What is the reason why jenkins reported an error when configuring docker URL (see the details below)?

  docker, question

1. After installing jenkins, download a docker build step plug plug-in, restart jenkins after installation, and then report an error “something wentwrong, cannot connect to” when configuring docker URL in system management-system settingshttp:// ,Cause: null “has been successfully used several times. when the above problems occur, I delete the entire. jenkins folder directly under the user folder, then restart java -jar jenkins.war, and reconfigure it. however, the above errors always occur. what is the cause of the problem? Thank you very much. I have been troubled for several days.

Since it is not http protocol, try changing http to tcp.