From 66aed0f0dae263b4255a46e49fed44f37cd1a990 Mon Sep 17 00:00:00 2001
From: Melora Hugues <dev@faercol.me>
Date: Sat, 11 Mar 2023 20:42:21 +0100
Subject: [PATCH] Make sure the notifier can work inside Docker

---
 .drone.yml                    |  6 ++---
 Dockerfile                    |  2 +-
 examples/docker-compose.yml   |  9 +++++++
 notifier/config/config.go     | 44 +++++++++++++++++++++++++++++++++--
 notifier/listener/listener.go |  3 +++
 5 files changed, 58 insertions(+), 6 deletions(-)
 create mode 100644 examples/docker-compose.yml

diff --git a/.drone.yml b/.drone.yml
index 5e8a5b2..d8c3c2a 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -21,7 +21,7 @@ steps:
   image: thegeeklab/drone-docker-buildx
   privileged: true
   settings:
-    repo: git.faercol.me/faercol/telegram-notifier
+    repo: git.faercol.me/notification/telegram-notifier
     tags: latest
     dry_run: true
     platforms:
@@ -37,7 +37,7 @@ steps:
   image: thegeeklab/drone-docker-buildx
   privileged: true
   settings:
-    repo: git.faercol.me/faercol/telegram-notifier
+    repo: git.faercol.me/notification/telegram-notifier
     registry: git.faercol.me
     tags: latest
     username:
@@ -73,7 +73,7 @@ steps:
   privileged: true
   settings:
     registry: git.faercol.me
-    repo: git.faercol.me/faercol/teelgram-notifier
+    repo: git.faercol.me/notification/telegram-notifier
     auto_tag: true
     platforms:
       - linux/amd64
diff --git a/Dockerfile b/Dockerfile
index d1d1252..0858740 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,7 +10,7 @@ FROM --platform=$TARGETPLATFORM alpine:latest
 WORKDIR /root
 COPY --from=builder go/src/git.faercol.me/telegram-notifier/build/notifier ./
 
-VOLUME [ "/config" "/input" ]
+VOLUME [ "/config", "/input" ]
 
 ENTRYPOINT [ "./notifier" ]
 CMD [ "-config", "/config/config.json" ]
diff --git a/examples/docker-compose.yml b/examples/docker-compose.yml
new file mode 100644
index 0000000..9cec29f
--- /dev/null
+++ b/examples/docker-compose.yml
@@ -0,0 +1,9 @@
+services:
+  telegram_exporter:
+    container_name: telegram_exporter
+    image: git.faercol.me/notification/telegram-notifier:latest
+    environment:
+      - SOCK_PATH=/input/input.sock
+    volumes:
+      - ./build/config:/config
+      - ./build/input:/input
diff --git a/notifier/config/config.go b/notifier/config/config.go
index 1ddbeb7..1fcc017 100644
--- a/notifier/config/config.go
+++ b/notifier/config/config.go
@@ -2,8 +2,11 @@ package config
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
+	"io/fs"
 	"os"
+	"strconv"
 
 	"github.com/sirupsen/logrus"
 )
@@ -46,20 +49,57 @@ func parseLevel(lvlStr string) logrus.Level {
 	return logrus.InfoLevel
 }
 
+var defaultConfig Config = Config{
+	Telegram: TelegramConfig{
+		ChannelID: 0,
+		Token:     "",
+	},
+	Log: LogConfig{
+		Level: logrus.InfoLevel,
+	},
+	Listener: ListenerConfig{
+		SockPath: "input/notifier.sock",
+	},
+}
+
+func checkOverride(conf *Config) {
+	if val, ok := os.LookupEnv("LOG_LEVEL"); ok {
+		conf.Log.Level = parseLevel(val)
+	}
+	if val, ok := os.LookupEnv("SOCK_PATH"); ok {
+		conf.Listener.SockPath = val
+	}
+	if val, ok := os.LookupEnv("TELEGRAM_CHANNEL_ID"); ok {
+		if intVal, err := strconv.Atoi(val); err == nil {
+			conf.Telegram.ChannelID = int64(intVal)
+		}
+	}
+	if val, ok := os.LookupEnv("TELEGRAM_TOKEN"); ok {
+		conf.Telegram.Token = val
+	}
+}
+
 func New(filepath string) (*Config, error) {
 	content, err := os.ReadFile(filepath)
 	if err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			conf := defaultConfig
+			checkOverride(&conf)
+			return &conf, nil
+		}
 		return nil, fmt.Errorf("failed to read config file %q: %w", filepath, err)
 	}
 	var jsonConf jsonConfig
 	if err := json.Unmarshal(content, &jsonConf); err != nil {
 		return nil, fmt.Errorf("failed to parse config file: %w", err)
 	}
-	return &Config{
+	conf := &Config{
 		Telegram: jsonConf.Telegram,
 		Log: LogConfig{
 			Level: parseLevel(jsonConf.Log.Level),
 		},
 		Listener: jsonConf.Listener,
-	}, nil
+	}
+	checkOverride(conf)
+	return conf, nil
 }
diff --git a/notifier/listener/listener.go b/notifier/listener/listener.go
index 42a359b..1f19e72 100644
--- a/notifier/listener/listener.go
+++ b/notifier/listener/listener.go
@@ -29,6 +29,9 @@ func New(sockPath string) (*Listener, error) {
 	if err != nil {
 		return nil, fmt.Errorf("failed to create unix socket: %w", err)
 	}
+	if err := os.Chmod(sockPath, 0o777); err != nil {
+		return nil, fmt.Errorf("failed to set permissions to unix socket: %w", err)
+	}
 
 	m := http.NewServeMux()