In the help msg of command host-evacuate，replace the optional arguments '--target_host' with '--target-host' more appropriate

[xiewj]

In the help msg of command host-evacuate，replace the optional arguments '--target_host' with '--target-host' more appropriate

[root@devstack162 devstack]# nova help host-evacuate
usage: nova host-evacuate [--target_host <target_host>] [--force] <host>

Evacuate all instances from failed host.

Positional arguments:
  <host> Name of host.

Optional arguments:
  --target_host <target_host> Name of target host. If no host is specified
                               the scheduler will select a target.
  --force Force to not verify the scheduler if a host is
                               provided. (Supported by API versions '2.29' -
                               '2.latest')

In the help information of other commands,never seen arguments with a '-' connection.People accustomed to the use of the '-'

[root@devstack162 devstack]# nova host-evacuate tecsovs --target-host host1
usage: nova [--version] [--debug] [--os-cache] [--timings]
            [--os-region-name <region-name>] [--service-type <service-type>]
            [--service-name <service-name>]
            [--os-endpoint-type <endpoint-type>]
            [--os-compute-api-version <compute-api-ver>]
            [--bypass-url <bypass-url>] [--insecure]
            [--os-cacert <ca-certificate>] [--os-cert <certificate>]
            [--os-key <key>] [--timeout <seconds>] [--os-auth-type <name>]
            [--os-auth-url OS_AUTH_URL] [--os-domain-id OS_DOMAIN_ID]
            [--os-domain-name OS_DOMAIN_NAME] [--os-project-id OS_PROJECT_ID]
            [--os-project-name OS_PROJECT_NAME]
            [--os-project-domain-id OS_PROJECT_DOMAIN_ID]
            [--os-project-domain-name OS_PROJECT_DOMAIN_NAME]
            [--os-trust-id OS_TRUST_ID]
            [--os-default-domain-id OS_DEFAULT_DOMAIN_ID]
            [--os-default-domain-name OS_DEFAULT_DOMAIN_NAME]
            [--os-user-id OS_USER_ID] [--os-username OS_USERNAME]
            [--os-user-domain-id OS_USER_DOMAIN_ID]
            [--os-user-domain-name OS_USER_DOMAIN_NAME]
            [--os-password OS_PASSWORD]
            <subcommand> ...
error: unrecognized arguments: --target-host host1
Try 'nova help ' for more information.
[root@devstack162 devstack]#

[Sylvain Bauza (sylvain-bauza)]

That's definitly not a bug, rather a nit about the option.