Kubernetes Solr operator JTS and Polygons jar file

Question

Is there a way to install/download the library jts-core in the folder SOLR_INSTALL/server/solr-webapp/webapp/WEB-INF/lib/ ? As specified in the official guide: https://solr.apache.org/guide/8_10/spatial-search.html#jts-and-polygons-flat

Actually, I tried to put in the middle an initContainer that downloads such jar, but I get obviously a Permission denied from the Solr container since only root can write on the final solr container.

I tried also to set a securityContext only for my initContainer , in order to run as root, but that configuration has no effect in the initContainer , I think it is not seen by the Solr CRD.

podOptions:
  initContainers:
  - name: "install-jts-core"
    image: solr:8.9.0
    command: ['sh', '-c', 'wget -O /opt/solr-8.9.0/server/solr-webapp/webapp/WEB-INF/lib/jts-core-1.15.1.jar https://repo1.maven.org/maven2/org/locationtech/jts/jts-core/1.15.1/jts-core-1.15.1.jar']
    securityContext:   <--- this has no effect on SolrCloud CRD
      runAsUser: 0

Another disperate attempt was to set a podSecurityContext.runAsUser: 0 , so for all containers in the pod, but Solr does not run as root , I discarded that option by the way.

Any hint/idea/solution please?

Thank you very much in advance.

Answer 1

I have recently found a solution that may not be elegant, but works well in any version of Solr image, below a configuration example:

podOptions:
  initContainers:
  - name: "install-jts-lib"
    image: solr:8.9.0
    command:
    - 'sh'
    - '-c'
    - |
      wget -O /tmp-webinf-lib/jts-core-1.15.1.jar https://repo1.maven.org/maven2/org/locationtech/jts/jts-core/1.15.1/jts-core-1.15.1.jar
      cp -R /opt/solr/server/solr-webapp/webapp/WEB-INF/lib/* /tmp-webinf-lib
    volumeMounts:
    - mountPath: /tmp-webinf-lib
      name: web-inf-lib
  volumes:
  - name: web-inf-lib
    source:
      emptyDir: {}
    defaultContainerMount:
      name: web-inf-lib
      mountPath: /opt/solr/server/solr-webapp/webapp/WEB-INF/lib

In this example, I create an emptyDir volume and attach it in any directory of the initContainer , but in the final Solr container I attach it in the target directory ($SOLR_HOME/server/solr-webapp/webapp/WEB-INF/lib) .

This will empty the ../WEB-INF/lib directory, but since I'm using the same Solr image , I can copy the content of ../WEB-INF/lib (jars and folders) of the initContainer at the end.

The effect is that the final container will have all the content it should have had plus the jts-core-1.15.1.jar jar.

This works also with other files or libraries you want to bring in the Solr container.

Let me know what do you think of this workaround 👍

Thank you.

Answer 2

In this case it is not about the permission or CRD; the file downloaded by a install-jts-core will not be available to other containers because of namespace isolation.

You can create a Dockerfile using solr as the base image and COPY the jar to into the image. Then replace image.repository solr helm parameter during helm install. This way you run a image with the library pre-installed.