Add Gotify notification client (#36)

Co-authored-by: Paul Götzinger <paul70079@gmail.com>

doc/configuration.md

@@ -49,6 +49,12 @@ notif:
       Content-Type: application/json
       Authorization: Token123456
     timeout: 10
+  gotify:
+    enable: false
+    endpoint: http://gotify.foo.com
+    token: Token123456
+    priority: 1
+    timeout: 10
 
 regopts:
   someregistryoptions:
@@ -146,6 +152,13 @@ providers:
   * `headers`: Map of additional headers to be sent.
   * `timeout`: Timeout specifies a time limit for the request to be made. (default: `10`).
 
+* `gotify`
+  * `enable`: Enable gotify notification (default: `false`).
+  * `endpoint`: Gotify base URL (e.g. `http://gotify.foo.com`). **required**
+  * `token`: Application token. **required**
+  * `priority`: The priority of the message.
+  * `timeout`: Timeout specifies a time limit for the request to be made. (default: `10`).
+
 ### regopts
 
 * `username`: Registry username.

doc/notifications.md

@@ -1,10 +1,17 @@
 # Notifications
 
+* [Gotify](#gotify)
 * [Mail](#mail)
 * [Slack](#slack)
 * [Telegram](#telegram)
 * [Webhook](#webhook)
 
+## Gotify
+
+Notifications can be sent using a [Gotify](https://gotify.net/) instance. [Follow the instructions](https://gotify.net/docs/install) to set up a Gotify server.
+
+![](../.res/notif-gotify.png)
+
 ## Mail
 
 Here is an email sample if you add `mail` notification:

internal/config/config.go

@@ -67,6 +67,10 @@ func Load(flags model.Flags, version string) (*Config, error) {
 				Method:  "GET",
 				Timeout: 10,
 			},
+			Gotify: model.NotifGotify{
+				Enable:  false,
+				Timeout: 10,
+			},
 		},
 	}
 

internal/config/config.test.yml

@@ -36,6 +36,12 @@ notif:
       Content-Type: application/json
       Authorization: Token123456
     timeout: 10
+  gotify:
+    enable: false
+    endpoint: http://gotify.foo.com
+    token: Token123456
+    priority: 1
+    timeout: 10
 
 regopts:
   someregopts:

internal/config/config_test.go

@@ -78,6 +78,13 @@ func TestLoad(t *testing.T) {
 						},
 						Timeout: 10,
 					},
+					Gotify: model.NotifGotify{
+						Enable:   false,
+						Endpoint: "http://gotify.foo.com",
+						Token:    "Token123456",
+						Priority: 1,
+						Timeout:  10,
+					},
 				},
 				RegOpts: map[string]model.RegOpts{
 					"someregopts": {

internal/model/notif.go

@@ -18,6 +18,7 @@ type Notif struct {
 	Slack    NotifSlack    `yaml:"slack,omitempty"`
 	Telegram NotifTelegram `yaml:"telegram,omitempty"`
 	Webhook  NotifWebhook  `yaml:"webhook,omitempty"`
+	Gotify   NotifGotify   `yaml:"gotify,omitempty"`
 }
 
 // NotifMail holds mail notification configuration details
@@ -56,3 +57,12 @@ type NotifWebhook struct {
 	Headers  map[string]string `yaml:"headers,omitempty"`
 	Timeout  int               `yaml:"timeout,omitempty"`
 }
+
+// NotifGotify holds gotify notification configuration details
+type NotifGotify struct {
+	Enable   bool   `yaml:"enable,omitempty"`
+	Endpoint string `yaml:"endpoint,omitempty"`
+	Token    string `yaml:"token,omitempty"`
+	Priority int    `yaml:"priority,omitempty"`
+	Timeout  int    `yaml:"timeout,omitempty"`
+}

internal/notif/client.go

@@ -2,6 +2,7 @@ package notif
 
 import (
 	"github.com/crazy-max/diun/internal/model"
+	"github.com/crazy-max/diun/internal/notif/gotify"
 	"github.com/crazy-max/diun/internal/notif/mail"
 	"github.com/crazy-max/diun/internal/notif/notifier"
 	"github.com/crazy-max/diun/internal/notif/slack"
@@ -38,6 +39,9 @@ func New(config model.Notif, app model.App) (*Client, error) {
 	if config.Webhook.Enable {
 		c.notifiers = append(c.notifiers, webhook.New(config.Webhook, app))
 	}
+	if config.Gotify.Enable {
+		c.notifiers = append(c.notifiers, gotify.New(config.Gotify, app))
+	}
 
 	log.Debug().Msgf("%d notifier(s) created", len(c.notifiers))
 	return c, nil

internal/notif/gotify/client.go

@@ -0,0 +1,101 @@
+package gotify
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"path"
+	"strconv"
+	"strings"
+	"text/template"
+	"time"
+
+	"github.com/crazy-max/diun/internal/model"
+	"github.com/crazy-max/diun/internal/notif/notifier"
+)
+
+// Client represents an active gotify notification object
+type Client struct {
+	*notifier.Notifier
+	cfg model.NotifGotify
+	app model.App
+}
+
+// New creates a new gotify notification instance
+func New(config model.NotifGotify, app model.App) notifier.Notifier {
+	return notifier.Notifier{
+		Handler: &Client{
+			cfg: config,
+			app: app,
+		},
+	}
+}
+
+// Name returns notifier's name
+func (c *Client) Name() string {
+	return "gotify"
+}
+
+// Send creates and sends a gotify notification with an entry
+func (c *Client) Send(entry model.NotifEntry) error {
+	hc := http.Client{
+		Timeout: time.Duration(c.cfg.Timeout) * time.Second,
+	}
+
+	title := fmt.Sprintf("Image update for %s", entry.Image.String())
+	if entry.Status == model.ImageStatusNew {
+		title = fmt.Sprintf("New image %s has been added", entry.Image.String())
+	}
+
+	var msgBuf bytes.Buffer
+	msgTpl := template.Must(template.New("gotify").Parse(`Docker 🐳 tag {{ .Image.Domain }}/{{ .Image.Path }}:{{ .Image.Tag }} which you subscribed to through {{ .Provider }} provider has been {{ if (eq .Status "new") }}newly added{{ else }}updated{{ end }}.`))
+	if err := msgTpl.Execute(&msgBuf, entry); err != nil {
+		return err
+	}
+
+	data := url.Values{}
+	data.Set("message", msgBuf.String())
+	data.Set("title", title)
+	data.Set("priority", strconv.Itoa(c.cfg.Priority))
+
+	u, err := url.Parse(c.cfg.Endpoint)
+	if err != nil {
+		return err
+	}
+	u.Path = path.Join(u.Path, "message")
+
+	q := u.Query()
+	q.Set("token", c.cfg.Token)
+	u.RawQuery = q.Encode()
+
+	req, err := http.NewRequest("POST", u.String(), strings.NewReader(data.Encode()))
+	if err != nil {
+		return err
+	}
+
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Add("Content-Length", strconv.Itoa(len(data.Encode())))
+	req.Header.Set("User-Agent", fmt.Sprintf("%s %s", c.app.Name, c.app.Version))
+
+	resp, err := hc.Do(req)
+	if err != nil {
+		return err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		var errBody struct {
+			Error            string `json:"error"`
+			ErrorCode        int    `json:"errorCode"`
+			ErrorDescription string `json:"errorDescription"`
+		}
+		err := json.NewDecoder(resp.Body).Decode(&errBody)
+		if err != nil {
+			return err
+		}
+		return fmt.Errorf("%d %s: %s", errBody.ErrorCode, errBody.Error, errBody.ErrorDescription)
+	}
+
+	return nil
+}

internal/notif/webhook/client.go

@@ -65,7 +65,7 @@ func (c *Client) Send(entry model.NotifEntry) error {
 		return err
 	}
 
-	req, err := http.NewRequest(c.cfg.Method, c.cfg.Endpoint, bytes.NewBuffer([]byte(body)))
+	req, err := http.NewRequest(c.cfg.Method, c.cfg.Endpoint, bytes.NewBuffer(body))
 	if err != nil {
 		return err
 	}