Deploying Go Application to DigitalOcean from MacOS: A Guide

Deploying a Go application to DigitalOcean from your local MacOS can be done using a combination of shell scripts and the go build command to compile your Go code. Here’s a step-by-step guide:

Prerequisites:
- A DigitalOcean account and an API token.
- DigitalOcean CLI (doctl) installed on your MacOS: Install it using Homebrew by running brew install doctl.
- SSH keys set up on your DigitalOcean account for secure access.
- Go installed on your MacOS.

Create a DigitalOcean Droplet:

First, you need to create a Droplet. You can do this through the DigitalOcean web interface, or using doctl:

doctl auth init  # Authenticate doctl with your API token
doctl compute droplet create my-go-app \
  --region nyc3 \
  --image ubuntu-20-04-x64 \
  --size s-1vcpu-1gb \
  --ssh-keys your_ssh_key_id \
  --wait

Replace your_ssh_key_id with your actual SSH key ID in DigitalOcean.

Write a MacOS Shell Script for Deployment:

Create a shell script named deploy.sh to handle the deployment process.

#!/bin/bash

set -e

# Variables
DO_DROPLET_IP="your_droplet_ip"   # Replace with the actual Droplet IP
SSH_USER="root"
GO_APP_NAME="my_go_app"
LOCAL_DIR="/path/to/your/go/app"  # Local directory containing your Go application
REMOTE_DIR="/opt/$GO_APP_NAME"

# Build the Go application
echo "Building the Go application..."
cd $LOCAL_DIR
GOOS=linux GOARCH=amd64 go build -o $GO_APP_NAME

# Copy files to the remote server
echo "Copying files to the remote server..."
scp $LOCAL_DIR/$GO_APP_NAME $SSH_USER@$DO_DROPLET_IP:/tmp/

# Remote commands to set up the application
echo "Setting up the application on the remote server..."
ssh $SSH_USER@$DO_DROPLET_IP << 'EOF'
  set -e
  
  GO_APP_NAME="my_go_app"
  REMOTE_DIR="/opt/$GO_APP_NAME"
  TMP_DIR="/tmp/$GO_APP_NAME"
  
  # Create the remote directory
  mkdir -p $REMOTE_DIR
  
  # Move the Go application to the remote directory
  mv /tmp/$GO_APP_NAME $REMOTE_DIR/
  
  # Make the Go application executable
  chmod +x $REMOTE_DIR/$GO_APP_NAME
  
  # Set up systemd service (for existence of init.d)
  cat << SERVICE > /etc/systemd/system/$GO_APP_NAME.service
  [Unit]
  Description=My Go App
  After=network.target

  [Service]
  ExecStart=$REMOTE_DIR/$GO_APP_NAME
  Restart=always
  User=root

  [Install]
  WantedBy=multi-user.target
  SERVICE

  # Enable and start the service
  systemctl enable $GO_APP_NAME
  systemctl start $GO_APP_NAME

  echo "Deployment is complete!"
EOF

Make Your Script Executable:
```
chmod +x deploy.sh
```
Run the Deployment Script:

Now, you can run your deployment script:
```
./deploy.sh
```

This script will:

Compile the Go application for a Linux environment (GOOS=linux GOARCH=amd64).
Copy the compiled binary to the DigitalOcean Droplet using scp.
SSH into the Droplet and move the binary to the desired directory.
Set up a systemd service to manage the Go application, enabling it to start on system boot and managing restart policies.

Make sure to replace placeholders (like your_droplet_ip, your_ssh_key_id, and /path/to/your/go/app) with your actual details for a smooth deployment process.

Deploying Go Application to DigitalOcean from MacOS: A Guide

Dive deeper: