Continuous Integration / Continuous Delivery (CI/CD) is an automated approach in which incremental code changes are made, built, tested and delivered. Organizations want to get their software solutions to market as quickly as possible without sacrificing quality or stability. While CI/CD is often associated with application code, it can also be beneficial for managing changes to PostgreSQL database clusters.
GitOps plays an important part in enabling CI/CD. If you are unfamiliar with GitOps, I recommend starting with my previous post on Postgres GitOps with Argo and Kubernetes.
Today I have a working sample to walk through for implementing basic CI/CD using Crunchy Postgres for Kubernetes, ArgoCD, and a self test container. In the following steps we will:
- Deploy a Postgres cluster to a developer namespace
- Run a series of tests on the deployed cluster
- Once the tests pass we will automatically deploy the same postgres cluster to a QA namespace.
- Crunchy Postgres for Kubernetes v5.3 or later.
- The sidecar functionality should be enabled. To enable the sidecar
functionality you will need to add the following to the
Deployment.spec.template.spec.containers.envsection of the
manager.yamlfile located in the
- name: PGO_FEATURE_GATES value: 'InstanceSidecars=true'
- ArgoCD v 2.6 or later deployed in the Kubernetes cluster.
- A private container registry containing the images you want to deploy. Most organizations will pull images, tag them and then upload them into their private registries. For this blog I am using a private registry for all images except the self test. That image is in a public repo in my docker registry.
- A git repository containing the Crunchy Postgres for Kubernetes manifest to be deployed. Here's a sample manifest you can use or you can fork my git repository.
resources: # - argocd-token.yaml - hippo-self-test-config.yaml - postgres.yaml
apiVersion: postgres-operator.crunchydata.com/v1beta1 kind: PostgresCluster metadata: name: hippo spec: image: <your_registry>/crunchy-postgres:ubi8-15.2-5.3.1-2 imagePullSecrets: - name: privatereg postgresVersion: 15 shutdown: false users: - name: hippo options: 'SUPERUSER' instances: - name: pgha1 replicas: 3 containers: - name: selftest image: bobpachcrunchy/postgres-self-test:1.0.0 imagePullPolicy: IfNotPresent env: - name: ARGOCD_APP_NAME valueFrom: configMapKeyRef: name: postgres-self-test-config key: auto-promote-argocd-app-name - name: ARGOCD_NAMESPACE valueFrom: configMapKeyRef: name: postgres-self-test-config key: argocd-namespace - name: AUTO_PROMOTE valueFrom: configMapKeyRef: name: postgres-self-test-config key: auto-promote - name: ARGOCD_SERVICE_ADDRESS valueFrom: configMapKeyRef: name: postgres-self-test-config key: argocd-service-address - name: ARGOCD_TOKEN valueFrom: secretKeyRef: key: token name: argocd-token - name: ARGOCD_VERIFY_TLS valueFrom: configMapKeyRef: name: postgres-self-test-config key: argocd-verify-tls - name: DB_USER valueFrom: configMapKeyRef: name: postgres-self-test-config key: db-user - name: DB_USER_PASSWORD valueFrom: secretKeyRef: key: password name: hippo-pguser-hippo - name: CLUSTER_NAME valueFrom: configMapKeyRef: name: postgres-self-test-config key: cluster-name - name: LOG_LEVEL valueFrom: configMapKeyRef: name: postgres-self-test-config key: log-level - name: LOG_PATH valueFrom: configMapKeyRef: name: postgres-self-test-config key: log-path - name: NAMESPACE valueFrom: fieldRef: apiVersion: v1 fieldPath: metadata.namespace - name: POSTGRES_CONN_ATTEMPTS valueFrom: configMapKeyRef: name: postgres-self-test-config key: postgres-conn-attempts - name: POSTGRES_CONN_INTERVAL valueFrom: configMapKeyRef: name: postgres-self-test-config key: postgres-conn-interval - name: SERVICE_PORT valueFrom: configMapKeyRef: name: postgres-self-test-config key: service-port - name: SSLMODE valueFrom: configMapKeyRef: name: postgres-self-test-config key: sslmode volumeMounts: - name: postgres-data readOnly: false mountPath: /pgdata dataVolumeClaimSpec: accessModes: - 'ReadWriteOnce' resources: requests: storage: 1Gi affinity: podAntiAffinity: preferredDuringSchedulingIgnoredDuringExecution: - weight: 1 podAffinityTerm: topologyKey: kubernetes.io/hostname labelSelector: matchLabels: postgres-operator.crunchydata.com/cluster: hippo postgres-operator.crunchydata.com/instance-set: pgha1 backups: pgbackrest: image: <your_registry>/crunchy-pgbackrest:ubi8-5.3.1-2 repos: - name: repo1 volume: volumeClaimSpec: accessModes: - 'ReadWriteOnce' resources: requests: storage: 1Gi
Note: For this blog the Postgres cluster name is "hippo". You should substitute this name and any other relevant values with your proper information.
Self Test Container
I have created a self test container for Crunchy Postgres for Kubernetes. This will be deployed as a sidecar in each Postgres pod. It runs read, write and delete tests in the cluster and confirms that replication is working as expected across all Postgres pods. If the tests pass it will synch an ArgoCD application resulting in the promotion of the Postgres cluster to another namespace. The sidecar uses a configmap to manage self test behavior and ArgoCD application sync. More information about the self test container and its configuration can be found in github.
apiVersion: v1 data: argocd-namespace: argocd argocd-service-address: <ip address of the argocd service> argocd-verify-tls: 'false' auto-promote: 'true' auto-promote-argocd-app-name: postgres-qa db-user: hippo cluster-name: hippo log-level: info log-path: /pgdata postgres-conn-attempts: '12' postgres-conn-interval: '5' service-port: '5432' sslmode: require kind: ConfigMap metadata: labels: vendor: crunchydata postgres-operator.crunchydata.com/cluster: hippo name: postgres-self-test-config
You will need an ArgoCD token to connect to the server to synch the target application after the tests pass. To get an ArgoCD token you will need to create a repository, project, role and policy. This can be done through the UI or CLI. For this blog we will use the UI. See ArgoCD documentation for CLI installation and commands.
Create an ArgoCD Repository
To add your git repository to Argo CD click on ‘Settings’ in the navigation bar on the left.
Click on ‘Repositories’ and the ‘Connect Repo’ buttons. Provide the necessary information and click ‘Save’. You should now have a connected repo. If not, please review your settings and try again.
Create an ArgoCD Project
Create an ArgoCD Project with the following properties:
- Project Name: cicd-project
- Description: A project used for the CI/CD pipeline.
- Source Repositories: < the git repository you registered with argocd >
- Server: https://kubernetes.default.svc
- Name: in-cluster
- Namespace: *
- Server: https://kubernetes.default.svc
- Name: in-cluster
- Namespace: *
Click on the Roles tab and click the Add Role button. Create a role and policy
with the following properties:
- Role Name: cicd-sync
- Description: Project role used to synch apps from the CI/CD pipeline.
- Action: sync
- Application: cicd-project/*
- Permission: allow
Click on the role name you just created and then click the Create button in the JWT Tokens section of the sidebar. Click OK when prompted. Copy and save the New Token in a safe place.
Base 64 encode the New Token.
echo < your new token > | base64
Copy the base64 encoded new token and paste it into the argocd-token.yaml file
apiVersion: v1 data: token: <your base64 encoded argocd token> kind: Secret metadata: name: argocd-token type: Opaque
For security reasons, you may choose not to store your Argocd token in git. If that is the case you can create the secret directly in your two namespaces.
kubectl apply -n postgres-dev -f argocd-token.yaml secret/argocd-token created kubectl apply -n postgres-qa -f argocd-token.yaml secret/argocd-token created
Otherwise, you can uncomment the # - argocd-token.yaml line in the kustomization.yaml file and it will get created when the cluster gets created.
Create the ArgoCD Applications
We will create two Argocd applications. Create the first one with the following properties:
- Application Name: postgres-dev
- Project Name: cicd-project
- Repository URL: < the git repository you registered with argocd >
- Path: < the path to the kustomization file in the git repo >
- Cluster URL: https://kubernetes.default.svc
- Namespace: postgres-dev
Create the second application with the same properties as the first one with two exceptions:
- Application Name: postgres-qa
- Namespace: postgres-qa
Deploy the Crunchy Postgres for Kubernetes Cluster
Note: Ensure that all yaml files have been checked into the git repo that you assigned to the cicd-project in ArgoCD. These files should have all of your edits. They will be used by ArgoCD to deploy into your postgres-dev and postgres-qa namespaces.
Click the synch button in the postgres-dev Argocd application then click the synchronize button in the right side panel. The postgres cluster will get deployed into the postgres-dev namespace.
Let's look at the pods in our postgres-dev namespace:
kubectl get pods -n postgres-dev NAME READY STATUS RESTARTS AGE hippo-backup-s5pz-bmjsd 0/1 Completed 0 2m5s hippo-pgha1-2zjd-0 5/5 Running 0 2m29s hippo-pgha1-9kf7-0 5/5 Running 0 2m29s hippo-pgha1-mrhq-0 5/5 Running 0 2m29s hippo-repo-host-0 2/2 Running 0 2m29s
Take a look at the self test container logs in the primary Postgres pod in the postgres-dev namespace to see if our tests passed.
kubectl logs $(kubectl get pod -l postgres-operator.crunchydata.com/role=master -o name -n postgres-dev) -n postgres-dev -c selftest 2023-05-24 14:44:24,961 - self_test - INFO - ******* STARTING NEW TEST RUN ******* 2023-05-24 14:44:30,024 - self_test - INFO - PostgreSQL database version: 2023-05-24 14:44:30,025 - self_test - INFO - ('PostgreSQL 15.1 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-15), 64-bit',) 2023-05-24 14:44:30,032 - self_test - INFO - Creating test database 2023-05-24 14:44:30,186 - self_test - INFO - Assigning test_db privileges to test_user 2023-05-24 14:44:30,210 - self_test - INFO - Creating test_schema in test_db 2023-05-24 14:44:30,404 - self_test - INFO - Creating test_table with data in test_schema 2023-05-24 14:44:30,417 - self_test - INFO - Validating DBConnectionType.PRIMARY_SERVICE Data: Expecting 1000 Rows 2023-05-24 14:44:30,418 - self_test - INFO - *** DBConnectionType.PRIMARY_SERVICE Validation Succeeded! *** 2023-05-24 14:44:40,458 - self_test - INFO - Validating DBConnectionType.REPLICA_SERVICE Data: Expecting 1000 Rows 2023-05-24 14:44:40,460 - self_test - INFO - *** DBConnectionType.REPLICA_SERVICE Validation Succeeded! *** 2023-05-24 14:44:40,472 - self_test - INFO - Validating DBConnectionType.REPLICA_POD Data for pod hippo-pgha1-2zjd-0: Expecting 1000 Rows 2023-05-24 14:44:40,473 - self_test - INFO - *** DBConnectionType.REPLICA_POD Validation Succeeded for pod hippo-pgha1-2zjd-0! *** 2023-05-24 14:44:40,481 - self_test - INFO - Validating DBConnectionType.REPLICA_POD Data for pod hippo-pgha1-9kf7-0: Expecting 1000 Rows 2023-05-24 14:44:40,482 - self_test - INFO - *** DBConnectionType.REPLICA_POD Validation Succeeded for pod hippo-pgha1-9kf7-0! *** 2023-05-24 14:44:40,663 - self_test - INFO - Successfully synched the postgres-qa ArgoCD application. 2023-05-24 14:44:40,663 - self_test - INFO - ******* SUCCESS: ALL TESTS PASSED ******* 2023-05-24 14:44:40,664 - self_test - INFO - Dropping test_table 2023-05-24 14:44:40,667 - self_test - INFO - Dropping test_schema 2023-05-24 14:44:40,670 - self_test - INFO - Dropping test_db 2023-05-24 14:44:40,697 - self_test - INFO - Dropping test_user
Now let's look at the pods in our postgres-qa namespace:
kubectl get pods -n postgres-qa NAME READY STATUS RESTARTS AGE hippo-backup-wxrx-rhzzh 0/1 Completed 0 63s hippo-pgha1-7x55-0 5/5 Running 0 81s hippo-pgha1-jdxw-0 5/5 Running 0 81s hippo-pgha1-lp89-0 5/5 Running 0 81s hippo-repo-host-0 2/2 Running 0 81s
Lastly, look at the two ArgoCD applications. They are now both marked as Synched.
We were able to deploy, test and promote a Crunchy Postgres for Kubernetes cluster using git and ArgoCD. The declarative nature of the manifest combined with the power of GitOps and ArgoCD makes creating a CI/CD pipeline easier than ever. This blog only covers a segment of a full end to end pipeline. In my next blog we will look at how to apply new images to an existing application using ArgoCD Image Updater. Stay tuned for part 2.
June 7, 2023 •More by this author