External libraries and plugins ¶

.jar files only

Whether loading external libraries, drivers or plugins, the approaches outlined here can only be used with .jar files. Plugin obr files can be extracted (unzipped) to access the included .jar

In some situations, you may want to load 3rd party plugins, drivers or libraries so that they are available to the product being installed.

An example of when this may be needed are for those products that do not ship with the appropriate MySQL and Oracle JDBC drivers.

There are 3 strategies for doing this, you can either:

use the required prerequisite shared home volume
create a custom volume specifically for this purpose
provide a custom command for the nfsPermissionFixer

Each approach will be discussed below.

Approach

Which approach is used is totally up to you. For convenience you may want to just use shared-home, or if you'd like to keep things clean you may decide to mount these 3rd party libraries in a volume of their own. This approach would be particularly useful when these libraries need to be shared with other Pod's in your cluster.

Shared home volume ¶

This approach consists of 3 high-level tasks:

Create sub-dir in shared-home volume
Copy libraries to sub-dir
Update additionalLibraries stanza in values.yaml

1. Create sub-dir ¶

Add the Pod definition below to a file called shared-home-browser.yaml

apiVersion: v1
kind: Pod
metadata:
  name: shared-home-browser
spec:
  containers:
    - name: browser
      image: debian:stable-slim
      volumeMounts:
        - mountPath: /shared-home
          name: shared-home
      command: [ "bash", "-c", "--" ]
      args: [ "while true; do sleep 30; done;" ]
  volumes:
    - name: shared-home
      persistentVolumeClaim:
        claimName: <shared-home-pvc-name>

Initialise the Pod in the same namespace in which the shared-home PVC was created

kubectl apply -f shared-home-browser.yaml

Once running execute the following command, it will create the sub-sir, libraries, under /shared-home

kubectl exec -it shared-home-browser -- bash -c "mkdir -p /shared-home/libraries"

2. Copy libraries to sub-dir ¶

Now copy the files you require to the sub-dir by using the kubectl cp command

kubectl cp my_library.jar shared-home-browser:/shared-home/libraries

3. Update `values.yaml` ¶

Update the stanza, additionalLibraries, in values.yaml accordingly:

jira:
  additionalLibraries:
    - volumeName: shared-home
      subDirectory: libraries
      fileName: my_library.jar

With this config these files (my_library.jar) will be injected into the container directory <product-installation-directory>/lib. For more info on how these files are injected into the appropriate product container location, see Jira's helper jira.additionalLibraries.

Custom volume ¶

This approach is very similar to the Shared home volume approach, only a custom volume is created and used as opposed shared-home.

Create a new volume for storing 3rd party libraries
Create sub-dir for the new volume
Copy libraries to sub-dir
Update additionalLibraries stanza in values.yaml
Update additionalVolumeMounts stanza in values.yaml
Update additional stanza in values.yaml

Steps

Because many of the steps for this approach are similar to the steps used for Shared home volume only those that differ will be discussed.

1. Create new volume ¶

Using the same approach taken for provisioning the shared-home volume, create a new EFS with a corresponding PV and PVC.

ReadOnlyMany

Ensure that the PV and PVC are setup with ReadOnlyMany access

2. Update `values.yaml` ¶

Assuming that the PVC representing the EFS is called third-party-libraries, update the values.yaml so that the PVC is added as an additional mount:

volumes:
  additional:
    - name: third-party-libraries
      persistentVolumeClaim:
        claimName: third-party-libraries

Now add this as an additionalVolumeMounts

additionalVolumeMounts:
  - volumeName: third-party-libraries
    mountPath: /libraries

Finally inject the desired libraries by defining them under additionalLibraries

additionalLibraries:
  - volumeName: third-party-libraries
    subDirectory: database_drivers
    fileName: my_library.jar

Custom command ¶

This example is based on the GitHub issue discussed here. The nfsPermissionFixer in the values.yaml is used for appropriately setting the permissions on the shared-home volume. The command it uses for this is already defined by default, however it can also be supplied with a custom command for adding 3rd party libraries to shared-home. The example below shows how this approach can be used for adding the JDBC MySQL driver:

nfsPermissionFixer:
  command: |
    if [[ ! -f /shared-home/drivers/mysql-driver.jar ]]; then
      mkdir -p /shared-home/drivers
      apk add dpkg
      wget https://dev.mysql.com/get/Downloads/Connector-J/mysql-connector-java_8.0.26-1debian10_all.deb
      dpkg-deb -R mysql-connector-java_8.0.26-1debian10_all.deb /tmp/
      cp /tmp/usr/share/java/mysql-connector-java-8.0.26.jar  /shared-home/drivers/mysql-driver.jar
    fi
    chgrp 2003 /shared-home; chmod g+w /shared-home

shared-home permissions

If taking this approach ensure the last thing your custom command does is apply the relevant permissions to the shared-home mount, see line 10 in yaml snippet above.

Each product chart has a <product>.sharedHome.permissionFix.command helper for doing this. look at Jira's helper jira.sharedHome.permissionFix.command for more details on how these permissions are applied by default.

Remember to also update the additionalLibraries stanza accordingly:

additionalLibraries: 
  - volumeName: shared-home
    subDirectory: drivers
    fileName: mysql-driver.jar