Added message_file option for custom msg in file (#47)

Added message_file option for custom msg in file

.travis.yml

@@ -17,7 +17,7 @@ jobs:
             -e "BUILD_JOB_NAME=test"
             -e "BUILD_NAME=$TRAVIS_BUILD_NUMBER"
             concourse-slack-alert-resource-travis:$TRAVIS_BUILD_NUMBER
-            /opt/resource/out
+            /opt/resource/out $PWD
 
 branches:
   only:

README.md

@@ -47,6 +47,7 @@ Sends a structured message to Slack based on the alert type.
 - `alert_type`: *Optional.* The type of alert to send to Slack. See [Alert Types](#alert-types). Defaults to `default`.
 - `channel`: *Optional.* Channel where this message is posted. Defaults to the `channel` setting in Source.
 - `message`: *Optional.* The status message at the top of the alert. Defaults to name of alert type.
+- `message_file`: *Optional.* File containing text which overrides `message`. If the file cannot be read, `message` will be used instead.
 - `color`: *Optional.* The color of the notification bar as a hexadecimal. Defaults to the icon color of the alert type.
 - `disable`: *Optional.* Disables the alert. Defaults to `false`.
 

concourse/resource.go

@@ -31,11 +31,12 @@ type InResponse struct {
 
 // OutParams are the parameters that can be configured for the out operation.
 type OutParams struct {
-	AlertType string `json:"alert_type"`
-	Message   string `json:"message"`
-	Color     string `json:"color"`
-	Disable   bool   `json:"disable"`
-	Channel   string `json:"channel"`
+	AlertType   string `json:"alert_type"`
+	Channel     string `json:"channel"`
+	Color       string `json:"color"`
+	Message     string `json:"message"`
+	MessageFile string `json:"message_file"`
+	Disable     bool   `json:"disable"`
 }
 
 // OutRequest is in the input for the out operation.

out/alert.go

@@ -4,12 +4,13 @@ import "github.com/arbourd/concourse-slack-alert-resource/concourse"
 
 // An Alert defines the notification that will be sent to Slack.
 type Alert struct {
-	Type     string
-	Channel  string
-	Color    string
-	IconURL  string
-	Message  string
-	Disabled bool
+	Type        string
+	Channel     string
+	Color       string
+	IconURL     string
+	Message     string
+	MessageFile string
+	Disabled    bool
 }
 
 // NewAlert constructs and returns an Alert.
@@ -81,6 +82,6 @@ func NewAlert(input *concourse.OutRequest) Alert {
 	if input.Params.Color != "" {
 		alert.Color = input.Params.Color
 	}
-
+	alert.MessageFile = input.Params.MessageFile
 	return alert
 }

out/main.go

@@ -4,19 +4,35 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
+	"path/filepath"
 	"strconv"
+	"strings"
 
 	"github.com/arbourd/concourse-slack-alert-resource/concourse"
 	"github.com/arbourd/concourse-slack-alert-resource/slack"
 )
 
-func buildMessage(alert Alert, m concourse.BuildMetadata) *slack.Message {
-	fallback := fmt.Sprintf("%s -- %s", fmt.Sprintf("%s: %s/%s/%s", alert.Message, m.PipelineName, m.JobName, m.BuildName), m.URL)
+func buildMessage(alert Alert, m concourse.BuildMetadata, path string) *slack.Message {
+	message := alert.Message
+
+	// Open and read message file if set
+	if alert.MessageFile != "" {
+		file := filepath.Join(path, alert.MessageFile)
+		f, err := ioutil.ReadFile(file)
+
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "error reading message_file: %v\nwill default to message instead\n", err)
+		} else {
+			message = strings.TrimSpace(string(f))
+		}
+	}
+
 	attachment := slack.Attachment{
-		Fallback:   fallback,
-		AuthorName: alert.Message,
+		Fallback:   fmt.Sprintf("%s -- %s", fmt.Sprintf("%s: %s/%s/%s", message, m.PipelineName, m.JobName, m.BuildName), m.URL),
+		AuthorName: message,
 		Color:      alert.Color,
 		Footer:     m.URL,
 		FooterIcon: alert.IconURL,
@@ -61,7 +77,7 @@ func previousBuildStatus(input *concourse.OutRequest, m concourse.BuildMetadata)
 	return previous.Status, nil
 }
 
-func out(input *concourse.OutRequest) (*concourse.OutResponse, error) {
+func out(input *concourse.OutRequest, path string) (*concourse.OutResponse, error) {
 	if input.Source.URL == "" {
 		return nil, errors.New("slack webhook url cannot be blank")
 	}
@@ -73,16 +89,16 @@ func out(input *concourse.OutRequest) (*concourse.OutResponse, error) {
 	if send && (alert.Type == "fixed" || alert.Type == "broke") {
 		status, err := previousBuildStatus(input, metadata)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("error getting last build status: %v", err)
 		}
 		send = (alert.Type == "fixed" && status != "succeeded") || (alert.Type == "broke" && status == "succeeded")
 	}
 
 	if send {
-		message := buildMessage(alert, metadata)
+		message := buildMessage(alert, metadata, path)
 		err := slack.Send(input.Source.URL, message)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("error sending slack message: %v", err)
 		}
 	}
 
@@ -98,19 +114,22 @@ func out(input *concourse.OutRequest) (*concourse.OutResponse, error) {
 }
 
 func main() {
+	// The first argument is the path to the build's sources.
+	path := os.Args[1]
+
 	var input *concourse.OutRequest
 	err := json.NewDecoder(os.Stdin).Decode(&input)
 	if err != nil {
-		log.Fatalln(err)
+		log.Fatalln(fmt.Errorf("error reading stdin: %v", err))
 	}
 
-	o, err := out(input)
+	o, err := out(input, path)
 	if err != nil {
 		log.Fatalln(err)
 	}
 
 	err = json.NewEncoder(os.Stdout).Encode(o)
 	if err != nil {
-		log.Fatalln(err)
+		log.Fatalln(fmt.Errorf("error writing stdout: %v", err))
 	}
 }

out/main_test.go

@@ -1,9 +1,11 @@
 package main
 
 import (
+	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"os"
+	"path/filepath"
 	"reflect"
 	"testing"
 
@@ -202,7 +204,7 @@ func TestOut(t *testing.T) {
 				os.Setenv(k, v)
 			}
 
-			got, err := out(c.outRequest)
+			got, err := out(c.outRequest, "")
 			if err != nil && !c.err {
 				t.Fatalf("unexpected error from out:\n\t(ERR): %s", err)
 			} else if err == nil && c.err {
@@ -261,6 +263,44 @@ func TestBuildMessage(t *testing.T) {
 				},
 				Channel: "general"},
 		},
+		"message file": {
+			alert: Alert{
+				Type:        "default",
+				Message:     "Testing",
+				MessageFile: "message_file",
+			},
+			want: &slack.Message{
+				Attachments: []slack.Attachment{
+					{
+						Fallback:   "message file: demo/test/1 -- https://ci.example.com/teams/main/pipelines/demo/jobs/test/builds/1",
+						AuthorName: "message file",
+						Fields: []slack.Field{
+							{Title: "Job", Value: "demo/test", Short: true},
+							{Title: "Build", Value: "1", Short: true},
+						},
+						Footer: "https://ci.example.com/teams/main/pipelines/demo/jobs/test/builds/1", FooterIcon: ""},
+				},
+			},
+		},
+		"message file failure": {
+			alert: Alert{
+				Type:        "default",
+				Message:     "Testing",
+				MessageFile: "bad file",
+			},
+			want: &slack.Message{
+				Attachments: []slack.Attachment{
+					{
+						Fallback:   "Testing: demo/test/1 -- https://ci.example.com/teams/main/pipelines/demo/jobs/test/builds/1",
+						AuthorName: "Testing",
+						Fields: []slack.Field{
+							{Title: "Job", Value: "demo/test", Short: true},
+							{Title: "Build", Value: "1", Short: true},
+						},
+						Footer: "https://ci.example.com/teams/main/pipelines/demo/jobs/test/builds/1", FooterIcon: ""},
+				},
+			},
+		},
 	}
 
 	metadata := concourse.BuildMetadata{
@@ -274,7 +314,21 @@ func TestBuildMessage(t *testing.T) {
 
 	for name, c := range cases {
 		t.Run(name, func(t *testing.T) {
-			got := buildMessage(c.alert, metadata)
+			path := ""
+			if c.alert.MessageFile != "" {
+				dir, err := ioutil.TempDir("", "example")
+				if err != nil {
+					t.Fatal(err)
+				}
+				path = dir
+
+				defer os.RemoveAll(dir)
+				if err := ioutil.WriteFile(filepath.Join(dir, "message_file"), []byte("message file"), 0666); err != nil {
+					t.Fatal(err)
+				}
+			}
+
+			got := buildMessage(c.alert, metadata, path)
 			if !reflect.DeepEqual(got, c.want) {
 				t.Fatalf("unexpected slack.Message value from buildSlackMessage:\n\t(GOT): %#v\n\t(WNT): %#v", got, c.want)
 			}