SSH Connection refused after multiple previous successful connections

December 30, 2018 1.1k views
CI/CD LAMP Stack Ubuntu 16.04

I am running a Wordpress One-Click install and I am using GitLab CI/CD to deploy to my droplet. My script is successfully connecting via SSH creating some folders, then using SCP to copy some files to the server successfully, then after a few SSH connections the droplet refuses the SSH connection and the job fails. Here is a chunk of the log from GitLab:

$ ssh-add <(echo "$SSH_PRIVATE_KEY")
Identity added: /dev/fd/63 (rsa w/o comment)
$ ssh "$PROD_SERVER_USER"@"$PROD_SERVER_ADDRESS" "mkdir -p \"$PROD_DIRECTORY\"/_tmp && mkdir -p \"$PROD_DIRECTORY\"/_old && mkdir -p \"$PROD_DIRECTORY\"/build"
Warning: Permanently added '#######' (ECDSA) to the list of known hosts.
$ scp "$BUILD_DIRECTORY"/build/* "$PROD_SERVER_USER"@"$PROD_SERVER_ADDRESS":"$PROD_DIRECTORY"/_tmp
$ ssh "$PROD_SERVER_USER"@"$PROD_SERVER_ADDRESS" "mv \"$PROD_DIRECTORY\"/build \"$PROD_DIRECTORY\"/_old && mv \"$PROD_DIRECTORY\"/_tmp \"$PROD_DIRECTORY\"/build"
ssh: connect to host ####### port 22: Connection refused
ERROR: Job failed: exit code 1

Does anyone know why it is suddenly refusing to connect?

Thanks

3 Answers
unixynet January 1, 2019
Accepted Answer

Do you have any rate limiting happening on port 22? Try this:

iptables -nL|grep "22\|ssh"

Cheers

Hey there yea I did! UFW was rate limiting port 22 so I just turned it off and it works perfectly now, thanks!

Thank you for this! I was stumped on it for ages. My script was doing the same thing - ssh-ing multiple times to execute various commands but there was no indication in the error message that rate limiting was the cause.

One way to solve it without turning off rate limiting is move all your commands into a bash script and then execute like this:

ssh user@droplet 'bash -s' < ./foo.sh 

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