prober.go RawHistoryFolder

1// Package httpprober provides HTTP probing functionality for health checks.
2package httpprober
3
4import (
5	"context"
6	"crypto/tls"
7	"fmt"
8	"net/http"
9	"time"
10)
11
12// DefaultTimeout is the default timeout for HTTP probes.
13const DefaultTimeout = 5 * time.Second
14
15// Prober implements the HTTPProber interface for health checking.
16type Prober struct {
17	client  *http.Client
18	timeout time.Duration
19}
20
21// Option configures the Prober.
22type Option func(*Prober)
23
24// WithTimeout sets the probe timeout.
25func WithTimeout(timeout time.Duration) Option {
26	return func(p *Prober) {
27		p.timeout = timeout
28	}
29}
30
31// WithHTTPClient sets a custom HTTP client.
32func WithHTTPClient(client *http.Client) Option {
33	return func(p *Prober) {
34		p.client = client
35	}
36}
37
38// New creates a new HTTP prober.
39func New(opts ...Option) *Prober {
40	p := &Prober{
41		timeout: DefaultTimeout,
42	}
43
44	for _, opt := range opts {
45		opt(p)
46	}
47
48	if p.client == nil {
49		p.client = &http.Client{
50			Timeout: p.timeout,
51			Transport: &http.Transport{
52				// #nosec G402 - InsecureSkipVerify is intentional for health probing
53				// internal services that may use self-signed certificates.
54				// This prober only checks reachability, not data integrity.
55				TLSClientConfig: &tls.Config{
56					InsecureSkipVerify: true,
57				},
58				DisableKeepAlives: true,
59			},
60			// Don't follow redirects - we want to see the actual response
61			CheckRedirect: func(req *http.Request, via []*http.Request) error {
62				return http.ErrUseLastResponse
63			},
64		}
65	}
66
67	return p
68}
69
70// Probe sends an HTTP GET request and returns the status code and response time.
71func (p *Prober) Probe(ctx context.Context, url string) (int, int64, error) {
72	start := time.Now()
73
74	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
75	if err != nil {
76		return 0, 0, fmt.Errorf("failed to create request: %w", err)
77	}
78
79	// Set a reasonable user agent
80	req.Header.Set("User-Agent", "Gordon-HealthCheck/1.0")
81
82	resp, err := p.client.Do(req)
83	if err != nil {
84		elapsed := time.Since(start).Milliseconds()
85		return 0, elapsed, fmt.Errorf("request failed: %w", err)
86	}
87	defer resp.Body.Close()
88
89	elapsed := time.Since(start).Milliseconds()
90	return resp.StatusCode, elapsed, nil
91}