feat: announce: mattermost (#2536)

Signed-off-by: Carlos Panato <ctadeu@gmail.com>

internal/pipe/announce/announce.go

@@ -8,6 +8,7 @@ import (
 	"github.com/goreleaser/goreleaser/internal/middleware/logging"
 	"github.com/goreleaser/goreleaser/internal/middleware/skip"
 	"github.com/goreleaser/goreleaser/internal/pipe/discord"
+	"github.com/goreleaser/goreleaser/internal/pipe/mattermost"
 	"github.com/goreleaser/goreleaser/internal/pipe/reddit"
 	"github.com/goreleaser/goreleaser/internal/pipe/slack"
 	"github.com/goreleaser/goreleaser/internal/pipe/smtp"
@@ -27,6 +28,7 @@ type Announcer interface {
 var announcers = []Announcer{
 	// XXX: keep asc sorting
 	discord.Pipe{},
+	mattermost.Pipe{},
 	reddit.Pipe{},
 	slack.Pipe{},
 	smtp.Pipe{},

internal/pipe/mattermost/mattermost.go

@@ -0,0 +1,147 @@
+package mattermost
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/apex/log"
+	"github.com/caarlos0/env/v6"
+
+	"github.com/goreleaser/goreleaser/internal/tmpl"
+	"github.com/goreleaser/goreleaser/pkg/context"
+)
+
+const (
+	defaultColor           = "#2D313E"
+	defaultUsername        = `GoReleaser`
+	defaultMessageTemplate = `{{ .ProjectName }} {{ .Tag }} is out! Check it out at {{ .GitURL }}/releases/tag/{{ .Tag }}`
+	defaultMessageTitle    = `{{ .ProjectName }} {{ .Tag }} is out!`
+)
+
+type Pipe struct{}
+
+func (Pipe) String() string                 { return "mattermost" }
+func (Pipe) Skip(ctx *context.Context) bool { return !ctx.Config.Announce.Mattermost.Enabled }
+
+type Config struct {
+	Webhook string `env:"MATTERMOST_WEBHOOK,notEmpty"`
+}
+
+func (Pipe) Default(ctx *context.Context) error {
+	if ctx.Config.Announce.Mattermost.MessageTemplate == "" {
+		ctx.Config.Announce.Mattermost.MessageTemplate = defaultMessageTemplate
+	}
+	if ctx.Config.Announce.Mattermost.TitleTemplate == "" {
+		ctx.Config.Announce.Mattermost.TitleTemplate = defaultMessageTitle
+	}
+	if ctx.Config.Announce.Mattermost.Username == "" {
+		ctx.Config.Announce.Mattermost.Username = defaultUsername
+	}
+	if ctx.Config.Announce.Teams.Color == "" {
+		ctx.Config.Announce.Teams.Color = defaultColor
+	}
+
+	return nil
+}
+
+func (Pipe) Announce(ctx *context.Context) error {
+	msg, err := tmpl.New(ctx).Apply(ctx.Config.Announce.Mattermost.MessageTemplate)
+	if err != nil {
+		return fmt.Errorf("announce: failed to announce to mattermost: %w", err)
+	}
+
+	title, err := tmpl.New(ctx).Apply(ctx.Config.Announce.Mattermost.TitleTemplate)
+	if err != nil {
+		return fmt.Errorf("announce: failed to announce to teams: %w", err)
+	}
+
+	var cfg Config
+	if err := env.Parse(&cfg); err != nil {
+		return fmt.Errorf("announce: failed to announce to mattermost: %w", err)
+	}
+
+	log.Infof("posting: %q", msg)
+
+	wm := &incomingWebhookRequest{
+		Username:    ctx.Config.Announce.Mattermost.Username,
+		IconEmoji:   ctx.Config.Announce.Mattermost.IconEmoji,
+		IconURL:     ctx.Config.Announce.Mattermost.IconURL,
+		ChannelName: ctx.Config.Announce.Mattermost.Channel,
+		Attachments: []*mattermostAttachment{
+			{
+				Title: title,
+				Text:  msg,
+				Color: ctx.Config.Announce.Teams.Color,
+			},
+		},
+	}
+
+	err = postWebhook(ctx, cfg.Webhook, wm)
+	if err != nil {
+		return fmt.Errorf("announce: failed to announce to mattermost: %w", err)
+	}
+
+	return nil
+}
+
+func postWebhook(ctx *context.Context, url string, msg *incomingWebhookRequest) error {
+	payload, err := json.Marshal(msg)
+	if err != nil {
+		return fmt.Errorf("failed to marshal the message: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(payload))
+	if err != nil {
+		return fmt.Errorf("failed new request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	r, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("announce: failed to announce to mattermost: %w", err)
+	}
+	closeBody(r)
+
+	return nil
+}
+
+func closeBody(r *http.Response) {
+	if r.Body != nil {
+		_, _ = io.Copy(ioutil.Discard, r.Body)
+		_ = r.Body.Close()
+	}
+}
+
+type incomingWebhookRequest struct {
+	Text        string                  `json:"text"`
+	Username    string                  `json:"username"`
+	IconURL     string                  `json:"icon_url"`
+	ChannelName string                  `json:"channel"`
+	Attachments []*mattermostAttachment `json:"attachments"`
+	IconEmoji   string                  `json:"icon_emoji"`
+}
+
+type mattermostAttachment struct {
+	Fallback   string                       `json:"fallback"`
+	Color      string                       `json:"color"`
+	Pretext    string                       `json:"pretext"`
+	AuthorName string                       `json:"author_name"`
+	AuthorLink string                       `json:"author_link"`
+	AuthorIcon string                       `json:"author_icon"`
+	Title      string                       `json:"title"`
+	TitleLink  string                       `json:"title_link"`
+	Text       string                       `json:"text"`
+	Fields     []*mattermostAttachmentField `json:"fields"`
+	Footer     string                       `json:"footer"`
+	FooterIcon string                       `json:"footer_icon"`
+}
+
+type mattermostAttachmentField struct {
+	Title string      `json:"title"`
+	Value interface{} `json:"value"`
+	Short bool        `json:"short"`
+}

internal/pipe/mattermost/mattermost_test.go

@@ -0,0 +1,99 @@
+package mattermost
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/goreleaser/goreleaser/pkg/config"
+	"github.com/goreleaser/goreleaser/pkg/context"
+)
+
+func TestStringer(t *testing.T) {
+	require.Equal(t, Pipe{}.String(), "mattermost")
+}
+
+func TestDefault(t *testing.T) {
+	ctx := context.New(config.Project{})
+	require.NoError(t, Pipe{}.Default(ctx))
+	require.Equal(t, ctx.Config.Announce.Mattermost.MessageTemplate, defaultMessageTemplate)
+}
+
+func TestAnnounceInvalidTemplate(t *testing.T) {
+	ctx := context.New(config.Project{
+		Announce: config.Announce{
+			Mattermost: config.Mattermost{
+				MessageTemplate: "{{ .Foo }",
+			},
+		},
+	})
+	require.EqualError(t, Pipe{}.Announce(ctx), `announce: failed to announce to mattermost: template: tmpl:1: unexpected "}" in operand`)
+}
+
+func TestAnnounceMissingEnv(t *testing.T) {
+	ctx := context.New(config.Project{
+		Announce: config.Announce{
+			Mattermost: config.Mattermost{},
+		},
+	})
+	require.NoError(t, Pipe{}.Default(ctx))
+	require.EqualError(t, Pipe{}.Announce(ctx), `announce: failed to announce to mattermost: env: environment variable "MATTERMOST_WEBHOOK" should not be empty`)
+}
+
+func TestSkip(t *testing.T) {
+	t.Run("skip", func(t *testing.T) {
+		require.True(t, Pipe{}.Skip(context.New(config.Project{})))
+	})
+
+	t.Run("dont skip", func(t *testing.T) {
+		ctx := context.New(config.Project{
+			Announce: config.Announce{
+				Mattermost: config.Mattermost{
+					Enabled: true,
+				},
+			},
+		})
+		require.False(t, Pipe{}.Skip(ctx))
+	})
+}
+
+func TestPostWebhook(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		rc := &incomingWebhookRequest{}
+
+		body, _ := ioutil.ReadAll(r.Body)
+		err := json.Unmarshal(body, rc)
+		require.NoError(t, err)
+		require.Equal(t, defaultColor, rc.Attachments[0].Color)
+		require.Equal(t, "Honk v1.0.0 is out!", rc.Attachments[0].Title)
+		require.Equal(t, "Honk v1.0.0 is out! Check it out at https://github.com/honk/honk/releases/tag/v1.0.0", rc.Attachments[0].Text)
+
+		w.WriteHeader(200)
+		_, err = w.Write([]byte{})
+		require.NoError(t, err)
+	}))
+	defer ts.Close()
+
+	ctx := context.New(config.Project{
+		ProjectName: "Honk",
+		Announce: config.Announce{
+			Mattermost: config.Mattermost{
+				Enabled: true,
+			},
+		},
+	})
+
+	ctx.Git.CurrentTag = "v1.0.0"
+	ctx.Git.URL = "https://github.com/honk/honk"
+
+	os.Setenv("MATTERMOST_WEBHOOK", ts.URL)
+	defer os.Unsetenv("MATTERMOST_WEBHOOK")
+
+	require.NoError(t, Pipe{}.Default(ctx))
+	require.NoError(t, Pipe{}.Announce(ctx))
+}

pkg/config/config.go

@@ -707,12 +707,13 @@ type GoMod struct {
 }
 
 type Announce struct {
-	Twitter Twitter `yaml:"twitter,omitempty"`
-	Reddit  Reddit  `yaml:"reddit,omitempty"`
-	Slack   Slack   `yaml:"slack,omitempty"`
-	Discord Discord `yaml:"discord,omitempty"`
-	Teams   Teams   `yaml:"teams,omitempty"`
-	SMTP    SMTP    `yaml:"smtp,omitempty"`
+	Twitter    Twitter    `yaml:"twitter,omitempty"`
+	Reddit     Reddit     `yaml:"reddit,omitempty"`
+	Slack      Slack      `yaml:"slack,omitempty"`
+	Discord    Discord    `yaml:"discord,omitempty"`
+	Teams      Teams      `yaml:"teams,omitempty"`
+	SMTP       SMTP       `yaml:"smtp,omitempty"`
+	Mattermost Mattermost `yaml:"mattermost,omitempty"`
 }
 
 type Twitter struct {
@@ -754,6 +755,17 @@ type Teams struct {
 	IconURL         string `yaml:"icon_url,omitempty"`
 }
 
+type Mattermost struct {
+	Enabled         bool   `yaml:"enabled,omitempty"`
+	MessageTemplate string `yaml:"message_template,omitempty"`
+	TitleTemplate   string `yaml:"title_template,omitempty"`
+	Color           string `yaml:"color,omitempty"`
+	Channel         string `yaml:"channel,omitempty"`
+	Username        string `yaml:"username,omitempty"`
+	IconEmoji       string `yaml:"icon_emoji,omitempty"`
+	IconURL         string `yaml:"icon_url,omitempty"`
+}
+
 type SMTP struct {
 	Enabled            bool     `yaml:"enabled,omitempty"`
 	Host               string   `yaml:"host,omitempty"`

pkg/defaults/defaults.go

@@ -15,6 +15,7 @@ import (
 	"github.com/goreleaser/goreleaser/internal/pipe/docker"
 	"github.com/goreleaser/goreleaser/internal/pipe/gofish"
 	"github.com/goreleaser/goreleaser/internal/pipe/gomod"
+	"github.com/goreleaser/goreleaser/internal/pipe/mattermost"
 	"github.com/goreleaser/goreleaser/internal/pipe/milestone"
 	"github.com/goreleaser/goreleaser/internal/pipe/nfpm"
 	"github.com/goreleaser/goreleaser/internal/pipe/project"
@@ -69,5 +70,6 @@ var Defaulters = []Defaulter{
 	teams.Pipe{},
 	twitter.Pipe{},
 	smtp.Pipe{},
+	mattermost.Pipe{},
 	milestone.Pipe{},
 }

www/docs/customization/announce/mattermost.md

@@ -0,0 +1,44 @@
+# Mattermost
+
+For it to work, you'll need to [create a new Incoming Webhook](https://docs.mattermost.com/developer/webhooks-incoming.html) in your own Mattermost deployment, and set some
+environment variables on your pipeline:
+
+- `MATTERMOST_WEBHOOK`
+
+Then, you can add something like the following to your `.goreleaser.yml` config:
+
+```yaml
+# .goreleaser.yml
+announce:
+  mattermost:
+    # Whether its enabled or not.
+    # Defaults to false.
+    enabled: true
+
+    # Title template to use while publishing.
+    # Defaults to `{{ .ProjectName }} {{ .Tag }} is out!`
+    title_template: 'GoReleaser {{ .Tag }} was just released!'
+
+    # Message template to use while publishing.
+    # Defaults to `{{ .ProjectName }} {{ .Tag }} is out! Check it out at {{ .GitURL }}/releases/tag/{{ .Tag }}`
+    message_template: 'Awesome project {{.Tag}} is out!'
+
+    # Color code of the message. You have to use hexadecimal.
+    # Defaults to `#2D313E` - the grey-ish from goreleaser
+    color: ''
+
+    # The name of the channel that the user selected as a destination for webhook messages.
+    channel: '#channel'
+
+    # Set your Webhook's user name.
+    username: ''
+
+    # Emoji to use as the icon for this message. Overrides icon_url.
+    icon_emoji: ''
+
+    # URL to an image to use as the icon for this message.
+    icon_url: ''
+```
+
+!!! tip
+    Learn more about the [name template engine](/customization/templates/).