Summary

This document has the purpose to provide instructions for migrating a Confluence Server or DC instance, running on physical hosts or virtual machines, to a Kubernetes cluster. 

Environment

• Confluence instance either DC or Server v7.19.x.
• Backend Postgres database installed on a separated host and accessible by the Kubernetes cluster.

Solution

Please follow the steps outlined below to complete this migration: 

1. Create a volume named connie-confluence-shared-home for hosting Confluence shared home in the Kubernetes cluster.
2. Transfer to the volume created above:
   
   1. The content of the shared home folder if the migration is from a Confluence DC instance with clustering enabled.

   2. The content of the folder named shared-home if the migration is from Server or Non Clustered instance.
      Once the copy has been completed, the file confluence.cfg.xml will appear like the one below:

      <?xml version="1.0" encoding="UTF-8"?>
      
      <confluence-configuration>
        <setupStep>complete</setupStep>
        <setupType>custom</setupType>
        <buildNumber>8804</buildNumber>
        <properties>
          <property name="access.mode">READ_WRITE</property>
          <property name="atlassian.license.message">--- LICENSE KEY ----</property>
          <property name="hibernate.setup">true</property>
          <property name="jwt.private.key">--- JWT private key ---</property>
          <property name="jwt.public.key">--- JWT private key ---</property>
          <property name="lucene.index.dir">${localHome}/index</property>
          <property name="synchrony.service.authtoken">--- Synchrony auth Token ---</property>
        </properties>
      </confluence-configuration>

      confluence.cfg.xml needs to be modified to enable the clustering configuration, the section to be added is enclosed between the comments Enable clustering:

      <?xml version="1.0" encoding="UTF-8"?>
      
      <confluence-configuration>
         <setupStep>complete</setupStep>
         <setupType>cluster</setupType>
         <buildNumber>8804</buildNumber>
         <properties>
           <property name="access.mode">READ_WRITE</property>
           <property name="atlassian.license.message">--- LICENSE KEY ----</property>
           <property name="hibernate.setup">true</property>
           <property name="jwt.private.key">--- JWT private key ---</property>
           <property name="jwt.public.key">--- JWT private key ---</property>
           <property name="lucene.index.dir">${localHome}/index</property>
           <property name="hibernate.setup">true</property>
           <property name="synchrony.service.authtoken">--- Synchrony auth Token ---</property>
           <!-- Enable clustering -->
           <property name="confluence.cluster">true</property>
           <property name="confluence.cluster.authentication.enabled">true</property>
           <property name="confluence.cluster.authentication.secret">73bf51061d2e1f3e73f643374a6d3f2ced8371f3</property>
           <!-- Enable clustering : in the line above it is advised to change the secret value -->
         </properties>
      </confluence-configuration>

      Besides this file make sure to copy the attachments folder to this PV from the Confluence Server instance. 
      
      

3. Make sure that the ownership of the files in the PV is assigned to user and group 2002, e.g. running the below command:

   sudo chown -R 2002:2002 <SHARED_HOME_PATH>

4. Create a secret for storing the Confluence DC License (replace $CONNIELICENSE  with the appropriate value all in one line):

   kubectl create secret generic connielicense --from-literal=license-key="$CONNIELICENSE" -n confluence

5. Create a secret to store the DB credentials (replace $DBPASSWORD  and $DBUSER  with the appropriate values):

   kubectl create secret generic conniedb --from-literal=username=$DBUSER --from-literal=password=$DBPASSWORD -n confluence

6. Create the following values.yaml  (replacing the values starting with $ appropriately and any other value that doesn't fit your needs)

   replicaCount: 1
   image:
     repository: atlassian/confluence
     pullPolicy: IfNotPresent
     tag: "7.19.18"
   serviceAccount:
     create: true
     name:
     imagePullSecrets: []
     annotations: {}
     role:
       create: true
     clusterRole:
       create: true
       name:
     roleBinding:
       create: true
     clusterRoleBinding:
       create: true
       name:
     eksIrsa:
       roleArn:
   database:
     type: mysql
     url: jdbc:postgresql://POSTGRESQL_CONNECTION_STRING
     credentials:
       secretName: conniedb
       usernameSecretKey: username
       passwordSecretKey: password
   volumes:
     localHome:
       persistentVolumeClaim:
         create: true
         storageClassName: $STORAGE_CLASS
         resources:
           requests:
             storage: 100Gi
       customVolume: {}
       mountPath: "/var/atlassian/application-data/confluence"
     sharedHome:
       persistentVolumeClaim:
         create: false
       customVolume:
         persistentVolumeClaim:
           claimName: connie-confluence-shared-home
       mountPath: "/var/atlassian/application-data/shared-home"
       subPath:
       nfsPermissionFixer:
         enabled: true
         mountPath: "/shared-home"
         imageRepo: alpine
         imageTag: latest
         command:
     synchronyHome:
       persistentVolumeClaim:
         create: true
         storageClassName: $STORAGE_CLASS
         resources:
           requests:
             storage: 5Gi
       customVolume: { }
       mountPath: "/var/atlassian/application-data/confluence"
     additional: []
     additionalSynchrony: []
     defaultPermissionsMode: 484
   ingress:
     create: false
     host: $FULLY_QUALIFIED_DOMAIN_NAME_CONFLUENCE_SITE
   confluence:
     service:
       port: 80
       type: ClusterIP
       loadBalancerIP:
       annotations: {}
     securityContextEnabled: true
     securityContext:
       fsGroup: 2002
     containerSecurityContext: {}
     umask: "0022"
     setPermissions: true
     ports:
       http: 8090
       hazelcast: 5701
     license:
       secretName: connielicense
       secretKey: license-key
     readinessProbe:
       initialDelaySeconds: 10
       periodSeconds: 5
       failureThreshold: 6
     accessLog:
       enabled: true
       mountPath: "/opt/atlassian/confluence/logs"
       localHomeSubPath: "logs"
     clustering:
       enabled: true
       usePodNameAsClusterNodeName: true
     s3AttachmentsStorage:
       bucketName:
       bucketRegion:
       endpointOverride:
     resources:
       jvm:
         maxHeap: "1g"
         minHeap: "1g"
         reservedCodeCache: "256m"
       container:
         requests:
           cpu: "2"
           memory: "2G"
     shutdown:
       terminationGracePeriodSeconds: 25
       command: "/shutdown-wait.sh"
     forceConfigUpdate: false
     additionalJvmArgs: []
     additionalLibraries: []
     additionalBundledPlugins: []
     additionalVolumeMounts: []
     additionalEnvironmentVariables: []
     additionalPorts: []
     additionalVolumeClaimTemplates: []
     topologySpreadConstraints: []
     jvmDebug:
       enabled: false
   synchrony:
     enabled: true
     replicaCount: 1
     podAnnotations: {}
     service:
       port: 80
       type: ClusterIP
       loadBalancerIP:
       annotations: {}
     securityContextEnabled: true
     securityContext:
       fsGroup: 2002
     containerSecurityContext: {}
     setPermissions: true
     ports:
       http: 8091
       hazelcast: 5701
     readinessProbe:
       healthcheckPath: "/synchrony/heartbeat"
       initialDelaySeconds: 5
       periodSeconds: 1
       failureThreshold: 10
     resources:
       jvm:
         minHeap: "1g"
         maxHeap: "2g"
         stackSize: "2048k"
       container:
         requests:
           cpu: "2"
           memory: "2.5G"
     additionalJvmArgs: []
     shutdown:
       terminationGracePeriodSeconds: 25
     additionalLibraries: []
     additionalVolumeMounts: []
     additionalPorts: []
     topologySpreadConstraints: []

7. Deploy using the above values.yaml  running:

   helm install connie atlassian-data-center/confluence --namespace confluence --values connie-values.yaml

8. Once the deployment is completed, check that the Confluence instance running on Kubernetes can be accessed correctly and the attachments are accessible.