[configuration] delayed postprocs, extra volmounts

Change:

- Allow post-processors to be delayed until after the first
  (alphabetical) pass. In the delayed pass, delayed post-processors
  are again executed alphabetically.

- In the interest of keeping configuration simple, we don't allow for
  multiple "levels" of delay. A post-processor is either run during the
  first pass, or delayed until after the first/normal pass.

- This also adds an "extra volmounts" variable to the navigator
  post-processor class, which can be used by other post-processors to
  signify that they want a volume to be mounted. The volume-mount post
  processor is now delayed to accommodate.

Test Plan:

- Using this in lint/navigator work, no new tests yet because there is
  no other post processor currently which adds an extra volume mount.

Signed-off-by: Rick Elrod <rick@elrod.me>

src/ansible_navigator/configuration_subsystem/configurator.py

@@ -234,7 +234,17 @@ def _apply_cli_params(self) -> None:
                 self._messages.append(LogMessage(level=logging.INFO, message=message))
 
     def _post_process(self) -> None:
+        delayed = []
+        normal = []
+
+        # Separate normal and delayed entries so they can be processed in that order.
         for entry in self._config.entries:
+            if entry.delay_post_process:
+                delayed.append(entry)
+            else:
+                normal.append(entry)
+
+        for entry in normal + delayed:
             if self._initial or entry.change_after_initial:
                 processor = getattr(self._config.post_processor, entry.name, None)
                 if callable(processor):

src/ansible_navigator/configuration_subsystem/definitions.py

@@ -60,6 +60,7 @@ class Entry(SimpleNamespace):
     apply_to_subsequent_cli: Should this be applied to future CLIs parsed
     choice: valid choices for this entry
     cli_parameters: argparse specific params
+    delay_post_process: Post process in normal (alphabetical) order or wait until after first pass?
     environment_variable_override: override the default environment variable
     name: the reference name for the entry
     settings_file_path_override: over the default settings file path
@@ -76,6 +77,7 @@ class Entry(SimpleNamespace):
     change_after_initial: bool = True
     choices: List = []
     cli_parameters: Union[None, CliParameters] = None
+    delay_post_process: bool = False
     environment_variable_override: Union[None, str] = None
     settings_file_path_override: Union[None, str] = None
     subcommands: Union[List[str], Constants] = Constants.ALL

src/ansible_navigator/configuration_subsystem/navigator_configuration.py

@@ -291,6 +291,7 @@ class Internals(SimpleNamespace):
         Entry(
             name="execution_environment_volume_mounts",
             cli_parameters=CliParameters(action="append", nargs="+", short="--eev"),
+            delay_post_process=True,
             settings_file_path_override="execution-environment.volume-mounts",
             short_description=(
                 "Specify volume to be bind mounted within an execution environment"

src/ansible_navigator/configuration_subsystem/navigator_post_processor.py

@@ -6,6 +6,8 @@
 import shlex
 import shutil
 
+from dataclasses import dataclass, field
+from enum import Enum
 from pathlib import Path
 from typing import List
 from typing import Tuple
@@ -46,13 +48,64 @@ def wrapper(*args, **kwargs):
     return wrapper
 
 
+class VolumeMountOption(Enum):
+    """Options that can be tagged on to the end of volume mounts.
+
+    Usually these are used for things like selinux relabeling, but there are
+    some other valid options as well, which can and should be added here as
+    needed. See ``man podman-run`` and ``man docker-run`` for valid choices and
+    keep in mind that we support both runtimes.
+    """
+
+    # Relabel as private
+    Z = "Z"
+
+    # Relabel as shared.
+    z = "z"  # pylint: disable=invalid-name
+
+
+@dataclass
+class VolumeMount:
+    """Describes EE volume mounts."""
+
+    #: The name of the config option requiring this volume mount.
+    calling_option: str
+
+    #: The source path of the volume mount.
+    src: str
+
+    #: The destination path in the container for the volume mount.
+    dest: str
+
+    #: Options for the bind mount.
+    options: List[VolumeMountOption] = field(default_factory=list)
+
+    def exists(self) -> bool:
+        """Determine if the volume mount source exists."""
+        return Path(self.src).exists()
+
+    def to_string(self) -> str:
+        """Render the volume mount in a way that (docker|podman) understands."""
+        out = f"{self.src}:{self.dest}"
+        if self.options:
+            joined_opts = ",".join(o.value for o in self.options)  # pylint: disable=not-an-iterable
+            out += f":{joined_opts}"
+        return out
+
+
 PostProcessorReturn = Tuple[List[LogMessage], List[ExitMessage]]
 
 
 class NavigatorPostProcessor:
     # pylint:disable=too-many-public-methods
     """application post processor"""
 
+    def __init__(self):
+        # Volume mounts accumulated from post processing various config entries.
+        # These get processed towards the end, in the (delayed)
+        # execution_environment_volume_mounts() post-processor.
+        self.extra_volume_mounts: List[VolumeMount] = []
+
     @staticmethod
     def _true_or_false(entry: Entry, config: ApplicationConfiguration) -> PostProcessorReturn:
         # pylint: disable=unused-argument
@@ -233,12 +286,12 @@ def execution_environment_image(
             entry.value.current = f"{entry.value.current}:latest"
         return messages, exit_messages
 
-    @staticmethod
     @_post_processor
     def execution_environment_volume_mounts(
-        entry: Entry, config: ApplicationConfiguration
+        self, entry: Entry, config: ApplicationConfiguration
     ) -> PostProcessorReturn:
         # pylint: disable=unused-argument
+        # pylint: disable=too-many-branches
         """Post process set_environment_variable"""
         messages: List[LogMessage] = []
         exit_messages: List[ExitMessage] = []
@@ -305,6 +358,18 @@ def execution_environment_volume_mounts(
                     return messages, exit_messages
 
             entry.value.current = parsed_volume_mounts
+
+        if self.extra_volume_mounts and entry.value.current is C.NOT_SET:
+            entry.value.current = []
+
+        for mount in self.extra_volume_mounts:
+            if not mount.exists():
+                exit_msg = (
+                    f"The volume mount source path '{mount.src}', needed by "
+                    f"{mount.calling_option}, does not exist."
+                )
+                exit_messages.append(ExitMessage(message=exit_msg))
+            entry.value.current.append(mount.to_string())
         return messages, exit_messages
 
     @staticmethod

tests/unit/configuration_subsystem/test_navigator_post_processor.py

@@ -0,0 +1,31 @@
+"""Tests for the navigator config post-processor."""
+
+import pytest
+
+from ansible_navigator.configuration_subsystem.navigator_post_processor import (
+    VolumeMount,
+    VolumeMountOption,
+)
+
+
+@pytest.mark.parametrize(
+    ("volmount", "expected"),
+    (
+        (VolumeMount("test_option", "/foo", "/bar"), "/foo:/bar"),
+        (VolumeMount("test_option", "/foo", "/bar", [VolumeMountOption.z]), "/foo:/bar:z"),
+        (
+            VolumeMount("test_option", "/foo", "/bar", [VolumeMountOption.z, VolumeMountOption.Z]),
+            "/foo:/bar:z,Z",
+        ),
+        (VolumeMount("test_option", "/foo", "/bar", []), "/foo:/bar"),
+    ),
+    ids=(
+        "normal mount",
+        "mount with relabel option",
+        "mount with a list of options",
+        "mount with empty list of options",
+    ),
+)
+def test_navigator_volume_mount_to_string(volmount, expected):
+    """Make sure volume mount ``to_string`` is sane."""
+    assert volmount.to_string() == expected