dockerkubernetesredisredisinsights

redisinsights with persistent volume in kubernetes


I have the following .yaml file to install redisinsights in kubernetes, with persistence support.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: redisinsight-storage-class
provisioner: 'kubernetes.io/gce-pd'
parameters:
  type: 'pd-standard'
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: redisinsight-volume-claim
spec:
  storageClassName: redisinsight-storage-class
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: redisinsight #deployment name
  labels:
    app: redisinsight #deployment label
spec:
  replicas: 1 #a single replica pod
  selector:
    matchLabels:
      app: redisinsight #which pods is the deployment managing, as defined by the pod template
  template: #pod template
    metadata:
      labels:
        app: redisinsight #label for pod/s
    spec:
      initContainers:
        - name: change-data-dir-ownership
          image: alpine:3.6
          command:
            - chmod
            - -R
            - '777'
            - /db
          volumeMounts:
            - name: redisinsight
              mountPath: /db
      containers:
        - name: redisinsight #Container name (DNS_LABEL, unique)
          image: redislabs/redisinsight:1.6.1 #repo/image
          imagePullPolicy: Always #Always pull image
          volumeMounts:
            - name: redisinsight #Pod volumes to mount into the container's filesystem. Cannot be updated.
              mountPath: /db
          ports:
            - containerPort: 8001 #exposed conainer port and protocol
              protocol: TCP
      volumes:
        - name: redisinsight
          persistentVolumeClaim:
            claimName: redisinsight-volume-claim
---
apiVersion: v1
kind: Service
metadata:
  name: redisinsight
spec:
  ports:
    - port: 8001
      name: redisinsight
  type: LoadBalancer
  selector:
    app: redisinsight

However, it fails to launch and gives an error:

INFO 2020-07-03 06:30:08,117 redisinsight_startup Registered SIGTERM handler
ERROR 2020-07-03 06:30:08,131 redisinsight_startup Error in main()
Traceback (most recent call last):
  File "./startup.py", line 477, in main
ValueError: invalid literal for int() with base 10: 'tcp://10.69.9.111:8001'
Traceback (most recent call last):
  File "./startup.py", line 495, in <module>
  File "./startup.py", line 477, in main
ValueError: invalid literal for int() with base 10: 'tcp://10.69.9.111:8001'

But the same docker image, when run locally via docker as:

docker run -v redisinsight:/db -p 8001:8001 redislabs/redisinsight

works fine. What am I doing wrong ?

It feels like redisinsights is trying to read port as an int but somehow gets a string and is confused. But I cannot understand how this works fine the local docker run.


Solution

  • UPDATE:

    RedisInsight's kubernetes documentation has been updated recently. It clearly describes how to create a RedisInsight k8s deployment with and without a service.

    IT also explains what to do when there's a service named "redisinsight" already:

    Note - If the deployment will be exposed by a service whose name is ‘redisinsight’, set REDISINSIGHT_HOST and REDISINSIGHT_PORT environment variables to override the environment variables created by the service.


    The problem is with the name of the service.

    From the documentation, it is mentioned that RedisInsight has an environment variable REDISINSIGHT_PORT which can configure the port in which RedisInsight can run.

    When you create a service in Kubernetes, all the pods that match the service, gets an environment variable <SERVICE_NAME>_PORT=<SERVICE_IP>:<SERVICE_PORT>.

    So when you try to create the above mentioned service with name redisinsight, Kubernetes passes the service environment variable REDISINSIGHT_PORT=<SERVICE_IP>:SERVICE_PORT. But the port environment variable (REDISINSIGHT_PORT) is documented to be a port number and not an endpoint which makes the pod to crash when redisinsight running on the pod tries to use the environment variable as the port number.

    So change the name of the service to be something different and not redisinsight and it should work.

    Here's a quick deployment and service file:

    Deployment:

    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: redisinsight #deployment name
      labels:
        app: redisinsight #deployment label
    spec:
      replicas: 1 #a single replica pod
      selector:
        matchLabels:
          app: redisinsight #which pods is the deployment managing, as defined by the pod template
      template: #pod template
        metadata:
          labels:
            app: redisinsight #label for pod/s
        spec:
          containers:
          - name:  redisinsight #Container name (DNS_LABEL, unique)
            image: redislabs/redisinsight:1.6.3 #repo/image
            imagePullPolicy: IfNotPresent
            volumeMounts:
            - name: db #Pod volumes to mount into the container's filesystem. Cannot be updated.
              mountPath: /db
            ports:
            - containerPort: 8001 #exposed conainer port and protocol
              protocol: TCP
          volumes:
          - name: db
            emptyDir: {} # node-ephemeral volume https://kubernetes.io/docs/concepts/storage/volumes/#emptydir
    

    Service:

    apiVersion: v1
    kind: Service
    metadata:
      name: redisinsight-http # name should not be redisinsight 
    spec:
      type: LoadBalancer
      ports:
        - port: 80
          targetPort: 8001
      selector:
        app: redisinsight
    

    Please note the name of the service.

    Logs of redisinsight pod:

     INFO 2020-09-02 11:46:20,689 redisinsight_startup Registered SIGTERM handler
     INFO 2020-09-02 11:46:20,689 redisinsight_startup Starting webserver...
     INFO 2020-09-02 11:46:20,689 redisinsight_startup Visit http://0.0.0.0:8001 in your web browser. Press CTRL-C to exit.
    

    Also the service end point (from minikube):

    $ minikube service list                                                                              
    |----------------------|------------------------------------|--------------|-------------------------|
    |      NAMESPACE       |                NAME                | TARGET PORT  |           URL           |
    |----------------------|------------------------------------|--------------|-------------------------|
    | default              | kubernetes                         | No node port |
    | default              | redisinsight-http                  |           80 | http://172.17.0.2:30860 |
    | kube-system          | ingress-nginx-controller-admission | No node port |
    | kube-system          | kube-dns                           | No node port |
    | kubernetes-dashboard | dashboard-metrics-scraper          | No node port |
    | kubernetes-dashboard | kubernetes-dashboard               | No node port |
    |----------------------|------------------------------------|--------------|-------------------------|
    

    BTW, If you don't want to create a service at all (which is not related the question), you can do port forwarding:

    kubectl port-forward <redisinsight-pod-name> 8001:8001