appservice: support assign managed service identity to webapp/functio…

…napp (#4837)

src/azure-cli-core/azure/cli/core/commands/arm.py

@@ -730,3 +730,78 @@ def _find_property(instance, path):
     for part in path:
         instance = _update_instance(instance, part, path)
     return instance
+
+
+def assign_implict_identity(getter, setter, identity_role=None, identity_scope=None):
+    import time
+    from azure.mgmt.authorization import AuthorizationManagementClient
+    from azure.mgmt.authorization.models import RoleAssignmentProperties
+    from msrestazure.azure_exceptions import CloudError
+
+    # get
+    resource = getter()
+    if resource.identity:
+        logger.warning('Implict identity is already configured')
+    else:
+        resource = setter(resource)
+
+    # create role assignment:
+    if identity_scope:
+        principal_id = resource.identity.principal_id
+
+        identity_role_id = resolve_role_id(identity_role, identity_scope)
+        assignments_client = get_mgmt_service_client(AuthorizationManagementClient).role_assignments
+        properties = RoleAssignmentProperties(identity_role_id, principal_id)
+
+        logger.info("Creating an assignment with a role '%s' on the scope of '%s'", identity_role_id, identity_scope)
+        retry_times = 36
+        assignment_id = _gen_guid()
+        for l in range(0, retry_times):
+            try:
+                assignments_client.create(identity_scope, assignment_id, properties)
+                break
+            except CloudError as ex:
+                if 'role assignment already exists' in ex.message:
+                    logger.info('Role assignment already exists')
+                    break
+                elif l < retry_times and ' does not exist in the directory ' in ex.message:
+                    time.sleep(5)
+                    logger.warning('Retrying role assignment creation: %s/%s', l + 1,
+                                   retry_times)
+                    continue
+                else:
+                    raise
+    return resource
+
+
+def resolve_role_id(role, scope):
+    import uuid
+    from azure.mgmt.authorization import AuthorizationManagementClient
+    client = get_mgmt_service_client(AuthorizationManagementClient).role_definitions
+
+    role_id = None
+    if re.match(r'/subscriptions/[^/]+/providers/Microsoft.Authorization/roleDefinitions/',
+                role, re.I):
+        role_id = role
+    else:
+        try:
+            uuid.UUID(role)
+            role_id = '/subscriptions/{}/providers/Microsoft.Authorization/roleDefinitions/{}'.format(
+                client.config.subscription_id, role)
+        except ValueError:
+            pass
+        if not role_id:  # retrieve role id
+            role_defs = list(client.list(scope, "roleName eq '{}'".format(role)))
+            if not role_defs:
+                raise CLIError("Role '{}' doesn't exist.".format(role))
+            elif len(role_defs) > 1:
+                ids = [r.id for r in role_defs]
+                err = "More than one role matches the given name '{}'. Please pick an id from '{}'"
+                raise CLIError(err.format(role, ids))
+            role_id = role_defs[0].id
+    return role_id
+
+
+def _gen_guid():
+    import uuid
+    return uuid.uuid4()

src/command_modules/azure-cli-appservice/azure/cli/command_modules/appservice/_help.py

@@ -44,6 +44,20 @@
           --facebook-oauth-scopes public_profile email
 """
 
+helps['webapp assign-identity'] = """
+    type: command
+    short-summary: (PREVIEW) assign managed service identity to the webapp
+    examples:
+        - name: assign local identity and assign a reader role to the current resource group.
+          text: >
+            az webapp assign-identity -g MyResourceGroup -n MyUniqueApp --role reader --scope /subscriptions/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/MyResourceGroup
+        - name: disable the identity when there is need.
+          text: >
+            az webapp config appsettings set -g MyResourceGroup -n MyUniqueApp --settings WEBSITE_DISABLE_MSI=true
+"""
+
+helps['functionapp assign-identity'] = helps['webapp assign-identity'].replace('webapp', 'functionapp')
+
 helps['webapp config'] = """
 type: group
 short-summary: Configure a web app.

src/command_modules/azure-cli-appservice/azure/cli/command_modules/appservice/_params.py

@@ -142,6 +142,9 @@ def get_hostname_completion_list(prefix, action, parsed_args, **kwargs):  # pyli
     register_cli_argument(scope + ' create', 'deployment_zip', options_list=('--deployment-zip', '-z'), help='perform deployment using zip file')
     register_cli_argument(scope + ' create', 'deployment_source_url', options_list=('--deployment-source-url', '-u'), help='Git repository URL to link with manual integration')
     register_cli_argument(scope + ' create', 'deployment_source_branch', options_list=('--deployment-source-branch', '-b'), help='the branch to deploy')
+    register_cli_argument(scope + ' assign-identity', 'disable_msi', action='store_true', help='disable the identity')
+    register_cli_argument(scope + ' assign-identity', 'scope', help="The scope the managed identity has access to")
+    register_cli_argument(scope + ' assign-identity', 'role', help="Role name or id the managed identity will be assigned")
 
 register_cli_argument('webapp config hostname', 'webapp_name', help="webapp name. You can configure the default using 'az configure --defaults web=<name>'", configured_default='web',
                       completer=get_resource_name_completion_list('Microsoft.Web/sites'), id_part='name')

src/command_modules/azure-cli-appservice/azure/cli/command_modules/appservice/commands.py

@@ -144,6 +144,7 @@ def _polish_bad_errors(ex):
 cli_command(__name__, 'webapp auth show', custom_path + 'get_auth_settings')
 cli_command(__name__, 'webapp auth update', custom_path + 'update_auth_settings')
 
+cli_command(__name__, 'webapp assign-identity', custom_path + 'assign_identity')
 
 if not supported_api_version(PROFILE_TYPE, max_api='2017-03-09-profile'):
     cli_command(__name__, 'appservice plan create', custom_path + 'create_app_service_plan', exception_handler=ex_handler_factory(creating_plan=True))
@@ -187,3 +188,4 @@ def _polish_bad_errors(ex):
     cli_command(__name__, 'functionapp deployment list-publishing-profiles',
                 custom_path + 'list_publish_profiles')
     cli_command(__name__, 'functionapp deployment user show', 'azure.mgmt.web.web_site_management_client#WebSiteManagementClient.get_publishing_user', cf_web_client, exception_handler=empty_on_404)
+    cli_command(__name__, 'functionapp assign-identity', custom_path + 'assign_identity')

src/command_modules/azure-cli-appservice/azure/cli/command_modules/appservice/custom.py

@@ -20,7 +20,7 @@
                                    SkuDescription, SslState, HostNameBinding, NameValuePair,
                                    BackupRequest, DatabaseBackupSetting, BackupSchedule,
                                    RestoreRequest, FrequencyUnit, Certificate, HostNameSslState,
-                                   RampUpRule, UnauthenticatedClientAction)
+                                   RampUpRule, UnauthenticatedClientAction, ManagedServiceIdentity)
 
 from azure.cli.core.commands.client_factory import get_mgmt_service_client
 from azure.cli.core.commands import LongRunningOperation
@@ -132,6 +132,23 @@ def _list_app(app_types, resource_group_name=None):
     return result
 
 
+def assign_identity(resource_group_name, name, role='Contributor', scope=None, disable_msi=False):
+    client = web_client_factory()
+
+    def getter():
+        return _generic_site_operation(resource_group_name, name, 'get')
+
+    def setter(webapp):
+        webapp.identity = ManagedServiceIdentity(type='SystemAssigned')
+        poller = client.web_apps.create_or_update(resource_group_name, name, webapp)
+        return LongRunningOperation()(poller)
+
+    from azure.cli.core.commands.arm import assign_implict_identity
+    webapp = assign_implict_identity(getter, setter, role, scope)
+    update_app_settings(resource_group_name, name, ['WEBSITE_DISABLE_MSI={}'.format(disable_msi)])
+    return webapp.identity
+
+
 def get_auth_settings(resource_group_name, name, slot=None):
     return _generic_site_operation(resource_group_name, name, 'get_auth_settings', slot)