flux-local

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flux-local is a set of tools and libraries for managing a local flux gitops repository focused on validation steps to help improve quality of commits, PRs, and general local testing.

This library uses command line tools like kustomize and helm to replicate the behavior of flux to gather objects in the cluster. It only looks at the local git repo, and not a live cluster. However, this is fine since the local repository has enough information and the definition is simple. Secrets are ignored as the content is not needed to validate the cluster is creating valid objects.

This library at first glance is little more than shell scripts running commands, but is easier to test, maintain, and evolve. This does not support all features of flux, but should be close enough for home use.

See documentation for full quickstart and API reference. See the github project.

flux-local CLI

The CLI is written in python and packaged as part of the flux-local python library, which can be installed using pip:

$ pip3 install flux-local

flux-local get

You can use the flux-local cli to inspect objects in the cluster, similar to how you might use the flux command on a real cluster.

This example lists all Kustomizations in the cluster:

$ flux-local get ks -o wide
NAME                 PATH                                                   HELMREPOS    RELEASES
apps                 ./tests/testdata/cluster/apps/prod                     0            0
infra-controllers    ./tests/testdata/cluster/infrastructure/controllers    0            0
infra-configs        ./tests/testdata/cluster/infrastructure/configs        2            0

This example lists all HelmReleases in the cluster:

$ flux-local get hr -A
NAMESPACE    NAME       REVISION    CHART              SOURCE
podinfo      podinfo    6.3.2       podinfo-podinfo    podinfo
metallb      metallb    4.1.14      metallb-metallb    bitnami

This example lists all HelmReleases in a specific namespace:

$ flux-local get hr -n metallb
NAME       REVISION    CHART              SOURCE
metallb    4.1.14      metallb-metallb    bitnami

flux-local build

You can use the flux-local cli to build all objects in a cluster, similar to how you use kustomize build, which is used underneath. Here is an example to build all flux Kustomization objects within a git repository, using kustomize cfg count to parse the yaml output:

$ flux-local build tests/testdata/cluster/ | kustomize cfg count
ClusterPolicy: 1
ConfigMap: 1
HelmRelease: 2
HelmRepository: 2
Namespace: 1

You can also specify the root to build all clusters.

Additionally, you can inflate HelmRelease objects inside each Kustomization by adding the --enable-helm command line flag. This example again shows kustomize cfg count to parse the yaml output which now includes the resources from HelmRelease objects defined in the cluster:

$ flux-local build tests/testdata/cluster/ --enable-helm --skip-crds | kustomize cfg count
ClusterPolicy: 1
ClusterRole: 2
ClusterRoleBinding: 2
ConfigMap: 3
DaemonSet: 1
Deployment: 3
HelmRelease: 2
HelmRepository: 2
Ingress: 1
Namespace: 1
Role: 3
RoleBinding: 3
Secret: 1
Service: 3
ServiceAccount: 2
ValidatingWebhookConfiguration: 1

flux-local diff

You may also use flux-local to verify your local changes to cluster resources have the desird effect. This is similar to flux diff but entirely local. This will run a local kustomize build first against the local repo then again against a prior repo revision, then prints the output:

$ flux-local diff ks apps
---

+++

@@ -2,6 +2,13 @@

   kind: Namespace
   metadata:
     name: podinfo
+- apiVersion: v1
+  data:
+    foo: bar
+  kind: ConfigMap
+  metadata:
+    name: podinfo-config
+    namespace: podinfo
 - apiVersion: helm.toolkit.fluxcd.io/v2beta1
   kind: HelmRelease
   metadata:

Additionally flux-local can inflate a HelmRelease locally and show diffs in the output objects. This is similar to flux diff but for HelmReleases:

$ flux-local diff hr -n podinfo podinfo
---

+++

@@ -33,8 +33,8 @@

     labels:
       app.kubernetes.io/managed-by: Helm
       app.kubernetes.io/name: podinfo
-      app.kubernetes.io/version: 6.3.2
-      helm.sh/chart: podinfo-6.3.2
+      app.kubernetes.io/version: 6.3.3
+      helm.sh/chart: podinfo-6.3.3
     name: podinfo
   spec:
     ports:
...

You may also use an external diff program such as dyff which is more compact for diffing yaml resources:

$ git status
On branch dev
Your branch is up to date with 'origin/dev'.

Changes not staged for commit:
	modified:   home/dev/hajimari-values.yaml

$ export DIFF="dyff between --omit-header --color on"
$ flux-local diff ks home --path clusters/dev/

spec.chart.spec.version  (HelmRelease/hajimari/hajimari)
  ± value change
    - 2.0.2
    + 2.0.1

$ flux-local diff hr hajimari -n hajimari --path clusters/dev/

metadata.labels.helm.sh/chart  (ClusterRoleBinding/default/hajimari)
  ± value change
    - hajimari-2.0.2
    + hajimari-2.0.1

metadata.labels.helm.sh/chart  (PersistentVolumeClaim/default/hajimari-data)
  ± value change
    - hajimari-2.0.2
    + hajimari-2.0.1

flux-local test

You can verify that the resources in the cluster are formatted properly before commit or as part of a CI system. The flux-local test command will build the Kustomization resources in the cluster:

$ flux-local test
============================================= test session starts =============================================
collected 18 items

clusters/dev .........                                                                                  [ 50%]
clusters/prod .........                                                                                 [100%]

============================================= 18 passed in 11.43s =============================================
$ flux-local test -v
============================================= test session starts =============================================
collected 18 items

./clusters/dev::certmanager::kustomization PASSED                                                       [  5%]
./clusters/dev::crds::kustomization PASSED                                                              [ 11%]
./clusters/dev::games::kustomization PASSED                                                             [ 16%]
./clusters/dev::home::kustomization PASSED                                                              [ 22%]
./clusters/dev::infrastructure::kustomization PASSED                                                    [ 27%]
./clusters/dev::monitoring::kustomization PASSED                                                        [ 33%]
./clusters/dev::network::kustomization PASSED                                                           [ 38%]
./clusters/dev::services::kustomization PASSED                                                          [ 44%]
./clusters/dev::settings::kustomization PASSED                                                          [ 50%]
./clusters/prod::certmanager::kustomization PASSED                                                      [ 55%]
./clusters/prod::crds::kustomization PASSED                                                             [ 61%]
./clusters/prod::games::kustomization PASSED                                                            [ 66%]
./clusters/prod::home::kustomization PASSED                                                             [ 72%]
./clusters/prod::infrastructure::kustomization PASSED                                                   [ 77%]
./clusters/prod::monitoring::kustomization PASSED                                                       [ 83%]
./clusters/prod::network::kustomization PASSED                                                          [ 88%]
./clusters/prod::services::kustomization PASSED                                                         [ 94%]
./clusters/prod::settings::kustomization PASSED                                                         [100%]

============================================= 18 passed in 11.81s ============================================

You may also validate HelmRelease objects can be templated properly with the --enable-helm flag. This will run kustomize build then run helm template on all the HelmRelease objects found. Additionally the --enable-kyverno flag will apply any found ClusterPolicy objects to all objects in the cluster and verify they pass:

$ flux-local test --enable-helm --enable-kyverno
============================================= test session starts =============================================
collected 81 items

clusters/dev .....................................                                                      [ 45%]
clusters/prod ............................................                                              [100%]

======================================== 81 passed in 75.40s (0:01:15) ========================================

GitHub Action

You may use flux-local as a github action to verify the health of the cluster on changes or PRs. The actions expect to find the flux and kustomize binaries installed.

test action

The test action will validate the cluster will build, and can optionally validate flux HelmRelease builds and also verify that all objects pass kyverno policies (e.g. for determining there are no deprecated api resources or that ingress objects are valid).

This example will run flux-local test against the cluster in clusters/prod with helm release expansion enabled.

- name: Setup Flux CLI
  uses: fluxcd/flux2/[email protected]
- uses: allenporter/flux-local/action/[email protected]
  with:
    path: clusters/prod
    enable-helm: true
    enable-kyverno: false

diff action

The diff action will show you the final diffs of Kustomization or HelmRelease objects that are fully built. While typically you can just read diffs to understand how kustomzations may be affected, this action also supports overlays and multiple clusters showing you the final output.

This is an example that diffs a HelmRelease:

- name: Setup Flux CLI
  uses: fluxcd/flux2/[email protected]
- uses: allenporter/flux-local/action/[email protected]
  id: diff
  with:
    live-branch: main
    path: clusters/prod
    resource: helmrelease
- name: PR Comments
  uses: mshick/add-pr-comment@v2
  if: ${{ steps.diff.outputs.diff != '' }}
  with:
    repo-token: ${{ secrets.GITHUB_TOKEN }}
    message-failure: Unable to post diff
    message: |
      `````diff
      ${{ steps.diff.outputs.diff }}
      `````

This is an example of a workflow that will diff Kustomization and HelmRelease objects in a repo with multiple clusters (dev and prod):

jobs:
  diffs:
    name: Compute diffs
    runs-on: ubuntu-latest
    strategy:
      matrix:
        cluster_path:
          - clusters/dev
          - clusters/prod
        resource:
          - helmrelease
          - kustomization
    steps:
      - name: Setup Flux CLI
        uses: fluxcd/flux2/[email protected]
      - uses: allenporter/flux-local/action/[email protected]
        id: diff
        with:
          live-branch: main
          path: ${{ matrix.cluster_path }}
          resource: ${{ matrix.resource }}
      - name: PR Comments
        uses: mshick/add-pr-comment@v2
        if: ${{ steps.diff.outputs.diff != '' }}
        with:
          repo-token: ${{ secrets.GITHUB_TOKEN }}
          message-id: ${{ github.event.pull_request.number }}/${{ matrix.cluster_path }}/${{ matrix.resource }}
          message-failure: Unable to post kustomization diff
          message: |
            `````diff
            ${{ steps.diff.outputs.diff }}
            `````

Library

The flux_local library documentation for details on the python APIs provided.