[FIXED] No such host error in Jenkins pipeline when pushing docker image to unauthorized private registry

Issue

I am trying to push a docker image to a private registry without any authentication configured. Below are how the jenkinsfile stages look like.

Without the writeFile command in the deploy stage I get no such host error

docker push <private-vm-name>:5000/temp/prototype-be:v1
The push refers to repository [<private-vm-name>:5000/temp/prototype-be]
Get https://<private-vm-name>:5000/v2/: dial tcp: lookup <private-vm-name> on 127.0.0.11:53: no such host

With the writeFile command I get an AccessDenied exception

java.nio.file.AccessDeniedException: /etc/docker

Could someone guide me on how could these errors be resolved in order to push to a private docker registry?

Thanks.

Jenkinsfile stages

        stage('Building docker image') {
            steps{
                script {
                    dockerImage = docker.build registry + ":v1"
                }
            }
        }

        stage('Pushing docker image') {
            steps{
                script {
                    writeFile file:"/etc/docker/daemon.json", text: "{
                            "insecure-registries": [
                               "<private-vm-name>:5000"
                            ]
                      }"
                    docker.withRegistry( 'http://<private-vm-name>:5000') {
                        dockerImage.push()
                    }
                }
            }
        }

Solution

As a workaround I executed the jenkins-server dind docker image with --insecure-registries flag. Since the docker container spawned by jenkins was now aware of the private docker registry, the above docker push command worked. Note I also changed the jenkins push command to use the server's ip address instead of the host-name so that I don't need to edit /etc/hosts.

Answered By - Andy Dufresne
Answer Checked By - Willingham (JavaFixing Volunteer)