compute-engine

Deploy Go web app

This document explains how to create a web service using Nginx and Go to host it in Google Compute Engine.

Prerequisites

• Update the SO
• Install Go 1.21
• Install Nginx

sudo apt update && sudo apt upgrade -y
wget https://go.dev/dl/go1.21.11.linux-amd64.tar.gz && sudo tar -C /usr/local -xzf go1.21.11.linux-amd64.tar.gz
sudo apt-get install nginx -y

Verify that Go works:

export PATH=$PATH:/usr/local/go/bin
go version

Configure the web server

We only want Nginx to work as a proxy for our application, so we will disable the default server page, and create a new one. For this, we will modify /etc/nginx/sites-available/default and add the following:

server {
    listen 80;
    server_name "";
    access_log /var/log/nginx/webapp.access.log;
    location / {
        proxy_pass http://127.0.0.1:8080;
    }       
}

Enable the site configuration by creating a symlink to it in sites-enabled, and telling Nginx to reload:

cd /etc/nginx/sites-enabled
sudo ln -s ../sites-available/default
sudo /etc/init.d/nginx reload

Now the Nginx proxy is created but nothing is listening on http://127.0.0.1:8080. Upload webserver.go to the VM and run the Go web server:

cd ~/
export PATH=$PATH:/usr/local/go/bin
PORT=8080 go run webserver.go

Now the server should be available and working.

Available endpoints

Path	Description
/	Hostname, remote addr, user-agent, and GCP env vars (PROJECT_ID, ZONE, INSTANCE_ID)
/headers	All request headers as JSON
/env	All environment variables as JSON
/info	Live GCP instance metadata (hostname, zone, machine-type, id)
/healthz	Health check — returns {"status":"ok"}

Logs are emitted as structured JSON to stdout, compatible with Google Cloud Logging.

Automate startup

We’ve now accomplished what we set out to do. But what if the machine restarts? We need to configure the system to run the Go process on start-up. First let’s build the server and move it to a shared directory:

go build webserver.go
sudo mv webserver /usr/sbin/webserver
sudo chown root:root /usr/sbin/webserver

Create a systemd unit file at /etc/systemd/system/webserver.service:

[Unit]
Description=Go Web Server
After=network.target

[Service]
ExecStart=/usr/sbin/webserver
Restart=always
RestartSec=5
User=www-data
Environment=PORT=8080
StandardOutput=journal
StandardError=journal

[Install]
WantedBy=multi-user.target

Reload systemd, enable the service to start on boot, and start it now:

sudo systemctl daemon-reload
sudo systemctl enable webserver
sudo systemctl start webserver

Check the service status and logs:

sudo systemctl status webserver
sudo journalctl -u webserver -f

And that’s it. systemd handles restarts automatically and integrates with journald for log collection.