AdvancedProduction Go

Lab: production Go

Apply net/http, JSON handling, profiling, and build decisions to realistic scenarios.

Lab · optionalGoAdvanced10 min

Recommended first

Building and deploying

By the end of this lesson you will be able to:

Structure an HTTP handler correctly using the standard library
Spot JSON encoding and decoding pitfalls
Interpret a pprof profile to locate a bottleneck
Choose between static binary, Docker image, and CGO for deployment

Optional scenario lab. Production Go is a series of small decisions: how to register routes, what a JSON mismatch looks like, where to look first in a profile. Practice them here.

Scenarios: production Go

1.
You register a handler with http.HandleFunc("/users", handleUsers). A request arrives at /users/42. What does the default ServeMux do?
Routes to handleUsers because /users is a prefix matchReturns 404 — there is no exact match for /users/42Panics because the path has a trailing segmentRoutes to handleUsers only if it ends with a slash
2.
A struct field is declared as Name string (no json tag). What key appears in the JSON output of json.Marshal?
nameNamename_fieldThe field is omitted entirely
3.
A Go CPU profile showing one function consuming 80% of the samples is a reliable signal to optimise that function first.
TrueFalse
4.
You need the smallest, most portable Linux binary — no shared library dependencies. Which build setting achieves this?
CGO_ENABLED=1 (the default)CGO_ENABLED=0 to produce a fully static binaryGOOS=linux GOARCH=armgo build -race
5.
You want to log every request's method, path, and duration without touching each individual handler. The right approach in net/http is:
Copy the logging code into every handlerWrap the root handler in a middleware function that records before and afterUse a global variable the handlers write toOverride the default ServeMux with a custom struct

The production-Go mindset: know your ServeMux's matching rules, keep your JSON tags explicit, profile before you optimise, and build statically by default.

Finished reading? Mark it complete to track your progress.

Building and deploying

Produce optimised Go binaries with build flags, cross-compile for any platform, create static binaries, build Docker images with multi-stage builds, and use go generate.