Allow building resources without a Kustomization (#20)

Allow building with `kustomize cfg grep` without needing to first build
from a `Kustomization`. Includes a breaking change to move `build` out
of `Kustomization` into the module level.

flux_local/kustomize.py

@@ -6,18 +6,27 @@
 
 This example returns the objects inside a Kustomization using `kustomize build`:
 ```python
-from flux_local.kustomize import Kustomize
+from flux_local import kustomize
 
-objects = await Kustomize.build('/path/to/objects').objects()
+objects = await kustomize.build('/path/to/objects').objects()
 for object in objects:
     print(f"Found object {object['apiVersion']} {object['kind']}")
 ```
 
 You can also filter documents to specific resource types or other fields:
 ```python
-from flux_local.kustomize import Kustomize
+from flux_local import kustomize
 
-objects = await Kustomize.build('/path/to/objects').grep('kind=ConfigMap').objects()
+objects = await kustomize.build('/path/to/objects').grep('kind=ConfigMap').objects()
+for object in objects:
+    print(f"Found ConfigMap: {object['metadata']['name']}")
+```
+
+It is also possible to find bare objects without a Kustomization:
+```python
+from flux_local import kustomize
+
+objects = await kustomize.grep('kind=ConfigMap', '/path/to/objects').objects()
 for object in objects:
     print(f"Found ConfigMap: {object['metadata']['name']}")
 ```
@@ -43,14 +52,7 @@ def __init__(self, cmds: list[list[str]]) -> None:
         """Initialize Kustomize."""
         self._cmds = cmds
 
-    @classmethod
-    def build(cls, path: Path) -> "Kustomize":
-        """Build cluster artifacts from the specified path."""
-        return Kustomize(cmds=[[KUSTOMIZE_BIN, "build", str(path)]])
-
-    def grep(
-        self, expr: str, path: Path | None = None, invert: bool = False
-    ) -> "Kustomize":
+    def grep(self, expr: str, invert: bool = False) -> "Kustomize":
         """Filter resources based on an expression.
 
         Example expressions:
@@ -60,8 +62,6 @@ def grep(
         out = [KUSTOMIZE_BIN, "cfg", "grep", expr]
         if invert:
             out.append("--invert-match")
-        if path:
-            out.append(str(path))
         return Kustomize(self._cmds + [out])
 
     async def run(self) -> str:
@@ -95,3 +95,16 @@ async def validate(self, policy_path: Path) -> None:
             ],
         ]
         await command.run_piped(cmds)
+
+
+def build(path: Path) -> Kustomize:
+    """Build cluster artifacts from the specified path."""
+    return Kustomize(cmds=[[KUSTOMIZE_BIN, "build", str(path)]])
+
+
+def grep(expr: str, path: Path, invert: bool = False) -> Kustomize:
+    """Filter resources in the specified path based on an expression."""
+    out = [KUSTOMIZE_BIN, "cfg", "grep", expr, str(path)]
+    if invert:
+        out.append("--invert-match")
+    return Kustomize([out])

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = flux-local
-version = 0.0.1
+version = 0.0.2
 description = flux-local is a python library and set of tools for managing a flux gitops repository, with validation steps to help improve quality of commits, PRs, and general local testing.
 long_description = file: README.md
 long_description_content_type = text/markdown

tests/test_helm.py

@@ -6,8 +6,8 @@
 import pytest
 from aiofiles.os import mkdir
 
+from flux_local import kustomize
 from flux_local.helm import Helm
-from flux_local.kustomize import Kustomize
 from flux_local.manifest import HelmRelease, HelmRepository
 
 TESTDATA_DIR = Path("tests/testdata/") / "helm-repo"
@@ -22,8 +22,8 @@ def tmp_config_path_fixture(tmp_path_factory: Any) -> Generator[Path, None, None
 @pytest.fixture(name="helm_repos")
 async def helm_repos_fixture() -> list[dict[str, Any]]:
     """Fixture for creating the HelmRepository objects"""
-    kustomize = Kustomize.build(TESTDATA_DIR).grep("kind=^HelmRepository$")
-    return await kustomize.objects()
+    cmd = kustomize.grep("kind=^HelmRepository$", TESTDATA_DIR)
+    return await cmd.objects()
 
 
 @pytest.fixture(name="helm")
@@ -43,8 +43,8 @@ async def helm_fixture(tmp_config_path: Path, helm_repos: list[dict[str, Any]])
 @pytest.fixture(name="helm_releases")
 async def helm_releases_fixture() -> list[dict[str, Any]]:
     """Fixture for creating the HelmRelease objects."""
-    kustomize = Kustomize.build(TESTDATA_DIR).grep("kind=^HelmRelease$")
-    return await kustomize.objects()
+    cmd = kustomize.grep("kind=^HelmRelease$", TESTDATA_DIR)
+    return await cmd.objects()
 
 
 async def test_update(helm: Helm) -> None:
@@ -58,9 +58,9 @@ async def test_template(helm: Helm, helm_releases: list[dict[str, Any]]) -> None
 
     assert len(helm_releases) == 1
     release = helm_releases[0]
-    kustomize = await helm.template(
+    obj = await helm.template(
         HelmRelease.from_doc(release), release["spec"].get("values")
     )
-    docs = await kustomize.grep("kind=ServiceAccount").objects()
+    docs = await obj.grep("kind=ServiceAccount").objects()
     names = [doc.get("metadata", {}).get("name") for doc in docs]
     assert names == ["metallb-controller", "metallb-speaker"]

tests/test_kustomize.py

@@ -4,47 +4,54 @@
 
 import pytest
 
-from flux_local import command
-from flux_local.kustomize import Kustomize
+from flux_local import command, kustomize
 
 TESTDATA_DIR = Path("tests/testdata")
 
 
 async def test_build() -> None:
     """Test a kustomize build command."""
-    result = await Kustomize.build(TESTDATA_DIR / "repo").run()
+    result = await kustomize.build(TESTDATA_DIR / "repo").run()
     assert "Secret" in result
     assert "ConfigMap" in result
     assert result == (TESTDATA_DIR / "repo/all.golden").read_text()
 
 
+async def test_build_grep() -> None:
+    """Test a kustomize build and grep command chained."""
+    result = await kustomize.build(TESTDATA_DIR / "repo").grep("kind=ConfigMap").run()
+    assert "Secret" not in result
+    assert "ConfigMap" in result
+    assert result == (TESTDATA_DIR / "repo/configmap.build.golden").read_text()
+
+
 async def test_grep() -> None:
-    """Test a kustomize build command."""
-    result = await Kustomize.build(TESTDATA_DIR / "repo").grep("kind=ConfigMap").run()
+    """Test a kustomize grep command."""
+    result = await kustomize.grep("kind=ConfigMap", TESTDATA_DIR / "repo").run()
     assert "Secret" not in result
     assert "ConfigMap" in result
-    assert result == (TESTDATA_DIR / "repo/configmap.golden").read_text()
+    assert result == (TESTDATA_DIR / "repo/configmap.grep.golden").read_text()
 
 
 async def test_objects() -> None:
     """Test loading yaml documents."""
-    kustomize = Kustomize.build(TESTDATA_DIR / "repo").grep("kind=ConfigMap")
-    result = await kustomize.objects()
+    cmd = kustomize.build(TESTDATA_DIR / "repo").grep("kind=ConfigMap")
+    result = await cmd.objects()
     assert len(result) == 1
     assert result[0].get("kind") == "ConfigMap"
     assert result[0].get("apiVersion") == "v1"
 
 
 async def test_validate_pass() -> None:
     """Test applying policies to validate resources."""
-    kustomize = Kustomize.build(TESTDATA_DIR / "repo")
-    await kustomize.validate(TESTDATA_DIR / "policies/pass.yaml")
+    cmd = kustomize.build(TESTDATA_DIR / "repo")
+    await cmd.validate(TESTDATA_DIR / "policies/pass.yaml")
 
 
 async def test_validate_fail() -> None:
     """Test applying policies to validate resources."""
-    kustomize = Kustomize.build(TESTDATA_DIR / "repo")
+    cmd = kustomize.build(TESTDATA_DIR / "repo")
     with pytest.raises(
         command.CommandException, match="require-test-annotation: validation error"
     ):
-        await kustomize.validate(TESTDATA_DIR / "policies/fail.yaml")
+        await cmd.validate(TESTDATA_DIR / "policies/fail.yaml")

tests/testdata/repo/configmap.grep.golden

@@ -0,0 +1,13 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  namespace: flux-system
+  name: cluster-settings
+  annotations:
+    config.kubernetes.io/index: '0'
+    config.kubernetes.io/path: 'cluster-settings.yaml'
+    internal.config.kubernetes.io/index: '0'
+    internal.config.kubernetes.io/path: 'cluster-settings.yaml'
+data:
+  CLUSTER: dev
+  DOMAIN: example.org