Step-by-Step Guide: Deploying a Golang API Backend on a Linux Server

Prerequisites:

• You have a Golang API project ready.
• You have access to a Linux server.
• Apache is installed and properly configured on the server.

Deployment Steps:

1. Check the .env File:

Ensure your Golang project has a properly configured .env file containing all the required environment variables.

2. Build the Binary:

a. If you're developing on Windows and wish to build a Linux binary, open a command prompt and set the GOOS environment variable to "linux":

   $env:GOOS = "linux"

b. Verify that GOOS is set correctly in your Go environment by running:

   go env

c. Build the binary using:

   go build

The resulting binary will have the same name as your repository's root directory.

3. Copy Binary and .env to the Server:

Transfer the binary and the .env file to your Linux server. You can use tools like SCP or SFTP to upload these files.

4. Create a Linux Service:

You can opt to run your Golang binary as a systemd service. Create a .service file in /etc/systemd/system/ (e.g., yourapp.service) with the following content:

   [Unit]
   Description=Your Golang API Service
   After=network.target

   [Service]
   ExecStart=/path/to/your/binary
   Restart=always
   WorkingDirectory=/path/to/your/project
   User=your_username
   Group=your_group_name

   [Install]
   WantedBy=multi-user.target

• ExecStart: Specify the path to your Golang binary.
• WorkingDirectory: Set this to the directory where your project is located.

• User and Group: Specify the user and group under which the service should run.

  Save the file and enable the service:

  sudo systemctl enable yourapp.service
  sudo systemctl start yourapp.service

5. Database Import and Migration:

• Ensure that your database is imported and properly configured.

• Make sure the "goose_db_version" table in the database contains data. If it's empty, delete the table to prevent migration issues, as an empty table can result in a "no version found" error.

• If you have a separate "goose.go" file, build it into a binary and copy both the binary and the migration folder to the project root on the server. Here's an example of building the "goose.go" file into a binary:

    go build -o do_migration ./migrations/goose.go

  Using the example above, you can run the migration with ./do_migration.

6. Configure Apache as a Reverse Proxy:

• Ensure that the Apache modules proxy and proxy_http are enabled:

  sudo a2enmod proxy
  sudo a2enmod proxy_http

• Configure your Apache virtual host to act as a reverse proxy. Edit your virtual host configuration file, typically located in /etc/apache2/sites-available/your-site.conf, and include the following:

  < VirtualHost *:80>
     ServerName yourdomain.com
  
     # Proxy requests to the Go binary
     ProxyPass /api http://127.0.0.1:8080
     ProxyPassReverse /api http://127.0.0.1:8080
  
     # Additional Apache configuration settings...
     < Directory /var/www/html>
          Options Indexes FollowSymLinks
          AllowOverride None
          Require all granted
      < /Directory>
  
      ErrorLog ${APACHE_LOG_DIR}/error.log
      CustomLog ${APACHE_LOG_DIR}/access.log combined
  < /VirtualHost>

• Restart Apache to apply the changes:

  sudo systemctl restart apache2

• If you are using a VPS with HaProxy, ensure proper port forwarding for port 80/443.

7. HTTPS / Certbot:

Implement HTTPS using Certbot for SSL/TLS certificates, as needed.

8. Testing:

You can now access your Golang API at http://domain.com/api. Ensure that everything is working as expected.

9. Common Problems:

• Golang Backend Responds with a 404 Error for Existing Endpoints and Contains Double Trailing Slashes //:
  • Check your Apache proxy configuration, making sure the ProxyPass directive doesn't have a trailing slash at the end, like http://localhost:8080/<-dont add '/' on the back.
• Apache's New Configuration Is Not Loaded After Modification:
  • Ensure you manually update the configurations for both HTTP and HTTPS if you've made changes. Certbot-generated configurations do not update automatically.

Your Golang API backend should now be successfully deployed on your Linux server and accessible via Apache's reverse proxy.