entry: lazy load subcommands

src/nomad_tools/aliasedlazygroup.py

@@ -0,0 +1,51 @@
+# https://click.palletsprojects.com/en/8.1.x/complex/#defining-the-lazy-group
+import importlib
+import click
+
+
+class AliasedLazyGroup(click.Group):
+    def __init__(self, *args, lazy_subcommands=None, **kwargs):
+        super().__init__(*args, **kwargs)
+        # lazy_subcommands is a map of the form:
+        #
+        #   {command-name} -> {module-name}.{command-object-name}
+        #
+        self.lazy_subcommands = lazy_subcommands or {}
+
+    def list_commands(self, ctx):
+        base = super().list_commands(ctx)
+        lazy = sorted(self.lazy_subcommands.keys())
+        return base + lazy
+
+    def _lazy_load(self, cmd_name):
+        # lazily loading a command, first get the module name and attribute name
+        import_path = self.lazy_subcommands[cmd_name]
+        modname, cmd_object_name = import_path.rsplit(".", 1)
+        # do the import
+        mod = importlib.import_module(modname)
+        # get the Command object from that module
+        cmd_object = getattr(mod, cmd_object_name)
+        # check the result to make debugging easier
+        if not isinstance(cmd_object, click.Command):
+            raise ValueError(
+                f"Lazy loading of {import_path} failed by returning "
+                "a non-command object"
+            )
+        return cmd_object
+
+    def get_command(self, ctx, cmd_name):
+        rv = click.Group.get_command(self, ctx, cmd_name)
+        if rv is not None:
+            return rv
+        matches = [x for x in self.list_commands(ctx) if x.startswith(cmd_name)]
+        if not matches:
+            return None
+        elif len(matches) != 1:
+            ctx.fail(f"Too many matches: {', '.join(sorted(matches))}")
+        return self._lazy_load(matches[0])
+
+    def resolve_command(self, ctx, args):
+        # always return the full command name
+        _, cmd, args = super().resolve_command(ctx, args)
+        assert cmd
+        return cmd.name, cmd, args

src/nomad_tools/common_click.py

@@ -71,10 +71,8 @@ def main_options():
     )
 
 
-def common_options():
-    return composed(
-        click.help_option("-h", "--help"),
-    )
+def help_h_option():
+    return click.help_option("-h", "--help")
 
 
 def verbose_option():

src/nomad_tools/entry.py

@@ -3,26 +3,9 @@
 import clickforward
 from click.shell_completion import BashComplete
 
-from . import (
-    entry_constrainteval,
-    entry_cp,
-    entry_dockers,
-    entry_downloadrelease,
-    entry_githubrunner,
-    entry_gitlab_runner,
-    entry_go,
-    entry_listattributes,
-    entry_listnodeattributes,
-    entry_nodenametoid,
-    entry_port,
-    entry_task,
-    entry_info,
-    entry_vardir,
-    entry_watch,
-)
-from .common_click import EPILOG, common_options, main_options
+from .aliasedlazygroup import AliasedLazyGroup
+from .common_click import EPILOG, help_h_option, main_options
 from .common_nomad import namespace_option
-from .aliasedgroup import AliasedGroup
 
 clickforward.init()
 
@@ -60,37 +43,39 @@
     %(complete_func)s_setup;
 """
 
+subcommands = """
+    constrainteval
+    cp
+    dockers
+    downloadrelease
+    githubrunner
+    gitlab-runner
+    go
+    info
+    listattributes
+    listnodeattributes
+    nodenametoid
+    port
+    task
+    vardir
+    watch
+    """.split()
+
 
 @click.command(
     "nomadtools",
-    cls=AliasedGroup,
+    cls=AliasedLazyGroup,
+    lazy_subcommands={cmd: f"{__package__}.entry_{cmd.replace('-', '_')}.cli" for cmd in subcommands},
     help="Collection of useful tools for HashiCorp Nomad.",
     epilog=EPILOG,
 )
 @namespace_option()
-@common_options()
+@help_h_option()
 @main_options()
 def cli():
     pass
 
 
-cli.add_command(entry_constrainteval.cli)
-cli.add_command(entry_cp.cli)
-cli.add_command(entry_dockers.cli)
-cli.add_command(entry_downloadrelease.cli)
-cli.add_command(entry_githubrunner.cli)
-cli.add_command(entry_gitlab_runner.cli)
-cli.add_command(entry_go.cli)
-cli.add_command(entry_listattributes.cli)
-cli.add_command(entry_listnodeattributes.cli)
-cli.add_command(entry_nodenametoid.cli)
-cli.add_command(entry_port.cli)
-cli.add_command(entry_info.cli)
-cli.add_command(entry_task.cli)
-cli.add_command(entry_vardir.cli)
-cli.add_command(entry_watch.cli)
-
-
 def main():
     cli(max_content_width=9999)
 

src/nomad_tools/entry_constrainteval.py

@@ -18,7 +18,7 @@
 from packaging.version import Version
 
 from .common import mynomad
-from .common_click import EPILOG, common_options, verbose_option
+from .common_click import EPILOG, help_h_option, verbose_option
 from .mytabulate import mytabulate
 
 log = logging.getLogger(__name__)
@@ -326,7 +326,7 @@ def grouper(thelist: List[str], count: int) -> List[List[str]]:
 @clickdc.adddc("args", NodeCacheArgs)
 @clickdc.adddc("constraintsargs", ConstraintArgs)
 @verbose_option()
-@common_options()
+@help_h_option()
 def cli(args: NodeCacheArgs, constraintsargs: ConstraintArgs):
     return main(args, constraintsargs)
 

src/nomad_tools/entry_cp.py

@@ -29,7 +29,7 @@
 from . import nomadlib, taskexec
 from .common import (
     cached_property,
-    common_options,
+    help_h_option,
     mynomad,
     namespace_option,
     nomad_find_job,
@@ -814,7 +814,7 @@ class Args:
 """,
 )
 @namespace_option()
-@common_options()
+@help_h_option()
 @clickdc.adddc("args", Args)
 def cli(args: Args):
     global ARGS

src/nomad_tools/entry_dockers.py

@@ -81,7 +81,7 @@ class Args:
     `nomadtools dockers ./file.nomad.hcl | xargs docker pull`.
     """,
 )
-@common.common_options()
+@common.help_h_option()
 @clickdc.adddc("args", Args)
 def cli(args: Args):
     logging.basicConfig(level=logging.DEBUG if args.verbose else logging.INFO)

src/nomad_tools/entry_downloadrelease.py

@@ -13,7 +13,7 @@
 import click
 import requests
 
-from .common_click import common_options
+from .common_click import help_h_option
 
 log = logging.getLogger(__name__)
 
@@ -85,7 +85,7 @@ def get_arch() -> str:
     is_flag=True,
     help="Instead of downloading, only show the chosen version",
 )
-@common_options()
+@help_h_option()
 def cli(
     pinversion: Optional[str],
     arch: str,

src/nomad_tools/entry_githubrunner.py

@@ -41,7 +41,7 @@
 from . import nomadlib
 from .aliasedgroup import AliasedGroup
 from .common import mynomad
-from .common_click import common_options
+from .common_click import help_h_option
 from .nomadlib.connection import urlquote
 from .nomadlib.datadict import DataDict
 
@@ -1182,7 +1182,7 @@ class Args:
 
 @click.command("githubrunner", cls=AliasedGroup)
 @clickdc.adddc("args", Args)
-@common_options()
+@help_h_option()
 def cli(args: Args):
     global ARGS
     ARGS = args

src/nomad_tools/entry_gitlab_runner.py

@@ -21,7 +21,7 @@
 
 from . import entry_watch, nomadlib, taskexec
 from .aliasedgroup import AliasedGroup
-from .common import (cached_property, common_options, get_package_file,
+from .common import (cached_property, help_h_option, get_package_file,
                      get_version, mynomad, quotearr)
 from .nomadlib.datadict import DataDict
 from .nomadlib.types import Job, JobTask, JobTaskConfig
@@ -679,7 +679,7 @@ class BuildFailure(Exception):
     envvar="CUSTOM_ENV_CI_RUNNER_ID",
     show_default=True,
 )
-@common_options()
+@help_h_option()
 def cli(verbose: int, configpath: Path, runner_id: int):
     # Read configuration
     configcontent = configpath.read_text()

src/nomad_tools/entry_go.py

@@ -23,7 +23,7 @@
 
 from . import entry_watch, taskexec
 from .common_base import NOMAD_NAMESPACE, quotearr
-from .common_click import EPILOG, common_options
+from .common_click import EPILOG, help_h_option
 from .common_nomad import namespace_option
 
 clickforward.init()
@@ -632,7 +632,7 @@ def __thread(self):
 """
     f"{EPILOG}",
 )
-@common_options()
+@help_h_option()
 @namespace_option()
 @clickdc.adddc("args", Args)
 @clickdc.adddc("notifyargs", entry_watch.NotifyOptions)

src/nomad_tools/entry_info.py

@@ -17,7 +17,7 @@
     cls=AliasedGroup,
     help="Get information about current Nomad state",
 )
-@common_click.common_options()
+@common_click.help_h_option()
 @common_click.verbose_option()
 def cli():
     pass

src/nomad_tools/entry_listattributes.py

@@ -8,7 +8,7 @@
 import clickdc
 
 from . import entry_constrainteval
-from .common import common_options, verbose_option
+from .common import help_h_option, verbose_option
 from .common_click import completor
 from .entry_constrainteval import ConstraintArgs, NodeCacheArgs, NodesAttributes
 
@@ -37,7 +37,7 @@ def get_all_nodes_attributes(args: Optional[NodeCacheArgs] = None):
 )
 @clickdc.adddc("args", NodeCacheArgs)
 @verbose_option()
-@common_options()
+@help_h_option()
 def cli(args: NodeCacheArgs, attributes: Tuple[str, ...]):
     logging.basicConfig()
     if attributes:

src/nomad_tools/entry_listnodeattributes.py

@@ -7,7 +7,7 @@
 import click
 import clickdc
 
-from .common import common_options, mynomad, verbose_option
+from .common import help_h_option, mynomad, verbose_option
 from .common_click import completor
 from .entry_constrainteval import NodeCacheArgs, NodesAttributes
 from .mytabulate import mytabulate
@@ -32,7 +32,7 @@ def get_all_node_names():
 )
 @clickdc.adddc("args", NodeCacheArgs)
 @verbose_option()
-@common_options()
+@help_h_option()
 def cli(args: NodeCacheArgs, nodenameorid: Tuple[str, ...]):
     logging.basicConfig()
     nodesattributes = NodesAttributes.load(args)

src/nomad_tools/entry_nodenametoid.py

@@ -5,7 +5,7 @@
 import click
 
 from .common import mynomad
-from .common_click import common_options, completor
+from .common_click import help_h_option, completor
 
 
 def get_nodenametoid() -> Dict[str, str]:
@@ -29,7 +29,7 @@ def get_nodenametoid() -> Dict[str, str]:
     required=True,
     shell_complete=completor(lambda: list(get_nodenametoid().keys())),
 )
-@common_options()
+@help_h_option()
 def cli(prefix: bool, nodename: Tuple[str, ...]):
     nodenametoid = get_nodenametoid()
     for name in nodename:

src/nomad_tools/entry_port.py

@@ -12,7 +12,7 @@
 from . import nomadlib
 from .common import (
     alias_option,
-    common_options,
+    help_h_option,
     mynomad,
     namespace_option,
     nomad_find_job,
@@ -135,7 +135,7 @@ def id_completor(
     type=re.compile,
     help="Show only ports which name matches this regex.",
 )
-@common_options()
+@help_h_option()
 @namespace_option()
 @click.argument("id", shell_complete=id_completor)
 @click.argument("label", required=False)