Add support for cfg via env vars and define external volumes

[mszostok]

ISSUE TYPE

• Feature Pull Request

SUMMARY

• Allows providing communicator configuration via env variables
• Env variables have higher priority that config from file
• Helm chart has:
  • extraEnv
  • extraVolumeMounts
  • extraVolumes

Fixes #480

Related documentation: kubeshop/botkube-docs#82

TESTING

Unit test proves that the reading configuration works as expected. However, below you will find an e2e tutorial.

BotKube with Vault via CSI driver

1. Create K8s cluster, e.g. k3s via lima-vm: limactl start template://k3s

   NOTE: The CSI needs to be supported, on k3d is problematic: [BUG] Fail to start longhorn with k3d k3d-io/k3d#206. Alternative is to just not play with the CSI driver and create your own volume that will be mounted, e.g. with predefined secret.

2. Install Vault:

   helm repo add hashicorp https://helm.releases.hashicorp.com
   helm repo update
   helm install vault hashicorp/vault \
       --set "server.dev.enabled=true" \
       --set "injector.enabled=false" \
       --set "csi.enabled=true"

3. Set Slack token:

   kubectl exec -it vault-0 -- /bin/sh

   vault kv put secret/slack token={token}

4. Configure Kubernetes authentication:

   vault auth enable kubernetes
   vault write auth/kubernetes/config \
       kubernetes_host="https://$KUBERNETES_PORT_443_TCP_ADDR:443"

   vault policy write internal-app - <<EOF
   path "secret/data/slack" {
     capabilities = ["read"]
   }
   EOF

   vault write auth/kubernetes/role/database \
       bound_service_account_names=botkube-sa \
       bound_service_account_namespaces=default \
       policies=internal-app \
       ttl=20m

5. Install the secrets store CSI driver:

   helm repo add secrets-store-csi-driver https://kubernetes-sigs.github.io/secrets-store-csi-driver/charts
   helm install csi secrets-store-csi-driver/secrets-store-csi-driver --set syncSecret.enabled=true

6. Create install parameters:

   cat > /tmp/values.yaml << ENDOFFILE
   extraObjects:
     - apiVersion: secrets-store.csi.x-k8s.io/v1
       kind: SecretProviderClass
       metadata:
         name: vault-database
       spec:
         provider: vault
         secretObjects:
           - data:
               - key: token
                 objectName: "slack-token"
             secretName: communication-slack
             type: Opaque
         parameters:
           vaultAddress: "http://vault.default:8200"
           roleName: "database"
           objects: |
             - objectName: "slack-token"
               secretPath: "secret/data/slack"
               secretKey: "token"
   
   communications:
     # Settings for Slack
     slack:
       enabled: true
       channel: 'random'
       notiftype: short
       # token - specified via env
   
   extraEnv:
     - name: COMMUNICATION_SLACK_TOKEN
       valueFrom:
         secretKeyRef:
           name: communication-slack
           key: token
   
   extraVolumeMounts:
     - name: secrets-store-inline
       mountPath: "/mnt/secrets-store"
       readOnly: true
   
   extraVolumes:
     - name: secrets-store-inline
       csi:
         driver: secrets-store.csi.k8s.io
         readOnly: true
         volumeAttributes:
           secretProviderClass: "vault-database"
   image:
     registry: mszostok
     repository: botkube
     tag: env-test-v2
   ENDOFFILE

7. Checkout this PR: gh pr checkout 601

8. Install BotKube:

   helm install botkube -f /tmp/values.yaml ./helm/botkube

[PrasadG193]

Is there an issue to track docs changes?

[pkosiec]

Works well 👍 Just one minor comment

[bhavin192]

I'm just looking at the Helm chart. Apart from the comment about extraEnv and few minor ones, rest chart changes look good!

[mszostok]

Hi @bhavin192!

Thanks for the review 👍 Here is the commit with applied changes: 32cb93c

Currently, I'm working on a document as mentioned in #601 (comment).

EDIT: PR for docs is ready: kubeshop/botkube-docs#82

---

Regarding README.md for Helm Chart, it would be nice to have it automatically generated, e.g. via helm-docs, or readme-generator-for-helm. For now, I described only properties that I added on this PR. However, I spot that the table is not complete and also contains removed properties too, e.g. ingress.urlPath

I created an issue to track that: #609

[mszostok]

@PrasadG193

Is there an issue to track docs changes?

Docs changes are handled in the same issue, here is the related PR: kubeshop/botkube-docs#82

Here is also a recording that shows how it works: https://www.loom.com/share/37f6a60f88194b55916ee256a534336c

[pierluigilenoci]

@mszostok could you please resolve the conflicts?