Merge pull request #74 from gigaroby/sentry-hook

Added sentry hook

.travis.yml

@@ -7,3 +7,4 @@ install:
   - go get github.com/stretchr/testify
   - go get github.com/stvp/go-udp-testing
   - go get github.com/tobi/airbrake-go
+  - go get github.com/getsentry/raven-go

hooks/sentry/README.md

@@ -0,0 +1,61 @@
+# Sentry Hook for Logrus <img src="http://i.imgur.com/hTeVwmJ.png" width="40" height="40" alt=":walrus:" class="emoji" title=":walrus:" />
+
+[Sentry](https://getsentry.com) provides both self-hosted and hosted
+solutions for exception tracking.
+Both client and server are
+[open source](https://github.com/getsentry/sentry).
+
+## Usage
+
+Every sentry application defined on the server gets a different
+[DSN](https://www.getsentry.com/docs/). In the example below replace
+`YOUR_DSN` with the one created for your application.
+
+```go
+import (
+  "github.com/Sirupsen/logrus"
+  "github.com/Sirupsen/logrus/hooks/sentry"
+)
+
+func main() {
+  log       := logrus.New()
+  hook, err := logrus_sentry.NewSentryHook(YOUR_DSN, []logrus.Level{
+    logrus.PanicLevel,
+    logrus.FatalLevel,
+    logrus.ErrorLevel,
+  })
+
+  if err == nil {
+    log.Hooks.Add(hook)
+  }
+}
+```
+
+## Special fields
+
+Some logrus fields have a special meaning in this hook,
+these are server_name and logger.
+When logs are sent to sentry these fields are treated differently.
+- server_name (also known as hostname) is the name of the server which
+is logging the event (hostname.example.com)
+- logger is the part of the application which is logging the event.
+In go this usually means setting it to the name of the package.
+
+## Timeout
+
+`Timeout` is the time the sentry hook will wait for a response
+from the sentry server.
+
+If this time elapses with no response from
+the server an error will be returned.
+
+If `Timeout` is set to 0 the SentryHook will not wait for a reply
+and will assume a correct delivery.
+
+The SentryHook has a default timeout of `100 milliseconds` when created
+with a call to `NewSentryHook`. This can be changed by assigning a value to the `Timeout` field:
+
+```go
+hook, _ := logrus_sentry.NewSentryHook(...)
+hook.Timeout = 20*time.Seconds
+```

hooks/sentry/sentry.go

@@ -0,0 +1,100 @@
+package logrus_sentry
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/getsentry/raven-go"
+)
+
+var (
+	severityMap = map[logrus.Level]raven.Severity{
+		logrus.DebugLevel: raven.DEBUG,
+		logrus.InfoLevel:  raven.INFO,
+		logrus.WarnLevel:  raven.WARNING,
+		logrus.ErrorLevel: raven.ERROR,
+		logrus.FatalLevel: raven.FATAL,
+		logrus.PanicLevel: raven.FATAL,
+	}
+)
+
+func getAndDel(d logrus.Fields, key string) (string, bool) {
+	var (
+		ok  bool
+		v   interface{}
+		val string
+	)
+	if v, ok = d[key]; !ok {
+		return "", false
+	}
+
+	if val, ok = v.(string); !ok {
+		return "", false
+	}
+	delete(d, key)
+	return val, true
+}
+
+// SentryHook delivers logs to a sentry server.
+type SentryHook struct {
+	// Timeout sets the time to wait for a delivery error from the sentry server.
+	// If this is set to zero the server will not wait for any response and will
+	// consider the message correctly sent
+	Timeout time.Duration
+
+	client *raven.Client
+	levels []logrus.Level
+}
+
+// NewSentryHook creates a hook to be added to an instance of logger
+// and initializes the raven client.
+// This method sets the timeout to 100 milliseconds.
+func NewSentryHook(DSN string, levels []logrus.Level) (*SentryHook, error) {
+	client, err := raven.NewClient(DSN, nil)
+	if err != nil {
+		return nil, err
+	}
+	return &SentryHook{100 * time.Millisecond, client, levels}, nil
+}
+
+// Called when an event should be sent to sentry
+// Special fields that sentry uses to give more information to the server
+// are extracted from entry.Data (if they are found)
+// These fields are: logger and server_name
+func (hook *SentryHook) Fire(entry *logrus.Entry) error {
+	packet := &raven.Packet{
+		Message:   entry.Message,
+		Timestamp: raven.Timestamp(entry.Time),
+		Level:     severityMap[entry.Level],
+		Platform:  "go",
+	}
+
+	d := entry.Data
+
+	if logger, ok := getAndDel(d, "logger"); ok {
+		packet.Logger = logger
+	}
+	if serverName, ok := getAndDel(d, "server_name"); ok {
+		packet.ServerName = serverName
+	}
+	packet.Extra = map[string]interface{}(d)
+
+	_, errCh := hook.client.Capture(packet, nil)
+	timeout := hook.Timeout
+	if timeout != 0 {
+		timeoutCh := time.After(timeout)
+		select {
+		case err := <-errCh:
+			return err
+		case <-timeoutCh:
+			return fmt.Errorf("no response from sentry server in %s", timeout)
+		}
+	}
+	return nil
+}
+
+// Levels returns the available logging levels.
+func (hook *SentryHook) Levels() []logrus.Level {
+	return hook.levels
+}

hooks/sentry/sentry_test.go

@@ -0,0 +1,97 @@
+package logrus_sentry
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/getsentry/raven-go"
+)
+
+const (
+	message     = "error message"
+	server_name = "testserver.internal"
+	logger_name = "test.logger"
+)
+
+func getTestLogger() *logrus.Logger {
+	l := logrus.New()
+	l.Out = ioutil.Discard
+	return l
+}
+
+func WithTestDSN(t *testing.T, tf func(string, <-chan *raven.Packet)) {
+	pch := make(chan *raven.Packet, 1)
+	s := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+		defer req.Body.Close()
+		d := json.NewDecoder(req.Body)
+		p := &raven.Packet{}
+		err := d.Decode(p)
+		if err != nil {
+			t.Fatal(err.Error())
+		}
+
+		pch <- p
+	}))
+	defer s.Close()
+
+	fragments := strings.SplitN(s.URL, "://", 2)
+	dsn := fmt.Sprintf(
+		"%s://public:secret@%s/sentry/project-id",
+		fragments[0],
+		fragments[1],
+	)
+	tf(dsn, pch)
+}
+
+func TestSpecialFields(t *testing.T) {
+	WithTestDSN(t, func(dsn string, pch <-chan *raven.Packet) {
+		logger := getTestLogger()
+
+		hook, err := NewSentryHook(dsn, []logrus.Level{
+			logrus.ErrorLevel,
+		})
+
+		if err != nil {
+			t.Fatal(err.Error())
+		}
+		logger.Hooks.Add(hook)
+		logger.WithFields(logrus.Fields{
+			"server_name": server_name,
+			"logger":      logger_name,
+		}).Error(message)
+
+		packet := <-pch
+		if packet.Logger != logger_name {
+			t.Errorf("logger should have been %s, was %s", logger_name, packet.Logger)
+		}
+
+		if packet.ServerName != server_name {
+			t.Errorf("server_name should have been %s, was %s", server_name, packet.ServerName)
+		}
+	})
+}
+
+func TestSentryHandler(t *testing.T) {
+	WithTestDSN(t, func(dsn string, pch <-chan *raven.Packet) {
+		logger := getTestLogger()
+		hook, err := NewSentryHook(dsn, []logrus.Level{
+			logrus.ErrorLevel,
+		})
+		if err != nil {
+			t.Fatal(err.Error())
+		}
+		logger.Hooks.Add(hook)
+
+		logger.Error(message)
+		packet := <-pch
+		if packet.Message != message {
+			t.Errorf("message should have been %s, was %s", message, packet.Message)
+		}
+	})
+}