feat: add mastodon (#3567)

This PR adds [mastodon](https://joinmastodon.org/) as an announcement
pipeline. 🥳


![mastodon-announce](https://user-images.githubusercontent.com/42128690/202544345-d90d8f10-0818-4bc2-bc35-3dbcba4254b0.png)


Resolves #3566

Signed-off-by: jolheiser <john.olheiser@gmail.com>

go.mod

@@ -26,6 +26,7 @@ require (
 	github.com/invopop/jsonschema v0.7.0
 	github.com/jarcoal/httpmock v1.2.0
 	github.com/klauspost/pgzip v1.2.5
+	github.com/mattn/go-mastodon v0.0.6
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/muesli/mango-cobra v1.2.0
 	github.com/muesli/roff v0.1.0
@@ -147,6 +148,7 @@ require (
 	github.com/sergi/go-diff v1.2.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/technoweenie/multipartstreamer v1.0.1 // indirect
+	github.com/tomnomnom/linkheader v0.0.0-20180905144013-02ca5825eb80 // indirect
 	github.com/xanzy/ssh-agent v0.3.1 // indirect
 	gitlab.com/digitalxero/go-conventional-commit v1.0.7 // indirect
 	go.opencensus.io v0.23.0 // indirect

go.sum

@@ -1145,6 +1145,8 @@ github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Ky
 github.com/mattn/go-isatty v0.0.14/go.mod h1:7GGIvUiUoEMVVmxf/4nioHXj79iQHKdU27kJ6hsGG94=
 github.com/mattn/go-isatty v0.0.16 h1:bq3VjFmv/sOjHtdEhmkEV4x1AJtvUvOJ2PFAZ5+peKQ=
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
+github.com/mattn/go-mastodon v0.0.6 h1:lqU1sOeeIapaDsDUL6udDZIzMb2Wqapo347VZlaOzf0=
+github.com/mattn/go-mastodon v0.0.6/go.mod h1:cg7RFk2pcUfHZw/IvKe1FUzmlq5KnLFqs7eV2PHplV8=
 github.com/mattn/go-runewidth v0.0.2/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
 github.com/mattn/go-runewidth v0.0.10/go.mod h1:RAqKPSqVFrSLVXbA8x7dzmKdmGzieGRCM46jaSJTDAk=
 github.com/mattn/go-runewidth v0.0.12/go.mod h1:RAqKPSqVFrSLVXbA8x7dzmKdmGzieGRCM46jaSJTDAk=
@@ -1505,6 +1507,8 @@ github.com/tidwall/pretty v1.0.0/go.mod h1:XNkn88O1ChpSDQmQeStsy+sBenx6DDtFZJxhV
 github.com/tmc/grpc-websocket-proxy v0.0.0-20170815181823-89b8d40f7ca8/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20190109142713-0ad062ec5ee5/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20201229170055-e5319fda7802/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
+github.com/tomnomnom/linkheader v0.0.0-20180905144013-02ca5825eb80 h1:nrZ3ySNYwJbSpD6ce9duiP+QkD3JuLCcWkdaehUS/3Y=
+github.com/tomnomnom/linkheader v0.0.0-20180905144013-02ca5825eb80/go.mod h1:iFyPdL66DjUD96XmzVL3ZntbzcflLnznH0fr99w5VqE=
 github.com/tv42/httpunix v0.0.0-20150427012821-b75d8614f926/go.mod h1:9ESjWnEqriFuLhtthL60Sar/7RFoluCcXsuvEwTV5KM=
 github.com/tv42/httpunix v0.0.0-20191220191345-2ba4b9c3382c/go.mod h1:hzIxponao9Kjc7aWznkXaL4U4TWaDSs8zcsY4Ka08nM=
 github.com/ugorji/go v1.1.4/go.mod h1:uQMGLiO92mf5W77hV/PUCpI3pbzQx3CRekS0kk+RGrc=

internal/pipe/announce/announce.go

@@ -10,6 +10,7 @@ import (
 	"github.com/goreleaser/goreleaser/internal/middleware/skip"
 	"github.com/goreleaser/goreleaser/internal/pipe/discord"
 	"github.com/goreleaser/goreleaser/internal/pipe/linkedin"
+	"github.com/goreleaser/goreleaser/internal/pipe/mastodon"
 	"github.com/goreleaser/goreleaser/internal/pipe/mattermost"
 	"github.com/goreleaser/goreleaser/internal/pipe/reddit"
 	"github.com/goreleaser/goreleaser/internal/pipe/slack"
@@ -33,6 +34,7 @@ var announcers = []Announcer{
 	// XXX: keep asc sorting
 	discord.Pipe{},
 	linkedin.Pipe{},
+	mastodon.Pipe{},
 	mattermost.Pipe{},
 	reddit.Pipe{},
 	slack.Pipe{},

internal/pipe/mastodon/mastodon.go

@@ -0,0 +1,59 @@
+package mastodon
+
+import (
+	"fmt"
+
+	"github.com/caarlos0/env/v6"
+	"github.com/caarlos0/log"
+	"github.com/goreleaser/goreleaser/internal/tmpl"
+	"github.com/goreleaser/goreleaser/pkg/context"
+	"github.com/mattn/go-mastodon"
+)
+
+const defaultMessageTemplate = `{{ .ProjectName }} {{ .Tag }} is out! Check it out at {{ .ReleaseURL }}`
+
+type Pipe struct{}
+
+func (Pipe) String() string                 { return "mastodon" }
+func (Pipe) Skip(ctx *context.Context) bool { return !ctx.Config.Announce.Mastodon.Enabled }
+
+type Config struct {
+	Server       string `env:"MASTODON_SERVER,notEmpty"`
+	ClientID     string `env:"MASTODON_CLIENT_ID,notEmpty"`
+	ClientSecret string `env:"MASTODON_CLIENT_SECRET,notEmpty"`
+	AccessToken  string `env:"MASTODON_ACCESS_TOKEN,notEmpty"`
+}
+
+func (Pipe) Default(ctx *context.Context) error {
+	if ctx.Config.Announce.Mastodon.MessageTemplate == "" {
+		ctx.Config.Announce.Mastodon.MessageTemplate = defaultMessageTemplate
+	}
+	return nil
+}
+
+func (Pipe) Announce(ctx *context.Context) error {
+	msg, err := tmpl.New(ctx).Apply(ctx.Config.Announce.Mastodon.MessageTemplate)
+	if err != nil {
+		return fmt.Errorf("announce: failed to announce to mastodon: %w", err)
+	}
+
+	var cfg Config
+	if err := env.Parse(&cfg); err != nil {
+		return fmt.Errorf("announce: failed to announce to mastodon: %w", err)
+	}
+
+	client := mastodon.NewClient(&mastodon.Config{
+		Server:       cfg.Server,
+		ClientID:     cfg.ClientID,
+		ClientSecret: cfg.ClientSecret,
+		AccessToken:  cfg.AccessToken,
+	})
+
+	log.Infof("posting: '%s'", msg)
+	if _, err := client.PostStatus(ctx, &mastodon.Toot{
+		Status: msg,
+	}); err != nil {
+		return fmt.Errorf("announce: failed to announce to mastodon: %w", err)
+	}
+	return nil
+}

internal/pipe/mastodon/mastodon_test.go

@@ -0,0 +1,57 @@
+package mastodon
+
+import (
+	"testing"
+
+	"github.com/goreleaser/goreleaser/pkg/config"
+	"github.com/goreleaser/goreleaser/pkg/context"
+	"github.com/stretchr/testify/require"
+)
+
+func TestStringer(t *testing.T) {
+	require.Equal(t, Pipe{}.String(), "mastodon")
+}
+
+func TestDefault(t *testing.T) {
+	ctx := context.New(config.Project{})
+	require.NoError(t, Pipe{}.Default(ctx))
+	require.Equal(t, ctx.Config.Announce.Mastodon.MessageTemplate, defaultMessageTemplate)
+}
+
+func TestAnnounceInvalidTemplate(t *testing.T) {
+	ctx := context.New(config.Project{
+		Announce: config.Announce{
+			Mastodon: config.Mastodon{
+				MessageTemplate: "{{ .Foo }",
+			},
+		},
+	})
+	require.EqualError(t, Pipe{}.Announce(ctx), `announce: failed to announce to mastodon: template: tmpl:1: unexpected "}" in operand`)
+}
+
+func TestAnnounceMissingEnv(t *testing.T) {
+	ctx := context.New(config.Project{
+		Announce: config.Announce{
+			Mastodon: config.Mastodon{},
+		},
+	})
+	require.NoError(t, Pipe{}.Default(ctx))
+	require.EqualError(t, Pipe{}.Announce(ctx), `announce: failed to announce to mastodon: env: environment variable "MASTODON_SERVER" should not be empty; environment variable "MASTODON_CLIENT_ID" should not be empty; environment variable "MASTODON_CLIENT_SECRET" should not be empty; environment variable "MASTODON_ACCESS_TOKEN" 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{
+				Mastodon: config.Mastodon{
+					Enabled: true,
+				},
+			},
+		})
+		require.False(t, Pipe{}.Skip(ctx))
+	})
+}

pkg/config/config.go

@@ -957,6 +957,7 @@ type GoMod struct {
 type Announce struct {
 	Skip       string     `yaml:"skip,omitempty" json:"skip,omitempty" jsonschema:"oneof_type=string;boolean"`
 	Twitter    Twitter    `yaml:"twitter,omitempty" json:"twitter,omitempty"`
+	Mastodon   Mastodon   `yaml:"mastodon,omitempty" json:"mastodon,omitempty"`
 	Reddit     Reddit     `yaml:"reddit,omitempty" json:"reddit,omitempty"`
 	Slack      Slack      `yaml:"slack,omitempty" json:"slack,omitempty"`
 	Discord    Discord    `yaml:"discord,omitempty" json:"discord,omitempty"`
@@ -982,6 +983,11 @@ type Twitter struct {
 	MessageTemplate string `yaml:"message_template,omitempty" json:"message_template,omitempty"`
 }
 
+type Mastodon struct {
+	Enabled         bool   `yaml:"enabled,omitempty" json:"enabled,omitempty"`
+	MessageTemplate string `yaml:"message_template,omitempty" json:"message_template,omitempty"`
+}
+
 type Reddit struct {
 	Enabled       bool   `yaml:"enabled,omitempty" json:"enabled,omitempty"`
 	ApplicationID string `yaml:"application_id,omitempty" json:"application_id,omitempty"`

pkg/defaults/defaults.go

@@ -18,6 +18,7 @@ import (
 	"github.com/goreleaser/goreleaser/internal/pipe/gomod"
 	"github.com/goreleaser/goreleaser/internal/pipe/krew"
 	"github.com/goreleaser/goreleaser/internal/pipe/linkedin"
+	"github.com/goreleaser/goreleaser/internal/pipe/mastodon"
 	"github.com/goreleaser/goreleaser/internal/pipe/mattermost"
 	"github.com/goreleaser/goreleaser/internal/pipe/milestone"
 	"github.com/goreleaser/goreleaser/internal/pipe/nfpm"
@@ -80,6 +81,7 @@ var Defaulters = []Defaulter{
 	teams.Pipe{},
 	twitter.Pipe{},
 	smtp.Pipe{},
+	mastodon.Pipe{},
 	mattermost.Pipe{},
 	milestone.Pipe{},
 	linkedin.Pipe{},

www/docs/customization/announce/mastodon.md

@@ -0,0 +1,27 @@
+# Mastodon
+
+For it to work, you'll need to create a new Mastodon app `https://social.yourdomain.tld/settings/applications/new`, and set
+some environment variables on your pipeline:
+
+- `MASTODON_SERVER`
+- `MASTODON_CLIENT_ID`
+- `MASTODON_CLIENT_SECRET`
+- `MASTODON_ACCESS_TOKEN`
+
+Then, you can add something like the following to your `.goreleaser.yaml` config:
+
+```yaml
+# .goreleaser.yaml
+announce:
+  mastodon:
+    # Whether its enabled or not.
+    # Defaults to false.
+    enabled: true
+
+    # Message template to use while publishing.
+    # Defaults to `{{ .ProjectName }} {{ .Tag }} is out! Check it out at {{ .ReleaseURL }}`
+    message_template: 'Awesome project {{.Tag}} is out!'
+```
+
+!!! tip
+    Learn more about the [name template engine](/customization/templates/).

www/mkdocs.yml

@@ -123,6 +123,7 @@ nav:
       - About: customization/announce/index.md
       - customization/announce/discord.md
       - customization/announce/linkedin.md
+      - customization/announce/mastodon.md
       - customization/announce/mattermost.md
       - customization/announce/reddit.md
       - customization/announce/slack.md