python-openstackclient/doc/source/cli/authentication.rst
Stephen Finucane c05be82de0 docs: Add examples of common auth methods
Took me a bit to figure out how to do token auth today. Document it.

Change-Id: I3edce59efd5ca5a6e31eef8c7cf3cf255234c82e
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>
2023-07-10 13:50:34 +01:00

11 KiB

Authentication

OpenStackClient leverages python-keystoneclient authentication plugins to support a number of different authentication methods.

Authentication Process

The user provides some number of authentication credential options. If an authentication type is not provided (--os-auth-type), the authentication options are examined to determine if one of the default types can be used. If no match is found an error is reported and OSC exits.

Note that the authentication call to the Identity service has not yet occurred. It is deferred until the last possible moment in order to reduce the number of unnecessary queries to the server, such as when further processing detects an invalid command.

Authentication Plugins

The Keystone client library implements the base set of plugins. Additional plugins may be available from the Keystone project or other sources.

There are at least three authentication types that are always available:

  • Password: A project, username and password are used to identify the user. An optional domain may also be included. This is the most common type and is the default any time a username is supplied. An authentication URL for the Identity service is also required. [Required: --os-auth-url, --os-project-name, --os-username; Optional: --os-password]
  • Token: This is slightly different from the usual token authentication in that a token and an authentication URL are supplied and the plugin retrieves a new token. [Required: --os-auth-url, --os-token]
  • Others: Other authentication plugins such as SAML, Kerberos, and OAuth1.0 are under development and also supported. To use them, they must be selected by supplying the --os-auth-type option.

Detailed Process

The authentication process in OpenStackClient is all contained in and handled by the ClientManager object.

  • On import api.auth:
    • obtains the list of installed Keystone authentication plugins from the keystoneclient.auth.plugin entry point.
    • builds a list of authentication options from the plugins.
  • The command line arguments are processed and a configuration is loaded from clouds.yaml if --os-cloud is provided.
  • A new ClientManager is created and supplied with the set of options from the command line, environment and/or clouds.yaml:
    • If --os-auth-type is provided and is a valid and available plugin

      it is used.

    • If --os-auth-type is not provided an authentication plugin is selected based on the existing options. This is a short-circuit evaluation, the first match wins.
      • If --os-username is supplied password is selected
      • If --os-token is supplied token is selected
      • If no selection has been made by now exit with error
    • Load the selected plugin class.
  • When an operation that requires authentication is attempted ClientManager makes the actual initial request to the Identity service.
    • if --os-auth-url is not supplied for any of the types except Token/Endpoint, exit with an error.

Authenticating using Identity Server API v3

To authenticate against an Identity Server API v3, the OS_IDENTITY_API_VERSION environment variable or --os-identity-api-version option must be changed to 3, instead of the default 2.0. Similarly OS_AUTH_URL or os-auth-url should also be updated.

$ export OS_IDENTITY_API_VERSION=3 (Defaults to 2.0)
$ export OS_AUTH_URL=http://localhost:5000/v3

Since Identity API v3 authentication is a bit more complex, there are additional options that may be set, either as command line options or environment variables. The most common case will be a user supplying both user name and password, along with the project name; previously in v2.0 this would be sufficient, but since the Identity API v3 has a Domain component, we need to tell the client in which domain the user and project exists.

If using a user name and password to authenticate, specify either it's owning domain name or ID.

  • --os-user-domain-name or OS_USER_DOMAIN_NAME
  • --os-user-domain-id or OS_USER_DOMAIN_ID

If using a project name as authorization scope, specify either it's owning domain name or ID.

  • --os-project-domain-name or OS_PROJECT_DOMAIN_NAME
  • --os-project-domain-id or OS_PROJECT_DOMAIN_ID

If using a domain as authorization scope, set either it's name or ID.

  • --os-domain-name or OS_DOMAIN_NAME
  • --os-domain-id or OS_DOMAIN_ID

Note that if the user and project share the same domain, then simply setting --os-default-domain or OS_DEFAULT_DOMAIN to the domain ID is sufficient.

Thus, a minimal set of environment variables would be:

$ export OS_IDENTITY_API_VERSION=3
$ export OS_AUTH_URL=http://localhost:5000/v3
$ export OS_DEFAULT_DOMAIN=default
$ export OS_USERNAME=admin
$ export OS_PASSWORD=secret
$ export OS_PROJECT_NAME=admin

Federated users support

The OpenStackClient also allows the use of Federated users to log in. It enables one to use the identity providers credentials such as Google or Facebook to log in the OpenStackClient instead of using the Keystone credentials.

This is useful in a Federated environment where one credential give access to many applications/services that the Federation supports. To check how to configure the OpenStackClient to allow Federated users to log in, please check the Authentication using federation. <manpage>

Examples

v3password

Using clouds.yaml:

clouds:
  demo:
    auth:
      auth_url: http://openstack.dev/identity
      project_name: demo
      project_domain_name: default
      user_domain_name: default
      username: demo
      password: password
    auth_type: v3password

or, using command line options:

$ openstack \
  --os-auth-url "http://openstack.dev/identity" \
  --os-project-name demo \
  --os-project-domain-name default \
  --os-user-domain-name default \
  --os-auth-type=v3password \
  --os-username demo \
  --os-password password \
  server list

or, using environment variables:

$ export OS_AUTH_URL="http://openstack.dev/identity"
$ export OS_PROJECT_NAME=demo
$ export OS_PROJECT_DOMAIN_NAME=default
$ export OS_AUTH_TYPE=v3password
$ export OS_USERNAME=demo
$ export OS_PASSWORD=password
$ openstack server list

Note

If a password is not provided, you will be prompted for one.

v3applicationcredential

Using clouds.yaml:

clouds:
  demo:
    auth:
      auth_url: http://openstack.dev/identity
      application_credential_id: ${APP_CRED_ID}
      application_credential_secret: ${APP_CRED_SECRET}
    auth_type: v3applicationcredential

or, using command line options:

$ openstack \
  --os-auth-url "http://openstack.dev/identity" \
  --os-auth-type=v3applicationcredential \
  --os-application-credential-id=${APP_CRED_ID} \
  --os-application-credential-secret=${APP_CRED_SECRET}
  server list

or, using environment variables:

$ export OS_AUTH_URL="http://openstack.dev/identity"
$ export OS_AUTH_TYPE=v3applicationcredential
$ export OS_APPLICATION_CREDENTIAL_ID=${APP_CRED_ID}
$ export OS_APPLICATION_CREDENTIAL_SECRET=${APP_CRED_SECRET}
$ openstack server list

Note

You can generate application credentials using the openstack application credential create command:

$ readarray -t lines <<< $(openstack application credential create test -f value -c id -c secret)
$ APP_CRED_ID=${lines[0]}
$ APP_CRED_SECRET=${lines[1]}

v3token

Using clouds.yaml:

clouds:
  demo:
    auth:
      auth_url: http://openstack.dev/identity
      project_name: demo
      project_domain_name: default
      token: ${TOKEN}
    auth_type: v3token

or, using command line options:

$ openstack \
  --os-auth-url "http://openstack.dev/identity" \
  --os-project-name demo \
  --os-project-domain-name default \
  --os-auth-type=v3token \
  --os-token ${TOKEN} \
  server list

or, using environment variables:

$ export OS_AUTH_URL="http://openstack.dev/identity"
$ export OS_PROJECT_NAME=demo
$ export OS_PROJECT_DOMAIN_NAME=default
$ export OS_AUTH_TYPE=v3token
$ export OS_TOKEN=${TOKEN}
$ openstack server list

Note

You can generate tokens using the openstack token issue command:

$ TOKEN=$(openstack token issue -f value -c id)

v3totp

Note

The TOTP mechanism is poorly suited to command line-driven API interactions. Where the TOTP mechanism is configured for a cloud, it is expected that it is to be used for initial authentication and to create a token or application credential, which can then be used for future interactions.

Note

The TOTP mechanism is often combined with other mechanisms to enable Multi-Factor Authentication, or MFA. The authentication type v3multifactor is used in this case, while the v3totp authentication type is specified alongside the other mechanisms in auth_methods.

Using clouds.yaml:

clouds:
  demo:
    auth:
      auth_url: http://openstack.dev/identity
      project_name: demo
      project_domain_name: default
      user_domain_name: default
      username: demo
      passcode: ${PASSCODE}
    auth_type: v3totp

or, using command line options:

$ openstack \
  --os-auth-url "http://openstack.dev/identity" \
  --os-project-name demo \
  --os-project-domain-name default \
  --os-user-domain-name default \
  --os-auth-type=v3totp \
  --os-username demo \
  --os-passcode ${PASSCODE} \
  server list

or, using environment variables:

$ export OS_AUTH_URL="http://openstack.dev/identity"
$ export OS_PROJECT_NAME=demo
$ export OS_PROJECT_DOMAIN_NAME=default
$ export OS_AUTH_TYPE=v3totp
$ export OS_USERNAME=demo
$ export OS_PASSCODE=${PASSCODE}
$ openstack server list

Note

The passcode will be generated by an authenticator application such FreeOTP or Google Authenticator. Refer to your cloud provider's documentation for information on how to configure an authenticator application, or to the Keystone documentation__ if you are configuring this for your own cloud.

Note

If a passcode is not provided, you will be prompted for one.