1 files changed, 189 insertions, 0 deletions
diff --git a/src/go/collectors/go.d.plugin/modules/httpcheck/collect.go b/src/go/collectors/go.d.plugin/modules/httpcheck/collect.go
new file mode 100644
index 000000000..8d88dc02f
--- /dev/null
+++ b/src/go/collectors/go.d.plugin/modules/httpcheck/collect.go
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package httpcheck
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/netdata/netdata/go/go.d.plugin/pkg/stm"
+	"github.com/netdata/netdata/go/go.d.plugin/pkg/web"
+)
+
+type reqErrCode int
+
+const (
+	codeTimeout reqErrCode = iota
+	codeRedirect
+	codeNoConnection
+)
+
+func (hc *HTTPCheck) collect() (map[string]int64, error) {
+	req, err := web.NewHTTPRequest(hc.Request)
+	if err != nil {
+		return nil, fmt.Errorf("error on creating HTTP requests to %s : %v", hc.Request.URL, err)
+	}
+
+	if hc.CookieFile != "" {
+		if err := hc.readCookieFile(); err != nil {
+			return nil, fmt.Errorf("error on reading cookie file '%s': %v", hc.CookieFile, err)
+		}
+	}
+
+	start := time.Now()
+	resp, err := hc.httpClient.Do(req)
+	dur := time.Since(start)
+
+	defer closeBody(resp)
+
+	var mx metrics
+
+	if hc.isError(err, resp) {
+		hc.Debug(err)
+		hc.collectErrResponse(&mx, err)
+	} else {
+		mx.ResponseTime = durationToMs(dur)
+		hc.collectOKResponse(&mx, resp)
+	}
+
+	if hc.metrics.Status != mx.Status {
+		mx.InState = hc.UpdateEvery
+	} else {
+		mx.InState = hc.metrics.InState + hc.UpdateEvery
+	}
+	hc.metrics = mx
+
+	return stm.ToMap(mx), nil
+}
+
+func (hc *HTTPCheck) isError(err error, resp *http.Response) bool {
+	return err != nil && !(errors.Is(err, web.ErrRedirectAttempted) && hc.acceptedStatuses[resp.StatusCode])
+}
+
+func (hc *HTTPCheck) collectErrResponse(mx *metrics, err error) {
+	switch code := decodeReqError(err); code {
+	case codeNoConnection:
+		mx.Status.NoConnection = true
+	case codeTimeout:
+		mx.Status.Timeout = true
+	case codeRedirect:
+		mx.Status.Redirect = true
+	default:
+		panic(fmt.Sprintf("unknown request error code : %d", code))
+	}
+}
+
+func (hc *HTTPCheck) collectOKResponse(mx *metrics, resp *http.Response) {
+	hc.Debugf("endpoint '%s' returned %d (%s) HTTP status code", hc.URL, resp.StatusCode, resp.Status)
+
+	if !hc.acceptedStatuses[resp.StatusCode] {
+		mx.Status.BadStatusCode = true
+		return
+	}
+
+	bs, err := io.ReadAll(resp.Body)
+	// golang net/http closes body on redirect
+	if err != nil && !errors.Is(err, io.EOF) && !strings.Contains(err.Error(), "read on closed response body") {
+		hc.Warningf("error on reading body : %v", err)
+		mx.Status.BadContent = true
+		return
+	}
+
+	mx.ResponseLength = len(bs)
+
+	if hc.reResponse != nil && !hc.reResponse.Match(bs) {
+		mx.Status.BadContent = true
+		return
+	}
+
+	if ok := hc.checkHeader(resp); !ok {
+		mx.Status.BadHeader = true
+		return
+	}
+
+	mx.Status.Success = true
+}
+
+func (hc *HTTPCheck) checkHeader(resp *http.Response) bool {
+	for _, m := range hc.headerMatch {
+		value := resp.Header.Get(m.key)
+
+		var ok bool
+		switch {
+		case value == "":
+			ok = m.exclude
+		case m.valMatcher == nil:
+			ok = !m.exclude
+		default:
+			ok = m.valMatcher.MatchString(value)
+		}
+
+		if !ok {
+			hc.Debugf("header match: bad header: exlude '%v' key '%s' value '%s'", m.exclude, m.key, value)
+			return false
+		}
+	}
+
+	return true
+}
+
+func decodeReqError(err error) reqErrCode {
+	if err == nil {
+		panic("nil error")
+	}
+
+	if errors.Is(err, web.ErrRedirectAttempted) {
+		return codeRedirect
+	}
+	var v net.Error
+	if errors.As(err, &v) && v.Timeout() {
+		return codeTimeout
+	}
+	return codeNoConnection
+}
+
+func (hc *HTTPCheck) readCookieFile() error {
+	if hc.CookieFile == "" {
+		return nil
+	}
+
+	fi, err := os.Stat(hc.CookieFile)
+	if err != nil {
+		return err
+	}
+
+	if hc.cookieFileModTime.Equal(fi.ModTime()) {
+		hc.Debugf("cookie file '%s' modification time has not changed, using previously read data", hc.CookieFile)
+		return nil
+	}
+
+	hc.Debugf("reading cookie file '%s'", hc.CookieFile)
+
+	jar, err := loadCookieJar(hc.CookieFile)
+	if err != nil {
+		return err
+	}
+
+	hc.httpClient.Jar = jar
+	hc.cookieFileModTime = fi.ModTime()
+
+	return nil
+}
+
+func closeBody(resp *http.Response) {
+	if resp == nil || resp.Body == nil {
+		return
+	}
+	_, _ = io.Copy(io.Discard, resp.Body)
+	_ = resp.Body.Close()
+}
+
+func durationToMs(duration time.Duration) int {
+	return int(duration) / (int(time.Millisecond) / int(time.Nanosecond))
+}