GitHub Actions SSH Authentication Failure: "ssh: handshake failed: ssh: unable to authenticate, attempted methods [publickey none]"

Question

I'm trying to set up a GitHub Actions workflow to deploy my .NET application to a remote server using SSH. However, I'm encountering an authentication error during the SSH handshake. Here's the error message I'm getting:

2024/06/19 02:51:53 ssh: handshake failed: ssh: unable to authenticate, attempted methods [publickey none], no supported methods remain

GitHub Actions Workflow:

name: Deploy to Hetzner

on:
  push:
    branches:
      - main

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout code
        uses: actions/checkout@v2

      - name: Set up .NET Core
        uses: actions/setup-dotnet@v2
        with:
          dotnet-version: '8.0.x'

      - name: Restore dependencies
        run: dotnet restore

      - name: Build
        run: dotnet publish -c Release -o out

      - name: Deploy to server
        uses: appleboy/[email protected]
        with:
          host: ${{ secrets.HOST }}
          username: ${{ secrets.USERNAME }}
          key: ${{ secrets.SSH_PRIVATE_KEY }}
          script: |
            mkdir -p /var/www/meal_prep
            rm -rf /var/www/meal_prep/*
            cp -r out/* /var/www/meal_prep
            sudo -S systemctl restart meal_prep.service

Generated SSH keys on my local machine using:

ssh-keygen -t rsa -b 4096 -C "[email protected]"

Copied the private key content (~/.ssh/id_rsa) to a GitHub repository secret named SSH_PRIVATE_KEY.

Copied the public key content (~/.ssh/id_rsa.pub) from local machine and added it to the ~/.ssh/authorized_keys file on the remote server.

nano ~/.ssh/authorized_keys and replaced the public key.

I can SSH into the remote server from my local machine without a password.

Ensured that the SSH daemon on the remote server allows the ssh-rsa algorithm by adding:

CASignatureAlgorithms +ssh-rsa

to the /etc/ssh/sshd_config file.

Despite these steps, the GitHub Actions workflow still fails with the authentication error. I've double-checked the secrets and configuration files, but nothing seems to work. Searched and tried different answer from the blogs/so answer, nothing seems to be working.

What could be causing the SSH authentication failure in my GitHub Actions workflow, and how can I resolve it? Are there any additional configurations or steps that I might be missing?

Answer 1

It took me atleast 24 hour to debug this and turned out that the proble was with the version of: appleboy/ssh-action@master.

I updated to the latest version the problem seems solved.