Discord notif (#111)

Co-authored-by: CrazyMax <crazy-max@users.noreply.github.com>

docs/notif/discord.md

@@ -0,0 +1,30 @@
+# Discord notifications
+
+Allow to send notifications to your Discord channel.
+
+## Configuration
+
+!!! example "File"
+    ```yaml
+    notif:
+      discord:
+        webhookURL: https://discordapp.com/api/webhooks/1234567890/Abcd-eFgh-iJklmNo_pqr
+        timeout: 10s
+    ```
+
+!!! abstract "Environment variables"
+    * `DIUN_NOTIF_DISCORD_WEBHOOK`
+    * `DIUN_NOTIF_DISCORD_TIMEOUT`
+
+| Name               | Default       | Description   |
+|--------------------|---------------|---------------|
+| `webhookURL`[^1]   |               | Discord [incoming webhook URL](https://support.discord.com/hc/en-us/articles/228383668-Intro-to-Webhooks) |
+| `timeout`          | `10s`         | Timeout specifies a time limit for the request to be made |
+
+## Sample
+
+![](../assets/notif/discord-1.png)
+
+![](../assets/notif/discord-2.png)
+
+[^1]: Value required

internal/config/config_test.go

@@ -50,6 +50,10 @@ func TestLoadFile(t *testing.T) {
 						Password: "guest",
 						Queue:    "queue",
 					},
+					Discord: &model.NotifDiscord{
+						WebhookURL: "https://discordapp.com/api/webhooks/1234567890/Abcd-eFgh-iJklmNo_pqr",
+						Timeout:    utl.NewDuration(10 * time.Second),
+					},
 					Gotify: &model.NotifGotify{
 						Endpoint: "http://gotify.foo.com",
 						Token:    "Token123456",

internal/config/fixtures/config.test.yml

@@ -13,6 +13,9 @@ notif:
     username: guest
     password: guest
     queue: queue
+  discord:
+    webhookURL: https://discordapp.com/api/webhooks/1234567890/Abcd-eFgh-iJklmNo_pqr
+    timeout: 10s
   gotify:
     endpoint: http://gotify.foo.com
     token: Token123456

internal/config/fixtures/config.validate.yml

@@ -13,6 +13,9 @@ notif:
     username: guest
     password: guest
     queue: queue
+  discord:
+    webhookURL: https://discordapp.com/api/webhooks/1234567890/Abcd-eFgh-iJklmNo_pqr
+    timeout: 10s
   gotify:
     endpoint: http://gotify.foo.com
     token: Token123456

internal/model/notif.go

@@ -15,6 +15,7 @@ type NotifEntry struct {
 // Notif holds data necessary for notification configuration
 type Notif struct {
 	Amqp       *NotifAmqp       `yaml:"amqp,omitempty" json:"amqp,omitempty"`
+	Discord    *NotifDiscord    `yaml:"discord,omitempty" json:"discord,omitempty"`
 	Gotify     *NotifGotify     `yaml:"gotify,omitempty" json:"gotify,omitempty"`
 	Mail       *NotifMail       `yaml:"mail,omitempty" json:"mail,omitempty"`
 	RocketChat *NotifRocketChat `yaml:"rocketchat,omitempty" json:"rocketchat,omitempty"`

internal/model/notif_discord.go

@@ -0,0 +1,25 @@
+package model
+
+import (
+	"time"
+
+	"github.com/crazy-max/diun/v4/pkg/utl"
+)
+
+// NotifDiscord holds Discord notification configuration details
+type NotifDiscord struct {
+	WebhookURL string         `yaml:"webhookURL,omitempty" json:"webhookURL,omitempty" validate:"required"`
+	Timeout    *time.Duration `yaml:"timeout,omitempty" json:"timeout,omitempty" validate:"required"`
+}
+
+// GetDefaults gets the default values
+func (s *NotifDiscord) GetDefaults() *NotifDiscord {
+	n := &NotifDiscord{}
+	n.SetDefaults()
+	return n
+}
+
+// SetDefaults sets the default values
+func (s *NotifDiscord) SetDefaults() {
+	s.Timeout = utl.NewDuration(10 * time.Second)
+}

internal/notif/client.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/crazy-max/diun/v4/internal/model"
 	"github.com/crazy-max/diun/v4/internal/notif/amqp"
+	"github.com/crazy-max/diun/v4/internal/notif/discord"
 	"github.com/crazy-max/diun/v4/internal/notif/gotify"
 	"github.com/crazy-max/diun/v4/internal/notif/mail"
 	"github.com/crazy-max/diun/v4/internal/notif/notifier"
@@ -41,6 +42,9 @@ func New(config *model.Notif, meta model.Meta) (*Client, error) {
 	if config.Amqp != nil {
 		c.notifiers = append(c.notifiers, amqp.New(config.Amqp, meta))
 	}
+	if config.Discord != nil {
+		c.notifiers = append(c.notifiers, discord.New(config.Discord, meta))
+	}
 	if config.Gotify != nil {
 		c.notifiers = append(c.notifiers, gotify.New(config.Gotify, meta))
 	}

internal/notif/discord/client.go

@@ -0,0 +1,143 @@
+package discord
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"text/template"
+	"time"
+
+	"github.com/crazy-max/diun/v4/internal/model"
+	"github.com/crazy-max/diun/v4/internal/notif/notifier"
+)
+
+// Client represents an active discord notification object
+type Client struct {
+	*notifier.Notifier
+	cfg  *model.NotifDiscord
+	meta model.Meta
+}
+
+// New creates a new discord notification instance
+func New(config *model.NotifDiscord, meta model.Meta) notifier.Notifier {
+	return notifier.Notifier{
+		Handler: &Client{
+			cfg:  config,
+			meta: meta,
+		},
+	}
+}
+
+// Name returns notifier's name
+func (c *Client) Name() string {
+	return "discord"
+}
+
+// Send creates and sends a discord notification with an entry
+// https://discord.com/developers/docs/resources/webhook#execute-webhook
+func (c *Client) Send(entry model.NotifEntry) error {
+	hc := http.Client{
+		Timeout: *c.cfg.Timeout,
+	}
+
+	content := fmt.Sprintf("@here Image update for %s", entry.Image.String())
+	if entry.Status == model.ImageStatusNew {
+		content = fmt.Sprintf("@here New image %s has been added", entry.Image.String())
+	}
+
+	tagTpl := "**{{ .Entry.Image.Domain }}/{{ .Entry.Image.Path }}:{{ .Entry.Image.Tag }}**"
+	if len(entry.Image.HubLink) > 0 {
+		tagTpl = "[**{{ .Entry.Image.Domain }}/{{ .Entry.Image.Path }}:{{ .Entry.Image.Tag }}**]({{ .Entry.Image.HubLink }})"
+	}
+
+	var textBuf bytes.Buffer
+	textTpl := template.Must(template.New("discord").Parse(fmt.Sprintf(`Docker tag %s which you subscribed to through **{{ .Entry.Provider }}** provider has been {{ if (eq .Entry.Status "new") }}newly added{{ else }}updated{{ end }} on **myserver**.`, tagTpl)))
+	if err := textTpl.Execute(&textBuf, struct {
+		Meta  model.Meta
+		Entry model.NotifEntry
+	}{
+		Meta:  c.meta,
+		Entry: entry,
+	}); err != nil {
+		return err
+	}
+
+	fields := []EmbedField{
+		{
+			Name:  "Hostname",
+			Value: c.meta.Hostname,
+		},
+		{
+			Name:  "Provider",
+			Value: entry.Provider,
+		},
+		{
+			Name:  "Created",
+			Value: entry.Manifest.Created.Format("Jan 02, 2006 15:04:05 UTC"),
+		},
+		{
+			Name:  "Digest",
+			Value: entry.Manifest.Digest.String(),
+		},
+		{
+			Name:  "Platform",
+			Value: entry.Manifest.Platform,
+		},
+	}
+	if len(entry.Image.HubLink) > 0 {
+		fields = append(fields, EmbedField{
+			Name:  "HubLink",
+			Value: entry.Image.HubLink,
+		})
+	}
+
+	dataBuf := new(bytes.Buffer)
+	if err := json.NewEncoder(dataBuf).Encode(Message{
+		Content:   content,
+		Username:  c.meta.Name,
+		AvatarURL: c.meta.Logo,
+		Embeds: []Embed{
+			{
+				Description: textBuf.String(),
+				Footer: EmbedFooter{
+					Text:    fmt.Sprintf("%s © %d %s %s", c.meta.Author, time.Now().Year(), c.meta.Name, c.meta.Version),
+					IconURL: c.meta.Logo,
+				},
+				Author: EmbedAuthor{
+					Name:    c.meta.Name,
+					URL:     c.meta.URL,
+					IconURL: c.meta.Logo,
+				},
+				Fields: fields,
+			},
+		},
+	}); err != nil {
+		return err
+	}
+
+	u, err := url.Parse(c.cfg.WebhookURL)
+	if err != nil {
+		return err
+	}
+
+	req, err := http.NewRequest("POST", u.String(), dataBuf)
+	if err != nil {
+		return err
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("User-Agent", c.meta.UserAgent)
+
+	resp, err := hc.Do(req)
+	if err != nil {
+		return err
+	}
+
+	if resp.StatusCode != http.StatusNoContent {
+		return fmt.Errorf("unexpected HTTP status %d: %s", resp.StatusCode, resp.Body)
+	}
+
+	return nil
+}

internal/notif/discord/model.go

@@ -0,0 +1,52 @@
+package discord
+
+// Message contains all the information for a message
+type Message struct {
+	Content   string  `json:"content"`
+	Username  string  `json:"username"`
+	AvatarURL string  `json:"avatar_url"`
+	Embeds    []Embed `json:"embeds"`
+}
+
+// Embed contains all the information for an embed object
+type Embed struct {
+	Title       string         `json:"title,omitempty"`
+	Description string         `json:"description,omitempty"`
+	URL         string         `json:"url,omitempty"`
+	Color       int            `json:"color,omitempty"`
+	Footer      EmbedFooter    `json:"footer,omitempty"`
+	Image       EmbedImage     `json:"image,omitempty"`
+	Thumbnail   EmbedThumbnail `json:"thumbnail,omitempty"`
+	Author      EmbedAuthor    `json:"author,omitempty"`
+	Fields      []EmbedField   `json:"fields,omitempty"`
+}
+
+// EmbedFooter contains all the information for an embed footer object
+type EmbedFooter struct {
+	Text    string `json:"text"`
+	IconURL string `json:"icon_url"`
+}
+
+// EmbedImage contains all the information for an embed image object
+type EmbedImage struct {
+	URL string `json:"url"`
+}
+
+// EmbedThumbnail contains all the information for an embed thumbnail object
+type EmbedThumbnail struct {
+	URL string `json:"url"`
+}
+
+// EmbedAuthor contains all the information for an embed author object
+type EmbedAuthor struct {
+	Name    string `json:"name"`
+	URL     string `json:"url"`
+	IconURL string `json:"icon_url"`
+}
+
+// EmbedField contains all the information for an embed field object
+type EmbedField struct {
+	Name   string `json:"name"`
+	Value  string `json:"value"`
+	Inline bool   `json:"inline,omitempty"`
+}

mkdocs.yml

@@ -66,6 +66,7 @@ nav:
     - .providers: config/providers.md
   - Notifications:
     - Amqp: notif/amqp.md
+    - Discord: notif/discord.md
     - Gotify: notif/gotify.md
     - Mail: notif/mail.md
     - Rocket.Chat: notif/rocketchat.md