I am trying to build and deploy nodejs app using gitlab ci/cd and kubernates cluster. the build pass successfully while the deployment failed. Meanwhile I added Kubernates cluster to gitlab (API url, CA certificate and service token) and the error that I got for running kubectl within the deploy due to issue related to KUBECONFIG and the below is gitlab-ci.yml that I am using

    stages:
      - build
      - deploy

    services:
      - docker:dind


    build_app:  
      stage: build
      image: docker:git
      only:
        - master
        - develop

      script:
        - docker login -u gitlab-ci-token -p ${CI_BUILD_TOKEN} ${CI_REGISTRY}
        - docker build -t ${CI_REGISTRY}/${CI_PROJECT_PATH} . 
        - docker tag ${CI_REGISTRY}/${CI_PROJECT_PATH} ${CI_REGISTRY}/${CI_PROJECT_PATH}:${CI_COMMIT_SHORT_SHA}
        - docker push ${CI_REGISTRY}/${CI_PROJECT_PATH}:${CI_COMMIT_SHORT_SHA}

    variables:
      DOCKER_HOST: tcp://docker:2375/
    deploy:
      stage: deploy
      image:
        name: bitnami/kubectl:latest
        entrypoint: [""]

      script:
        - USER_TOKEN=$(cat /var/run/secrets/kubernetes.io/serviceaccount/token)
        - CERTIFICATE_AUTHORITY_DATA=$(cat /var/run/secrets/kubernetes.io/serviceaccount/ca.crt | base64 -i -w0 -)
        - kubectl config set-cluster k8s --server="https://kubernetes.default.svc"
        - kubectl config set clusters.k8s.certificate-authority-data ${CERTIFICATE_AUTHORITY_DATA}
        - kubectl config set-credentials gitlab --token="${USER_TOKEN}"
        - kubectl config set-context default --cluster=k8s --user=gitlab
        - kubectl config use-context default
        - kubectl set image deployment test-flight web=${CI_REGISTRY}/${CI_PROJECT_PATH}:${CI_COMMIT_SHORT_SHA} -n test-flight-dev

$ USER_TOKEN=$(cat /var/run/secrets/kubernetes.io/serviceaccount/token) cat: /var/run/secrets/kubernetes.io/serviceaccount/token: No such file or directory

Update: Creating Environment and attach it to the stage solve the issue of identifying the cluster which the deployment will be, and so the cluster can get the action to apply the command