git obtain rev list

def get_git_branches(url, secretfileId) {
    def isport = url.split(':'); def port = ''
    if (isport.size() >= 3) {
        port = '-p ' + isport[2].split('/')[0]
    }
    def revisions_list = []; def branches = []
    withCredentials([[$class: 'FileBinding', credentialsId: secretfileId, variable: 'GITLAB_SSH_KEY']]) {
        revisions_list = sh(returnStdout: true, script: "GIT_SSH_COMMAND='ssh $port -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -i $GITLAB_SSH_KEY' git ls-remote -t -h $url").split('\r?\n')
    }
    for (def revision in revisions_list) {
        def branch = revision.split('\t')[1].replaceAll('refs/heads/', '').replaceAll('refs/tags/', '').replaceAll(/[\^].*/, '')
        branches.add(branch)
    }
    return branches.unique()
}

....

def configs_branches = get_git_branches(configs_repo_url, gitlab_secretfileId)
...