feat(config): add --exclude-recipe to leave recipes out of a run

README.md

@@ -185,6 +185,14 @@ Without `-s` all secrets of the recipes selected by `-r` are purged.
 alakazam example.com.yml ps --wait --timeout 300
 ```
 
+### Excluding Recipes
+
+`-er`/`--exclude-recipe` leaves single recipes out of a run entirely:
+
+```
+alakazam -er traefik example.com.yml clean-deploy -n
+```
+
 ### Run CMDs
 
 Escaping can be akward:

alakazam.py

@@ -551,6 +551,32 @@ def get_merged_instance_configs(config_path: Path, group_configs: Dict[str, Any]
     return instances
 
 
+def exclude_from_configs(configs: Dict[str, Dict[str, Any]], recipes: Tuple[str]) -> Dict[str, Dict[str, Any]]:
+    """
+    Removes the given recipes from every instance configuration.
+
+    An excluded recipe is not merely left undeployed, it is invisible for the whole run: it is
+    neither listed, nor configured, nor purged, nor waited for. That is what keeps a rebuild from
+    touching an app whose state has to survive it, such as the certificates of a reverse proxy.
+
+    Args:
+        configs (dict): Instances as keys and their app configurations as values
+        recipes (tuple): Recipe names to leave out, all recipes are kept if empty
+
+    Returns:
+        dict: The configurations without those recipes
+    """
+    if not recipes:
+        return configs
+    for recipe in recipes:
+        if not any(recipe in apps for apps in configs.values()):
+            logging.warning(f"'{recipe}' is excluded but not configured for this path")
+    return {
+        instance: {name: config for name, config in apps.items() if name not in recipes}
+        for instance, apps in configs.items()
+    }
+
+
 def merge_connection_configs(configs: Dict[str, Any]) -> Dict[str, Any]:
     """
     Merge connection configurations from the 'combine.yml' to extend instance configurations with inter-app secrets and settings.
@@ -1526,9 +1552,10 @@ def execute_cmds(app_config: Dict[str, Any], commands: Tuple[str] = tuple(), ini
 @click.group(context_settings={"help_option_names": ['-h', '--help']})
 @click.option('-l', '--log', 'loglevel', help='Desired logging level ("debug", "info", "warning", "error", "critical")')
 @click.option('-e', '--exclude', help='Path to a directory that contains a group of instance configurations to be excluded.', multiple=True, type=click.Path(exists=True))
+@click.option('exclude_recipes', '-er', '--exclude-recipe', multiple=True, metavar='<RecipeName>', help='Leave these recipes untouched, this option can be specified multiple times.')
 @click.option('hide_secrets', '--hide-secrets', is_flag=True, help='Keep secret values out of the output, for runs whose logs are kept.')
 @click.argument('group_path', type=click.Path(exists=True))
-def cli(loglevel: str, group_path: str, exclude: Tuple[str], hide_secrets: bool) -> None:
+def cli(loglevel: str, group_path: str, exclude: Tuple[str], exclude_recipes: Tuple[str], hide_secrets: bool) -> None:
     """
     Alakazam is a meta-configuration app-connector and an abra wrapper, designed as a proof-of-concept to simplify the management of environment configuration files across multiple instances.
 
@@ -1569,6 +1596,10 @@ def cli(loglevel: str, group_path: str, exclude: Tuple[str], hide_secrets: bool)
     config_sets = read_config(str(ROOT_PATH / "config-sets.yml"))
     instance_configs = get_merged_instance_configs(_group_path, all_group_configs, exclude_paths, config_sets)
     INSTANCE_CONFIGS = merge_connection_configs(instance_configs)
+    # dropping the recipes here rather than at every filter is what makes the exclusion complete:
+    # get_apps(), create_secrets(), configure_apps() and the rest all read INSTANCE_CONFIGS.
+    # ALL_CONFIGS stays whole, it is the cross-instance view that backup looks up its bot in
+    INSTANCE_CONFIGS = exclude_from_configs(INSTANCE_CONFIGS, exclude_recipes)
     all_configs = get_merged_instance_configs(ROOT_PATH, all_group_configs, exclude_paths, config_sets)
     ALL_CONFIGS = merge_connection_configs(all_configs)
     fetch_recipes(INSTANCE_CONFIGS)

tests/test_exclude_recipes.py

@@ -0,0 +1,89 @@
+"""Tests for leaving single recipes out of a run."""
+
+import logging
+import os
+import sys
+
+import pytest
+from click.testing import CliRunner
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+import alakazam
+from alakazam import exclude_from_configs
+
+CONFIGS = {
+    "a.org": {"authentik": {"app_domain": "login.a.org"}, "traefik": {"app_domain": "a.org"}},
+    "b.org": {"traefik": {"app_domain": "b.org"}, "nextcloud": {"app_domain": "cloud.b.org"}},
+}
+
+
+class TestExcludeFromConfigs:
+    def test_nothing_excluded_returns_the_configs_unchanged(self):
+        assert exclude_from_configs(CONFIGS, ()) is CONFIGS
+
+    def test_the_recipe_is_gone_from_every_instance(self):
+        result = exclude_from_configs(CONFIGS, ("traefik",))
+        assert sorted(result["a.org"]) == ["authentik"]
+        assert sorted(result["b.org"]) == ["nextcloud"]
+
+    def test_several_recipes(self):
+        result = exclude_from_configs(CONFIGS, ("traefik", "nextcloud"))
+        assert result["b.org"] == {}
+
+    def test_the_original_is_not_modified(self):
+        exclude_from_configs(CONFIGS, ("traefik",))
+        assert "traefik" in CONFIGS["a.org"]
+
+    def test_an_unknown_recipe_is_reported(self, caplog):
+        """A typo would otherwise exclude nothing and look like it worked."""
+        with caplog.at_level(logging.WARNING):
+            exclude_from_configs(CONFIGS, ("treafik",))
+        assert "'treafik' is excluded but not configured" in caplog.text
+
+    def test_a_known_recipe_is_not_reported(self, caplog):
+        with caplog.at_level(logging.WARNING):
+            exclude_from_configs(CONFIGS, ("traefik",))
+        assert caplog.text == ""
+
+
+class TestExcludeReachesTheCommands:
+    """One filter in cli() has to cover every consumer of INSTANCE_CONFIGS."""
+
+    @pytest.fixture
+    def env(self, tmp_path, monkeypatch):
+        root = tmp_path / "root"
+        (root / "group").mkdir(parents=True)
+        (root / "alaka.yml").write_text(
+            "authentik:\n    version: 1.0.0\ntraefik:\n    version: 2.0.0\n")
+        (root / "group" / "example.com.yml").write_text("authentik:\ntraefik:\n")
+        (root / "alakazam.yml").write_text(f"root: {root}\n")
+        monkeypatch.setattr(alakazam, "get_settings_path", lambda: str(root / "alakazam.yml"))
+        monkeypatch.setattr(alakazam, "get_abra_dir", lambda: root / ".abra")
+        monkeypatch.setattr(alakazam, "fetch_recipes", lambda *a, **k: None)
+        monkeypatch.setattr(alakazam, "abra", lambda *a, **k: "")
+        return root
+
+    def invoke(self, root, args):
+        return CliRunner().invoke(alakazam.cli, args + [str(root / "group"), "ls"])
+
+    def test_without_the_flag_both_recipes_are_listed(self, env):
+        result = self.invoke(env, [])
+        assert result.exit_code == 0, result.output
+        assert "authentik" in result.output
+        assert "traefik" in result.output
+
+    def test_the_excluded_recipe_disappears(self, env):
+        result = self.invoke(env, ["-er", "traefik"])
+        assert result.exit_code == 0, result.output
+        assert "authentik" in result.output
+        assert "traefik" not in result.output
+
+    def test_the_long_option_works_too(self, env):
+        result = self.invoke(env, ["--exclude-recipe", "traefik"])
+        assert "traefik" not in result.output
+
+    def test_it_can_be_given_more_than_once(self, env):
+        result = self.invoke(env, ["-er", "traefik", "-er", "authentik"])
+        assert "traefik" not in result.output
+        assert "authentik" not in result.output