Add git sync option and unit tests for the Helm chart

.github/workflows/ci.yml

@@ -363,6 +363,17 @@ ${{ hashFiles('requirements/requirements-python${{matrix.python-version}}.txt')
       - name: "Tests"
         run: ./scripts/ci/ci_run_airflow_testing.sh
 
+  helm-tests:
+    timeout-minutes: 5
+    name: "Checks: Helm tests"
+    runs-on: ubuntu-latest
+    env:
+      CI_JOB_TYPE: "Tests"
+    steps:
+      - uses: actions/checkout@master
+      - name: "Helm Tests"
+        run: ./scripts/ci/ci_run_helm_testing.sh
+
   requirements:
     timeout-minutes: 80
     name: "Requirements"

CI.rst

@@ -33,7 +33,7 @@ environments we use. Most of our CI jobs are written as bash scripts which are e
 the CI jobs and we are mapping all the CI-specific environment variables to generic "CI" variables.
 The only two places where CI-specific code might be are:
 
-- CI-specific declaration file (for example it is `<.github/workflow/ci.yml>`_ for GitHub Actions
+- CI-specific declaration file (for example it is `<.github/workflows/ci.yml>`_ for GitHub Actions
 - The ``get_environment_for_builds_on_ci`` function in `<scripts/ci/libraries/_build_images.sh>`_ where mapping is
   performed from the CI-environment specific to generic values. Example for that is CI_EVENT_TYPE variable
   which determines whether we are running a ``push``. ``schedule`` or ``pull_request`` kind of CI job. For

airflow/kubernetes/worker_configuration.py

@@ -127,6 +127,10 @@ def _get_init_containers(self) -> List[k8s.V1Container]:
                     name='GIT_SSH_KEY_FILE',
                     value='/etc/git-secret/ssh'
                 ),
+                k8s.V1EnvVar(
+                    name='GIT_SYNC_ADD_USER',
+                    value='true'
+                ),
                 k8s.V1EnvVar(
                     name='GIT_SYNC_SSH',
                     value='true'

chart/README.md

@@ -66,7 +66,7 @@ The command removes all the Kubernetes components associated with the chart and
 
 ## Updating DAGs
 
-The recommended way to update your DAGs with this chart is to build a new docker image with the latest code (`docker build -t my-company/airflow:8a0da78 .`), push it to an accessible registry (`docker push my-company/airflow:8a0da78`), then update the Airflow pods with that image:
+The recommended way to update your DAGs with this chart is to build a new docker image with the latest DAG code (`docker build -t my-company/airflow:8a0da78 .`), push it to an accessible registry (`docker push my-company/airflow:8a0da78`), then update the Airflow pods with that image:
 
 ```bash
 helm upgrade airflow . \
@@ -76,6 +76,42 @@ helm upgrade airflow . \
 
 For local development purpose you can also build the image locally and use it via deployment method described by Breeze.
 
+## Mounting DAGS using Git-Sync side car with Persistence enabled
+
+This option will use a Persistent Volume Claim with an accessMode of `ReadWriteMany`. The scheduler pod will sync DAGs from a git repository onto the PVC every configured number of seconds. The other pods will read the synced DAGs. Not all volume  plugins have support for `ReadWriteMany` accessMode. Refer [Persistent Volume Access Modes](https://kubernetes.io/docs/concepts/storage/persistent-volumes/#access-modes) for details
+
+```bash
+helm upgrade airflow . \
+  --set dags.persistence.enabled=true \
+  --set dags.gitSync.enabled=true
+  # you can also override the other persistence or gitSync values
+  # by setting the  dags.persistence.* and dags.gitSync.* values
+  # Please refer to values.yaml for details
+```
+
+## Mounting DAGS using Git-Sync side car without Persistence
+This option will use an always running Git-Sync side car on every scheduler,webserver and worker pods. The Git-Sync side car containers will sync DAGs from a git repository every configured number of seconds. If you are using the KubernetesExecutor, Git-sync will run as an initContainer on your worker pods.
+
+```bash
+helm upgrade airflow . \
+  --set dags.persistence.enabled=false \
+  --set dags.gitSync.enabled=true
+  # you can also override the other gitSync values
+  # by setting the  dags.gitSync.* values
+  # Refer values.yaml for details
+```
+
+## Mounting DAGS from an externally populated PVC
+In this approach, Airflow will read the DAGs from a PVC which has `ReadOnlyMany` or `ReadWriteMany` accessMode. You will have to ensure that the PVC is populated/updated with the required DAGs(this won't be handled by the chart). You can pass in the name of the  volume claim to the chart
+
+```bash
+helm upgrade airflow . \
+  --set dags.persistence.enabled=true \
+  --set dags.persistence.existingClaim=my-volume-claim
+  --set dags.gitSync.enabled=false
+```
+
+
 ## Parameters
 
 The following tables lists the configurable parameters of the Airflow chart and their default values.
@@ -159,6 +195,8 @@ The following tables lists the configurable parameters of the Airflow chart and
 | `webserver.resources.requests.cpu`                    | CPU Request of webserver                                                                                     | `~`                                               |
 | `webserver.resources.requests.memory`                 | Memory Request of webserver                                                                                  | `~`                                               |
 | `webserver.defaultUser`                               | Optional default airflow user information                                                                    | `{}`                                              |
+| `dags.persistence.*`                               | Dag persistence configutation                                                                    | Please refer to `values.yaml`                                    |
+| `dags.gitSync.*`                               | Git sync configuration                                                                   | Please refer to `values.yaml`                                    |
 
 
 Specify each parameter using the `--set key=value[,key=value]` argument to `helm install`. For example,

chart/templates/_helpers.yaml

@@ -93,6 +93,80 @@
   {{ end }}
 {{- end }}
 
+{{/*  Git ssh key volume */}}
+{{- define "git_sync_ssh_key_volume"}}
+- name: git-sync-ssh-key
+  secret:
+    secretName: {{ .Values.dags.gitSync.sshKeySecret }}
+    defaultMode: 288
+{{- end }}
+
+{{/*  Git sync container */}}
+{{- define "git_sync_container"}}
+- name: {{ .Values.dags.gitSync.containerName }}
+  image: "{{ .Values.dags.gitSync.containerRepository }}:{{ .Values.dags.gitSync.containerTag }}"
+  env:
+    {{- if .Values.dags.gitSync.sshKeySecret }}
+    - name: GIT_SSH_KEY_FILE
+      value: "/etc/git-secret/ssh"
+    - name: GIT_SYNC_SSH
+      value: "true"
+    {{- if .Values.dags.gitSync.knownHosts }}
+    - name: GIT_KNOWN_HOSTS
+      value: "true"
+    - name: GIT_SSH_KNOWN_HOSTS_FILE
+      value: "/etc/git-secret/known_hosts"
+    {{- else }}
+    - name: GIT_KNOWN_HOSTS
+      value: "false"
+    {{- end }}
+    {{ else if .Values.dags.gitSync.credentialsSecret }}
+    - name: GIT_SYNC_USERNAME
+      valueFrom:
+        secretKeyRef:
+          name: {{ .Values.dags.gitSync.credentialsSecret | quote }}
+          key: GIT_SYNC_USERNAME
+    - name: GIT_SYNC_PASSWORD
+      valueFrom:
+        secretKeyRef:
+          name: {{ .Values.dags.gitSync.credentialsSecret | quote }}
+          key: GIT_SYNC_PASSWORD
+    {{- end }}
+    - name: GIT_SYNC_REV
+      value: {{ .Values.dags.gitSync.rev | quote }}
+    - name: GIT_SYNC_BRANCH
+      value: {{ .Values.dags.gitSync.branch | quote }}
+    - name: GIT_SYNC_REPO
+      value: {{ .Values.dags.gitSync.repo | quote }}
+    - name: GIT_SYNC_DEPTH
+      value: {{ .Values.dags.gitSync.depth | quote }}
+    - name: GIT_SYNC_ROOT
+      value: {{ .Values.dags.gitSync.root | quote }}
+    - name: GIT_SYNC_DEST
+      value: {{ .Values.dags.gitSync.dest | quote }}
+    - name: GIT_SYNC_ADD_USER
+      value: "true"
+    - name: GIT_SYNC_WAIT
+      value: {{ .Values.dags.gitSync.wait | quote }}
+    - name: GIT_SYNC_MAX_SYNC_FAILURES
+      value: {{ .Values.dags.gitSync.maxFailures | quote }}
+  volumeMounts:
+  - name: dags
+    mountPath: {{ .Values.dags.gitSync.root }}
+  {{- if and  .Values.dags.gitSync.enabled  .Values.dags.gitSync.sshKeySecret }}
+  - name: git-sync-ssh-key
+    mountPath: /etc/git-secret/ssh
+    readOnly: true
+    subPath: gitSshKey
+  {{- if .Values.dags.gitSync.knownHosts }}
+  - name: config
+    mountPath: /etc/git-secret/known_hosts
+    readOnly: true
+    subPath: known_hosts
+  {{- end }}
+  {{- end }}
+{{- end }}
+
 # This helper will change when customers deploy a new image.
 {{ define "airflow_image" -}}
 {{ printf "%s:%s" (.Values.images.airflow.repository | default .Values.defaultAirflowRepository) (.Values.images.airflow.tag | default .Values.defaultAirflowTag) }}
@@ -185,9 +259,30 @@ log_connections = {{ .Values.pgbouncer.logConnections }}
 {{ (printf "%s/logs" .Values.airflowHome) | quote }}
 {{- end }}
 
+{{ define "airflow_dags" -}}
+{{- if .Values.dags.gitSync.enabled -}}
+{{ (printf "%s/dags/%s/%s" .Values.airflowHome .Values.dags.gitSync.dest .Values.dags.gitSync.subPath ) }}
+{{- else -}}
+{{ (printf "%s/dags" .Values.airflowHome) }}
+{{- end -}}
+{{- end -}}
+
+{{ define "airflow_dags_volume_claim" -}}
+{{- if and .Values.dags.persistence.enabled .Values.dags.persistence.existingClaim -}}
+{{ .Values.dags.persistence.existingClaim }}
+{{- else -}}
+{{ .Release.Name }}-dags
+{{- end -}}
+{{- end -}}
+
+{{ define "airflow_dags_mount_path" -}}
+{{ (printf "%s/dags" .Values.airflowHome) }}
+{{- end }}
+
 {{ define "airflow_config_path" -}}
 {{ (printf "%s/airflow.cfg" .Values.airflowHome) | quote }}
 {{- end }}
+
 {{ define "airflow_webserver_config_path" -}}
 {{ (printf "%s/webserver_config.py" .Values.airflowHome) | quote }}
 {{- end }}

chart/templates/configmap.yaml

@@ -35,6 +35,7 @@ data:
   # These are system-specified config overrides.
   airflow.cfg: |
     [core]
+    dags_folder = {{ include "airflow_dags" . }}
     load_examples = False
     colored_console_log = False
     executor = {{ .Values.executor }}
@@ -87,13 +88,42 @@ data:
     namespace = {{ .Release.Namespace }}
     airflow_configmap = {{ include "airflow_config" . }}
     airflow_local_settings_configmap = {{ include "airflow_config" . }}
-    worker_container_repository = {{ .Values.images.airflow.repository }}
-    worker_container_tag = {{ .Values.images.airflow.tag }}
+    worker_container_repository = {{ .Values.images.airflow.repository | default .Values.defaultAirflowRepository }}
+    worker_container_tag = {{ .Values.images.airflow.tag | default .Values.defaultAirflowTag }}
     worker_container_image_pull_policy = {{ .Values.images.airflow.pullPolicy }}
     worker_service_account_name = {{ .Release.Name }}-worker-serviceaccount
     image_pull_secrets = {{ template "registry_secret" . }}
-    dags_in_image = True
+    dags_in_image = {{ if or .Values.dags.gitSync.enabled .Values.dags.persistence.enabled }}False{{ else }}True{{ end }}
     delete_worker_pods = True
+    run_as_user = {{ .Values.uid }}
+    fs_group = {{ .Values.gid }}
+    {{- if or .Values.dags.gitSync.enabled .Values.dags.persistence.enabled }}
+    git_dags_folder_mount_point = {{ include "airflow_dags_mount_path" . }}
+    dags_volume_mount_point = {{ include "airflow_dags_mount_path" . }}
+    {{- if .Values.dags.persistence.enabled }}
+    dags_volume_claim = {{ .Release.Name }}-dags
+    dags_volume_subpath = {{.Values.dags.gitSync.dest }}/{{ .Values.dags.gitSync.subPath }}
+    {{- else }}
+    git_repo = {{ .Values.dags.gitSync.repo }}
+    git_branch = {{ .Values.dags.gitSync.branch }}
+    git_sync_rev = {{ .Values.dags.gitSync.rev }}
+    git_sync_depth = {{ .Values.dags.gitSync.depth }}
+    git_sync_root = {{ .Values.dags.gitSync.root }}
+    git_sync_dest = {{ .Values.dags.gitSync.dest }}
+    git_sync_container_repository = {{ .Values.dags.gitSync.containerRepository }}
+    git_sync_container_tag = {{ .Values.dags.gitSync.containerTag }}
+    git_sync_init_container_name = {{ .Values.dags.gitSync.containerName }}
+    git_sync_run_as_user = {{ .Values.uid }}
+    {{- if  .Values.dags.gitSync.knownHosts }}
+    git_ssh_known_hosts_configmap_name = {{ include "airflow_config" . }}
+    {{- end }}
+    {{- if .Values.dags.gitSync.sshKeySecret }}
+    git_ssh_key_secret_name = {{ .Values.dags.gitSync.sshKeySecret }}
+    {{- else if .Values.dags.gitSync.credentialsSecret }}
+    git_sync_credentials_secret = {{ .Values.dags.gitSync.credentialsSecret }}
+    {{- end }}
+    {{- end }}
+    {{- end }}
 
     [kubernetes_secrets]
     AIRFLOW__CORE__SQL_ALCHEMY_CONN = {{ printf "%s=connection" (include "airflow_metadata_secret" .) }}
@@ -120,3 +150,7 @@ data:
   airflow_local_settings.py: |
     {{ .Values.scheduler.airflowLocalSettings | nindent 4 }}
 {{- end }}
+{{- if and .Values.dags.gitSync.enabled  .Values.dags.gitSync.knownHosts }}
+  known_hosts: |
+    {{ .Values.dags.gitSync.knownHosts | nindent 4 }}
+{{- end }}

chart/templates/dags-persistent-volume-claim.yaml

@@ -0,0 +1,41 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+{{- if and (not .Values.dags.persistence.existingClaim ) .Values.dags.persistence.enabled }}
+kind: PersistentVolumeClaim
+apiVersion: v1
+metadata:
+  name: {{ .Release.Name }}-dags
+  labels:
+    tier: airflow
+    component: dags-pvc
+    release: {{ .Release.Name }}
+    chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"
+    heritage: {{ .Release.Service }}
+spec:
+  accessModes: [{{ .Values.dags.persistence.accessMode | quote }}]
+  resources:
+    requests:
+      storage: {{ .Values.dags.persistence.size | quote }}
+  {{- if .Values.dags.persistence.storageClass }}
+  {{- if (eq "-" .Values.dags.persistence.storageClass) }}
+  storageClassName: ""
+  {{- else }}
+  storageClassName: "{{ .Values.dags.persistence.storageClass }}"
+  {{- end }}
+  {{- end }}
+{{- end }}

chart/templates/scheduler/scheduler-deployment.yaml

@@ -144,6 +144,11 @@ spec:
               mountPath: {{ template "airflow_local_setting_path" . }}
               subPath: airflow_local_settings.py
               readOnly: true
+{{- end }}
+{{- if .Values.dags.gitSync.enabled }}
+            - name: dags
+              mountPath: {{ template "airflow_dags_mount_path" . }}
+        {{- include "git_sync_container" . | indent 8 }}
 {{- end }}
         # Always start the garbage collector sidecar.
         - name: scheduler-gc
@@ -177,6 +182,17 @@ spec:
         - name: config
           configMap:
             name: {{ template "airflow_config" . }}
+        {{- if .Values.dags.persistence.enabled }}
+        - name: dags
+          persistentVolumeClaim:
+            claimName: {{ template "airflow_dags_volume_claim" . }}
+        {{- else if .Values.dags.gitSync.enabled }}
+        - name: dags
+          emptyDir: {}
+        {{- end }}
+        {{- if and  .Values.dags.gitSync.enabled  .Values.dags.gitSync.sshKeySecret }}
+        {{- include "git_sync_ssh_key_volume" . | indent 8 }}
+        {{- end }}
 {{- if not $stateful }}
         - name: logs
           emptyDir: {}

chart/templates/webserver/webserver-deployment.yaml

@@ -68,6 +68,7 @@ spec:
       restartPolicy: Always
       securityContext:
         runAsUser: {{ .Values.uid }}
+        fsGroup: {{ .Values.gid }}
       {{- if or .Values.registry.secretName .Values.registry.connection }}
       imagePullSecrets:
         - name: {{ template "registry_secret" . }}
@@ -82,6 +83,9 @@ spec:
           {{- include "custom_airflow_environment" . | indent 10 }}
           {{- include "standard_airflow_environment" . | indent 10 }}
       containers:
+{{- if and (.Values.dags.gitSync.enabled) (not .Values.dags.persistence.enabled) }}
+{{- include "git_sync_container" . | indent 8 }}
+{{- end }}
         - name: webserver
           image: {{ template "airflow_image" . }}
           imagePullPolicy: {{ .Values.images.airflow.pullPolicy }}
@@ -105,6 +109,10 @@ spec:
               subPath: airflow_local_settings.py
               readOnly: true
 {{- end }}
+{{- if or .Values.dags.gitSync.enabled .Values.dags.persistence.enabled }}
+            - name: dags
+              mountPath: {{ template "airflow_dags_mount_path" . }}
+{{- end }}
 {{- if .Values.webserver.extraVolumeMounts }}
 {{ toYaml .Values.webserver.extraVolumeMounts | indent 12 }}
 {{- end }}
@@ -134,6 +142,17 @@ spec:
         - name: config
           configMap:
             name: {{ template "airflow_config" . }}
+        {{- if .Values.dags.persistence.enabled }}
+        - name: dags
+          persistentVolumeClaim:
+            claimName: {{ .Release.Name }}-dags
+        {{- else if .Values.dags.gitSync.enabled }}
+        - name: dags
+          emptyDir: {}
+        {{- if  .Values.dags.gitSync.sshKeySecret }}
+        {{- include "git_sync_ssh_key_volume" . | indent 8 }}
+        {{- end }}
+        {{- end }}
 {{- if .Values.webserver.extraVolumes }}
 {{ toYaml .Values.webserver.extraVolumes | indent 8 }}
 {{- end }}