Merge pull request #9 from mittwald/feat/logging

feat: add option to log all executed requests

mittwaldv2/client_opt_logging.go

@@ -0,0 +1,21 @@
+package mittwaldv2
+
+import (
+	"context"
+	"log/slog"
+
+	"github.com/mittwald/api-client-go/pkg/httpclient"
+)
+
+// WithRequestLogging adds a logging middleware to the request runner chain
+// allowing you to log all executed HTTP requests in a slog.Logger of your
+// choice.
+//
+// Be mindful of the log{Request,Response}Bodies parameters; these will cause
+// the logger to print the full request bodies without redaction, which may
+// easily leak sensitive data.
+func WithRequestLogging(logger *slog.Logger, logRequestBodies, logResponseBodies bool) ClientOption {
+	return func(ctx context.Context, runner httpclient.RequestRunner) (httpclient.RequestRunner, error) {
+		return httpclient.NewLoggingClient(runner, logger, logRequestBodies, logResponseBodies), nil
+	}
+}

pkg/httpclient/client_logging.go

@@ -0,0 +1,59 @@
+package httpclient
+
+import (
+	"bytes"
+	"io"
+	"log/slog"
+	"net/http"
+)
+
+type loggingClient struct {
+	inner             RequestRunner
+	logger            *slog.Logger
+	logRequestBodies  bool
+	logResponseBodies bool
+}
+
+func NewLoggingClient(inner RequestRunner, logger *slog.Logger, logRequestBodies, logResponseBodies bool) RequestRunner {
+	return &loggingClient{
+		inner:             inner,
+		logger:            logger,
+		logRequestBodies:  logRequestBodies,
+		logResponseBodies: logResponseBodies,
+	}
+}
+
+func (c *loggingClient) Do(request *http.Request) (*http.Response, error) {
+	l := c.logger.With("req.method", request.Method, "req.url", request.URL.String())
+
+	if c.logRequestBodies && request.Body != nil {
+		body, err := io.ReadAll(request.Body)
+		if err != nil {
+			return nil, err
+		}
+
+		request.Body = io.NopCloser(bytes.NewBuffer(body))
+		l = l.With("req.body", string(body))
+	}
+
+	l.Debug("executing request")
+
+	response, err := c.inner.Do(request)
+
+	if response != nil {
+		l = l.With("res.status", response.StatusCode)
+		if c.logResponseBodies && response.Body != nil {
+			body, err := io.ReadAll(response.Body)
+			if err != nil {
+				return nil, err
+			}
+
+			response.Body = io.NopCloser(bytes.NewBuffer(body))
+			l = l.With("res.body", string(body))
+		}
+	}
+
+	l.Debug("received response")
+
+	return response, err
+}