An HTTP client that gives up in Go

A shared client with a timeout, and a request carrying a context.

var client = &http.Client{Timeout: 10 * time.Second}

func fetch(ctx context.Context, url string) (int, string, error) {
    request, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
    if err != nil {
        return 0, "", fmt.Errorf("build request: %w", err)
    }
    request.Header.Set("Accept", "application/json")

    response, err := client.Do(request)
    if err != nil {
        return 0, "", fmt.Errorf("get %s: %w", url, err)
    }
    defer response.Body.Close()

    body, err := io.ReadAll(io.LimitReader(response.Body, 1<<20))
    if err != nil {
        return response.StatusCode, "", fmt.Errorf("read body: %w", err)
    }
    return response.StatusCode, string(body), nil
}

How it works

1. Never use http.DefaultClient in production: it has no timeout.
2. NewRequestWithContext is what makes cancellation work.
3. Close the body, always, and drain it if you reuse the connection.

Keywords and builtins used here

• defer
• error
• func
• if
• int
• return
• string
• var

The run, in numbers

Lines

21

Characters to type

638

Tokens

175

Three-star pace

110 tpm

At the three-star pace of 110 tokens a minute, this run takes about 95 seconds.

Type this snippet

Step 5 of 5 in HTTP, step 20 of 26 in Standard library & project layout.

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