Improve data location selection

Dockerfile

@@ -9,10 +9,9 @@ COPY src /app/src
 COPY go.mod /app/
 COPY .golangci.yml /app/
 
-RUN go mod tidy
-RUN golangci-lint run
-RUN go test ./src/...
-
+RUN go mod tidy; \
+    golangci-lint run; \
+    go test ./src/...
 RUN CGO_ENABLED=1 go build -o app src/main/main.go
 
 FROM alpine:latest
@@ -21,6 +20,9 @@ WORKDIR /app
 
 COPY --from=1 /app/app .
 COPY ./templates /app/templates
-RUN touch config.json database.db
 
-CMD ["./app"]
+RUN mkdir data
+ENV DATABASE_PATH=./data/database.db
+ENV CONFIG_PATH=./data/config.json
+
+CMD "./app"

src/ecodash/config.go

@@ -70,7 +70,11 @@ func formatURL(url string) (string, error) {
 }
 
 func LoadConfig() (config *Config, err error) {
-	db, err := sql.Open("sqlite", "./database.db")
+	var dbPath string
+	if dbPath = os.Getenv("DATABASE_PATH"); dbPath == "" {
+		dbPath = "./database.db"
+	}
+	db, err := sql.Open("sqlite", dbPath)
 	if err != nil {
 		return &Config{}, err
 	}
@@ -99,7 +103,11 @@ func LoadConfig() (config *Config, err error) {
 	})
 	defaultConfig.db = db
 
-	data, err := os.ReadFile("config.json")
+	var confPath string
+	if confPath = os.Getenv("CONFIG_PATH"); confPath == "" {
+		confPath = "./config.json"
+	}
+	data, err := os.ReadFile(confPath)
 	if err != nil {
 		// if the data file doesn't exist, we consider it a first run
 		if os.IsNotExist(err) {

src/ecodash/http.go

@@ -153,7 +153,12 @@ func (config *Config) saveAdminForm(c *fiber.Ctx) error {
 	}
 
 	*config = form
-	return os.WriteFile("config.json", js, 0o600)
+
+	var confPath string
+	if confPath = os.Getenv("CONFIG_PATH"); confPath == "" {
+		confPath = "./config.json"
+	}
+	return os.WriteFile(confPath, js, 0o600)
 }
 
 func averageExcludingCurrentDay(data []float32) float32 {