Test — Module 18: Build, Tooling, and Deployment¶

Topic: [[go]] Module: [[go/18. Build, Tooling, and Deployment]]

Before You Begin¶

[!WARNING] Do not look at ANSWERS.md or your notes during the test. The purpose of this test is to surface what you truly know vs. what you think you know. An inflated score is worthless. An honest score shows you exactly where to focus next.

Instructions: 1. Close all notes, the module README, and any reference materials. 2. Set a timer. Note your start time below. 3. Attempt every question — partial credit exists. 4. After finishing, grade yourself using ANSWERS.md. 5. Record your score in the Grading Record at the bottom.

Start time: ___________ End time: ___________ Total time: ___________

Scoring Table¶

Passing score: 15/22 (68%)  ·  Target score: 18/22 (82%)

Section 1: Recall (5 questions × 1 pt = 5 pts)¶

Quick recall questions. Answer from memory in 1–3 sentences each.

1.1 What does the -ldflags "-X pkg.Var=value" flag do, and what type must Var be for this to work?

Your answer:

1.2 What environment variables do you set to cross-compile a Go binary for Linux on a macOS machine?

Your answer:

1.3 What does CGO_ENABLED=0 do, and why is it necessary when building a Go binary for a FROM scratch Docker container?

Your answer:

1.4 What Go command do you run to check for known security vulnerabilities in your module's dependencies?

Your answer:

1.5 In a multi-stage Dockerfile for a Go service, why should you copy go.mod and go.sum and run go mod download before copying the rest of the source code?

Your answer:

Section 2: Conceptual Understanding (3 questions × 2 pts = 6 pts)¶

Demonstrate that you understand the "why", not just the "what".

2.1 Explain what a build constraint (//go:build) is and give two concrete use cases where you would use one. Explain how file name conventions (e.g., signal_linux.go) relate to build constraints.

Your answer:

2.2 Describe the purpose of go.sum in the Go module system. What attack does it prevent? What is the role of the checksum database (sum.golang.org) in this security model?

Your answer:

2.3 Explain the difference between go vet, staticcheck, and golangci-lint. When would you use each? Why is running all three in CI better than running just one?

Your answer:

Section 3: Applied / Practical (2 questions × 3 pts = 6 pts)¶

Show that you can use your knowledge to solve real problems.

3.1 Write the go build command(s) that produce a release binary for Linux/amd64 with the following properties: - Fully static (no shared library dependencies) - Debug symbols stripped - Version variable github.com/acme/myapp/internal/version.Version set to v2.1.0 - Commit variable github.com/acme/myapp/internal/version.Commit set to the current git commit hash (show the shell substitution) - Output binary named myapp-linux-amd64

Your answer:

3.2 Write a GitHub Actions workflow job named test that: - Triggers as part of a workflow that runs on push to main and on pull_request - Checks out code with actions/checkout@v4 - Sets up Go 1.22 with module caching enabled - Runs go test -race -coverprofile=coverage.out ./...

Include the full YAML for just this job (not the full workflow file).

Your answer:

Section 4: Scenario / Debugging (1 question × 3 pts = 3 pts)¶

Analyze a realistic scenario and identify what's wrong or what should be done.

4.1 A developer reports the following:

"I built our Go service on my Mac and it ran fine locally. I built it again with GOOS=linux GOARCH=amd64 go build -o server . and pushed the server binary into our FROM scratch Docker image. When the container starts, it crashes immediately with: standard_init_linux.go:228: exec user process caused: no such file or directory"

Identify:

a) What is the root cause of this error?

b) What single environment variable was missing from the go build command?

c) How would you verify that the fix worked before pushing to the container registry?

d) The developer also mentions their service makes outbound HTTPS calls to a third-party API. They switch to FROM scratch but now the HTTPS calls fail with certificate errors. What is missing and how do you fix it?

Your answer:

Section 5: Essay / Discussion (1 question × 2 pts = 2 pts)¶

Open-ended. There is more than one good answer. Show your reasoning.

5.1 "A CI pipeline for a Go service should run at least three separate jobs: one for tests, one for linting, and one for building." Explain why separating these into three jobs (rather than one sequential job) is better practice. Consider: parallelism, failure isolation, feedback speed, and what each job's failure tells you about the codebase.

Your answer (aim for 3–6 sentences):

Section 6: Bonus Challenge (1 question × +5 pts)¶

[!NOTE] This question is optional. It will not count against you if you skip it or get it wrong. Only attempt it after completing Sections 1–5.

6.1 Write a complete .goreleaser.yml configuration file for a Go project at github.com/acme/myapp that: - Builds for linux/amd64, linux/arm64, darwin/amd64, darwin/arm64, and windows/amd64 - Disables CGO for all builds - Stamps Version, Commit, and BuildDate into github.com/acme/myapp/internal/version variables - Strips symbols (-s -w) - Produces .tar.gz archives (.zip for Windows) - Generates a checksums.txt file - Runs go mod tidy as a pre-hook

Explain in a comment or annotation what command you would run to test this configuration locally without publishing a release.

Your answer:

Self-Assessment¶

After grading your test, answer these questions honestly:

What did I get right and why?

Your reflection:

What did I get wrong and why did I make that mistake?

Your reflection:

What should I review before moving to the capstone project?

Your reflection:

What score did I get? Do I feel it accurately reflects my understanding?

Your reflection:

Grading Record¶

Append a new row each time you take this test. Do not overwrite previous attempts.

Grade scale: A ≥ 90% (≥20/22)  ·  B ≥ 80% (≥18/22)  ·  C ≥ 70% (≥15/22)  ·  D ≥ 60% (≥13/22)  ·  F < 60%

See ANSWERS.md for the answer key. Review it only after completing the test.