I am trying to clone a private git repository(gitLab) into a kubernetes pod, using SSH keys for authentication. I have stored my keys in a secret. Here is the yaml file for the job that does the desired task.

Heres the same question, but doesnt give the exact solution :

https://stackoverflow.com/questions/41067668/clone-a-secure-git-repo-in-kubernetes-pod

Logs of the init container after execution:

fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/community/x86_64/APKINDEX.tar.gz
v3.7.1-66-gfc22ab4fd3 [http://dl-cdn.alpinelinux.org/alpine/v3.7/main]
v3.7.1-55-g7d5f104fa7 [http://dl-cdn.alpinelinux.org/alpine/v3.7/community]
OK: 9064 distinct packages available
OK: 23 MiB in 23 packages
Cloning into '/tmp'...
Host key verification failed.
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

The yaml file which works perfectly for public repo:

apiVersion: batch/v1

kind: Job

metadata:

  name: nest-build-kaniko

  labels:

    app: nest-kaniko-example

spec:

  template:

    spec:

      containers:
        -

          image: 'gcr.io/kaniko-project/executor:latest'

          name: kaniko

          args: ["--dockerfile=/workspace/Dockerfile",
                "--context=/workspace/",
                "--destination=aws.dest.cred"]

          volumeMounts:
            -

              mountPath: /workspace

              name: source
            -

              name: aws-secret

              mountPath: /root/.aws/
            -

              name: docker-config

              mountPath: /kaniko/.docker/

      initContainers:
        -

          name: download

          image: alpine:3.7

          command: ["/bin/sh","-c"]

          args: ['apk add --no-cache git && git clone https://github.com/username/repo.git /tmp/']

          volumeMounts:
            -

              mountPath: /tmp

              name: source

      restartPolicy: Never

      volumes:
        -

          emptyDir: {}

          name: source
        -

          name: aws-secret

          secret:

            secretName: aws-secret
        -

          name: docker-config

          configMap:

            name: docker-config

The yaml file after using git-sync for cloning private repository:

apiVersion: batch/v1

kind: Job

metadata:

  name: nest-build-kaniko

  labels:

    app: nest-kaniko-example

spec:

  template:

    spec:

      containers:
        -

          image: 'gcr.io/kaniko-project/executor:latest'

          name: kaniko

          args: ["--dockerfile=/workspace/Dockerfile",
                "--context=/workspace/",
                "--destination=aws.dest.cred"]

          volumeMounts:
            -

              mountPath: /workspace

              name: source
            -

              name: aws-secret

              mountPath: /root/.aws/
            -

              name: docker-config

              mountPath: /kaniko/.docker/

      initContainers:
        -

          name: git-sync

          image: gcr.io/google_containers/git-sync-amd64:v2.0.4

          volumeMounts:
            -

              mountPath: /git/tmp

              name: source
            -

              name: git-secret

              mountPath: "/etc/git-secret"

          env:
            - name: GIT_SYNC_REPO

              value: "git@gitlab.com:username/repo.git"
            - name: GIT_SYNC_SSH

              value: "true"
            - name: GIT_SYNC_DEST

              value: "/tmp"
            - name: GIT_SYNC_ONE_TIME

              value: "true"

          securityContext:

            runAsUser: 0

      restartPolicy: Never

      volumes:
        -

          emptyDir: {}

          name: source
        -

          name: aws-secret

          secret:

            secretName: aws-secret
        -

          name: git-secret

          secret:

            secretName: git-creds

            defaultMode: 256
        -

          name: docker-config

          configMap:

            name: docker-config