Error loading key "/dev/fd/63: Error when trigger the CI/CD in Gitlab

Question

Gitlab CI/CD failed while connecting to the Digital Ocean Droplet, via ssh:

This is my CI file

before_script:
  - apt-get update -qq
  - apt-get install -qq git
  # Setup SSH deploy keys
  - 'which ssh-agent || ( apt-get install -qq openssh-client )'
  - eval $(ssh-agent -s)
  - ssh-add <(echo "${SSH_PRIVATE_KEY}" | base64 --decode | tr -d "\r")
  - mkdir -p ~/.ssh
  - '[[ -f /.dockerenv ]] && echo -e "Host *\n\tStrictHostKeyChecking no\n\n" > ~/.ssh/config'
    
deploy:
  type: deploy
  environment:
    name: production
  script:
    - ssh root@xxx.xxx.xxx.xxx "cd /var/www/html/customer-web && git checkout master && git pull origin master && npm install && npm run build && exit"
  only:
    - master

when I trigger this, I'm getting the following error

$ eval $(ssh-agent -s)
Agent pid 267
$ ssh-add <(echo "${SSH_PRIVATE_KEY}" | base64 --decode | tr -d "\r")
Error loading key "/dev/fd/63": invalid format
Cleaning up project directory and file based variables
00:01
ERROR: Job failed: exit code 1

and I am saving the ~/.ssh/id_rsa in CI/CD variable too. any one have idea why this error comes and failed.

Answer 1

The key i generated with OPENSSH, not in RSA after i generate the key in RSA the issue has been fixed