Download single file from private Git repository in declarative Jenkins pipeline

Question

I already had a look at this question , but I wonder how I can securely download a single from a private Git repository in a declarative pipeline, preferably using a credentials ID or similar.

I assume I have to use something like:

sh 'git archive ... || tar --extract'

Answer 1

for this purpose there is a ssh agent plugin that can be used within the pipeline script:

sshagent(credentials: ['credentials-id']) {
  sh "git archive --remote=${git_repository_url} --format=tar ${branch_name} ${path_to_file} | tar xf -"
}

Note: path_to_file can be either the path to a file, or just the filename