Creating custom images to support third-party drivers and libraries

You can create custom images to support third-party drivers and libraries that are needed to connect to third-party systems such as SQL Server databases.

To create a custom image, complete the following steps.

1. Identify the location of the image to update:
   • Compute image:

     $ oc describe pod ds-engine-compute-0 | grep 'is-en-compute-image:'
     Image: image-registry.openshift-image-registry.svc:5000/ds/is-en-compute-image:b1592-develop-b2300

   • Conductor image:

     $ oc describe pod is-en-conductor-0 | grep 'is-engine-image:'
     Image: image-registry.openshift-image-registry.svc:5000/ds/is-engine-image:b1649-develop-b2356

2. Log in to your Docker registry.
   If the docker registry appears as 'image-registry.openshift-image-registry.svc:5000', then it's the internal route to the registry on the cluster. Run one of the following commands to get the external route:

   • For a Red Hat® OpenShift® Container Platform 4.x cluster, run:

     $ oc registry info
     default-route-openshift-image-registry.apps.zlnov16.cp.fyre.ibm.com

   • For a Red Hat OpenShift Container Platform 3.11 cluster, run:

     $ oc get route/docker-registry -n default --template {{.spec.host}}

3. Update Docker to add the registry as an insecure registry if you're using the internal registry on the cluster. Use the current oc session token for login:

   $ docker login default-route-openshift-image-registry.apps.zlnov16.cp.fyre.ibm.com -u $(oc whoami) -p $(oc whoami -t)
   

4. Verify that you can pull the image from the registry in OpenShift:

   $ docker pull default-route-openshift-image-registry.apps.zlnov16.cp.fyre.ibm.com/ds/is-engine-image:b1649-develop-b2356

5. Create a Dockerfile:

   FROM default-route-openshift-image-registry.apps.zlnov16.cp.fyre.ibm.com/ds/is-engine-image:b1649-develop-b2356
   #Use COPY to copy local files to the build container
   #Use RUN to execute commands in the build container
   #copy local file install_packages.sh to /tmp in the container
   COPY install_packages.sh /tmp
   #run install_packages.sh 
   RUN sh /tmp/install_packages.sh

6. Build and tag the image with a new suffix (run the command in the directory that contains the Dockerfile):

   $ docker build -t default-route-openshift-image-registry.apps.zlnov16.cp.fyre.ibm.com/ds/is-engine-image:b1649-develop-b2356-UPDATE1

7. Push the image to the registry:

   $ docker push default-route-openshift-image-registry.apps.zlnov16.cp.fyre.ibm.com/ds/is-engine-image:b1649-develop-b2356-UPDATE1

8. Update the image tag used by the ds-engine-compute StatefulSet. On the cluster, only the internal route for the registry can be used.

   $ oc edit sts is-en-conductor

9. Optional: For some situations where entries to Pod /etc/hosts need to be added, follow the instructions in https://kubernetes.io/docs/concepts/services-networking/add-entries-to-pod-etc-hosts-with-host-aliases.
   For example, to add the entry "1.2.3.4 myhost1.fyre.ibm.com myhost1" to the is-en-conductor-0 pod /etc/hosts file, you can complete the following steps:

   1. Backup the is-en-conductor statefulset:

      $ oc get sts is-en-conductor -o yaml > is-en-conductor_backup.yaml

   2. Create a new file:

      $ cp is-en-conductor_backup.yaml is-en-conductor.yaml

   3. Update the is-en-conductor.yaml file by adding this section under spec: -> template: -> spec:

      hostAliases:
      - ip: "1.2.3.4"
        hostnames:
        - "myhost1.fyre.ibm.com"
        - "myhost1"

   4. Update the sts is-en-conductor:

      $ oc replace -f is-en-conductor.yaml

   5. Wait for the is-en-conductor-0 pod to be restarted by checking:

      $ oc get pod | grep is-en-conductor-0

   6. Confirm the entry is added to the /etc/hosts file:

      $ oc exec -it is-en-conductor-0 -- cat /etc/hosts