Error: Jenkins is having trouble accessing the Docker socket and the Dockerfile

The error message you're encountering indicates that Jenkins is having trouble accessing the Docker socket and the Dockerfile in your Jenkins job's workspace. This is often due to permissions and configuration issues.

Here are the steps to troubleshoot and resolve this issue:

Docker Socket Permission:

The error message "permission denied" indicates that Jenkins doesn't have the necessary permission to access the Docker daemon socket (/var/run/docker.sock).

Add Jenkins to Docker Group:

The most common approach to address this is to add the jenkins user (or the user under which Jenkins is running) to the docker group. This allows the user to access the Docker daemon socket without needing sudo privileges.

Run the following commands in your terminal to add the Jenkins user to the docker group:

sudo usermod -aG docker jenkins

newgrp docker  # This command activates the group change for the current shell session

Restart Jenkins:

After adding the Jenkins user to the docker group, restart the Jenkins service to apply the changes:

sudo service jenkins restart

Check Workspace and Dockerfile Path:

The error message also mentions that it can't find the Dockerfile at /var/lib/jenkins/workspace/git_docker/dev2doc/Dockerfile.

Verify that the Dockerfile is actually located at this path in your Jenkins job's workspace.

If the Dockerfile is in a different directory, make sure the path is correct in your Jenkins job configuration.

Check Job Configuration:

In your Jenkins job configuration, make sure you have correctly specified the path to the Dockerfile in the "Docker Build and Publish" or equivalent step.

Ensure that the relative path is accurate.

Rebuild the Job:

After making these changes, try rebuilding your Jenkins job to see if the issue is resolved.

Make sure to push a change to your Git repository to trigger the Jenkins job.

Jenkins Workspace Permissions:

Sometimes, workspace permission issues can arise. Ensure that the Jenkins workspace directory and its contents have appropriate permissions for the jenkins user.

Docker Daemon Restart (Rare):

If none of the above steps work, try restarting the Docker daemon:

sudo service docker restart

Remember, granting Jenkins access to the Docker daemon has security implications, so make sure to follow best practices for securing your Jenkins and Docker installations.