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httpclient

About 235 words

Enforces HTTP client best practices including timeouts.

Category

Resources

What It Checks

This analyzer detects:

  • HTTP clients without timeouts
  • Use of http.DefaultClient (has no timeout)
  • Missing context in requests

Why It Matters

HTTP requests without timeouts can hang forever:

  • Slow servers cause goroutine leaks
  • Connection pool exhaustion
  • Service unresponsiveness

Examples

Bad: Default Client

func fetchData(url string) ([]byte, error) {
    // http.DefaultClient has no timeout!
    resp, err := http.Get(url)
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()
    return io.ReadAll(resp.Body)
}

Good: Custom Client with Timeout

var httpClient = &http.Client{
    Timeout: 30 * time.Second,
}

func fetchData(url string) ([]byte, error) {
    resp, err := httpClient.Get(url)
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()
    return io.ReadAll(resp.Body)
}

Good: Request with Context

func fetchData(ctx context.Context, url string) ([]byte, error) {
    req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
    if err != nil {
        return nil, err
    }

    resp, err := httpClient.Do(req)
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()
    return io.ReadAll(resp.Body)
}
var httpClient = &http.Client{
    Timeout: 30 * time.Second,
    Transport: &http.Transport{
        DialContext: (&net.Dialer{
            Timeout:   10 * time.Second,
            KeepAlive: 30 * time.Second,
        }).DialContext,
        MaxIdleConns:          100,
        MaxIdleConnsPerHost:   10,
        IdleConnTimeout:       90 * time.Second,
        TLSHandshakeTimeout:   10 * time.Second,
        ExpectContinueTimeout: 1 * time.Second,
    },
}

Configuration

# .golint-sl.yaml
analyzers:
  httpclient: true  # enabled by default

When to Disable

  • Internal tools where timeout isn't critical
  • Tests with mock servers
analyzers:
  httpclient: false