Add generic HTTP postback `Messenger` support.

This is a major feature that builds upon the `Messenger` interface
that has been in listmonk since its inception (with SMTP as the only
messenger). This commit introduces a new Messenger implementation, an
HTTP "postback", that can post campaign messages as a standard JSON
payload to arbitrary HTTP servers. These servers can in turn push them
to FCM, SMS, or any or any such upstream, enabling listmonk to be a
generic campaign messenger for any type of communication, not just
e-mails.

Postback HTTP endpoints can be defined in settings and they can be
selected on campaigns.

cmd/admin.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"sort"
 	"syscall"
 	"time"
 
@@ -29,11 +30,22 @@ func handleGetConfigScript(c echo.Context) error {
 		out = configScript{
 			RootURL:       app.constants.RootURL,
 			FromEmail:     app.constants.FromEmail,
-			Messengers:    app.manager.GetMessengerNames(),
 			MediaProvider: app.constants.MediaProvider,
 		}
 	)
 
+	// Sort messenger names with `email` always as the first item.
+	var names []string
+	for name := range app.messengers {
+		if name == emailMsgr {
+			continue
+		}
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	out.Messengers = append(out.Messengers, emailMsgr)
+	out.Messengers = append(out.Messengers, names...)
+
 	app.Lock()
 	out.NeedsRestart = app.needsRestart
 	out.Update = app.update

cmd/campaigns.go

@@ -220,11 +220,6 @@ func handleCreateCampaign(c echo.Context) error {
 		o = c
 	}
 
-	if !app.manager.HasMessenger(o.MessengerID) {
-		return echo.NewHTTPError(http.StatusBadRequest,
-			fmt.Sprintf("Unknown messenger %s", o.MessengerID))
-	}
-
 	uu, err := uuid.NewV4()
 	if err != nil {
 		app.log.Printf("error generating UUID: %v", err)
@@ -243,7 +238,7 @@ func handleCreateCampaign(c echo.Context) error {
 		o.ContentType,
 		o.SendAt,
 		pq.StringArray(normalizeTags(o.Tags)),
-		"email",
+		o.Messenger,
 		o.TemplateID,
 		o.ListIDs,
 	); err != nil {
@@ -312,6 +307,7 @@ func handleUpdateCampaign(c echo.Context) error {
 		o.SendAt,
 		o.SendLater,
 		pq.StringArray(normalizeTags(o.Tags)),
+		o.Messenger,
 		o.TemplateID,
 		o.ListIDs)
 	if err != nil {
@@ -492,6 +488,7 @@ func handleTestCampaign(c echo.Context) error {
 	if err := c.Bind(&req); err != nil {
 		return err
 	}
+
 	// Validate.
 	if c, err := validateCampaignFields(req, app); err != nil {
 		return echo.NewHTTPError(http.StatusBadRequest, err.Error())
@@ -532,6 +529,9 @@ func handleTestCampaign(c echo.Context) error {
 	camp.Subject = req.Subject
 	camp.FromEmail = req.FromEmail
 	camp.Body = req.Body
+	camp.Messenger = req.Messenger
+	camp.ContentType = req.ContentType
+	camp.TemplateID = req.TemplateID
 
 	// Send the test messages.
 	for _, s := range subs {
@@ -560,11 +560,14 @@ func sendTestMessage(sub models.Subscriber, camp *models.Campaign, app *App) err
 			fmt.Sprintf("Error rendering message: %v", err))
 	}
 
-	return app.messenger.Push(messenger.Message{
-		From:    camp.FromEmail,
-		To:      []string{sub.Email},
-		Subject: m.Subject(),
-		Body:    m.Body(),
+	return app.messengers[camp.Messenger].Push(messenger.Message{
+		From:        camp.FromEmail,
+		To:          []string{sub.Email},
+		Subject:     m.Subject(),
+		ContentType: camp.ContentType,
+		Body:        m.Body(),
+		Subscriber:  sub,
+		Campaign:    camp,
 	})
 }
 
@@ -600,9 +603,13 @@ func validateCampaignFields(c campaignReq, app *App) (campaignReq, error) {
 		return c, errors.New("no lists selected")
 	}
 
+	if !app.manager.HasMessenger(c.Messenger) {
+		return c, fmt.Errorf("unknown messenger %s", c.Messenger)
+	}
+
 	camp := models.Campaign{Body: c.Body, TemplateBody: tplTag}
 	if err := c.CompileTemplate(app.manager.TemplateFuncs(&camp)); err != nil {
-		return c, fmt.Errorf("Error compiling campaign body: %v", err)
+		return c, fmt.Errorf("error compiling campaign body: %v", err)
 	}
 
 	return c, nil

cmd/init.go

@@ -25,6 +25,8 @@ import (
 	"github.com/knadh/listmonk/internal/media/providers/filesystem"
 	"github.com/knadh/listmonk/internal/media/providers/s3"
 	"github.com/knadh/listmonk/internal/messenger"
+	"github.com/knadh/listmonk/internal/messenger/email"
+	"github.com/knadh/listmonk/internal/messenger/postback"
 	"github.com/knadh/listmonk/internal/subimporter"
 	"github.com/knadh/stuffbin"
 	"github.com/labstack/echo"
@@ -290,11 +292,11 @@ func initImporter(q *Queries, db *sqlx.DB, app *App) *subimporter.Importer {
 		}, db.DB)
 }
 
-// initMessengers initializes various messenger backends.
-func initMessengers(m *manager.Manager) messenger.Messenger {
+// initSMTPMessenger initializes the SMTP messenger.
+func initSMTPMessenger(m *manager.Manager) messenger.Messenger {
 	var (
 		mapKeys = ko.MapKeys("smtp")
-		servers = make([]messenger.Server, 0, len(mapKeys))
+		servers = make([]email.Server, 0, len(mapKeys))
 	)
 
 	items := ko.Slices("smtp")
@@ -302,37 +304,71 @@ func initMessengers(m *manager.Manager) messenger.Messenger {
 		lo.Fatalf("no SMTP servers found in config")
 	}
 
-	// Load the default SMTP messengers.
+	// Load the config for multipme SMTP servers.
 	for _, item := range items {
 		if !item.Bool("enabled") {
 			continue
 		}
 
 		// Read the SMTP config.
-		var s messenger.Server
+		var s email.Server
 		if err := item.UnmarshalWithConf("", &s, koanf.UnmarshalConf{Tag: "json"}); err != nil {
-			lo.Fatalf("error loading SMTP: %v", err)
+			lo.Fatalf("error reading SMTP config: %v", err)
 		}
 
 		servers = append(servers, s)
-		lo.Printf("loaded SMTP: %s@%s", item.String("username"), item.String("host"))
+		lo.Printf("loaded email (SMTP) messenger: %s@%s",
+			item.String("username"), item.String("host"))
 	}
 	if len(servers) == 0 {
 		lo.Fatalf("no SMTP servers enabled in settings")
 	}
 
-	// Initialize the default e-mail messenger.
-	msgr, err := messenger.NewEmailer(servers...)
+	// Initialize the e-mail messenger with multiple SMTP servers.
+	msgr, err := email.New(servers...)
 	if err != nil {
 		lo.Fatalf("error loading e-mail messenger: %v", err)
 	}
-	if err := m.AddMessenger(msgr); err != nil {
-		lo.Printf("error registering messenger %s", err)
-	}
 
 	return msgr
 }
 
+// initPostbackMessengers initializes and returns all the enabled
+// HTTP postback messenger backends.
+func initPostbackMessengers(m *manager.Manager) []messenger.Messenger {
+	items := ko.Slices("messengers")
+	if len(items) == 0 {
+		return nil
+	}
+
+	var out []messenger.Messenger
+	for _, item := range items {
+		if !item.Bool("enabled") {
+			continue
+		}
+
+		// Read the Postback server config.
+		var (
+			name = item.String("name")
+			o    postback.Options
+		)
+		if err := item.UnmarshalWithConf("", &o, koanf.UnmarshalConf{Tag: "json"}); err != nil {
+			lo.Fatalf("error reading Postback config: %v", err)
+		}
+
+		// Initialize the Messenger.
+		p, err := postback.New(o)
+		if err != nil {
+			lo.Fatalf("error initializing Postback messenger %s: %v", name, err)
+		}
+		out = append(out, p)
+
+		lo.Printf("loaded Postback messenger: %s", name)
+	}
+
+	return out
+}
+
 // initMediaStore initializes Upload manager with a custom backend.
 func initMediaStore() media.Store {
 	switch provider := ko.String("upload.provider"); provider {

cmd/install.go

@@ -123,7 +123,7 @@ func install(lastVer string, db *sqlx.DB, fs stuffbin.FileSystem, prompt bool) {
 		"richtext",
 		nil,
 		pq.StringArray{"test-campaign"},
-		"email",
+		emailMsgr,
 		1,
 		pq.Int64Array{1},
 	); err != nil {

cmd/main.go

@@ -22,19 +22,23 @@ import (
 	"github.com/knadh/stuffbin"
 )
 
+const (
+	emailMsgr = "email"
+)
+
 // App contains the "global" components that are
 // passed around, especially through HTTP handlers.
 type App struct {
-	fs        stuffbin.FileSystem
-	db        *sqlx.DB
-	queries   *Queries
-	constants *constants
-	manager   *manager.Manager
-	importer  *subimporter.Importer
-	messenger messenger.Messenger
-	media     media.Store
-	notifTpls *template.Template
-	log       *log.Logger
+	fs         stuffbin.FileSystem
+	db         *sqlx.DB
+	queries    *Queries
+	constants  *constants
+	manager    *manager.Manager
+	importer   *subimporter.Importer
+	messengers map[string]messenger.Messenger
+	media      media.Store
+	notifTpls  *template.Template
+	log        *log.Logger
 
 	// Channel for passing reload signals.
 	sigChan chan os.Signal
@@ -122,18 +126,31 @@ func main() {
 	// Initialize the main app controller that wraps all of the app's
 	// components. This is passed around HTTP handlers.
 	app := &App{
-		fs:        fs,
-		db:        db,
-		constants: initConstants(),
-		media:     initMediaStore(),
-		log:       lo,
+		fs:         fs,
+		db:         db,
+		constants:  initConstants(),
+		media:      initMediaStore(),
+		messengers: make(map[string]messenger.Messenger),
+		log:        lo,
 	}
 	_, app.queries = initQueries(queryFilePath, db, fs, true)
 	app.manager = initCampaignManager(app.queries, app.constants, app)
 	app.importer = initImporter(app.queries, db, app)
-	app.messenger = initMessengers(app.manager)
 	app.notifTpls = initNotifTemplates("/email-templates/*.html", fs, app.constants)
 
+	// Initialize the default SMTP (`email`) messenger.
+	app.messengers[emailMsgr] = initSMTPMessenger(app.manager)
+
+	// Initialize any additional postback messengers.
+	for _, m := range initPostbackMessengers(app.manager) {
+		app.messengers[m.Name()] = m
+	}
+
+	// Attach all messengers to the campaign manager.
+	for _, m := range app.messengers {
+		app.manager.AddMessenger(m)
+	}
+
 	// Start the campaign workers. The campaign batches (fetch from DB, push out
 	// messages) get processed at the specified interval.
 	go app.manager.Run(time.Second * 5)
@@ -164,7 +181,9 @@ func main() {
 		app.db.DB.Close()
 
 		// Close the messenger pool.
-		app.messenger.Close()
+		for _, m := range app.messengers {
+			m.Close()
+		}
 
 		// Signal the close.
 		closerWait <- true

cmd/notifications.go

@@ -28,14 +28,13 @@ func (app *App) sendNotification(toEmails []string, subject, tplName string, dat
 		return err
 	}
 
-	err := app.manager.PushMessage(manager.Message{
-		From:      app.constants.FromEmail,
-		To:        toEmails,
-		Subject:   subject,
-		Body:      b.Bytes(),
-		Messenger: "email",
-	})
-	if err != nil {
+	m := manager.Message{}
+	m.From = app.constants.FromEmail
+	m.To = toEmails
+	m.Subject = subject
+	m.Body = b.Bytes()
+	m.Messenger = emailMsgr
+	if err := app.manager.PushMessage(m); err != nil {
 		app.log.Printf("error sending admin notification (%s): %v", subject, err)
 		return err
 	}

cmd/public.go

@@ -367,7 +367,7 @@ func handleSelfExportSubscriberData(c echo.Context) error {
 
 	// Send the data as a JSON attachment to the subscriber.
 	const fname = "data.json"
-	if err := app.messenger.Push(messenger.Message{
+	if err := app.messengers[emailMsgr].Push(messenger.Message{
 		From:    app.constants.FromEmail,
 		To:      []string{data.Email},
 		Subject: "Your data",

cmd/settings.go

@@ -4,6 +4,8 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"regexp"
+	"strings"
 	"syscall"
 	"time"
 
@@ -22,14 +24,24 @@ type settings struct {
 	AppMaxSendErrors int      `json:"app.max_send_errors"`
 	AppMessageRate   int      `json:"app.message_rate"`
 
-	Messengers []interface{} `json:"messengers"`
-
 	PrivacyUnsubHeader    bool     `json:"privacy.unsubscribe_header"`
 	PrivacyAllowBlocklist bool     `json:"privacy.allow_blocklist"`
 	PrivacyAllowExport    bool     `json:"privacy.allow_export"`
 	PrivacyAllowWipe      bool     `json:"privacy.allow_wipe"`
 	PrivacyExportable     []string `json:"privacy.exportable"`
 
+	UploadProvider             string `json:"upload.provider"`
+	UploadFilesystemUploadPath string `json:"upload.filesystem.upload_path"`
+	UploadFilesystemUploadURI  string `json:"upload.filesystem.upload_uri"`
+	UploadS3AwsAccessKeyID     string `json:"upload.s3.aws_access_key_id"`
+	UploadS3AwsDefaultRegion   string `json:"upload.s3.aws_default_region"`
+	UploadS3AwsSecretAccessKey string `json:"upload.s3.aws_secret_access_key,omitempty"`
+	UploadS3Bucket             string `json:"upload.s3.bucket"`
+	UploadS3BucketDomain       string `json:"upload.s3.bucket_domain"`
+	UploadS3BucketPath         string `json:"upload.s3.bucket_path"`
+	UploadS3BucketType         string `json:"upload.s3.bucket_type"`
+	UploadS3Expiry             string `json:"upload.s3.expiry"`
+
 	SMTP []struct {
 		Enabled       bool                `json:"enabled"`
 		Host          string              `json:"host"`
@@ -47,21 +59,22 @@ type settings struct {
 		TLSSkipVerify bool                `json:"tls_skip_verify"`
 	} `json:"smtp"`
 
-	UploadProvider string `json:"upload.provider"`
-
-	UploadFilesystemUploadPath string `json:"upload.filesystem.upload_path"`
-	UploadFilesystemUploadURI  string `json:"upload.filesystem.upload_uri"`
-
-	UploadS3AwsAccessKeyID     string `json:"upload.s3.aws_access_key_id"`
-	UploadS3AwsDefaultRegion   string `json:"upload.s3.aws_default_region"`
-	UploadS3AwsSecretAccessKey string `json:"upload.s3.aws_secret_access_key,omitempty"`
-	UploadS3Bucket             string `json:"upload.s3.bucket"`
-	UploadS3BucketDomain       string `json:"upload.s3.bucket_domain"`
-	UploadS3BucketPath         string `json:"upload.s3.bucket_path"`
-	UploadS3BucketType         string `json:"upload.s3.bucket_type"`
-	UploadS3Expiry             string `json:"upload.s3.expiry"`
+	Messengers []struct {
+		Enabled       bool   `json:"enabled"`
+		Name          string `json:"name"`
+		RootURL       string `json:"root_url"`
+		Username      string `json:"username"`
+		Password      string `json:"password,omitempty"`
+		MaxConns      int    `json:"max_conns"`
+		Timeout       string `json:"timeout"`
+		MaxMsgRetries int    `json:"max_msg_retries"`
+	} `json:"messengers"`
 }
 
+var (
+	reAlphaNum = regexp.MustCompile(`[^a-z0-9\-]`)
+)
+
 // handleGetSettings returns settings from the DB.
 func handleGetSettings(c echo.Context) error {
 	app := c.Get("app").(*App)
@@ -75,6 +88,9 @@ func handleGetSettings(c echo.Context) error {
 	for i := 0; i < len(s.SMTP); i++ {
 		s.SMTP[i].Password = ""
 	}
+	for i := 0; i < len(s.Messengers); i++ {
+		s.Messengers[i].Password = ""
+	}
 	s.UploadS3AwsSecretAccessKey = ""
 
 	return c.JSON(http.StatusOK, okResp{s})
@@ -111,13 +127,43 @@ func handleUpdateSettings(c echo.Context) error {
 			if len(cur.SMTP) > i &&
 				set.SMTP[i].Host == cur.SMTP[i].Host &&
 				set.SMTP[i].Username == cur.SMTP[i].Username {
+				// Copy the existing password as password's needn't be
+				// sent from the frontend for updating entries.
 				set.SMTP[i].Password = cur.SMTP[i].Password
 			}
 		}
 	}
 	if !has {
 		return echo.NewHTTPError(http.StatusBadRequest,
-			"Minimum one SMTP block should be enabled.")
+			"At least one SMTP block should be enabled.")
+	}
+
+	// Validate and sanitize postback Messenger names. Duplicates are disallowed
+	// and "email" is a reserved name.
+	names := map[string]bool{emailMsgr: true}
+
+	for i := range set.Messengers {
+		if set.Messengers[i].Password == "" {
+			if len(cur.Messengers) > i &&
+				set.Messengers[i].RootURL == cur.Messengers[i].RootURL &&
+				set.Messengers[i].Username == cur.Messengers[i].Username {
+				// Copy the existing password as password's needn't be
+				// sent from the frontend for updating entries.
+				set.Messengers[i].Password = cur.Messengers[i].Password
+			}
+		}
+
+		name := reAlphaNum.ReplaceAllString(strings.ToLower(set.Messengers[i].Name), "")
+		if _, ok := names[name]; ok {
+			return echo.NewHTTPError(http.StatusBadRequest,
+				fmt.Sprintf("Duplicate messenger name `%s`.", name))
+		}
+		if len(name) == 0 {
+			return echo.NewHTTPError(http.StatusBadRequest, "Invalid messenger name.")
+		}
+
+		set.Messengers[i].Name = name
+		names[name] = true
 	}
 
 	// S3 password?

frontend/public/index.html

@@ -7,7 +7,7 @@
     <link rel="icon" href="<%= BASE_URL %>frontend/favicon.png" />
     <link href="https://fonts.googleapis.com/css?family=Inter:400,600" rel="stylesheet" />
     <title><%= htmlWebpackPlugin.options.title %></title>
-    <script src="<%= BASE_URL %>api/config.js"></script>
+    <script src="<%= BASE_URL %>api/config.js" id="server-config"></script>
   </head>
   <body>
     <noscript>

frontend/src/components/Editor.vue

@@ -11,11 +11,14 @@
             <b-radio v-model="form.radioFormat"
               @input="onChangeFormat" :disabled="disabled" name="format"
               native-value="html">Raw HTML</b-radio>
+            <b-radio v-model="form.radioFormat"
+              @input="onChangeFormat" :disabled="disabled" name="format"
+              native-value="plain">Plain text</b-radio>
           </div>
         </b-field>
       </div>
       <div class="column is-6 has-text-right">
-          <b-button @click="togglePreview" type="is-primary"
+          <b-button @click="onTogglePreview" type="is-primary"
             icon-left="file-find-outline">Preview</b-button>
       </div>
     </div>
@@ -37,9 +40,13 @@
     <div v-if="form.format === 'html'"
       ref="htmlEditor" id="html-editor" class="html-editor"></div>
 
+    <!-- plain text editor //-->
+    <b-input v-if="form.format === 'plain'" v-model="form.body" @input="onEditorChange"
+      type="textarea" ref="plainEditor" class="plain-editor" />
+
     <!-- campaign preview //-->
     <campaign-preview v-if="isPreviewing"
-      @close="togglePreview"
+      @close="onTogglePreview"
       type='campaign'
       :id='id'
       :title='title'
@@ -136,7 +143,7 @@ export default {
               esc: {
                 key: 27,
                 handler: () => {
-                  this.toggleFullscreen(true);
+                  this.onToggleFullscreen(true);
                 },
               },
             },
@@ -163,8 +170,8 @@ export default {
             ],
 
             handlers: {
-              image: this.toggleMedia,
-              fullscreen: () => this.toggleFullscreen(false),
+              image: this.onToggleMedia,
+              fullscreen: () => this.onToggleFullscreen(false),
             },
           },
         },
@@ -227,16 +234,16 @@ export default {
       });
     },
 
-    togglePreview() {
+    onTogglePreview() {
       this.isPreviewing = !this.isPreviewing;
     },
 
-    toggleMedia() {
+    onToggleMedia() {
       this.lastSel = this.$refs.quill.quill.getSelection();
       this.isMediaVisible = !this.isMediaVisible;
     },
 
-    toggleFullscreen(onlyMinimize) {
+    onToggleFullscreen(onlyMinimize) {
       if (onlyMinimize) {
         if (!this.isEditorFullscreen) {
           return;

frontend/src/main.js

@@ -16,6 +16,22 @@ Vue.config.productionTip = false;
 Vue.prototype.$api = api;
 Vue.prototype.$utils = utils;
 
+Vue.prototype.$reloadServerConfig = () => {
+  // Get the config.js <script> tag, remove it, and re-add it.
+  let s = document.querySelector('#server-config');
+  const url = s.getAttribute('src');
+  s.remove();
+
+  s = document.createElement('script');
+  s.setAttribute('src', url);
+  s.setAttribute('id', 'server-config');
+  s.onload = () => {
+    store.commit('setModelResponse',
+      { model: models.serverConfig, data: humps.camelizeKeys(window.CONFIG) });
+  };
+  document.body.appendChild(s);
+};
+
 // window.CONFIG is loaded from /api/config.js directly in a <script> tag.
 if (window.CONFIG) {
   store.commit('setModelResponse',

frontend/src/views/Campaign.vue

@@ -69,6 +69,14 @@
                   </b-select>
                 </b-field>
 
+                <b-field label="Messenger" label-position="on-border">
+                  <b-select placeholder="Messenger" v-model="form.messenger"
+                    :disabled="!canEdit" required>
+                    <option v-for="m in serverConfig.messengers"
+                      :value="m" :key="m">{{ m }}</option>
+                  </b-select>
+                </b-field>
+
                 <b-field label="Tags" label-position="on-border">
                   <b-taginput v-model="form.tags" :disabled="!canEdit"
                     ellipsis icon="tag-outline" placeholder="Tags"></b-taginput>
@@ -206,12 +214,12 @@ export default Vue.extend({
         subject: this.form.subject,
         lists: this.form.lists.map((l) => l.id),
         from_email: this.form.fromEmail,
-        content_type: 'richtext',
-        messenger: 'email',
+        messenger: this.form.messenger,
         type: 'regular',
         tags: this.form.tags,
         template_id: this.form.templateId,
-        body: this.form.body,
+        content_type: this.form.content.contentType,
+        body: this.form.content.body,
         subscribers: this.form.testEmails,
       };
 
@@ -255,7 +263,7 @@ export default Vue.extend({
         subject: this.form.subject,
         lists: this.form.lists.map((l) => l.id),
         from_email: this.form.fromEmail,
-        messenger: 'email',
+        messenger: this.form.messenger,
         type: 'regular',
         tags: this.form.tags,
         send_later: this.form.sendLater,
@@ -305,7 +313,7 @@ export default Vue.extend({
   },
 
   computed: {
-    ...mapState(['lists', 'templates', 'loading']),
+    ...mapState(['serverConfig', 'loading', 'lists', 'templates']),
 
     canEdit() {
       return this.isNew
@@ -353,6 +361,8 @@ export default Vue.extend({
           this.activeTab = 1;
         }
       });
+    } else {
+      this.form.messenger = 'email';
     }
 
     this.$nextTick(() => {

frontend/src/views/Lists.vue

@@ -183,7 +183,7 @@ export default Vue.extend({
   },
 
   computed: {
-    ...mapState(['lists', 'serverConfig', 'loading']),
+    ...mapState(['serverConfig', 'loading', 'lists']),
   },
 
   mounted() {

frontend/src/views/Settings.vue

@@ -330,8 +330,7 @@
                       </div>
                       <div class="column is-3">
                         <b-field label="Retries" label-position="on-border"
-                          message="The number of times a message should be retried
-                                  if sending fails.">
+                          message="Number of times to rety when a message fails.">
                           <b-numberinput v-model="item.max_msg_retries" name="max_msg_retries"
                               type="is-light"
                               controls-position="compact"
@@ -378,7 +377,95 @@
 
             <b-button @click="addSMTP" icon-left="plus" type="is-primary">Add new</b-button>
           </b-tab-item><!-- mail servers -->
+
+          <b-tab-item label="Messengers">
+            <div class="items messengers">
+              <div class="block box" v-for="(item, n) in form.messengers" :key="n">
+                <div class="columns">
+                  <div class="column is-2">
+                    <b-field label="Enabled">
+                      <b-switch v-model="item.enabled" name="enabled"
+                          :native-value="true" />
+                    </b-field>
+                    <b-field>
+                      <a @click.prevent="$utils.confirm(null, () => removeMessenger(n))"
+                        href="#" class="is-size-7">
+                        <b-icon icon="trash-can-outline" size="is-small" /> Delete
+                      </a>
+                    </b-field>
+                  </div><!-- first column -->
+
+                  <div class="column" :class="{'disabled': !item.enabled}">
+                    <div class="columns">
+                      <div class="column is-4">
+                        <b-field label="Name" label-position="on-border"
+                          message="eg: my-sms. Alphanumeric / dash.">
+                          <b-input v-model="item.name" name="name"
+                            placeholder='mymessenger' :maxlength="200" />
+                        </b-field>
+                      </div>
+                      <div class="column is-8">
+                        <b-field label="URL" label-position="on-border"
+                          message="Root URL of the Postback server.">
+                          <b-input v-model="item.root_url" name="root_url"
+                            placeholder='https://postback.messenger.net/path' :maxlength="200" />
+                        </b-field>
+                      </div>
+                    </div><!-- host -->
+
+                    <div class="columns">
+                      <div class="column">
+                        <b-field grouped>
+                          <b-field label="Username" label-position="on-border" expanded>
+                            <b-input v-model="item.username" name="username" :maxlength="200" />
+                          </b-field>
+                          <b-field label="Password" label-position="on-border" expanded
+                            message="Enter a value to change.">
+                            <b-input v-model="item.password"
+                              name="password" type="password" placeholder="Enter to change"
+                              :maxlength="200" />
+                          </b-field>
+                        </b-field>
+                      </div>
+                    </div><!-- auth -->
+                    <hr />
+
+                    <div class="columns">
+                      <div class="column is-4">
+                        <b-field label="Max. connections" label-position="on-border"
+                          message="Maximum concurrent connections to the server.">
+                          <b-numberinput v-model="item.max_conns" name="max_conns" type="is-light"
+                              controls-position="compact"
+                              placeholder="25" min="1" max="65535" />
+                        </b-field>
+                      </div>
+                      <div class="column is-4">
+                        <b-field label="Retries" label-position="on-border"
+                          message="Number of times to rety when a message fails.">
+                          <b-numberinput v-model="item.max_msg_retries" name="max_msg_retries"
+                              type="is-light"
+                              controls-position="compact"
+                              placeholder="2" min="1" max="1000" />
+                        </b-field>
+                      </div>
+                      <div class="column is-4">
+                        <b-field label="Request imeout" label-position="on-border"
+                          message="Request timeout duration (s for second, m for minute).">
+                          <b-input v-model="item.timeout" name="timeout"
+                            placeholder="5s" :pattern="regDuration" :maxlength="10" />
+                        </b-field>
+                      </div>
+                    </div>
+                    <hr />
+                  </div>
+                </div><!-- second container column -->
+              </div><!-- block -->
+            </div><!-- mail-servers -->
+
+            <b-button @click="addMessenger" icon-left="plus" type="is-primary">Add new</b-button>
+          </b-tab-item><!-- messengers -->
         </b-tabs>
+
       </form>
     </section>
   </section>
@@ -421,6 +508,24 @@ export default Vue.extend({
       this.form.smtp.splice(i, 1, s);
     },
 
+    addMessenger() {
+      this.form.messengers.push({
+        enabled: true,
+        root_url: '',
+        name: '',
+        username: '',
+        password: '',
+        max_conns: 25,
+        max_msg_retries: 2,
+        timeout: '5s',
+      });
+    },
+
+    removeMessenger(i) {
+      this.form.messengers.splice(i, 1);
+    },
+
+
     onSubmit() {
       const form = JSON.parse(JSON.stringify(this.form));
 
@@ -442,6 +547,13 @@ export default Vue.extend({
         form['upload.s3.aws_secret_access_key'] = '';
       }
 
+      for (let i = 0; i < form.messengers.length; i += 1) {
+        // If it's the dummy UI password placeholder, ignore it.
+        if (form.messengers[i].password === dummyPassword) {
+          form.messengers[i].password = '';
+        }
+      }
+
       this.isLoading = true;
       this.$api.updateSettings(form).then((data) => {
         if (data.needsRestart) {
@@ -461,6 +573,7 @@ export default Vue.extend({
           this.$api.getHealth().then(() => {
             clearInterval(pollId);
             this.getSettings();
+            this.$reloadServerConfig();
           });
         }, 500);
       }, () => {
@@ -480,6 +593,12 @@ export default Vue.extend({
           d.smtp[i].password = dummyPassword;
         }
 
+        for (let i = 0; i < d.messengers.length; i += 1) {
+          // The backend doesn't send passwords, so add a dummy so that it
+          // the password looks filled on the UI.
+          d.messengers[i].password = dummyPassword;
+        }
+
         if (d['upload.provider'] === 's3') {
           d['upload.s3.aws_secret_access_key'] = dummyPassword;
         }

go.mod

@@ -15,6 +15,7 @@ require (
 	github.com/labstack/echo v3.3.10+incompatible
 	github.com/labstack/gommon v0.3.0 // indirect
 	github.com/lib/pq v1.3.0
+	github.com/mailru/easyjson v0.7.6
 	github.com/nats-io/nats-server/v2 v2.1.7 // indirect
 	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
 	github.com/olekukonko/tablewriter v0.0.4 // indirect

go.sum

@@ -34,6 +34,8 @@ github.com/jaytaylor/html2text v0.0.0-20200220170450-61d9dc4d7195 h1:j0UEFmS7wSj
 github.com/jaytaylor/html2text v0.0.0-20200220170450-61d9dc4d7195/go.mod h1:CVKlgaMiht+LXvHG173ujK6JUhZXKb2u/BQtjPDIvyk=
 github.com/jmoiron/sqlx v1.2.0 h1:41Ip0zITnmWNR/vHV+S4m+VoUivnWY5E4OJfLZjCJMA=
 github.com/jmoiron/sqlx v1.2.0/go.mod h1:1FEQNm3xlJgrMD+FBdI9+xvCksHtbpVBBw5dYhBSsks=
+github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
+github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/knadh/email v0.0.0-20200206100304-6d2c7064c2e8 h1:HVq7nA5uWjpo93WsWjva1YIBuQrr8UkWQEUbzg1DX+E=
 github.com/knadh/email v0.0.0-20200206100304-6d2c7064c2e8/go.mod h1:Fy2gCFfZhay8jplf/Csj6cyH/oshQTkLQYZbKkcV+SY=
 github.com/knadh/goyesql v2.0.0+incompatible h1:hJFJrU8kaiLmvYt9I/1k1AB7q+qRhHs/afzTfQ3eGqk=
@@ -63,6 +65,8 @@ github.com/lib/pq v1.0.0 h1:X5PMW56eZitiTeO7tKzZxFCSpbFZJtkMMooicw2us9A=
 github.com/lib/pq v1.0.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/lib/pq v1.3.0 h1:/qkRGz8zljWiDcFvgpwUpwIAPu3r07TDvs3Rws+o/pU=
 github.com/lib/pq v1.3.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
+github.com/mailru/easyjson v0.7.6 h1:8yTIVnZgCoiM1TgqoeTl+LfU5Jg6/xL3QhGQnimLYnA=
+github.com/mailru/easyjson v0.7.6/go.mod h1:xzfreul335JAWq5oZzymOObrkdz5UnU4kGfJJLY9Nlc=
 github.com/mattn/go-colorable v0.1.2 h1:/bC9yWikZXAL9uJdulbSfyVNIR3n3trXl+v8+1sx8mU=
 github.com/mattn/go-colorable v0.1.2/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
 github.com/mattn/go-isatty v0.0.8/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=

internal/manager/manager.go

@@ -74,10 +74,10 @@ type CampaignMessage struct {
 
 // Message represents a generic message to be pushed to a messenger.
 type Message struct {
-	From      string
-	To        []string
-	Subject   string
-	Body      []byte
+	messenger.Message
+	Subscriber models.Subscriber
+
+	// Messenger is the messenger backend to use: email|postback.
 	Messenger string
 }
 
@@ -171,15 +171,6 @@ func (m *Manager) PushMessage(msg Message) error {
 	return nil
 }
 
-// GetMessengerNames returns the list of registered messengers.
-func (m *Manager) GetMessengerNames() []string {
-	names := make([]string, 0, len(m.messengers))
-	for n := range m.messengers {
-		names = append(names, n)
-	}
-	return names
-}
-
 // HasMessenger checks if a given messenger is registered.
 func (m *Manager) HasMessenger(id string) bool {
 	_, ok := m.messengers[id]
@@ -253,10 +244,13 @@ func (m *Manager) messageWorker() {
 
 			// Outgoing message.
 			out := messenger.Message{
-				From:    msg.from,
-				To:      []string{msg.to},
-				Subject: msg.subject,
-				Body:    msg.body,
+				From:        msg.from,
+				To:          []string{msg.to},
+				Subject:     msg.subject,
+				ContentType: msg.Campaign.ContentType,
+				Body:        msg.body,
+				Subscriber:  msg.Subscriber,
+				Campaign:    msg.Campaign,
 			}
 
 			// Attach List-Unsubscribe headers?
@@ -267,7 +261,7 @@ func (m *Manager) messageWorker() {
 				out.Headers = h
 			}
 
-			if err := m.messengers[msg.Campaign.MessengerID].Push(out); err != nil {
+			if err := m.messengers[msg.Campaign.Messenger].Push(out); err != nil {
 				m.logger.Printf("error sending message in campaign %s: %v", msg.Campaign.Name, err)
 
 				select {
@@ -283,10 +277,13 @@ func (m *Manager) messageWorker() {
 			}
 
 			err := m.messengers[msg.Messenger].Push(messenger.Message{
-				From:    msg.From,
-				To:      msg.To,
-				Subject: msg.Subject,
-				Body:    msg.Body,
+				From:        msg.From,
+				To:          msg.To,
+				Subject:     msg.Subject,
+				ContentType: msg.ContentType,
+				Body:        msg.Body,
+				Subscriber:  msg.Subscriber,
+				Campaign:    msg.Campaign,
 			})
 			if err != nil {
 				m.logger.Printf("error sending message '%s': %v", msg.Subject, err)
@@ -394,9 +391,9 @@ func (m *Manager) scanCampaigns(tick time.Duration) {
 // addCampaign adds a campaign to the process queue.
 func (m *Manager) addCampaign(c *models.Campaign) error {
 	// Validate messenger.
-	if _, ok := m.messengers[c.MessengerID]; !ok {
+	if _, ok := m.messengers[c.Messenger]; !ok {
 		m.src.UpdateCampaignStatus(c.ID, models.CampaignStatusCancelled)
-		return fmt.Errorf("unknown messenger %s on campaign %s", c.MessengerID, c.Name)
+		return fmt.Errorf("unknown messenger %s on campaign %s", c.Messenger, c.Name)
 	}
 
 	// Load the template.

internal/messenger/emailer.go → internal/messenger/email/email.go

@@ -1,4 +1,4 @@
-package messenger
+package email
 
 import (
 	"crypto/tls"
@@ -8,6 +8,7 @@ import (
 	"net/textproto"
 
 	"github.com/jaytaylor/html2text"
+	"github.com/knadh/listmonk/internal/messenger"
 	"github.com/knadh/smtppool"
 )
 
@@ -35,9 +36,8 @@ type Emailer struct {
 	servers []*Server
 }
 
-// NewEmailer creates and returns an e-mail Messenger backend.
-// It takes multiple SMTP configurations.
-func NewEmailer(servers ...Server) (*Emailer, error) {
+// New returns an SMTP e-mail Messenger backend with a the given SMTP servers.
+func New(servers ...Server) (*Emailer, error) {
 	e := &Emailer{
 		servers: make([]*Server, 0, len(servers)),
 	}
@@ -86,7 +86,7 @@ func (e *Emailer) Name() string {
 }
 
 // Push pushes a message to the server.
-func (e *Emailer) Push(m Message) error {
+func (e *Emailer) Push(m messenger.Message) error {
 	// If there are more than one SMTP servers, send to a random
 	// one from the list.
 	var (

internal/messenger/messenger.go

@@ -1,6 +1,10 @@
 package messenger
 
-import "net/textproto"
+import (
+	"net/textproto"
+
+	"github.com/knadh/listmonk/models"
+)
 
 // Messenger is an interface for a generic messaging backend,
 // for instance, e-mail, SMS etc.
@@ -16,9 +20,15 @@ type Message struct {
 	From        string
 	To          []string
 	Subject     string
+	ContentType string
 	Body        []byte
 	Headers     textproto.MIMEHeader
 	Attachments []Attachment
+
+	Subscriber models.Subscriber
+
+	// Campaign is generally the same instance for a large number of subscribers.
+	Campaign *models.Campaign
 }
 
 // Attachment represents a file or blob attachment that can be

internal/messenger/postback/postback.go

@@ -0,0 +1,183 @@
+package postback
+
+import (
+	"bytes"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"time"
+
+	"github.com/knadh/listmonk/internal/messenger"
+	"github.com/knadh/listmonk/models"
+)
+
+// postback is the payload that's posted as JSON to the HTTP Postback server.
+//easyjson:json
+type postback struct {
+	Subject     string      `json:"subject"`
+	ContentType string      `json:"content_type"`
+	Body        string      `json:"body"`
+	Recipients  []recipient `json:"recipients"`
+	Campaign    *campaign   `json:"campaign"`
+}
+
+type campaign struct {
+	UUID string   `db:"uuid" json:"uuid"`
+	Name string   `db:"name" json:"name"`
+	Tags []string `db:"tags" json:"tags"`
+}
+
+type recipient struct {
+	UUID    string                   `db:"uuid" json:"uuid"`
+	Email   string                   `db:"email" json:"email"`
+	Name    string                   `db:"name" json:"name"`
+	Attribs models.SubscriberAttribs `db:"attribs" json:"attribs"`
+	Status  string                   `db:"status" json:"status"`
+}
+
+// Options represents HTTP Postback server options.
+type Options struct {
+	Name     string        `json:"name"`
+	Username string        `json:"username"`
+	Password string        `json:"password"`
+	RootURL  string        `json:"root_url"`
+	MaxConns int           `json:"max_conns"`
+	Retries  int           `json:"retries"`
+	Timeout  time.Duration `json:"timeout"`
+}
+
+// Postback represents an HTTP Message server.
+type Postback struct {
+	authStr string
+	o       Options
+	c       *http.Client
+}
+
+// New returns a new instance of the HTTP Postback messenger.
+func New(o Options) (*Postback, error) {
+	authStr := ""
+	if o.Username != "" && o.Password != "" {
+		authStr = fmt.Sprintf("Basic %s", base64.StdEncoding.EncodeToString(
+			[]byte(o.Username+":"+o.Password)))
+	}
+
+	return &Postback{
+		authStr: authStr,
+		o:       o,
+		c: &http.Client{
+			Timeout: o.Timeout,
+			Transport: &http.Transport{
+				MaxIdleConnsPerHost:   o.MaxConns,
+				MaxConnsPerHost:       o.MaxConns,
+				ResponseHeaderTimeout: o.Timeout,
+				IdleConnTimeout:       o.Timeout,
+			},
+		},
+	}, nil
+}
+
+// Name returns the messenger's name.
+func (p *Postback) Name() string {
+	return p.o.Name
+}
+
+// Push pushes a message to the server.
+func (p *Postback) Push(m messenger.Message) error {
+	pb := postback{
+		Subject:     m.Subject,
+		ContentType: m.ContentType,
+		Body:        string(m.Body),
+		Recipients: []recipient{{
+			UUID:    m.Subscriber.UUID,
+			Email:   m.Subscriber.Email,
+			Name:    m.Subscriber.Name,
+			Status:  m.Subscriber.Status,
+			Attribs: m.Subscriber.Attribs,
+		}},
+	}
+
+	if m.Campaign != nil {
+		pb.Campaign = &campaign{
+			UUID: m.Campaign.UUID,
+			Name: m.Campaign.Name,
+			Tags: m.Campaign.Tags,
+		}
+	}
+
+	b, err := pb.MarshalJSON()
+	if err != nil {
+		return err
+	}
+
+	return p.exec(http.MethodPost, p.o.RootURL, b, nil)
+}
+
+// Flush flushes the message queue to the server.
+func (p *Postback) Flush() error {
+	return nil
+}
+
+// Close closes idle HTTP connections.
+func (p *Postback) Close() error {
+	p.c.CloseIdleConnections()
+	return nil
+}
+
+func (p *Postback) exec(method, rURL string, reqBody []byte, headers http.Header) error {
+	var (
+		err      error
+		postBody io.Reader
+	)
+
+	// Encode POST / PUT params.
+	if method == http.MethodPost || method == http.MethodPut {
+		postBody = bytes.NewReader(reqBody)
+	}
+
+	req, err := http.NewRequest(method, rURL, postBody)
+	if err != nil {
+		return err
+	}
+
+	if headers != nil {
+		req.Header = headers
+	} else {
+		req.Header = http.Header{}
+	}
+	req.Header.Set("User-Agent", "listmonk")
+
+	// Optional BasicAuth.
+	if p.authStr != "" {
+		req.Header.Set("Authorization", p.authStr)
+	}
+
+	// If a content-type isn't set, set the default one.
+	if req.Header.Get("Content-Type") == "" {
+		if method == http.MethodPost || method == http.MethodPut {
+			req.Header.Add("Content-Type", "application/json")
+		}
+	}
+
+	// If the request method is GET or DELETE, add the params as QueryString.
+	if method == http.MethodGet || method == http.MethodDelete {
+		req.URL.RawQuery = string(reqBody)
+	}
+
+	r, err := p.c.Do(req)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		// Drain and close the body to let the Transport reuse the connection
+		io.Copy(ioutil.Discard, r.Body)
+		r.Body.Close()
+	}()
+
+	if r.StatusCode != http.StatusOK {
+		return fmt.Errorf("non-OK response from Postback server: %d", r.StatusCode)
+	}
+
+	return nil
+}

internal/messenger/postback/postback_easyjson.go

@@ -0,0 +1,358 @@
+// Code generated by easyjson for marshaling/unmarshaling. DO NOT EDIT.
+
+package postback
+
+import (
+	json "encoding/json"
+	models "github.com/knadh/listmonk/models"
+	easyjson "github.com/mailru/easyjson"
+	jlexer "github.com/mailru/easyjson/jlexer"
+	jwriter "github.com/mailru/easyjson/jwriter"
+)
+
+// suppress unused package warning
+var (
+	_ *json.RawMessage
+	_ *jlexer.Lexer
+	_ *jwriter.Writer
+	_ easyjson.Marshaler
+)
+
+func easyjsonDf11841fDecodeGithubComKnadhListmonkInternalMessengerPostback(in *jlexer.Lexer, out *postback) {
+	isTopLevel := in.IsStart()
+	if in.IsNull() {
+		if isTopLevel {
+			in.Consumed()
+		}
+		in.Skip()
+		return
+	}
+	in.Delim('{')
+	for !in.IsDelim('}') {
+		key := in.UnsafeFieldName(false)
+		in.WantColon()
+		if in.IsNull() {
+			in.Skip()
+			in.WantComma()
+			continue
+		}
+		switch key {
+		case "subject":
+			out.Subject = string(in.String())
+		case "content_type":
+			out.ContentType = string(in.String())
+		case "body":
+			out.Body = string(in.String())
+		case "recipients":
+			if in.IsNull() {
+				in.Skip()
+				out.Recipients = nil
+			} else {
+				in.Delim('[')
+				if out.Recipients == nil {
+					if !in.IsDelim(']') {
+						out.Recipients = make([]recipient, 0, 0)
+					} else {
+						out.Recipients = []recipient{}
+					}
+				} else {
+					out.Recipients = (out.Recipients)[:0]
+				}
+				for !in.IsDelim(']') {
+					var v1 recipient
+					easyjsonDf11841fDecodeGithubComKnadhListmonkInternalMessengerPostback1(in, &v1)
+					out.Recipients = append(out.Recipients, v1)
+					in.WantComma()
+				}
+				in.Delim(']')
+			}
+		case "campaign":
+			if in.IsNull() {
+				in.Skip()
+				out.Campaign = nil
+			} else {
+				if out.Campaign == nil {
+					out.Campaign = new(campaign)
+				}
+				easyjsonDf11841fDecodeGithubComKnadhListmonkInternalMessengerPostback2(in, out.Campaign)
+			}
+		default:
+			in.SkipRecursive()
+		}
+		in.WantComma()
+	}
+	in.Delim('}')
+	if isTopLevel {
+		in.Consumed()
+	}
+}
+func easyjsonDf11841fEncodeGithubComKnadhListmonkInternalMessengerPostback(out *jwriter.Writer, in postback) {
+	out.RawByte('{')
+	first := true
+	_ = first
+	{
+		const prefix string = ",\"subject\":"
+		out.RawString(prefix[1:])
+		out.String(string(in.Subject))
+	}
+	{
+		const prefix string = ",\"content_type\":"
+		out.RawString(prefix)
+		out.String(string(in.ContentType))
+	}
+	{
+		const prefix string = ",\"body\":"
+		out.RawString(prefix)
+		out.String(string(in.Body))
+	}
+	{
+		const prefix string = ",\"recipients\":"
+		out.RawString(prefix)
+		if in.Recipients == nil && (out.Flags&jwriter.NilSliceAsEmpty) == 0 {
+			out.RawString("null")
+		} else {
+			out.RawByte('[')
+			for v2, v3 := range in.Recipients {
+				if v2 > 0 {
+					out.RawByte(',')
+				}
+				easyjsonDf11841fEncodeGithubComKnadhListmonkInternalMessengerPostback1(out, v3)
+			}
+			out.RawByte(']')
+		}
+	}
+	{
+		const prefix string = ",\"campaign\":"
+		out.RawString(prefix)
+		if in.Campaign == nil {
+			out.RawString("null")
+		} else {
+			easyjsonDf11841fEncodeGithubComKnadhListmonkInternalMessengerPostback2(out, *in.Campaign)
+		}
+	}
+	out.RawByte('}')
+}
+
+// MarshalJSON supports json.Marshaler interface
+func (v postback) MarshalJSON() ([]byte, error) {
+	w := jwriter.Writer{}
+	easyjsonDf11841fEncodeGithubComKnadhListmonkInternalMessengerPostback(&w, v)
+	return w.Buffer.BuildBytes(), w.Error
+}
+
+// MarshalEasyJSON supports easyjson.Marshaler interface
+func (v postback) MarshalEasyJSON(w *jwriter.Writer) {
+	easyjsonDf11841fEncodeGithubComKnadhListmonkInternalMessengerPostback(w, v)
+}
+
+// UnmarshalJSON supports json.Unmarshaler interface
+func (v *postback) UnmarshalJSON(data []byte) error {
+	r := jlexer.Lexer{Data: data}
+	easyjsonDf11841fDecodeGithubComKnadhListmonkInternalMessengerPostback(&r, v)
+	return r.Error()
+}
+
+// UnmarshalEasyJSON supports easyjson.Unmarshaler interface
+func (v *postback) UnmarshalEasyJSON(l *jlexer.Lexer) {
+	easyjsonDf11841fDecodeGithubComKnadhListmonkInternalMessengerPostback(l, v)
+}
+func easyjsonDf11841fDecodeGithubComKnadhListmonkInternalMessengerPostback2(in *jlexer.Lexer, out *campaign) {
+	isTopLevel := in.IsStart()
+	if in.IsNull() {
+		if isTopLevel {
+			in.Consumed()
+		}
+		in.Skip()
+		return
+	}
+	in.Delim('{')
+	for !in.IsDelim('}') {
+		key := in.UnsafeFieldName(false)
+		in.WantColon()
+		if in.IsNull() {
+			in.Skip()
+			in.WantComma()
+			continue
+		}
+		switch key {
+		case "uuid":
+			out.UUID = string(in.String())
+		case "name":
+			out.Name = string(in.String())
+		case "tags":
+			if in.IsNull() {
+				in.Skip()
+				out.Tags = nil
+			} else {
+				in.Delim('[')
+				if out.Tags == nil {
+					if !in.IsDelim(']') {
+						out.Tags = make([]string, 0, 4)
+					} else {
+						out.Tags = []string{}
+					}
+				} else {
+					out.Tags = (out.Tags)[:0]
+				}
+				for !in.IsDelim(']') {
+					var v4 string
+					v4 = string(in.String())
+					out.Tags = append(out.Tags, v4)
+					in.WantComma()
+				}
+				in.Delim(']')
+			}
+		default:
+			in.SkipRecursive()
+		}
+		in.WantComma()
+	}
+	in.Delim('}')
+	if isTopLevel {
+		in.Consumed()
+	}
+}
+func easyjsonDf11841fEncodeGithubComKnadhListmonkInternalMessengerPostback2(out *jwriter.Writer, in campaign) {
+	out.RawByte('{')
+	first := true
+	_ = first
+	{
+		const prefix string = ",\"uuid\":"
+		out.RawString(prefix[1:])
+		out.String(string(in.UUID))
+	}
+	{
+		const prefix string = ",\"name\":"
+		out.RawString(prefix)
+		out.String(string(in.Name))
+	}
+	{
+		const prefix string = ",\"tags\":"
+		out.RawString(prefix)
+		if in.Tags == nil && (out.Flags&jwriter.NilSliceAsEmpty) == 0 {
+			out.RawString("null")
+		} else {
+			out.RawByte('[')
+			for v5, v6 := range in.Tags {
+				if v5 > 0 {
+					out.RawByte(',')
+				}
+				out.String(string(v6))
+			}
+			out.RawByte(']')
+		}
+	}
+	out.RawByte('}')
+}
+func easyjsonDf11841fDecodeGithubComKnadhListmonkInternalMessengerPostback1(in *jlexer.Lexer, out *recipient) {
+	isTopLevel := in.IsStart()
+	if in.IsNull() {
+		if isTopLevel {
+			in.Consumed()
+		}
+		in.Skip()
+		return
+	}
+	in.Delim('{')
+	for !in.IsDelim('}') {
+		key := in.UnsafeFieldName(false)
+		in.WantColon()
+		if in.IsNull() {
+			in.Skip()
+			in.WantComma()
+			continue
+		}
+		switch key {
+		case "uuid":
+			out.UUID = string(in.String())
+		case "email":
+			out.Email = string(in.String())
+		case "name":
+			out.Name = string(in.String())
+		case "attribs":
+			if in.IsNull() {
+				in.Skip()
+			} else {
+				in.Delim('{')
+				out.Attribs = make(models.SubscriberAttribs)
+				for !in.IsDelim('}') {
+					key := string(in.String())
+					in.WantColon()
+					var v7 interface{}
+					if m, ok := v7.(easyjson.Unmarshaler); ok {
+						m.UnmarshalEasyJSON(in)
+					} else if m, ok := v7.(json.Unmarshaler); ok {
+						_ = m.UnmarshalJSON(in.Raw())
+					} else {
+						v7 = in.Interface()
+					}
+					(out.Attribs)[key] = v7
+					in.WantComma()
+				}
+				in.Delim('}')
+			}
+		case "status":
+			out.Status = string(in.String())
+		default:
+			in.SkipRecursive()
+		}
+		in.WantComma()
+	}
+	in.Delim('}')
+	if isTopLevel {
+		in.Consumed()
+	}
+}
+func easyjsonDf11841fEncodeGithubComKnadhListmonkInternalMessengerPostback1(out *jwriter.Writer, in recipient) {
+	out.RawByte('{')
+	first := true
+	_ = first
+	{
+		const prefix string = ",\"uuid\":"
+		out.RawString(prefix[1:])
+		out.String(string(in.UUID))
+	}
+	{
+		const prefix string = ",\"email\":"
+		out.RawString(prefix)
+		out.String(string(in.Email))
+	}
+	{
+		const prefix string = ",\"name\":"
+		out.RawString(prefix)
+		out.String(string(in.Name))
+	}
+	{
+		const prefix string = ",\"attribs\":"
+		out.RawString(prefix)
+		if in.Attribs == nil && (out.Flags&jwriter.NilMapAsEmpty) == 0 {
+			out.RawString(`null`)
+		} else {
+			out.RawByte('{')
+			v8First := true
+			for v8Name, v8Value := range in.Attribs {
+				if v8First {
+					v8First = false
+				} else {
+					out.RawByte(',')
+				}
+				out.String(string(v8Name))
+				out.RawByte(':')
+				if m, ok := v8Value.(easyjson.Marshaler); ok {
+					m.MarshalEasyJSON(out)
+				} else if m, ok := v8Value.(json.Marshaler); ok {
+					out.Raw(m.MarshalJSON())
+				} else {
+					out.Raw(json.Marshal(v8Value))
+				}
+			}
+			out.RawByte('}')
+		}
+	}
+	{
+		const prefix string = ",\"status\":"
+		out.RawString(prefix)
+		out.String(string(in.Status))
+	}
+	out.RawByte('}')
+}

models/models.go

@@ -164,7 +164,7 @@ type Campaign struct {
 	ContentType string         `db:"content_type" json:"content_type"`
 	Tags        pq.StringArray `db:"tags" json:"tags"`
 	TemplateID  int            `db:"template_id" json:"template_id"`
-	MessengerID string         `db:"messenger" json:"messenger"`
+	Messenger   string         `db:"messenger" json:"messenger"`
 
 	// TemplateBody is joined in from templates by the next-campaigns query.
 	TemplateBody string             `db:"template_body" json:"-"`

queries.sql

@@ -561,16 +561,17 @@ WITH camp AS (
         send_at=(CASE WHEN $8 THEN $7::TIMESTAMP WITH TIME ZONE WHEN NOT $8 THEN NULL ELSE send_at END),
         status=(CASE WHEN NOT $8 THEN 'draft' ELSE status END),
         tags=$9::VARCHAR(100)[],
-        template_id=(CASE WHEN $10 != 0 THEN $10 ELSE template_id END),
+        messenger=(CASE WHEN $10 != '' THEN $10 ELSE messenger END),
+        template_id=(CASE WHEN $11 != 0 THEN $11 ELSE template_id END),
         updated_at=NOW()
     WHERE id = $1 RETURNING id
 ),
 d AS (
     -- Reset list relationships
-    DELETE FROM campaign_lists WHERE campaign_id = $1 AND NOT(list_id = ANY($11))
+    DELETE FROM campaign_lists WHERE campaign_id = $1 AND NOT(list_id = ANY($12))
 )
 INSERT INTO campaign_lists (campaign_id, list_id, list_name)
-    (SELECT $1 as campaign_id, id, name FROM lists WHERE id=ANY($11::INT[]))
+    (SELECT $1 as campaign_id, id, name FROM lists WHERE id=ANY($12::INT[]))
     ON CONFLICT (campaign_id, list_id) DO UPDATE SET list_name = EXCLUDED.list_name;
 
 -- name: update-campaign-counts