SSH Key Setup for GitHub Actions JAR Deployment

SSH Key Setup for GitHub Actions JAR Deployment | Generated by AI

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To generate an SSH key for GitHub Actions to deploy a JAR file, follow these steps:

Generate an SSH Key Pair:
- On your local machine or a secure environment, run:
```
ssh-keygen -t ed25519 -C "your_email@example.com" -f github-actions-deploy
```
- If your system doesn’t support Ed25519, use:
```
ssh-keygen -t rsa -b 4096 -C "your_email@example.com" -f github-actions-deploy
```
- Press Enter to accept the default file location and optionally set a passphrase (recommended for security). This creates two files:
  - github-actions-deploy (private key)
  - github-actions-deploy.pub (public key)
Add the Public Key to the Target Server:
- Copy the public key:
```
cat github-actions-deploy.pub
```
- Log in to the server where you’ll deploy the JAR file.
- Append the public key to ~/.ssh/authorized_keys on the server:
```
echo "your-public-key-content" >> ~/.ssh/authorized_keys
```
- Ensure the authorized_keys file has the correct permissions:
```
chmod 600 ~/.ssh/authorized_keys
```
Store the Private Key in GitHub Secrets:
- Go to your GitHub repository: Settings > Secrets and variables > Actions > Secrets.
- Click New repository secret.
- Name the secret (e.g., SSH_PRIVATE_KEY).
- Paste the contents of the private key (github-actions-deploy):
```
cat github-actions-deploy
```
- Save the secret.

Configure the GitHub Actions Workflow:

Create or edit a workflow file (e.g., .github/workflows/deploy.yml).

Add a step to use the SSH key for deploying the JAR. Below is an example workflow:

name: Deploy JAR

on:
  push:
    branches:
      - main

jobs:
  deploy:
    runs-on: ubuntu-latest

    steps:
    - name: Checkout code
      uses: actions/checkout@v4

    - name: Set up Java
      uses: actions/setup-java@v4
      with:
        java-version: '17' # Adjust to your Java version
        distribution: 'temurin'

    - name: Build JAR
      run: mvn clean package # Adjust for your build tool (e.g., Gradle)

    - name: Install SSH Key
      uses: shimataro/ssh-key-action@v2
      with:
        key: $
        known_hosts: 'optional-known-hosts' # See note below

    - name: Add Known Hosts
      run: |
        ssh-keyscan -H <server-ip-or-hostname> >> ~/.ssh/known_hosts
      # Replace <server-ip-or-hostname> with your server's IP or hostname

    - name: Deploy JAR to Server
      run: |
        scp target/your-app.jar user@<server-ip-or-hostname>:/path/to/deploy/
        ssh user@<server-ip-or-hostname> "sudo systemctl restart your-service" # Adjust for your deployment process

Notes:
- Replace target/your-app.jar with the path to your JAR file.
- Replace user@<server-ip-or-hostname> with your server’s SSH user and address.
- Adjust the deployment command (e.g., sudo systemctl restart your-service) to match how you start or deploy the JAR on your server.
- The known_hosts step is critical to avoid SSH host verification issues. If you know the server’s host key, you can pre-populate it in the shimataro/ssh-key-action step, or use ssh-keyscan as shown.

Secure the Workflow:
- Ensure the private key is never exposed in logs or outputs.
- Restrict repository permissions to prevent unauthorized access to secrets.
- If using a passphrase for the SSH key, add it as another secret and include it in the shimataro/ssh-key-action step:
```
with:
  key: $
  passphrase: $
  known_hosts: 'optional-known-hosts'
```
Test the Workflow:
- Push a change to the main branch (or the branch specified in the workflow).
- Monitor the workflow in the Actions tab of your GitHub repository to ensure the JAR is built and deployed correctly.
Troubleshooting:
- Permission denied: Verify the SSH key is correctly added to the server’s authorized_keys and that the user has permission to access the target directory.
- Host verification failed: Ensure the known_hosts step is correctly configured with the server’s IP or hostname.
- Build issues: Confirm the Java version and build commands match your project setup.

This setup securely integrates SSH-based deployment into your GitHub Actions workflow for deploying a JAR file. If you need specific adjustments (e.g., for a particular server setup or build tool), let me know!

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