feat: add optional .env support for environment configuration

.env.example

@@ -0,0 +1,36 @@
+# Installation
+INSTALL_PORT=80
+AUTO_INSTALL=false
+
+# Database
+DB_TYPE=
+DB_USERNAME=
+DB_PASSWORD=
+DB_HOST=
+DB_NAME=
+DB_FILE=
+
+# Site
+LANGUAGE=en-US
+SITE_NAME=Apache Answer
+SITE_URL=
+CONTACT_EMAIL=
+
+# Admin
+ADMIN_NAME=
+ADMIN_PASSWORD=
+ADMIN_EMAIL=
+
+# Content
+EXTERNAL_CONTENT_DISPLAY=ask_before_display
+
+# Swagger
+SWAGGER_HOST=
+SWAGGER_ADDRESS_PORT=
+
+# Server
+SITE_ADDR=0.0.0.0:3000
+
+# Logging
+LOG_LEVEL=INFO
+LOG_PATH=

.gitignore

@@ -33,3 +33,6 @@ dist/
 
 # Lint setup generated file
 .husky/
+
+# Environment variables
+.env

README.md

@@ -46,6 +46,15 @@ You can also check out the [plugins here](https://answer.apache.org/plugins).
 - [mockgen](https://github.com/uber-go/mock?tab=readme-ov-file#installation) >= 0.6.0
 - [wire](https://github.com/google/wire/) >= 0.5.0
 
+### Environment Configuration
+
+    You may create a `.env` file in the project root.
+    Copy `.env.example` and fill required values.
+
+    ```bash
+    cp .env.example .env
+
+
 ### Build
 
 ```bash

cmd/main.go

@@ -31,12 +31,18 @@ import (
 	"github.com/apache/answer/internal/base/path"
 	"github.com/apache/answer/internal/schema"
 	"github.com/gin-gonic/gin"
+	"github.com/joho/godotenv"
 	"github.com/segmentfault/pacman"
 	"github.com/segmentfault/pacman/contrib/log/zap"
 	"github.com/segmentfault/pacman/contrib/server/http"
 	"github.com/segmentfault/pacman/log"
 )
 
+func init() {
+	// Load .env if present, ignore error to keep backward compatibility
+	_ = godotenv.Load()
+}
+
 // go build -ldflags "-X github.com/apache/answer/cmd.Version=x.y.z"
 var (
 	// Name is the name of the project

data/conf/config.yaml

@@ -0,0 +1,25 @@
+debug: false
+server:
+  http:
+    addr: 0.0.0.0:80
+data:
+  database:
+    driver: sqlite3
+    connection: ./data/answer.db
+  cache:
+    file_path: data/cache/cache.db
+i18n:
+  bundle_dir: data/i18n
+service_config:
+  upload_path: data/uploads
+  clean_up_uploads: true
+  clean_orphan_uploads_period_hours: 48
+  purge_deleted_files_period_days: 30
+swaggerui:
+  show: true
+  protocol: http
+  host: 127.0.0.1
+  address: :80
+ui:
+  base_url: ""
+  api_base_url: ""