Initial structure

internal/checks/http.go

@@ -0,0 +1,62 @@
+package checks
+
+import (
+	"context"
+	"crypto/tls"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/jasper/quptime/internal/config"
+)
+
+// maxBodyRead is the cap on how much body a check will pull when
+// BodyMatch is non-empty. Anything beyond is ignored.
+const maxBodyRead = 1 << 20 // 1 MiB
+
+type httpProber struct{}
+
+func (httpProber) Probe(ctx context.Context, c *config.Check) Result {
+	client := &http.Client{
+		Timeout: c.Timeout,
+		Transport: &http.Transport{
+			TLSClientConfig: &tls.Config{MinVersion: tls.VersionTLS12},
+		},
+	}
+	start := time.Now()
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, c.Target, nil)
+	if err != nil {
+		return Result{OK: false, Detail: "build request: " + err.Error()}
+	}
+	req.Header.Set("User-Agent", "quptime/1.0")
+	resp, err := client.Do(req)
+	if err != nil {
+		return Result{OK: false, Detail: err.Error(), Latency: time.Since(start)}
+	}
+	defer resp.Body.Close()
+
+	expected := c.ExpectStatus
+	if expected == 0 {
+		expected = 200
+	}
+	if resp.StatusCode != expected {
+		return Result{
+			OK:      false,
+			Detail:  "status " + resp.Status,
+			Latency: time.Since(start),
+		}
+	}
+
+	if c.BodyMatch != "" {
+		body, err := io.ReadAll(io.LimitReader(resp.Body, maxBodyRead))
+		if err != nil {
+			return Result{OK: false, Detail: "read body: " + err.Error(), Latency: time.Since(start)}
+		}
+		if !strings.Contains(string(body), c.BodyMatch) {
+			return Result{OK: false, Detail: "body match miss", Latency: time.Since(start)}
+		}
+	}
+
+	return Result{OK: true, Latency: time.Since(start)}
+}