
Client attribute |
Display processing details |
Boolean |
False |
|
Client attribute |
Show pywbemtools version |
|||
Client attribute |
Control warnings display |
Boolean |
||
Client attribute |
Define file path |
String |
Default file |
|
Client attribute |
Run with debugger |
Boolean |
||
Client attribute |
Show help |
String |
Server definitions and server attributes are attached to a connection definition and are used when defined for the current connection definition in the interactive mode. Client attribute exist for the life of an interactive session in the interactive mode. Thus –verbose entered on the command line is used for all commands in the interactive mode. –user entered on the command line applies to the current server definition only.
2.2.1.1. Defining the WBEM server
The target WBEM server can be defined on the command line in several ways with the following arguments :
General options that define the WBEM server to be used.
The following 3 mutually exclusive general options define the WBEM server that wil be the target of pywbem cli server-request commands (ex. class get <class name).
The --server general option defines the URI of a real WBEM server. The attributes of the server used by pywbemcli are defined by the connection characteristics general options (ex. –user, etc.)
pwybmcli -s http:myserver
* The :ref:`--name general option` defines the name of a :term:`connection definition`
in a :term:`connections file`. This name must have been previously created
by saving the name of a server definition with the :ref:`Command
connection save` command.
pwybmcli -n mytestserver connection show
defines the use of the previously defined connection ``mytestserver`` and
executes the pywbem command ``connection show``.
Connection definitions can be stored in a :term:`connections file`
and are managed with the :ref:`Connection command group`.
* The :ref:`--mock-server general option` defines a :ref:`Mock WBEM Server` that
is created upon pywbemcli startup. The MOF or python files that are defined
with as values of the option define the characteristics of thes mock WBEM server
(The CIM objects that will be build in the mock environment and that can be
accesses as if they were a real WBEM server).
The mock WBEM server allows testing or demonstrating pywbemcli without
having access to a real WBEM server.
pwybmcli -m mytestmof.mof -m mytestscript.py class enumerate
defines the use of the pywbemcli mock WBEM server script ``myscript.py`` and
executes the pywbem command ``class enumerate`` to show the first level
of the class hiearchy class names in the default namespace.
Define connection characteristics for a WBEM server by using the
The following general options can be used for specifying additional information for the connection and become part of the connection definition (i.e. connection) for a WBEM server.
The --default-namespace general option defines the default namespace to be used if a command does not specify a namespace.
The --user general option defines the user name for authenticating with the WBEM server.
The --password general option defines the password for authenticating with the WBEM server.
The --verify general option defines whether the client verifies certificates received from the WBEM server.
The --use-pull general option defines whether pywbemcli issues requests like
instance enumerate
as pull operations or as the traditional operations. See Pull operations.The --pull-max-cnt general option defines the maximum number of instances the WBEM server can return in a single response to an Open or Pull client request
The --certfile general option defines the client certificate file.
The --keyfile general option defines the client key file.
The --ca-certs general option defines a collection of certificates against which certificates received from the WBEM server are verified.
The --timeout general option defines the client side timeout for operations.
NOTE: Not all of the above general options are used by the mock WBEM server. Thus, since the mock WBEM server has no security layer, the
--keyfile
,--certfile
, and--ca-certs
options will be rejected if a mock WBEM server is specifiedA connection definition can be named and persisted in a pywbemcli connections file identified by a connection name so that it can be used by pywbem with the --name general option.
2.2.1.2. Controlling operation behavior and monitoring operations
Several general options control the behavior and monitoring of the operations executed against the WBEM server.
The DMTF specifications allow alternative forms of some operations, pywbemcli implements this flexibility and controls the choice of either the pull operations or the traditional operations through the --use-pull general option. With this option the user can choose to use either type of operation if that operation is available on the WBEM server. See Pywbemcli and the DMTF pull operations for more information on pull operations.
Since the pull operations include the ability to select the maximum size of returned chunks of data, the --pull-max-cnt general option can be used to control response chunk sizes.
In many cases it is important to the user to be able to monitor details of the operations executed against the WBEM server, either the APIs executed in pywbem, or the HTTP requests and responses and the time statistics for these operations.
The --log general option provides the capability to log information about this flow including:
The API calls and responses/exceptions executed by pywbem.
the HTTP requests and responses that pass between pywbemcli and the WBEM server.
The --log general option configures the logging including what is logged and the destination for the log output.
Thus, for example, the following command enumerates qualifiers and writes
the log entries for the CIM-XML HTTP requests and responses to the pywbemcli log
file pywbemcli.log
:
$ pywbemcli --output-format table --server http://localhost --log http=file qualifier enumerate
<displays table of qualifier declarations>
$ cat pywbemcli.log
2019-09-16 21:14:04,296-pywbem.http.1-21020-Connection:1-21020 WBEMConnection(url='http://localhost', ...)
2019-09-16 21:14:04,297-pywbem.http.1-21020-Request:1-21020 POST /cimom 11 http://localhost
CIMOperation:'MethodCall' CIMMethod:'EnumerateQualifiers' CIMObject:u'root/cimv2'
<?xml version="1.0" encoding="utf-8" ?>
<CIM CIMVERSION="2.0" DTDVERSION="2.0"><MESSAGE ID="1001" PROTOCOLVERSION="1.0">
...
</CIM>
. . .
2.2.1.3. Controlling output formats
Pywbemcli supports multiple output formats for command results by using the --output-format general option.
The output formats fall into several groups (table formats, CIM object formats, text formats, and a tree format); however, not all formats are supported or applicable for all commands. For more details, see Output formats.
2.2.1.4. Other miscellaneous general options
The --verbose general option displays extra information about the pywbemcli internal processing.
The --warn general option controls the display of warnings.
The --version general option displays pywbemcli version information and the --help general option provides top level help
2.2.1.5. General options descriptions
This section defines in detail the requirements, characteristics, and any special syntax of each general option.
2.2.1.6. --server
general option
The argument value of the --server
/-s
general option is a string that is
the URL of the WBEM server to which pywbemcli will connect, in the format:
[SCHEME://]HOST[:PORT]
Where:
SCHEME: The protocol to be used. Must be “https” or “http”. Default: “https”.
HOST: The WBEM server host. Must be a short hostname, fully qualified DNS hostname, literal IPv4 address, or literal IPv6 address. See RFC3986 and RFC6874 for details.
PORT: The WBEM server port to be used. Default: 5988 for HTTP, and 5989 for HTTPS.
This option is mutually exclusive with the --name general option and the --mock-server general option since each defines a connection to a WBEM server.
In the interactive mode the connection is not actually established until a command requiring access to the WBEM server is entered.
Examples for the argument value of this option include:
https://localhost:15345 # https, port 15345, hostname localhost
http://10.2.3.9 # http, port 5988, IPv4 address 10.2.3.9
https://10.2.3.9 # https, port 5989, IPv4 address 10.2.3.9
http://[2001:db8::1234-eth0] # http, port 5988, IPv6 address 2001:db8::1234, interface eth0
2.2.1.7. --name
general option
The argument value of the --name
/-n
general option is a string that is
the name of a connection definition in the connections file.
The parameters for this named connection definition will be loaded from the
connections file to become the current WBEM connection in pywbemcli.
In the interactive mode the connection is not actually established until a command requiring access to the WBEM server is entered.
This option is mutually exclusive with the --server general option and the --mock-server general option since each defines a connection to a WBEM server.
The following example creates a connection definition named myserver
in the connections file, and then uses that connection to execute
class get
:
$ pywbemcli --server http://localhost --user me --password mypw connection save myserver
$ pywbemcli --name myserver class get CIM_ManagedElement
<displays MOF for CIM_ManagedElement>
See connection command group for more information on managing connections.
2.2.1.8. --default-namespace
general option
The argument value of the --default-namespace
/-d
general option is a
string that defines the default CIM namespace to use for the target
WBEM server.
If this option is not specified, the default namespace will be root/cimv2
.
The default namespace will be used if the --namespace
/-n
command option
is not used on a command.
Some commands execute against multiple or all namespaces, for example the
the class find
command.
2.2.1.9. --user
general option
The argument value of the --user
/-u
general option is a string that is
the user name for authenticating with the WBEM server.
2.2.1.10. --password
general option
The argument value of the --password
/-p
general option is a string that
is the password for authenticating with the WBEM server.
This option is normally required if the --user general option is defined. If passwords are saved into the connections file, they are not encrypted in the file.
If the WBEM operations performed by any pywbemcli command require a password,
the password is prompted for if --user
/-u
is used (in both modes of
operation) and --password
/-p
is not used.
$ pywbemcli --server http://localhost --user me class get
Enter password: <password>
. . . <The display output from get class>
If both --user
/-u
and --password
/-p
are used, the command is
executed without a password prompt:
$ pywbemcli --server http://localhost --user me --password blah class get
. . . <The display output from get class>
If the operations performed by a particular pywbemcli command do not require a password or no user is supplied, no password is prompted. For example:
$ pywbemcli --help
. . . <help output>
For script integration, it is important to have a way to avoid the interactive password prompt. This can be done by storing the password string in an environment variable or specifying it on the command line. See Environment variables for general options.
The pywbemcli connection export command outputs the (bash/Windows) shell commands to set all needed environment variables.
The environment variable output is OS dependent. Thus for example in Unix type OSs:
$ pywbemcli --server http://localhost --user fred connection export
export PYWBEMCLI_SERVER=http://localhost
export PYWBEMCLI_NAMESPACE=root/cimv2
...
This ability can be used to set those environment variables and thus to persist the connection name in the shell environment, from where it will be used in any subsequent pywbemcli commands:
$ eval $(pywbemcli --server http://localhost --user fred connection export)
$ env | grep PYWBEMCLI
export PYWBEMCLI_SERVER=http://localhost
export PYWBEMCLI_NAMESPACE=root/cimv2
$ pywbemcli server namespaces
. . . <list of namespaces for the defined server>
2.2.1.11. --timeout
general option
The argument value of the --timeout
/-t
general option is an integer
that defines the client side read timeout in seconds. The pywbem client
includes a timeout mechanism that closes a WBEM connection and terminates the
current pywbemcli request if there is no response to a WBEM server request
in the time defined by timeout with multiple retries. A read timeout
occurs any time no bytes have been received on the underlying socket for
timeout seconds.
See pywbemcli --help
for the actual retry count value. Thus, the actual
time to command failure is multiple times the value of this option. Therefore
a request that does not receive any response data and with timeout value of
5 would timeout in, for example ( 5 sec * 3 (request and retries)) = 15 seconds.
Pywbemcli defaults to a predefined read timeout (normally 30 seconds) if this option is not defined.
The connection functionality has a separate timeout time set by pywbem and set at 10 seconds also with retries. The connection timeout is not modifiable by pywbemcli.
In general the timeout value should only be modified where there is a specific reason such as specific commands or servers that have very long delay before returning data.
2.2.1.12. --verify
general option
The pair of --verify
and --no-verify
general options control whether or
not the client verifies any certificates received from the WBEM server.
By default or if --verify
is specified, any certificates returned by the
server are verified. If --no-verify
is specified, any certificates returned
by the server are accepted without verification.
This general option uses the approach with two long option names to allow the user to specifically enable or disable certificate verification when this general option is used in interactive mode.
2.2.1.13. --certfile
general option
The argument value of the --certfile
general option is the file path of a
PEM file containing a X.509 client certificate to be presented to the WBEM
server during the TLS/SSL handshake, enabling 2-way (mutual) authentication.
This option is used only with HTTPS.
If --certfile
is not used, no client certificate is presented to the server,
resulting in 1-way authentication during the TLS/SSL handshake.
For more information on authentication types, see: https://pywbem.readthedocs.io/en/stable/client/security.html#authentication-types
2.2.1.14. --keyfile
general option
The argument value of the --keyfile
general option is the file path of a
PEM file containing the private key belonging to the public key that is
part of the X.509 certificate. See --certfile general option for more
information.
Not required if the private key is part of the file defined in the
--certfile
option. --keyfile
is not allowed if --certfile
is not
provided. Default: No client key file. The client private key should then be
part of the file defined by --certfile
.
2.2.1.15. --ca-certs
general option
The argument value of the --ca-certs
general option specifies which
X.509 certificates are used on the client side for validating the X.509
certificate received from the WBEM server during SSL/TLS handshake when HTTPS
is used.
The client-side and server-side certificates may be CA certificates (i.e. certificates issued by a certificate authority) or self-signed certificates.
Its value must be one of:
The path name of a file in PEM format that contains one or more certificates. See the description of the ‘CAfile’ argument of the OpenSSL SSL_CTX_load_verify_locations() function for details.
The path name of a directory with files in PEM format, each of which contains exactly one certificate. The file names must follow a particular naming convention. See the description of the ‘CApath’ argument of the OpenSSL SSL_CTX_load_verify_locations() function for details.
The string ‘certifi’ (only for pywbem version 1.0 or later). This choice will cause the certificates provided by the certifi package to be used. That package provides the certificates from the Mozilla Included CA Certificate List. Note that this list only contains CA certificates, so this choice does not work if the WBEM server uses self-signed certificates.
The default behavior depends on the version of the installed pywbem package:
Starting with pywbem version 1.0, the default is the behavior described above for the string ‘certifi’.
Before pywbem version 1.0, the default is the path name of the first existing directory from a list of system directories where certificates are expected to be stored.
The version of the installed pywbem package can be displayed using the --version general option.
Specifying the --no-verify
option (see --verify general option)
bypasses client side verification of the WBEM server certificate.
2.2.1.16. --timestats
general option
The --timestats
/ --no-timestats
-T
general option is a boolean
option that enables the display of time statistics on the interactions with the
WBEM server.
When the option is included on the command line, the display of statistics is enabled after each command in the interactive mode and before exit in the command mode.
Statistics are always gathered in pywbemcli for the current connection for every
command executed. They can be displayed at any time in the interactive mode with
the command statistics show
.
For more information on statistics gathered by pywbemcli and WBEM servers see section statistics command group .
2.2.1.17. --use-pull
general option
The argument value of the --use-pull
/-u
general option determines
whether the Pull operations or traditional operations are
used for the instance enumerate
, instance references
, instance
associators
and instance query
commands. See
Pywbemcli and the DMTF pull operations for more information on pull
operations. The choices for the argument value are as follows:
yes
- pull operations will be used and if the server does not support pull, the request will fail.no
- forces pywbemcli to try only the traditional non-pull operations.either
- (default) pywbem tries both; first pull operations and then traditional operations. This is the recommended setting since it will generate a valid response from any server.
2.2.1.18. --pull-max-cnt
general option
The argument value of the --pull-max-cnt
general option is an integer
passed to the WBEM server with the open and pull operation requests.
This integer tells the server the maximum number of objects
to be returned for each pull request if pull operations are used. This must
be a positive non-zero integer. The default is 1000. See Pywbemcli and the DMTF pull operations for more information on pull operations.
2.2.1.19. --mock-server
general option
The argument value of the --mock-server
/-m
general option is the file
path of a MOF or Python script file that loads a mock WBEM server in the
pywbemcli process with mock data (i.e. CIM objects).
This allows users to write MOF and scripts that define a Server environment including CIM namespaces, CIM qualifier declarations, CIM classes, and CIM instances that responds to pywbemcli commands.
This option may be specified multiple times to define multiple MOF and Python files that make up the definition of a mock server. The files must have the suffix “.mof” for MOF files and “.py” for Python scripts.
When this option is used, the security options (i.e. user
, password
,
etc.) are irrelevant. They are rejected by pywemcli.
Section Mock WBEM Server defines the characteristics of the MOF and Python files that define a mock server environment.
A mock server may be saved in the connections file and is cached if saved in the default connections file. This can significantly speed up the loading of the mock server definition when pywbemcli is started.
The following example creates a mock server with two files defining the mock
data, shows what parameters are defined for the connection, and then saves that
connection named mymockserver
where classdefs.mof could contain CIM qualifier
declarations and CIM class definitions and insts.py could contain CIM
instance definitions:
$ pywbemcli --mock-server classdefs.mof --mock-server insts.py --default-namespace root/myhome
pywbemcli> connection show
name: not-saved (current)
server:
mock-server: classdefs.mof, insts.py
. . .
pywbemcli> connection save mymockserver
pywbemcli> connection show
Connection status:
name value (state)
----------------- ------------------------------------------
name mock1 (current)
server
default-namespace root/cimv2
user
password
timeout 30
use-pull
pull-max-cnt 1000
verify True
certfile
keyfile
mock-server tests/unit/pywbemcli/simple_mock_model.mof
ca-certs
pywbemcli>class enumerate --names-only
CIM_BaseEmb
CIM_BaseRef
CIM_Foo
CIM_FooAssoc
pywbemcli>
See chapter Mock WBEM Server for more information on defining the files for a mock server.
2.2.1.20. --output-format
general option
The argument value of the --output-format
/-o
general option is a string
that defines the output format in which the result of any pywbemcli commands
is displayed. The default output format depends on the command.
For details, see Output formats.
2.2.1.21. --log
general option
The argument value of the --log
/-l
general option defines the
destination and parameters of logging of the requests and responses to the WBEM
server.
For details, see Pywbemcli defined logging.
2.2.1.22. --verbose
general option
The --verbose
/-v
general option is a boolean option that enables the
display of extra information about the processing.
In particular it outputs text for a number of commands that normally return nothing upon successful execution(ex. instance delete, instance enumerate that returns no CIM objects) to indicate the successful command completion.
2.2.1.23. --connections-file
general option
The --connections-file
/-C
general option allows the user to select
a path name for the connections file.
By default, the path name of the connections file is the value of the
PYWBEMCLI_CONNECTIONS_FILE
environment variable or if not set, the file
.pywbemcli_connections.yaml
in the user’s home directory.
The user’s home directory depends on the operating system used and is
determined with os.path.expanduser("~")
, which works on all operating
systems including Windows. See expanduser()
for details.
The actually used path name of the connections file is shown in the connection list command.
The connection definition definitions in the connections file are managed with the commands in the connection command group.
2.2.1.24. --warn
general option
The --warn
/--no-warn
general option is a boolean option that controls
the display of all Python warnings.
If --warn
is used, all Python warnings are shown once. If --no-warn
is
used (default), the PYTHONWARNINGS
environment variable determines which
warnings are shown. If that variable is not set, no warnings are shown. See
PYTHONWARNINGS
for details.
2.2.1.25. --pdb
general option
The --pdb
general option is a boolean option that enables debugging
with the built-in pdb debugger.
If debugging is enabled, execution of each pywbemcli command will pause just before the command within pywbemcli is executed, and the pdb debugger prompt will appear. See pdb debugger commands for details on how to operate the built-in pdb debugger.
In addition to the --pdb
option,
An alternate debugger such as pdb++ debugger can also be used.
2.2.1.26. --version
general option
The --version
general option displays the version of the pywbemcli
command and the version of the pywbem package used by it, and then exits.
2.2.1.27. --help
general option
The --help
/-h
general option displays help text which describes the
command groups, commands, and general options, and then exits. A specific
help exists for each command group, and command and pywbemcli --help
presents the help on the general options
2.2.2. Environment variables for general options
:: index:: pair: general options; environment variables
Pywbemcli defines environment variables corresponding to its general options as follows:
Environment variable |
Corresponding general option |
---|---|
PYWBEMCLI_SERVER |
|
PYWBEMCLI_NAME |
|
PYWBEMCLI_USER |
|
PYWBEMCLI_PASSWORD |
|
PYWBEMCLI_OUTPUT_FORMAT |
|
PYWBEMCLI_DEFAULT_NAMESPACE |
|
PYWBEMCLI_TIMEOUT |
|
PYWBEMCLI_KEYFILE |
|
PYWBEMCLI_CERTFILE |
|
PYWBEMCLI_CA_CERTS |
|
PYWBEMCLI_USE_PULL |
|
PYWBEMCLI_PULL_MAX_CNT |
|
PYWBEMCLI_STATS_ENABLED |
|
PYWBEMCLI_MOCK_SERVER (1) |
|
PYWBEMCLI_LOG |
|
PYWBEMCLI_PDB |
|
PYWBEMCLI_CONNECTIONS_FILE |
|
PYWBEMCLI_SPINNER |
No option attached |
Notes:
The
--mock-server
general option can be specified multiple times. To do that with the PYWBEMCLI_MOCK_SERVER environment variable, separate the multiple path names with space.
If these environment variables are set, the corresponding general options default to the value of the environment variables. If both an environment variable and its corresponding general option are set, the command line option overrides the environment variable with no warning.
Environment variables are not provided for command options or command arguments.
In the following example, the pywbemcli command uses server
http://localhost
defined by the environment variable:
$ export PYWBEMCLI_SERVER=http://localhost
$ pywbemcli class get CIM_ManagedElement
<displays MOF for CIM_ManagedElement>
The pywbemcli connection export command outputs the (bash/Windows) shell commands to set all of the environment variables:
$ pywbemcli --server http://localhost --user fred connection export
export PYWBEMCLI_SERVER=http://localhost
export PYWBEMCLI_NAMESPACE=root/cimv2
. . .
This can be used to set those environment variables and thus to persist the connection name in the shell environment, from where it will be used in any subsequent pywbemcli commands until removed. The following shows the display of the pywbbemcli environment variables that are set :
$ eval $(pywbemcli --server http://localhost --user fred)
$ env | grep PYWBEMCLI
export PYWBEMCLI_SERVER=http://localhost
export PYWBEMCLI_NAMESPACE=root/cimv2
. . .
$ pywbemcli server namespaces
. . . <list of namespaces for the defined server>
In addition, an environment variable is provided to disable the
spinner that is displayed when waiting for responses. The environment
variable is PYWBEMCLI_SPINNER
and the spinner is disabled when
this environment variable is set.
2.2.3. Pywbemcli and the DMTF pull operations
The DMTF specifications and pywbem includes two ways to execute the enumerate
instance type operations (Associators
, References
,
EnumerateInstances
, ExecQuery
):
The traditional operations (ex.
EnumerateInstances
) where the WBEM server returns all of the response instances as a single responseThe pull operations (ex.
OpenEnumerateInstances
, etc.) where the client and the server cooperate with client requests for Open… and subsequent Pull… requests to return groups of response instances.
Pywbem implements an overlay of the above two operations called the Iter..
operations where each Iter..
operation executes either the traditional or
pull operation depending on the --use-pull general option of the
connection.
While the pull operations may not be supported by all WBEM servers they can be significantly more efficient for large responses when they are available. Pywbem implements the client side of these operation and pywbemcli provides for the use of these operations through two general options:
--use-pull
- This option allows the user to select from the the following alternatives:either
- (default) pywbemcli first tries the open operation and if that is not implemented by the server retries the operation with the corresponding traditional operation. The result of this first operation determines whether pull or the traditional operation are used for any further requests during the current pywbem interactive session.yes
- Forces the use of the pull operations and fails if that is not implemented by the server.no
- Forces the use of the traditional operation.
--pull-max-cnt
- Sets the maximum count of objects the server is allowed to return for each open/pull operation. The default is 1000 objects which from experience is a logical choice.
The default alternative either
is probably the most logical setting for
--use-pull
, unless you are specifically testing the use of pull
operations.
However, there are some limitations with using the either
choice as follows:
The original operations did not support the filtering of responses with a query language query (
--filter-query-language
and--filter-query
) which requests that the WBEM server filter the responses before they are returned. This can greatly reduce the size of the responses if effectively used but is used only when the pull operations are available on the server.The pull operations do not support some of the options that traditional operations do:
--include-qualifiers
- Since even the traditional operations specification deprecated this option and the user cannot depend on it being honored, the most logical solution is to never use this option.--local-only
- Since even the traditional operations specification deprecated this option and the user cannot depend on it being honored by the WBEM server, the most logical solution is to never use this option.
The following example forces the use of the pull operations and expects the WBEM server to return no more than 10 instances per request. It fails if the pull operations are not supported in the WBEM server:
$ pywbemcli --server http://localhost --use-pull=yes --pull-max-cnt=10 instance enumerate CIM_Foo
2.2.4. Output formats
Pywbemcli supports multiple output formats to present command results. The output format can be selected with the --output-format general option. The allowed output formats are different for the various command groups and commands.
The output formats fall into the following groups:
Table formats - The Table formats format the result as a table with rows and columns. Many of the result types allow table formatted response display including:
instance get
,instance enumerate
,instance references
,instance associators
where the table formats are alternatives to the CIM model formats that shows the properties for each instance as a column in a table.instance count
server
commandsclass find
connection
commands
CIM object formats - The CIM object formats format a result that consists of CIM objects in MOF, CIM-XML or pywbem repr format. All of the commands that return CIM objects support these output formats.
ASCII tree format - The ASCII tree format formats the result as a tree, using ASCII characters to represent the tree to show the hierarchial relationship between CIM classes. The only command supporting the ASCII tree format is
class tree
, and it supports only that one output format. The tree format is not supported by any other command today.TEXT format - The Text formats is used for commands that output small quantites of text (ex. the interop namespace name) and that could be used as part of a command line redirection.
When an unsupported output format is specified for a command response, it is
rejected with an exception. For example, the command class enumerate
only
supports the CIM object formats and will generate an exception if the
command pywbemcli -o table class enumerate
is entered.
2.2.4.1. Output formats for groups and commands
Each of the commands may allow only a subset of the possible ouput formats. Thus, the server brand only outputs data in a table format so there is no defined default format for the --output-format general option.
The following shows the default format for each command and the alternate formats where the values mean:
objects: xml
, repr
, or txt
table: table
, plain
, simple
, grid
, psql
, rst
, text
,
or html
Group |
Command |
Default |
Alternates |
Comments |
---|---|---|---|---|
class |
associators |
‘mof’ |
objects |
See Note 1 below |
class |
delete |
None |
None |
Nothing returned |
class |
enumerate |
‘mof’ |
objects |
See Note 1 below |
class |
find |
‘simple’ |
table |
|
class |
get |
‘mof’ |
objects |
See Note 1 below |
class |
invokemethod |
‘mof’ |
objects |
See Note 1 below |
class |
references |
‘mof’ |
objects |
See Note 1 below |
class |
tree |
None |
None |
Only outputs as ascii tree |
instance |
associators |
‘mof’ |
objects, table |
Output as cim object or table of properties |
instance |
count |
‘simple’ |
table |
|
instance |
create |
None |
None |
Nothing returned |
instance |
delete |
None |
None |
Nothing returned |
instance |
enumerate |
‘mof’ |
objects, table |
|
instance |
get |
‘mof’ |
objects, table |
|
instance |
invokemethod |
‘mof’ |
objects, table |
|
instance |
modify |
None |
None |
Nothing returned |
instance |
references |
‘mof’ |
table |
|
qualifier |
enumerate |
‘mof’ |
table |
|
qualifier |
get |
‘mof’ |
table |
|
server |
brand |
‘text’ |
text |
Alternate is table format |
server |
centralinsts |
‘simple’ |
table |
|
server |
info |
‘simple’ |
table |
|
server |
interop |
‘text’ |
text |
Alternate is table format |
server |
namespaces |
‘simple’ |
table |
Alternate is text format |
server |
profiles |
‘simple’ |
table |
|
connection |
delete |
None |
table |
|
connection |
export |
None |
table |
|
connection |
list |
‘simple’ |
table |
|
connection |
save |
None |
table |
|
connection |
select |
None |
None |
|
connection |
show |
None |
None |
Currently ignores output format |
connection |
test |
None |
None |
NOTES:
The display of classes with the
--names-only
/--no
or--summary
/-s
command options allows table output formats in addition to the objects output formats.
2.2.4.2. Table formats
The different variations of the table format define different formatting of the
borders for tables. The following are examples of the table formats with a
single command class find CIM_Foo
:
--output-format table
: Tables with a single-line border. This is the default:Find class CIM_Foo* +-------------+-----------------+ | Namespace | Classname | |-------------+-----------------| | root/cimv2 | CIM_Foo | | root/cimv2 | CIM_Foo_sub | | root/cimv2 | CIM_Foo_sub2 | | root/cimv2 | CIM_Foo_sub_sub | +-------------+-----------------+
--output-format simple
: Tables with a line between header row and data rows, but otherwise without borders:Find class CIM_Foo* Namespace Classname ----------- --------------- root/cimv2 CIM_Foo root/cimv2 CIM_Foo_sub root/cimv2 CIM_Foo_sub2 root/cimv2 CIM_Foo_sub_sub
--output-format plain
: Tables do not use any pseudo-graphics to draw borders:Find class CIM_Foo* Namespace Classname root/cimv2 CIM_Foo root/cimv2 CIM_Foo_sub root/cimv2 CIM_Foo_sub2 root/cimv2 CIM_Foo_sub_sub
--output-format grid
: Tables tables formatted by Emacs’ table.el package. It corresponds togrid_tables
in Pandoc Markdown extensions:Find class CIM_Foo* +-------------+-----------------+ | Namespace | Classname | +=============+=================+ | root/cimv2 | CIM_Foo | +-------------+-----------------+ | root/cimv2 | CIM_Foo_sub | +-------------+-----------------+ | root/cimv2 | CIM_Foo_sub2 | +-------------+-----------------+ | root/cimv2 | CIM_Foo_sub_sub | +-------------+-----------------+
--output-format rst
: Tables in reStructuredText markup:Find class CIM_Foo* =========== =============== Namespace Classname =========== =============== root/cimv2 CIM_Foo root/cimv2 CIM_Foo_sub root/cimv2 CIM_Foo_sub2 root/cimv2 CIM_Foo_sub_sub =========== ===============
--output-format psql
: Like tables formatted by Postgres’ psql cli:Find class CIM_Foo* =========== =============== Namespace Classname =========== =============== root/cimv2 CIM_Foo root/cimv2 CIM_Foo_sub root/cimv2 CIM_Foo_sub2 root/cimv2 CIM_Foo_sub_sub =========== ===============
--output-format html
: Tables formatted as html table:<p>Find class CIM_Foo*</p> <table> <thead> <tr><th>Namespace </th><th>Classname </th></tr> </thead> <tbody> <tr><td>root/cimv2 </td><td>CIM_Foo </td></tr> <tr><td>root/cimv2 </td><td>CIM_Foo_sub </td></tr> <tr><td>root/cimv2 </td><td>CIM_Foo_sub2 </td></tr> <tr><td>root/cimv2 </td><td>CIM_Foo_sub_sub</td></tr> </tbody> </table>
2.2.4.3. CIM object formats
The output of CIM objects allows multiple formats as follows:
--output-format mof
: Format for CIM classes, CIM instances, and CIM Parameters.MOF is the format used to define and document the CIM models released by the DMTF and SNIA. It textually defines the components and structure and data of CIM elements such as classes, instances, and qualifier declarations as shown in the following example of a CIM instance:
instance of CIM_Foo { InstanceID = "CIM_Foo1"; IntegerProp = 1; };
The MOF output of CIM classes, CIM instances or CIM qualifier declaractions is normally compiler ready and can be recompiled by a MOF compiler such as the pywbem MOF compiler.
The
CIMInstanceName
object (i.e. instance path) does not have a MOF format. Rather it is a formatted UNICODE string format as documented in DMTF specifications DSP0004 and :termL`DSP0207`.The following is an example of the output of an instance of
CIMInstanceName
://ACME.com/cimv2/Test:CIM_RegisteredProfile.InstanceID=”Acme.1”
--output-format xml
: CIM-XML format for CIM elements such as classes, instances and qualifier declarations. Besides being used as a protocol for WBEM servers, CIM-XML is also an alternative format for representing the CIM models released by the DMTF and SNIA. The XML syntax is defined in the DMTF specification DSP0201.This is the format used in the DMTF CIM-XML protocol:
<VALUE.OBJECTWITHLOCALPATH> <LOCALINSTANCEPATH> <LOCALNAMESPACEPATH> <NAMESPACE NAME="root"/> <NAMESPACE NAME="cimv2"/> </LOCALNAMESPACEPATH> <INSTANCENAME CLASSNAME="CIM_Foo"> <KEYBINDING NAME="InstanceID"> <KEYVALUE VALUETYPE="string">CIM_Foo1</KEYVALUE> </KEYBINDING> </INSTANCENAME> </LOCALINSTANCEPATH> <INSTANCE CLASSNAME="CIM_Foo"> <PROPERTY NAME="InstanceID" PROPAGATED="false" TYPE="string"> <VALUE>CIM_Foo1</VALUE> </PROPERTY> <PROPERTY NAME="IntegerProp" PROPAGATED="false" TYPE="uint32"> <VALUE>1</VALUE> </PROPERTY> </INSTANCE> </VALUE.OBJECTWITHLOCALPATH>
--output-format repr
: Python repr format of the objects.This is the structure and data of the pywbem Python objects representing each CIM objects and can be useful in understanding the pywbem interpretation of the CIM objects:
CIMInstance(classname='CIM_Foo', path=CIMInstanceName(classname='CIM_Foo', keybindings=NocaseDict({'InstanceID': 'CIM_Foo1'}), namespace='root/cimv2', host=None), properties=NocaseDict({ 'InstanceID': CIMProperty(name='InstanceID', value='CIM_Foo1', type='string', reference_class=None, embedded_object=None, is_array=False, array_size=None, class_origin=None, propagated=False, qualifiers=NocaseDict({})), 'IntegerProp': CIMProperty(name='IntegerProp', value=1, type='uint32', reference_class=None, embedded_object=None, is_array=False, array_size=None, class_origin=None, propagated=False, qualifiers=NocaseDict({}))}), property_list=None, qualifiers=NocaseDict({}))
NOTE: The above is output as a single line and has been manually formatted for this documentation.
--output-format txt
: Python str format of the objects.This should be considered the output of last resort as it simply uses the
__str__()
method of the Python class for each CIM object to output.Thus, for example, a
class enumerate
command of a model with only a single class creates output of the form:CIMClass(classname='CIM_Foo', ...)
2.2.4.4. ASCII tree format
This output format is an ASCII based output that shows the tree structure of
the results of the class tree
command. It is the only output format
supported by this command, and therefore it is automatically selected and
cannot be specified explicitly with the --output-format general option.
$ pywbemcli --mock-server tests/unit/simple_mock_model.mof class tree
root
+-- CIM_Foo
+-- CIM_Foo_sub
| +-- CIM_Foo_sub_sub
+-- CIM_Foo_sub2
This shows a very simple mock repository with 4 classes where CIM_Foo is the top level in the hierarchy, CIM_Foo_sub and CIM_Foo_sub2 are its subclasses, and CIM_Foo_sub_sub is the subclass of CIM_Foo_sub.
2.2.4.5. Text formats
The TEXT format group outputs the data returned from the command as text to the console without any formatting except for formatting lists and comma separated strings. It is useful for use with data that might be redirected to other commands or output that is simple enough that a single line of output is sufficient.
$ pywbemcli --mock-server tests/unit/testmock/wbemserver_mock.py -o table server namespaces
Server Namespaces:
Namespace Name
----------------
interop
$ pywbemcli --mock-server tests/unit/testmock/wbemserver_mock.py -o text server namespaces
interop
2.2.4.6. Pywbemcli defined logging
Pywbemcli provides logging to either a file or the standard error stream of information passing between the pywbemcli client and a WBEM server using the standard Python logging facility.
Logging is configured and enabled using the --log general option on the commmand line or the PYWBEMCLI_LOG environment variable.
Pywbemcli can log operation calls that send requests to a WBEM server and their responses and the HTTP messages between the pywbemcli client and the WBEM server including both the pywbem APIs and their responses and the HTTP requests and responses.
The default is no logging if the --log
option is not specified.
The argument value of the --log
option and the value of the PYWBEMCLI_LOG
environment variable is a log configuration string with the format defined in
the ABNF rule LOG_CONFIG_STRING
, below. The log configuration string
defines a list of
one or more log configurations, each with fields COMPONENT
, DESTINATION
,
and DETAIL
:
LOG_CONFIG_STRING := CONFIG [ "," CONFIG ]
CONFIG := COMPONENT [ "=" DESTINATION [ ":" DETAIL ]]
COMPONENT := ( "all" / "api" / "http" )
DESTINATION := ( "stderr" / "file" )
DETAIL := ( "all" / "path" / "summary" )
For example the following log configuration string logs the pywbem API calls and writes summary information to a log file and the HTTP requests and responses to stderr:
$ pywbemcli --log api=file:summary,http=stderr
The simplest log configuration string to enable logging is all=stderr
or
all=file
.
The COMPONENT
field defines the component for which logging is enabled:
api
- Logs the calls to the pywbem methods that make requests to a WBEM server. This logs both the requests and response including any exceptions generated by error responses from the WBEM server.http
- Logs the headers and data for HTTP requests and responses to the WBEM server.all
- (Default) Logs both theapi
andhttp
components.
The DESTINATION
field specifies the log destination:
stderr
- Output log to stderr.file
- (default) Log to the pywbemcli log filepywbemcli.log
in the current directory. Logs are appended to an existing log file.
The DETAIL
component of the log configuration string defines the level of
logging information for the api and http components. Because enormous quantities
of information can be generated this option exists to limit the amount of
information generated. The possible keywords are:
all
- (Default) Logs the full request including all input parameters and the complete response including all data. Exceptions are fully logged.paths
- Logs the full request but only the path component of the api responses. This reduces the data included in the responses. Exceptions are fully logged.summary
- Logs the requests but only the count of objects received in the response. Exceptions are fully logged.
The log output is routed to the output defined by DESTINATION
and includes the
information determined by the COMPONENT
and DETAIL
fields.
The log output format is:
<Date time>-<Component>.<connection id>-<Direction>:<connection id> <PywbemOperation>(<data>)
For example, logging only of the summary API information would look something like the following:
$ pywbemcli -s http://localhost -u blah -p pw -l api=file:summary class enumerate -o
produces log output for the class enumerate operation in the log file
pywbemcli.log as follows showing the input parameters to the pywbem method
EnumerateClassName
and the number of objects in the response:
2019-07-09 18:27:22,103-pywbem.api.1-27716-Request:1-27716 EnumerateClassNames(ClassName=None, DeepInheritance=False, namespace=None)
2019-07-09 18:27:22,142-pywbem.api.1-27716-Return:1-27716 EnumerateClassNames(list of str; count=103)
2.2.5. Pywbemcli persisted connection definitions
Pywbemcli can manage persisted connection definitions via the
connection command group. These connection definitions are persisted in
a connections file named .pywbemcli_connections.yaml
in
the user’s home directory. A connection definition has a name
and defines all parameters necessary to connect to a WBEM server. Once defined
these connection definitions can be used with the --name general option
or in the interactive mode by defining a current connection with the
connection select command.
A new persistent connection definition can be created with the connection save command.
At any point in time, pywbemcli can communicate with only a single WBEM server.
That is the current connection.
In the command mode, this is the WBEM server defined by the general options
--server
or --mock-server
or --name
. In the interactive mode, the
current connection can be changed within an interactive session using the
connection select command so that within a single session, the user can
work with multiple WBEM servers (at different points in time).
The following example creates a persisted connection definition, using interactive mode:
$ pywbemcli
pywbemcli> --server http://localhost --user usr1 --password blah connection save testconn
pywbemcli> connection list
WBEM server connections: (#: default, *: current)
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
| name | server | namespace | user | timeout | verify | mock-server |
|-----------+------------------+-------------+--------+-----------+----------+----------------------------------------|
| testconn | http://localhost | root/cimv2 | usr1 | 30 | True | |
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
Since the connection definition is persisted, it is available in command mode as well as in new interactive sessions:
$ pywbemcli connection list
WBEM server connections: (#: default, *: current)
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
| name | server | namespace | user | timeout | verify | mock-server |
|-----------+------------------+-------------+--------+-----------+----------+----------------------------------------|
| testconn | http://localhost | root/cimv2 | usr1 | 30 | True | |
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
$ pywbemcli
pywbemcli> connection list
WBEM server connections: (#: default, *: current)
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
| name | server | namespace | user | timeout | verify | mock-server |
|-----------+------------------+-------------+--------+-----------+----------+----------------------------------------|
| testconn | http://localhost | root/cimv2 | usr1 | 30 | True | |
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
Other connection definitions can be added, this time using command mode:
$ pywbemcli --server http://blah2 --user you --password xxx connection save Ronald
$ pywbemcli connection list
WBEM server connections: (#: default, *: current)
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
| name | server | namespace | user | timeout | verify | mock-server |
|-----------+------------------+-------------+--------+-----------+----------+----------------------------------------|
| Ronald | http://blah2 | root/cimv2 | you | 30 | True | |
| testconn | http://localhost | root/cimv2 | usr1 | 30 | True | |
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
The following example shows how to select current connections in interactive
mode. Note the marker *
in front of the name, which indicates the current
connection. The connection show command when used without a connection
name shows the current connection:
$ pywbemcli
pywbemcli> connection select Ronald
pywbemcli> connection list
WBEM server connections: (#: default, *: current)
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
| name | server | namespace | user | timeout | verify | mock-server |
|-----------+------------------+-------------+--------+-----------+----------+----------------------------------------|
| *Ronald | http://blah2 | root/cimv2 | you | 30 | True | |
| testconn | http://localhost | root/cimv2 | usr1 | 30 | True | |
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
pywbemcli> connection show
name: Ronald (current)
server: http://blah2
mock-server:
. . .
pywbemcli> connection select testconn
pywbemcli> connection list
WBEM server connections: (#: default, *: current)
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
| name | server | namespace | user | timeout | verify | mock-server |
|-----------+------------------+-------------+--------+-----------+----------+----------------------------------------|
| Ronald | http://blah2 | root/cimv2 | you | 30 | True | |
| *testconn | http://localhost | root/cimv2 | usr1 | 30 | True | |
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
pywbemcli> connection show
name: testconn (current)
server: http://localhost
mock-server:
. . .
pywbemcli> connection show Ronald
name: Ronald
server: http://blah2
mock-server:
. . .
The concept of a current connection that can be selected is useful mostly for
the interactive mode. In command mode, the connection specified with one of the
-server
, --mock-server
, or --name
general options automatically is
considered the current connection, and there is no concept of selecting a
current connection other than using these options.
Therefore, pywbemcli additionally supports the concept of a persisted default
connection.
The following example defines a persisted default connection and then uses it in command mode:
$ pywbemcli connection select Ronald --default
"Ronald" default and current
$ pywbemcli connection list
WBEM server connections: (#: default, *: current)
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
| name | server | namespace | user | timeout | verify | mock-server |
|-----------+------------------+-------------+--------+-----------+----------+----------------------------------------|
| #Ronald | http://blah2 | root/cimv2 | you | 30 | True | |
| testconn | http://localhost | root/cimv2 | usr1 | 30 | True | |
+-----------+------------------+-------------+--------+-----------+----------+----------------------------------------+
$ pywbemcli connection show
name: Ronald (default, current)
server: http://blah2
mock-server:
. . .
Connections can be deleted with the connection delete
command either with
the command argument containing the connection name or with no name provided so
pywbemcli presents a list of connections to choose from:
$ pywbemcli connection delete Ronald
Deleted default connection "Ronald".
or:
$ pywbemcli connection delete
Select a connection or <CTRL-C> to abort.
0: Ronald
1: testconn
Input integer between 0 and 1 or Ctrl-C to exit selection: 0
Deleted default connection "Ronald".