feat: Skip runner download and install if it's already done (#446)

Co-authored-by: Steve Wilson <[email protected]>

Author: Swsystem-ATuin

template/gitlab-runner.tpl

@@ -34,8 +34,11 @@ then
   yum install amazon-ecr-credential-helper -y
 fi
 
-curl --fail --retry 6 -L https://packages.gitlab.com/install/repositories/runner/gitlab-runner/script.rpm.sh | bash
-yum install gitlab-runner-${gitlab_runner_version} -y
+if ! ( rpm -q gitlab-runner >/dev/null )
+then
+  curl --fail --retry 6 -L https://packages.gitlab.com/install/repositories/runner/gitlab-runner/script.rpm.sh | bash
+  yum install gitlab-runner-${gitlab_runner_version} -y
+fi
 
 if [[ `echo ${docker_machine_download_url}` == "" ]]
 then