K3s - Kaniko - Error -The Pod "kaniko-demo" is invalid

Question

during my internship, I have to launch a build on kubernetes. My setup is with K3s.

I must have an error in my deployment file, do you have an explanation please?

Thank you.

deployment.yml

---
kind: Namespace
apiVersion: v1
metadata:
  name: demo
  labels:
    name: demo
---
kind: Pod
apiVersion: v1
metadata:
  name: kaniko-demo
  namespace: demo
spec:
  containers:
    - name: kaniko-demo
      image: gcr.io/kaniko-project/executor:latest
      args:
        [
          "--dockerfile=Dockerfile_Kubernetes01",
          "--context=dir:///context",
          "--cache=true",
          "--destination=reg.gitlab.reewayy.io/incubator/npivaut/k3s_kaniko",
          "--cache=true",
          "--cache-dir=/cache",
        ]
      volumeMounts:
        - name: kaniko-secret
          mountPath: /kaniko/.docker
        - name: kaniko-context
          mountPath: /context
        - name: kaniko-cache
          mountPath: /cache
  restartPolicy: Never
  volumes:
    - name: kaniko-secret
      secret:
        secretName: regcred
        items:
          - key: .dockerconfigjson
            path: config.json
    - name: kaniko-context
      hostPath:
        path: /tmp/kaniko_context
    - name: kaniko-context
      hostPath:
        path: /tmp/kaniko_cache

kubectl apply -f /home/nicolas/demo-reewayy/k3s/kubernetes-deployment-01.yaml 
namespace/demo unchanged
The Pod "kaniko-demo" is invalid: 
* spec.volumes[2].name: Duplicate value: "kaniko-context"
* spec.containers[0].volumeMounts[2].name: Not found: "kaniko-cache"

Dockerfile

FROM alpine/git as source
COPY deployment_key /root/.ssh/id_rsa
RUN git clone ssh://git@gitlab.reewayy.io:32222/incubator/npivaut.git ;\
    cd /git/npivaut && git pull


FROM gradle:7.5.1-jdk17-focal as build
COPY --from=source /git/demo-reewayy /home/gradle/project
USER gradle
WORKDIR /home/gradle/project
RUN gradle :assemble

FROM ibm-semeru-runtimes:open-17-jre-jammy
RUN mkdir /opt/reewayy/demo-reewayy
COPY --from=build /home/gradle/project/build/libs/demo-0.0.1-SNAPSHOT.jar /opt/reewayy/demo/demo-0.0.1-SNAPSHOT.jar
COPY --from=build /home/gradle/project/src/main/resources/application.properties /opt/reewayy/demo/application.properties
RUN useradd -s /bin/bash -u 1000 -U -m -d /home/reewayy reewayy && chown -R reewayy.reewayy /opt/reewayy/
USER reewayy
CMD ["java","-jar","/opt/reewayy/demo-reewayy/demo-0.0.1-SNAPSHOT.jar"]

My internship mentor told me to optimize the deployment file but I have trouble understanding the error...

Answer 1

The error message tells it all:

The Pod "kaniko-demo" is invalid: 
* spec.volumes[2].name: Duplicate value: "kaniko-context"
* spec.containers[0].volumeMounts[2].name: Not found: "kaniko-cache"

You have two volumes with the same name, and one of the volumeMounts referring to a non-existing volume.

You should use:

kind: Pod
apiVersion: v1
spec:
  containers:
    - name: kaniko-demo
...
      volumeMounts:
        - name: kaniko-secret
          mountPath: /kaniko/.docker
        - name: kaniko-context
          mountPath: /context
        - name: kaniko-cache
          mountPath: /cache
...
  volumes:
    - name: kaniko-secret
      secret:
        secretName: regcred
        items:
          - key: .dockerconfigjson
            path: config.json
    - name: kaniko-context
      hostPath:
        path: /tmp/kaniko_context
    - name: kaniko-cache  ### <- fix that one!
      hostPath:
        path: /tmp/kaniko_cache

Answer 2

Thanks for the leads. I understand a little better. My mentor told me in passing that I could remove the _cache. I will try to solve the rest of my errors which I strangely did not have before.

The Pod "kaniko-demo" is invalid: spec: Forbidden: pod updates may not change fields other than `spec.containers[*].image`, `spec.initContainers[*].image`, `spec.activeDeadlineSeconds`, `spec.tolerations` (only additions to existing tolerations) or `spec.terminationGracePeriodSeconds` (allow it to be set to 1 if it was previously negative)
  core.PodSpec{
    Volumes: []core.Volume{
        {
            Name: "kaniko-secret",
            VolumeSource: core.VolumeSource{
                ... // 3 identical fields
                AWSElasticBlockStore: nil,
                GitRepo:              nil,
                Secret: &core.SecretVolumeSource{
-                   SecretName:  "reg-credentials",
+                   SecretName:  "regcred",
                    Items:       {{Key: ".dockerconfigjson", Path: "config.json"}},
                    DefaultMode: &420,
                    Optional:    nil,
                },
                NFS:   nil,
                ISCSI: nil,
                ... // 21 identical fields
            },
        },
+       {
+           Name:         "kaniko-context",
+           VolumeSource: core.VolumeSource{HostPath: &core.HostPathVolumeSource{Path: "/tmp/kaniko_context", Type: &""}},
+       },
        {Name: "kube-api-access-5pptr", VolumeSource: {Projected: &{Sources: {{ServiceAccountToken: &{ExpirationSeconds: 3607, Path: "token"}}, {ConfigMap: &{LocalObjectReference: {Name: "kube-root-ca.crt"}, Items: {{Key: "ca.crt", Path: "ca.crt"}}}}, {DownwardAPI: &{Items: {{Path: "namespace", FieldRef: &{APIVersion: "v1", FieldPath: "metadata.namespace"}}}}}}, DefaultMode: &420}}},
    },
    InitContainers: nil,
    Containers: []core.Container{
        {
-           Name:    "kaniko",
+           Name:    "kaniko-demo",
            Image:   "gcr.io/kaniko-project/executor:latest",
            Command: nil,
            Args: []string{
-               "--dockerfile=Dockerfile_Kubernetes01",
+               "--dockerfile=Dockerfileun",
                "--context=dir:///context",
                "--cache=true",
                ... // 3 identical elements
            },
            WorkingDir: "",
            Ports:      nil,
            EnvFrom:    nil,
            Env:        nil,
            Resources:  {},
            VolumeMounts: []core.VolumeMount{
                {Name: "kaniko-secret", MountPath: "/kaniko/.docker"},
                {
-                   Name:             "kube-api-access-5pptr",
+                   Name:             "kaniko-context",
-                   ReadOnly:         true,
+                   ReadOnly:         false,
-                   MountPath:        "/var/run/secrets/kubernetes.io/serviceaccount",
+                   MountPath:        "/context",
                    SubPath:          "",
                    MountPropagation: nil,
                    SubPathExpr:      "",
                },
            },
            VolumeDevices: nil,
            LivenessProbe: nil,
            ... // 10 identical fields
        },
    },
    EphemeralContainers: nil,
    RestartPolicy:       "Never",
    ... // 26 identical fields