Added support for paasta CLI plugins

debian/paasta-tools.links

@@ -26,6 +26,7 @@ opt/venvs/paasta-tools/bin/get_mesos_leader.py usr/bin/get_mesos_leader
 opt/venvs/paasta-tools/bin/kill_orphaned_docker_containers.py usr/bin/kill_orphaned_docker_containers
 opt/venvs/paasta-tools/bin/list_marathon_service_instances.py usr/bin/list_marathon_service_instances
 opt/venvs/paasta-tools/bin/paasta-api usr/bin/paasta-api
+opt/venvs/paasta-tools/bin/paasta-fsm usr/bin/paasta-fsm
 opt/venvs/paasta-tools/bin/paasta_autoscale_cluster usr/bin/paasta_autoscale_cluster
 opt/venvs/paasta-tools/bin/paasta_cleanup_maintenance usr/bin/paasta_cleanup_maintenance
 opt/venvs/paasta-tools/bin/paasta_cleanup_tron_namespaces usr/bin/paasta_cleanup_tron_namespaces

general_itests/steps/fsm_steps.py

@@ -21,7 +21,7 @@
 from behave import when
 from service_configuration_lib import read_services_configuration
 
-from paasta_tools.cli.cmds.fsm import paasta_fsm
+from paasta_tools.cli.fsm_cmd import paasta_fsm
 from paasta_tools.utils import SystemPaastaConfig
 
 
@@ -47,7 +47,7 @@ def step_impl_when_fsm_auto(context):
 
     fake_args = mock.Mock(yelpsoa_config_root=context.fake_yelpsoa_configs)
     with mock.patch(
-        "paasta_tools.cli.cmds.fsm.load_system_paasta_config", autospec=True
+        "paasta_tools.cli.fsm_cmd.load_system_paasta_config", autospec=True
     ) as mock_load_system_paasta_config:
         mock_load_system_paasta_config.return_value = SystemPaastaConfig(
             config={}, directory=context.fake_yelpsoa_configs

paasta_tools/cli/cli.py

@@ -16,6 +16,8 @@
 """A command line tool for viewing information from the PaaSTA stack."""
 import argparse
 import logging
+import os
+import subprocess
 import sys
 import warnings
 
@@ -39,6 +41,34 @@ def error(self, message):
         sys.exit(1)
 
 
+def list_external_commands():
+    p = subprocess.check_output(["/bin/bash", "-p", "-c", "compgen -A command paasta-"])
+    lines = p.decode("utf-8").strip().split("\n")
+    return {l.replace("paasta-", "", 1) for l in lines}
+
+
+def calling_external_command():
+    if len(sys.argv) > 1:
+        return sys.argv[1] in list_external_commands()
+    else:
+        return False
+
+
+def get_command_help(command):
+    return f"(run 'paasta {command} -h' for usage)"
+
+
+def external_commands_items():
+    for command in list_external_commands():
+        command_help = get_command_help(command)
+        yield command, command_help
+
+
+def exec_subcommand(argv):
+    command = sys.argv[1]
+    os.execlp(f"paasta-{command}", *argv[1:])
+
+
 def add_subparser(command, subparsers):
     """Given a command name, paasta_cmd, execute the add_subparser method
     implemented in paasta_cmd.py.
@@ -94,6 +124,9 @@ def get_argparser():
     for command in sorted(paasta_commands_dir(cmds)):
         add_subparser(command, subparsers)
 
+    for command, command_help in external_commands_items():
+        subparsers.add_parser(command, help=command_help)
+
     return parser
 
 
@@ -117,6 +150,13 @@ def main(argv=None):
     """
     logging.basicConfig()
     warnings.filterwarnings("ignore", category=DeprecationWarning)
+
+    # if we are an external command, we need to exec out early.
+    # The reason we exec out early is so we don't bother trying to parse
+    # "foreign" arguments, which would cause a stack trace.
+    if calling_external_command():
+        exec_subcommand(sys.argv)
+
     try:
         args, parser = parse_args(argv)
         if args.command is None:

paasta_tools/cli/cmds/fsm.py → paasta_tools/cli/fsm_cmd.py

@@ -12,6 +12,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+import argparse
 import contextlib
 import shutil
 import sys
@@ -50,10 +51,9 @@ def symlink_aware_copymode(*args, **kwargs):
         shutil.copymode = orig_copymode
 
 
-def add_subparser(subparsers):
-    fsm_parser = subparsers.add_parser(
+def parse_args():
+    fsm_parser = argparse.ArgumentParser(
         "fsm",
-        help="Generate boilerplate configs for a new PaaSTA Service",
         description=(
             "'paasta fsm' is used to generate example soa-configs, which is useful during initial "
             "service creation. Currently 'fsm' generates 'yelp-specific' configuration, but can still "
@@ -73,6 +73,7 @@ def add_subparser(subparsers):
         ),
     )
     fsm_parser.set_defaults(command=paasta_fsm)
+    return fsm_parser.parse_args()
 
 
 def get_paasta_config(yelpsoa_config_root):
@@ -110,3 +111,12 @@ def paasta_fsm(args):
     paasta_print("Customize Them If It Makes You Happy -- http://y/paasta For Details")
     paasta_print("Remember To Add, Commit, And Push When You're Done:")
     paasta_print()
+
+
+def main():
+    args = parse_args()
+    paasta_fsm(args)
+
+
+if __name__ == "__main__":
+    main()

setup.py

@@ -89,6 +89,7 @@ def get_install_requires():
             "paasta=paasta_tools.cli.cli:main",
             "paasta-api=paasta_tools.api.api:main",
             "paasta-deployd=paasta_tools.deployd.master:main",
+            "paasta-fsm=paasta_tools.cli.fsm_cmd:main",
             "paasta_autoscale_cluster=paasta_tools.autoscale_cluster:main",
             "paasta_cleanup_tron_namespaces=paasta_tools.cleanup_tron_namespaces:main",
             "paasta_list_kubernetes_service_instances=paasta_tools.list_kubernetes_service_instances:main",