Add Docker deployment support

- Create Dockerfile with multi-stage build for optimized image size
- Add GitHub Actions workflow for automatic image publishing to ghcr.io
- Add PORT and HOST fallback defaults in config (8080 and 0.0.0.0)
- Update README with Docker Compose installation instructions

.github/workflows/docker-publish.yml

@@ -0,0 +1,42 @@
+name: Docker Build and Push
+
+on:
+  push:
+    branches: [ main ]
+    tags: [ 'v*' ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Login to GitHub Container Registry
+      uses: docker/login-action@v2
+      with:
+        registry: ghcr.io
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: Extract metadata
+      id: meta
+      uses: docker/metadata-action@v4
+      with:
+        images: ghcr.io/${{ github.repository }}
+        tags: |
+          type=ref,event=branch
+          type=ref,event=tag
+          type=sha
+          type=raw,value=latest,enable={{is_default_branch}}
+
+    - name: Build and push
+      uses: docker/build-push-action@v4
+      with:
+        context: .
+        push: true
+        tags: ${{ steps.meta.outputs.tags }}
+        labels: ${{ steps.meta.outputs.labels }}

Dockerfile

@@ -0,0 +1,22 @@
+FROM golang:1.24-alpine AS builder
+
+RUN apk add --no-cache gcc musl-dev sqlite-dev
+
+WORKDIR /app
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN CGO_ENABLED=1 GOOS=linux go build -a -installsuffix cgo -o apocapoc-api cmd/api/main.go
+
+FROM alpine:latest
+RUN apk --no-cache add ca-certificates sqlite-libs
+
+WORKDIR /root/
+
+COPY --from=builder /app/apocapoc-api .
+
+EXPOSE 8080
+
+CMD ["./apocapoc-api"]

README.md

@@ -13,6 +13,49 @@ Self-hosted habit tracking service with a clean, hexagonal architecture.
 
 ## Quick Start
 
+### Using Docker Compose (Recommended)
+
+1. Create a `docker-compose.yml` file:
+
+```yaml
+services:
+  api:
+    image: ghcr.io/davidfolch/apocapoc-api:latest
+    ports:
+      - "8080:8080"
+    environment:
+      - DB_TYPE=sqlite
+      - DB_PATH=/data/apocapoc.db
+      - JWT_SECRET=YOUR_SECRET_HERE
+      - JWT_EXPIRY=24h
+      - REFRESH_TOKEN_EXPIRY=168h
+      - CORS_ORIGINS=http://localhost:3000
+      - DEFAULT_TIMEZONE=UTC
+    volumes:
+      - habit-data:/data
+    restart: unless-stopped
+
+volumes:
+  habit-data:
+```
+
+2. **Important**: Replace `YOUR_SECRET_HERE` with a secure random string for `JWT_SECRET`
+
+3. Start the service:
+
+```bash
+docker-compose up -d
+```
+
+The API will be available at `http://localhost:8080`
+
+**Configuration options:**
+- `JWT_SECRET`: **Required**. Use a long random string
+- `JWT_EXPIRY`: Token expiration (e.g., `24h`, `48h`)
+- `REFRESH_TOKEN_EXPIRY`: Refresh token expiration (e.g., `168h` = 7 days)
+- `CORS_ORIGINS`: Comma-separated list of allowed origins
+- `DEFAULT_TIMEZONE`: Timezone for date calculations (e.g., `UTC`, `Europe/Madrid`)
+
 ### Using the binary
 
 1. Download the latest release

internal/infrastructure/config/config.go

@@ -25,8 +25,8 @@ func Load() (*Config, error) {
 	cfg := &Config{
 		DBType:             os.Getenv("DB_TYPE"),
 		DBPath:             os.Getenv("DB_PATH"),
-		Port:               os.Getenv("PORT"),
+		Port:               getEnvOrDefault("PORT", "8080"),
-		Host:               os.Getenv("HOST"),
+		Host:               getEnvOrDefault("HOST", "0.0.0.0"),
 		JWTSecret:          os.Getenv("JWT_SECRET"),
 		JWTExpiry:          os.Getenv("JWT_EXPIRY"),
 		RefreshTokenExpiry: os.Getenv("REFRESH_TOKEN_EXPIRY"),
@@ -40,12 +40,6 @@ func Load() (*Config, error) {
 	if cfg.DBPath == "" {
 		return nil, fmt.Errorf("DB_PATH is required")
 	}
-	if cfg.Port == "" {
-		return nil, fmt.Errorf("PORT is required")
-	}
-	if cfg.Host == "" {
-		return nil, fmt.Errorf("HOST is required")
-	}
 	if cfg.JWTSecret == "" {
 		return nil, fmt.Errorf("JWT_SECRET is required")
 	}
@@ -64,3 +58,10 @@ func Load() (*Config, error) {
 
 	return cfg, nil
 }
+
+func getEnvOrDefault(key, defaultValue string) string {
+	if value := os.Getenv(key); value != "" {
+		return value
+	}
+	return defaultValue
+}