Configuring Db2 Community Edition on OCP

After installing Db2 Community Edition into an OpenShift cluster, you configure it to connect to the Agile Service Manager application discovery service.

Db2 server prerequisites

1. Capture the primary storage and the database pods.
   Example of a primary storage pod:

   # kubectl get pod | grep pss
   fvt-topology-nasm-app-disco-pss-deployment-6c5b55594f-gbphr       1/2     Running     5          41m

   Example of the database pod:

   kubectl get pod | grep db2u-0
   Example system output:
   
   asm204-db2u-0   1/1   Running   0   27h

2. Copy the create_db2_database.sh script from the primary storage pod to the OCP /tmp directory.
   Example:

   kubectl cp  fvt-topology-nasm-app-disco-pss-deployment-6c5b55594f-gbphr:/opt/IBM/taddm/utils/create_db2_database.sh /tmp/create_db2_database.sh

3. Copy the create_db2_database.sh script from the previous step to the tmp directory in the database pod.
   Example:

   kubectl cp create_database.sh asm204-db2u-0:/tmp

4. Enter the database pod and provide execute permissions to the script.
   Example:

   kubectl exec -it asm204-db2u-0 /bin/bash
   sudo chmod a+x /tmp/create_db2_database.sh
   

5. Add 'archuser' Db2 user.

   oc rsh ${tools_pod} addLdapUser.py -u archuser -p archuser -r admin

   For more details, refer to Managing Db2 users with LDAP on a Red Hat OpenShift cluster
6. As the db2inst1 user, create a database instance.
   Run the following command from the tmp directory. In the following example, the database is called 'taddm':

   ./create_db2_database.sh taddm
   

   Tip: If the system output consists of the following message, a database called 'taddm' already exists:

   DB2 version 1.5.4
   INFO: Database with same name taddm already exists.

   If this occurs, run the 'drop database' command, then recreate the 'taddm' database, as in the following example:

   db2 drop database taddm

   System output if successful:

   DB20000I  The DROP DATABASE command completed successfully.

   Rerun the following command:

   ./create_db2_database.sh taddm
   

7. Confirm that the database has been created:

   db2 list database directory

   Example system output if the database exists:

   System Database Directory
   
   Number of entries in the directory = 1
   
   Database 1 entry:
   
    Database alias                       = TADDM
    Database name                        = TADDM
    Local database directory             = /mnt/blumeta0/db2/databases
    Database release level               = 15.00
    Comment                              =
    Directory entry type                 = Indirect
    Catalog database partition number    = 0
    Alternate server hostname            =
    Alternate server port number         =
   

   Test the database connection:

   db2 connect to TADDM user db2inst1 using db2inst1

   Example system output:

   Database Connection Information
   
    Database server        = DB2/LINUXX8664 11.5.4.0
    SQL authorization ID   = DB2INST1
    Local database alias   = TADDM
   

8. Check that 'archuser' Db2 user can be connected to the TADDM database.

   oc exec -ti ${db2u_pod} bash
   su - db2inst1
   db2 connect to taddm user archuser using archuser

   Example system output:

   Database Connection Information
   
   Database server        = DB2/LINUXX8664 11.5.4.0
   SQL authorization ID   = ARCHUSER
   Local database alias   = TADDM

9. Exit pod.

OCP application discovery server configuration

10. On the OCP application discovery server, create a configuration file called db2-secret.yaml, as in the following example:

    apiVersion: v1
    kind: Secret
    metadata:
      name: db2-secret
      namespace: production
    data:
      DBARCHIVEUSER: YXJjaHVzZXI=
      DBUSER: ZGIyaW5zdDE=
      DB_ARCH_PASSWORD: YXJjaHVzZXI=
      DB_PASSWORD: ZGIyaW5zdDE=
    type: Opaque 
    

    Note: The values of the following parameters have to be base64 encoded:

    DBARCHIVEUSER

    Default value: archuser

    DBUSER

    Default value: db2inst1

    DB_ARCH_PASSWORD

    Default value: archuser

    DB_PASSWORD

    Default value: db2inst1

11. Create a secret that stores DB details by running the following command:

    kubectl apply -f db2-secret.yaml

12. Populate the database details in the Netcool Operations Insight on Red Hat OpenShift Operator properties.
    The following sample shows the database parameters to connect the application discovery service with the pre-configured database:

    appDisco:
      enabled: true
      dburl : 'db2hostname.com'
      dbsecret: 'db2-secret'
      secure: false
      certSecret: ''
    

    dburl

    The URL of the server on which DB2 is installed.

    For DB2 on OCP, the format of dburl is:

    <Service Name>.<Namespace Name>.svc.cluster.local

    Example:

    asm204-db2u.production.svc.cluster.local

    Run 'oc get svc' to obtain the service name, for example:

    oc get svc | grep asm204-db2u
    asm204-db2u
    ClusterIP   172.30.200.131   <none>
    50000/TCP,50001/TCP,25000/TCP,25001/TCP,25002/TCP,25003/TCP,25004/TCP,25005/TCP   27h
    

    dbsecret

    The name of the secret in the same namespace as the instance to be installed.

    It must contain the following keys:

    DBUSER

    The name of the DB2 user.

    DB_PASSWORD

    The password of the DB2 user.

    DBARCHIVEUSER

    The name of the DB2 archive user.

    DB_ARCH_PASSWORD

    The password of the DB2 archive user.

    secure

    'False' if the connection to DB2 is insecure.

    certSecret

    Applicable only if 'secure' property is 'true'.

# kubectl exec -it <releasename>-topology-nasm-app-disco-pss-deployment-<pod-id> /opt/IBM/taddm/dist/bin/control status

kubectl exec -it appd204-topology-nasm-app-disco-pss-deployment-84dbdb89c9-sjk9m /opt/IBM/taddm/dist/bin/control status

Defaulting container name to pss.
Use 'kubectl describe pod/appd204-topology-nasm-app-disco-pss-deployment-84dbdb89c9-sjk9m -n production' to see all of the containers in this pod.
DbInit: Started
Liberty: Started
StorageService: Started

TADDM: Running