Deploying Go Applications

Learn deploying go applications through an executable example, then connect the small demonstration to production code.

Deployment moves a compiled and configured program into an environment that can run and operate it. Prepare health checks, environment configuration, database migration plans, release verification and rollback.

The example models a health endpoint using httptest, so it runs without cloud credentials or an open port.

Follow this diagram before executing the example. Check where a value or decision changes what runs next.

Typical workflow: run tests and scans; build a versioned artifact; apply compatible changes; deploy gradually; observe health and error rates; roll back when needed. Keep secrets outside source control.

This example is a complete program. Save it as main.go or paste it into the Go Playground.

Go code

package main

import (
	"fmt"
	"net/http"
	"net/http/httptest"
)

func main() {
	mux := http.NewServeMux()
	mux.HandleFunc("GET /healthz", func(w http.ResponseWriter, r *http.Request) { fmt.Fprint(w, "ok") })
	recorder := httptest.NewRecorder()
	mux.ServeHTTP(recorder, httptest.NewRequest("GET", "/healthz", nil))
	fmt.Println("Health status:", recorder.Code, "Body:", recorder.Body.String())
}

Output

Health status: 200 Body: ok

The router matches GET /healthz and responds with status 200 and body ok. A production readiness endpoint may also need to check whether essential dependencies are ready.

• Liveness and readiness checks can have different responsibilities.
• Deploying a new binary must not silently skip database compatibility and rollback planning.

Add a readiness endpoint that returns 503 until an initialization flag becomes true.

Tip: Edit the example above, predict the output, and run the modified code to test your reasoning.

You have practiced Deploying Go Applications in a small, self-contained program. The important habit is to predict what runs, inspect the actual output and distinguish the language rule from the particular example.

Before continuing, make sure you can explain the program to someone who has not seen it, including the line that changes its result.