various chart improvments

[Spirit-act]

Hello,

I tested this Helm Chart for our setup and discovered some drawbacks.

Changes:

Add support for environment variables

• Add default envs for a simple deployment with the included Redis
• Add a helper to the _helpers.tpl to convert the envs from the value.yaml to the correct format
• I needed to build a workaround for the remotecv pod. For some reason remotecv does not take the env vars automatically

args:
  - "--host=$(REDIS_HOST)"
  - "--port=$(REDIS_PORT)"
  - "--with-healthcheck"
  - "--server-port=$(HTTP_SERVER_PORT)"
  - "--password=$(REDIS_PASSWORD)"

Add initContainer to remotecv

Remotecv requires connection to Redis. If Redis is deployed with this Helm Chart, it is not accessible right from the start. I added an initContainer which waits until the configured Redis is accessible.

initContainers:
  - name: wait-for-redis
    image: busybox
    command:
      - /bin/sh
      - -c
      - >
        COUNT=0
        while [ $(echo -e "AUTH $REDIS_PASSWORD\r\nPING\r\n" | nc $REDIS_HOST $REDIS_PORT | grep -c "PONG") -ne 1 ]; do
          if [[ $COUNT -ge 10 ]]; then
            echo "Waited to long restarting POD"
            exit 1;
          fi

          echo "Waiting for Redis...";
          sleep 1;
          ((COUNT++))
        done

This feature should probably be added to the remotecv container.

Config / values.yaml changes

• move thumbor config in a configmap but keep thumbor.key in the secret
• control Redis and remotecv installation via separate variables (not within the thumbor_config)
• scale redis to only the master pod in the default deployment. For small deployments with only one Pod for each component (thumbor, remotecv, redis) it should be enough. It can easily be scaled up again, if replicas are needed (documented variable).

Comments

• add more documenting comments to the values.yaml
• regenerate README.md with helm-docs

Other

• I have increased the Chart version to 1.0.0 because of the possible breaking changes (We will be using this Chart in prod).
• I have changed the Markdown Syntax in the top README.md according to the linter.

If something is not clear, please ask. I am happy to answer.