Merge pull request #10 from filippog/template-functions

Introduce template functions

format.go

@@ -0,0 +1,80 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"log"
+	"strings"
+	"text/template"
+
+	promtmpl "github.com/prometheus/alertmanager/template"
+)
+
+type Formatter struct {
+	MsgTemplate *template.Template
+	MsgOnce     bool
+}
+
+func NewFormatter(config *Config) (*Formatter, error) {
+	funcMap := template.FuncMap{
+		"ToUpper": strings.ToUpper,
+		"ToLower": strings.ToLower,
+		"Join":    strings.Join,
+	}
+
+	tmpl, err := template.New("msg").Funcs(funcMap).Parse(config.MsgTemplate)
+	if err != nil {
+		return nil, err
+	}
+	return &Formatter{
+		MsgTemplate: tmpl,
+		MsgOnce:     config.MsgOnce,
+	}, nil
+}
+
+func (f *Formatter) FormatMsg(ircChannel string, data interface{}) string {
+	output := bytes.Buffer{}
+	var msg string
+	if err := f.MsgTemplate.Execute(&output, data); err != nil {
+		msg_bytes, _ := json.Marshal(data)
+		msg = string(msg_bytes)
+		log.Printf("Could not apply msg template on alert (%s): %s",
+			err, msg)
+		log.Printf("Sending raw alert")
+		alertHandlingErrors.WithLabelValues(ircChannel, "format_msg").Inc()
+	} else {
+		msg = output.String()
+	}
+	return msg
+}
+
+func (f *Formatter) GetMsgsFromAlertMessage(ircChannel string,
+	data *promtmpl.Data) []AlertMsg {
+	msgs := []AlertMsg{}
+	if f.MsgOnce {
+		msg := f.FormatMsg(ircChannel, data)
+		msgs = append(msgs,
+			AlertMsg{Channel: ircChannel, Alert: msg})
+	} else {
+		for _, alert := range data.Alerts {
+			msg := f.FormatMsg(ircChannel, alert)
+			msgs = append(msgs,
+				AlertMsg{Channel: ircChannel, Alert: msg})
+		}
+	}
+	return msgs
+}

format_test.go

@@ -0,0 +1,114 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"reflect"
+	"testing"
+
+	promtmpl "github.com/prometheus/alertmanager/template"
+)
+
+func TestTemplateErrorsCreateRawAlertMsg(t *testing.T) {
+	testingConfig := Config{MsgTemplate: "Bogus template {{ nil }}"}
+	formatter, _ := NewFormatter(&testingConfig)
+
+	expectedAlertMsgs := []AlertMsg{
+		AlertMsg{
+			Channel: "#somechannel",
+			Alert:   `{"status":"resolved","labels":{"alertname":"airDown","instance":"instance1:3456","job":"air","service":"prometheus","severity":"ticket","zone":"global"},"annotations":{"DESCRIPTION":"service /prometheus has irc gateway down on instance1","SUMMARY":"service /prometheus air down on instance1"},"startsAt":"2017-05-15T13:49:37.834Z","endsAt":"2017-05-15T13:50:37.835Z","generatorURL":"https://prometheus.example.com/prometheus/...","fingerprint":"66214a361160fb6f"}`,
+		},
+		AlertMsg{
+			Channel: "#somechannel",
+			Alert:   `{"status":"resolved","labels":{"alertname":"airDown","instance":"instance2:7890","job":"air","service":"prometheus","severity":"ticket","zone":"global"},"annotations":{"DESCRIPTION":"service /prometheus has irc gateway down on instance2","SUMMARY":"service /prometheus air down on instance2"},"startsAt":"2017-05-15T11:47:37.834Z","endsAt":"2017-05-15T11:48:37.834Z","generatorURL":"https://prometheus.example.com/prometheus/...","fingerprint":"25a874c99325d1ce"}`,
+		},
+	}
+
+	var alertMessage = promtmpl.Data{}
+	if err := json.Unmarshal([]byte(testdataSimpleAlertJson), &alertMessage); err != nil {
+		t.Fatal(fmt.Sprintf("Could not unmarshal %s", testdataSimpleAlertJson))
+	}
+
+	alertMsgs := formatter.GetMsgsFromAlertMessage("#somechannel", &alertMessage)
+
+	if !reflect.DeepEqual(expectedAlertMsgs, alertMsgs) {
+		t.Error(fmt.Sprintf(
+			"Unexpected alert msg.\nExpected: %s\nActual: %s",
+			expectedAlertMsgs, alertMsgs))
+
+	}
+
+}
+
+func TestAlertsDispatchedOnce(t *testing.T) {
+	testingConfig := Config{
+		MsgTemplate: "Alert {{ .GroupLabels.alertname }} is {{ .Status }}",
+		MsgOnce:     true,
+	}
+	formatter, _ := NewFormatter(&testingConfig)
+
+	expectedAlertMsgs := []AlertMsg{
+		AlertMsg{
+			Channel: "#somechannel",
+			Alert:   "Alert airDown is resolved",
+		},
+	}
+
+	var alertMessage = promtmpl.Data{}
+	if err := json.Unmarshal([]byte(testdataSimpleAlertJson), &alertMessage); err != nil {
+		t.Fatal(fmt.Sprintf("Could not unmarshal %s", testdataSimpleAlertJson))
+	}
+
+	alertMsgs := formatter.GetMsgsFromAlertMessage("#somechannel", &alertMessage)
+
+	if !reflect.DeepEqual(expectedAlertMsgs, alertMsgs) {
+		t.Error(fmt.Sprintf(
+			"Unexpected alert msg.\nExpected: %s\nActual: %s",
+			expectedAlertMsgs, alertMsgs))
+
+	}
+}
+
+func TestStringsFunctions(t *testing.T) {
+	testingConfig := Config{
+		MsgTemplate: "Alert {{ .GroupLabels.alertname | ToUpper }} is {{ .Status }}",
+		MsgOnce:     true,
+	}
+	formatter, _ := NewFormatter(&testingConfig)
+
+	expectedAlertMsgs := []AlertMsg{
+		AlertMsg{
+			Channel: "#somechannel",
+			Alert:   "Alert AIRDOWN is resolved",
+		},
+	}
+
+	var alertMessage = promtmpl.Data{}
+	if err := json.Unmarshal([]byte(testdataSimpleAlertJson), &alertMessage); err != nil {
+		t.Fatal(fmt.Sprintf("Could not unmarshal %s", testdataSimpleAlertJson))
+	}
+
+	alertMsgs := formatter.GetMsgsFromAlertMessage("#somechannel", &alertMessage)
+
+	if !reflect.DeepEqual(expectedAlertMsgs, alertMsgs) {
+		t.Error(fmt.Sprintf(
+			"Unexpected alert msg.\nExpected: %s\nActual: %s",
+			expectedAlertMsgs, alertMsgs))
+
+	}
+
+}

http.go

@@ -15,7 +15,6 @@
 package main
 
 import (
-	"bytes"
 	"encoding/json"
 	"io"
 	"io/ioutil"
@@ -23,7 +22,6 @@ import (
 	"net/http"
 	"strconv"
 	"strings"
-	"text/template"
 
 	"github.com/gorilla/mux"
 	promtmpl "github.com/prometheus/alertmanager/template"
@@ -56,8 +54,7 @@ type HTTPServer struct {
 	StoppedRunning chan bool
 	Addr           string
 	Port           int
-	MsgTemplate    *template.Template
+	formatter      *Formatter
-	MsgOnce        bool
 	AlertMsgs      chan AlertMsg
 	httpListener   HTTPListener
 }
@@ -69,7 +66,7 @@ func NewHTTPServer(config *Config, alertMsgs chan AlertMsg) (
 
 func NewHTTPServerForTesting(config *Config, alertMsgs chan AlertMsg,
 	httpListener HTTPListener) (*HTTPServer, error) {
-	tmpl, err := template.New("msg").Parse(config.MsgTemplate)
+	formatter, err := NewFormatter(config)
 	if err != nil {
 		return nil, err
 	}
@@ -77,8 +74,7 @@ func NewHTTPServerForTesting(config *Config, alertMsgs chan AlertMsg,
 		StoppedRunning: make(chan bool),
 		Addr:           config.HTTPHost,
 		Port:           config.HTTPPort,
-		MsgTemplate:    tmpl,
+		formatter:      formatter,
-		MsgOnce:        config.MsgOnce,
 		AlertMsgs:      alertMsgs,
 		httpListener:   httpListener,
 	}
@@ -86,39 +82,6 @@ func NewHTTPServerForTesting(config *Config, alertMsgs chan AlertMsg,
 	return server, nil
 }
 
-func (server *HTTPServer) FormatMsg(ircChannel string, data interface{}) string {
-	output := bytes.Buffer{}
-	var msg string
-	if err := server.MsgTemplate.Execute(&output, data); err != nil {
-		msg_bytes, _ := json.Marshal(data)
-		msg = string(msg_bytes)
-		log.Printf("Could not apply msg template on alert (%s): %s",
-			err, msg)
-		log.Printf("Sending raw alert")
-		alertHandlingErrors.WithLabelValues(ircChannel, "format_msg").Inc()
-	} else {
-		msg = output.String()
-	}
-	return msg
-}
-
-func (server *HTTPServer) GetMsgsFromAlertMessage(ircChannel string,
-	data *promtmpl.Data) []AlertMsg {
-	msgs := []AlertMsg{}
-	if server.MsgOnce {
-		msg := server.FormatMsg(ircChannel, data)
-		msgs = append(msgs,
-			AlertMsg{Channel: ircChannel, Alert: msg})
-	} else {
-		for _, alert := range data.Alerts {
-			msg := server.FormatMsg(ircChannel, alert)
-			msgs = append(msgs,
-				AlertMsg{Channel: ircChannel, Alert: msg})
-		}
-	}
-	return msgs
-}
-
 func (server *HTTPServer) RelayAlert(w http.ResponseWriter, r *http.Request) {
 	vars := mux.Vars(r)
 	ircChannel := "#" + vars["IRCChannel"]
@@ -143,7 +106,7 @@ func (server *HTTPServer) RelayAlert(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	handledAlertGroups.WithLabelValues(ircChannel).Inc()
-	for _, alertMsg := range server.GetMsgsFromAlertMessage(
+	for _, alertMsg := range server.formatter.GetMsgsFromAlertMessage(
 		ircChannel, &alertMessage) {
 		select {
 		case server.AlertMsgs <- alertMsg:

http_test.go

@@ -116,39 +116,6 @@ func TestAlertsDispatched(t *testing.T) {
 	}
 }
 
-func TestAlertsDispatchedOnce(t *testing.T) {
-	listener := NewFakeHTTPListener()
-	testingConfig := MakeHTTPTestingConfig()
-	testingConfig.MsgOnce = true
-	testingConfig.MsgTemplate = "Alert {{ .GroupLabels.alertname }} is {{ .Status }}"
-
-	expectedAlertMsgs := []AlertMsg{
-		AlertMsg{
-			Channel: "#somechannel",
-			Alert:   "Alert airDown is resolved",
-		},
-	}
-	expectedStatusCode := 200
-
-	response := RunHTTPTest(
-		t, testdataSimpleAlertJson, "/somechannel",
-		testingConfig, listener)
-
-	if expectedStatusCode != response.StatusCode {
-		t.Error(fmt.Sprintf("Expected %d status in response, got %d",
-			expectedStatusCode, response.StatusCode))
-	}
-
-	for _, expectedAlertMsg := range expectedAlertMsgs {
-		alertMsg := <-listener.AlertMsgs
-		if !reflect.DeepEqual(expectedAlertMsg, alertMsg) {
-			t.Error(fmt.Sprintf(
-				"Unexpected alert msg.\nExpected: %s\nActual: %s",
-				expectedAlertMsg, alertMsg))
-		}
-	}
-}
-
 func TestRootReturnsError(t *testing.T) {
 	listener := NewFakeHTTPListener()
 	testingConfig := MakeHTTPTestingConfig()
@@ -180,39 +147,3 @@ func TestInvalidDataReturnsError(t *testing.T) {
 			expectedStatusCode, response.StatusCode))
 	}
 }
-
-func TestTemplateErrorsCreateRawAlertMsg(t *testing.T) {
-	listener := NewFakeHTTPListener()
-	testingConfig := MakeHTTPTestingConfig()
-	testingConfig.MsgTemplate = "Bogus template {{ nil }}"
-
-	expectedAlertMsgs := []AlertMsg{
-		AlertMsg{
-			Channel: "#somechannel",
-			Alert:   `{"status":"resolved","labels":{"alertname":"airDown","instance":"instance1:3456","job":"air","service":"prometheus","severity":"ticket","zone":"global"},"annotations":{"DESCRIPTION":"service /prometheus has irc gateway down on instance1","SUMMARY":"service /prometheus air down on instance1"},"startsAt":"2017-05-15T13:49:37.834Z","endsAt":"2017-05-15T13:50:37.835Z","generatorURL":"https://prometheus.example.com/prometheus/...","fingerprint":"66214a361160fb6f"}`,
-		},
-		AlertMsg{
-			Channel: "#somechannel",
-			Alert:   `{"status":"resolved","labels":{"alertname":"airDown","instance":"instance2:7890","job":"air","service":"prometheus","severity":"ticket","zone":"global"},"annotations":{"DESCRIPTION":"service /prometheus has irc gateway down on instance2","SUMMARY":"service /prometheus air down on instance2"},"startsAt":"2017-05-15T11:47:37.834Z","endsAt":"2017-05-15T11:48:37.834Z","generatorURL":"https://prometheus.example.com/prometheus/...","fingerprint":"25a874c99325d1ce"}`,
-		},
-	}
-	expectedStatusCode := 200
-
-	response := RunHTTPTest(
-		t, testdataSimpleAlertJson, "/somechannel",
-		testingConfig, listener)
-
-	if expectedStatusCode != response.StatusCode {
-		t.Error(fmt.Sprintf("Expected %d status in response, got %d",
-			expectedStatusCode, response.StatusCode))
-	}
-
-	for _, expectedAlertMsg := range expectedAlertMsgs {
-		alertMsg := <-listener.AlertMsgs
-		if !reflect.DeepEqual(expectedAlertMsg, alertMsg) {
-			t.Error(fmt.Sprintf(
-				"Unexpected alert msg.\nExpected: %s\nActual: %s",
-				expectedAlertMsg, alertMsg))
-		}
-	}
-}