daemon: send slack notifications (#281)

Makefile

@@ -215,6 +215,8 @@ mocks:
 		./daemon/inertiad/project/deployment.go Deployer
 	counterfeiter -o ./daemon/inertiad/build/mocks/builder.go \
 		./daemon/inertiad/build/builder.go ContainerBuilder
+	counterfeiter -o ./daemon/inertiad/notifier/mocks/notifier.go \
+		./daemon/inertiad/notifier/notifier.go Notifier
 
 ## scripts: recompile script assets
 .PHONY: scripts

daemon/inertiad/notifier/notifier.go

@@ -0,0 +1,104 @@
+package notifier
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+)
+
+// Notifier manages notifications
+type Notifier interface {
+	Notify(string) error
+}
+
+// SlackNotifier represents slack notifications
+type SlackNotifier struct {
+	hookURL string
+}
+
+// NewNotifier creates a notifier with web hook url to slack channel
+func NewNotifier(webhook string) *SlackNotifier {
+	url := webhook
+
+	if webhook == "test" { // temporary for testing
+		url = "https://hooks.slack.com/services/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"
+	}
+	// os.Getenv("SLACK_URL")
+
+	n := &SlackNotifier{
+		hookURL: url,
+	}
+
+	return n
+}
+
+// Color is used to represent message color for different states (i.e success, fail)
+type Color string
+
+const (
+	// Green when build successful
+	Green Color = "good"
+	// Yellow ...
+	Yellow Color = "warning"
+	// Red when build unsuccessful
+	Red Color = "danger"
+)
+
+// NotifyOptions is used to configure formatting of notifications
+type NotifyOptions struct {
+	Color   Color
+	Warning bool
+}
+
+// MessageArray builds the json message to be posted to webhook
+type MessageArray struct {
+	Attachments []Message `json:"attachments"`
+}
+
+// Message builds the attachments content of Message
+type Message struct {
+	Text  string `json:"text"`
+	Color string `json:"color"`
+}
+
+// Notify sends the notification
+func (n *SlackNotifier) Notify(text string, options *NotifyOptions) error {
+	// check if url is empty
+	if n.hookURL == "" {
+		return nil
+	}
+
+	msg := MessageArray{
+		Attachments: []Message{
+			{
+				Text:  "*" + text + "*",
+				Color: colorToString(options.Color),
+			},
+		},
+	}
+	bytesRepresentation, err := json.Marshal(msg)
+	if err != nil {
+		return fmt.Errorf("failed to encode request: %s", err.Error())
+	}
+
+	resp, err := http.Post(n.hookURL, "application/json", bytes.NewBuffer(bytesRepresentation))
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	bodyString := string(body)
+
+	if resp.StatusCode < 200 || resp.StatusCode > 299 {
+		return errors.New("Http request rejected by Slack. Error: " + bodyString)
+	}
+
+	return nil
+}
+
+func colorToString(color Color) string {
+	return string(color)
+}

daemon/inertiad/project/deployment.go

@@ -19,6 +19,7 @@ import (
 	"github.com/ubclaunchpad/inertia/daemon/inertiad/containers"
 	"github.com/ubclaunchpad/inertia/daemon/inertiad/crypto"
 	"github.com/ubclaunchpad/inertia/daemon/inertiad/git"
+	"github.com/ubclaunchpad/inertia/daemon/inertiad/notifier"
 	gogit "gopkg.in/src-d/go-git.v4"
 	"gopkg.in/src-d/go-git.v4/plumbing/transport/ssh"
 )
@@ -182,12 +183,38 @@ func (d *Deployment) Deploy(
 		fmt.Fprintln(out, "Continuing...")
 	}
 
+	// Send build start slack notification
+	notification := notifier.NewNotifier("test")
+	notifyErr := notification.Notify("Build started", &notifier.NotifyOptions{
+		Color:   notifier.Green,
+		Warning: true,
+	})
+	if notifyErr != nil {
+		return func() error { return nil }, notifyErr
+	}
+
 	// Build project
 	deploy, err := d.builder.Build(strings.ToLower(d.buildType), *conf, cli, out)
 	if err != nil {
+		notifyErr = notification.Notify("Build error", &notifier.NotifyOptions{
+			Color:   notifier.Red,
+			Warning: true,
+		})
+		if notifyErr != nil {
+			fmt.Fprintln(out, notifyErr)
+		}
 		return func() error { return nil }, err
 	}
 
+	// Send build complete slack notification
+	notifyErr = notification.Notify("Build completed", &notifier.NotifyOptions{
+		Color:   "good",
+		Warning: true,
+	})
+	if notifyErr != nil {
+		return func() error { return nil }, notifyErr
+	}
+
 	// Deploy
 	return func() error {
 		d.active = true

daemon/inertiad/project/deployment_test.go

@@ -118,6 +118,7 @@ func TestGetStatusIntegration(t *testing.T) {
 		builder:   fakeBuilder,
 	}
 	status, err := deployment.GetStatus(cli)
+
 	assert.NoError(t, err)
 	assert.False(t, status.BuildContainerActive)
 	assert.Equal(t, "test", status.BuildType)