Set default Docker directories

Dockerfile

@@ -5,6 +5,8 @@ RUN apt update && \
     apt install ca-certificates \
     && rm -rf /var/lib/apt/lists/*
 
+RUN mkdir /data
+
 ENV PREMIUMIZEARR_CONFIG_DIR_PATH=/data
 ENV PREMIUMIZEARR_LOGGING_DIR_PATH=/data
 

cmd/premiumizearrd/main.go

@@ -78,6 +78,19 @@ func main() {
 
 	config, err := config.LoadOrCreateConfig(configFile)
 
+	// Override config data directories if running in docker
+	if utils.IsRunningInDockerContainer() {
+		if config.BlackholeDirectory == "" {
+			config.BlackholeDirectory = "/blackhole"
+		}
+		if config.DownloadsDirectory == "" {
+			config.DownloadsDirectory = "/downloads"
+		}
+		if config.UnzipDirectory == "" {
+			config.UnzipDirectory = "/unzip"
+		}
+	}
+
 	if err != nil {
 		panic(err)
 	}

internal/utils/utils.go

@@ -118,3 +118,16 @@ func EnvOrDefault(envName string, defaultValue string) string {
 	}
 	return envValue
 }
+
+func IsRunningInDockerContainer() bool {
+	// docker creates a .dockerenv file at the root
+	// of the directory tree inside the container.
+	// if this file exists then the viewer is running
+	// from inside a container so return true
+
+	if _, err := os.Stat("/.dockerenv"); err == nil {
+		return true
+	}
+
+	return false
+}