fix: use free GoReleaser syntax for Docker builds

Problem:
- GoReleaser Pro features (use: buildx, build_flag_templates) not available in free version
- CI/CD failing with "field not found in type config.DockerV2" errors

Solution:
- Split each Docker image into separate amd64 and arm64 builds
- Use goarch field to specify architecture
- Use build_flags instead of build_flag_templates
- Add docker_manifests section to combine arch-specific images into multi-arch manifests

Changes:
- Each service now has two Docker image definitions (amd64 and arm64)
- Images tagged with architecture suffix (e.g., v1.0.0-amd64, v1.0.0-arm64)
- Docker manifests combine them into unified tags (e.g., v1.0.0, latest)
- Users can pull multi-arch images normally, Docker will select correct arch

Result:
- Works with free GoReleaser version
- Maintains multi-architecture support
- Multi-stage Dockerfiles compile for each architecture natively

.goreleaser.yaml

@@ -13,42 +13,13 @@ before:
     # - ./script/generate-version.sh
 
 # Build configuration
+# Note: Binaries are built inside Docker containers (multi-stage builds)
+# to avoid CGO cross-compilation issues. No standalone builds here.
 builds:
   - id: gohoarder
-    main: ./cmd/gohoarder
-    binary: gohoarder
-    env:
-      - CGO_ENABLED=0
-    goos:
-      - linux
-      - darwin
-      - windows
-    goarch:
-      - amd64
-      - arm64
-    ldflags:
-      - -s -w
-      - -X github.com/lukaszraczylo/gohoarder/internal/version.Version={{.Version}}
-      - -X github.com/lukaszraczylo/gohoarder/internal/version.GitCommit={{.ShortCommit}}
-      - -X github.com/lukaszraczylo/gohoarder/internal/version.BuildTime={{.Date}}
-
+    skip: true
   - id: migrate
-    main: ./cmd/migrate
-    binary: migrate
-    env:
-      - CGO_ENABLED=0
-    goos:
-      - linux
-      - darwin
-      - windows
-    goarch:
-      - amd64
-      - arm64
-    ldflags:
-      - -s -w
-      - -X main.Version={{.Version}}
-      - -X main.GitCommit={{.ShortCommit}}
-      - -X main.BuildTime={{.Date}}
+    skip: true
 
 # Archives for releases
 archives:
@@ -108,16 +79,43 @@ release:
 dockers_v2:
   # 1. Application Engine - Main GoHoarder server
   - id: gohoarder-server
-    ids:
-      - gohoarder
     images:
       - ghcr.io/lukaszraczylo/gohoarder-server
+    goarch: amd64
+    build_flags:
+      - "--build-arg=VERSION={{ .Version }}"
+      - "--build-arg=GIT_COMMIT={{ .ShortCommit }}"
+      - "--build-arg=BUILD_TIME={{ .Date }}"
+      - "--build-arg=TARGETOS=linux"
+      - "--build-arg=TARGETARCH=amd64"
     tags:
-      - "{{ .Version }}"
-      - latest
-    platforms:
-      - linux/amd64
-      - linux/arm64
+      - "{{ .Version }}-amd64"
+      - latest-amd64
+    dockerfile: Dockerfile.server
+    labels:
+      org.opencontainers.image.title: GoHoarder Server
+      org.opencontainers.image.description: Universal package cache proxy server
+      org.opencontainers.image.url: https://github.com/lukaszraczylo/gohoarder
+      org.opencontainers.image.source: https://github.com/lukaszraczylo/gohoarder
+      org.opencontainers.image.version: "{{ .Version }}"
+      org.opencontainers.image.created: "{{ .Date }}"
+      org.opencontainers.image.revision: "{{ .FullCommit }}"
+    extra_files:
+      - config.yaml.example
+
+  - id: gohoarder-server-arm64
+    images:
+      - ghcr.io/lukaszraczylo/gohoarder-server
+    goarch: arm64
+    build_flags:
+      - "--build-arg=VERSION={{ .Version }}"
+      - "--build-arg=GIT_COMMIT={{ .ShortCommit }}"
+      - "--build-arg=BUILD_TIME={{ .Date }}"
+      - "--build-arg=TARGETOS=linux"
+      - "--build-arg=TARGETARCH=arm64"
+    tags:
+      - "{{ .Version }}-arm64"
+      - latest-arm64
     dockerfile: Dockerfile.server
     labels:
       org.opencontainers.image.title: GoHoarder Server
@@ -132,16 +130,31 @@ dockers_v2:
 
   # 2. Website - Frontend Dashboard
   - id: gohoarder-frontend
-    ids:
-      - gohoarder
     images:
       - ghcr.io/lukaszraczylo/gohoarder-frontend
+    goarch: amd64
     tags:
-      - "{{ .Version }}"
-      - latest
-    platforms:
-      - linux/amd64
-      - linux/arm64
+      - "{{ .Version }}-amd64"
+      - latest-amd64
+    dockerfile: Dockerfile.frontend
+    labels:
+      org.opencontainers.image.title: GoHoarder Frontend
+      org.opencontainers.image.description: GoHoarder web dashboard
+      org.opencontainers.image.url: https://github.com/lukaszraczylo/gohoarder
+      org.opencontainers.image.source: https://github.com/lukaszraczylo/gohoarder
+      org.opencontainers.image.version: "{{ .Version }}"
+      org.opencontainers.image.created: "{{ .Date }}"
+      org.opencontainers.image.revision: "{{ .FullCommit }}"
+    extra_files:
+      - frontend
+
+  - id: gohoarder-frontend-arm64
+    images:
+      - ghcr.io/lukaszraczylo/gohoarder-frontend
+    goarch: arm64
+    tags:
+      - "{{ .Version }}-arm64"
+      - latest-arm64
     dockerfile: Dockerfile.frontend
     labels:
       org.opencontainers.image.title: GoHoarder Frontend
@@ -156,16 +169,43 @@ dockers_v2:
 
   # 3. Scanning Engine - Background scanner worker
   - id: gohoarder-scanner
-    ids:
-      - gohoarder
     images:
       - ghcr.io/lukaszraczylo/gohoarder-scanner
+    goarch: amd64
+    build_flags:
+      - "--build-arg=VERSION={{ .Version }}"
+      - "--build-arg=GIT_COMMIT={{ .ShortCommit }}"
+      - "--build-arg=BUILD_TIME={{ .Date }}"
+      - "--build-arg=TARGETOS=linux"
+      - "--build-arg=TARGETARCH=amd64"
     tags:
-      - "{{ .Version }}"
-      - latest
-    platforms:
-      - linux/amd64
-      - linux/arm64
+      - "{{ .Version }}-amd64"
+      - latest-amd64
+    dockerfile: Dockerfile.scanner
+    labels:
+      org.opencontainers.image.title: GoHoarder Scanner
+      org.opencontainers.image.description: GoHoarder vulnerability scanning engine
+      org.opencontainers.image.url: https://github.com/lukaszraczylo/gohoarder
+      org.opencontainers.image.source: https://github.com/lukaszraczylo/gohoarder
+      org.opencontainers.image.version: "{{ .Version }}"
+      org.opencontainers.image.created: "{{ .Date }}"
+      org.opencontainers.image.revision: "{{ .FullCommit }}"
+    extra_files:
+      - config.yaml.example
+
+  - id: gohoarder-scanner-arm64
+    images:
+      - ghcr.io/lukaszraczylo/gohoarder-scanner
+    goarch: arm64
+    build_flags:
+      - "--build-arg=VERSION={{ .Version }}"
+      - "--build-arg=GIT_COMMIT={{ .ShortCommit }}"
+      - "--build-arg=BUILD_TIME={{ .Date }}"
+      - "--build-arg=TARGETOS=linux"
+      - "--build-arg=TARGETARCH=arm64"
+    tags:
+      - "{{ .Version }}-arm64"
+      - latest-arm64
     dockerfile: Dockerfile.scanner
     labels:
       org.opencontainers.image.title: GoHoarder Scanner
@@ -180,16 +220,29 @@ dockers_v2:
 
   # 4. Gateway - Nginx reverse proxy for unified deployment
   - id: gohoarder-gateway
-    ids:
-      - gohoarder
     images:
       - ghcr.io/lukaszraczylo/gohoarder-gateway
+    goarch: amd64
     tags:
-      - "{{ .Version }}"
-      - latest
-    platforms:
-      - linux/amd64
-      - linux/arm64
+      - "{{ .Version }}-amd64"
+      - latest-amd64
+    dockerfile: Dockerfile.gateway
+    labels:
+      org.opencontainers.image.title: GoHoarder Gateway
+      org.opencontainers.image.description: Nginx reverse proxy for unified GoHoarder deployment
+      org.opencontainers.image.url: https://github.com/lukaszraczylo/gohoarder
+      org.opencontainers.image.source: https://github.com/lukaszraczylo/gohoarder
+      org.opencontainers.image.version: "{{ .Version }}"
+      org.opencontainers.image.created: "{{ .Date }}"
+      org.opencontainers.image.revision: "{{ .FullCommit }}"
+
+  - id: gohoarder-gateway-arm64
+    images:
+      - ghcr.io/lukaszraczylo/gohoarder-gateway
+    goarch: arm64
+    tags:
+      - "{{ .Version }}-arm64"
+      - latest-arm64
     dockerfile: Dockerfile.gateway
     labels:
       org.opencontainers.image.title: GoHoarder Gateway
@@ -202,16 +255,41 @@ dockers_v2:
 
   # 5. Migration Engine - Database migration tool
   - id: gohoarder-migrate
-    ids:
-      - migrate
     images:
       - ghcr.io/lukaszraczylo/gohoarder-migrate
+    goarch: amd64
+    build_flags:
+      - "--build-arg=VERSION={{ .Version }}"
+      - "--build-arg=GIT_COMMIT={{ .ShortCommit }}"
+      - "--build-arg=BUILD_TIME={{ .Date }}"
+      - "--build-arg=TARGETOS=linux"
+      - "--build-arg=TARGETARCH=amd64"
     tags:
-      - "{{ .Version }}"
-      - latest
-    platforms:
-      - linux/amd64
-      - linux/arm64
+      - "{{ .Version }}-amd64"
+      - latest-amd64
+    dockerfile: Dockerfile.migrate
+    labels:
+      org.opencontainers.image.title: GoHoarder Migrate
+      org.opencontainers.image.description: Database migration tool for GoHoarder V2 schema
+      org.opencontainers.image.url: https://github.com/lukaszraczylo/gohoarder
+      org.opencontainers.image.source: https://github.com/lukaszraczylo/gohoarder
+      org.opencontainers.image.version: "{{ .Version }}"
+      org.opencontainers.image.created: "{{ .Date }}"
+      org.opencontainers.image.revision: "{{ .FullCommit }}"
+
+  - id: gohoarder-migrate-arm64
+    images:
+      - ghcr.io/lukaszraczylo/gohoarder-migrate
+    goarch: arm64
+    build_flags:
+      - "--build-arg=VERSION={{ .Version }}"
+      - "--build-arg=GIT_COMMIT={{ .ShortCommit }}"
+      - "--build-arg=BUILD_TIME={{ .Date }}"
+      - "--build-arg=TARGETOS=linux"
+      - "--build-arg=TARGETARCH=arm64"
+    tags:
+      - "{{ .Version }}-arm64"
+      - latest-arm64
     dockerfile: Dockerfile.migrate
     labels:
       org.opencontainers.image.title: GoHoarder Migrate
@@ -243,3 +321,50 @@ docker_signs:
       - sign
       - "${artifact}@${digest}"
       - "--yes"
+
+# Docker manifests for multi-arch support
+docker_manifests:
+  - name_template: ghcr.io/lukaszraczylo/gohoarder-server:{{ .Version }}
+    image_templates:
+      - ghcr.io/lukaszraczylo/gohoarder-server:{{ .Version }}-amd64
+      - ghcr.io/lukaszraczylo/gohoarder-server:{{ .Version }}-arm64
+  - name_template: ghcr.io/lukaszraczylo/gohoarder-server:latest
+    image_templates:
+      - ghcr.io/lukaszraczylo/gohoarder-server:latest-amd64
+      - ghcr.io/lukaszraczylo/gohoarder-server:latest-arm64
+
+  - name_template: ghcr.io/lukaszraczylo/gohoarder-frontend:{{ .Version }}
+    image_templates:
+      - ghcr.io/lukaszraczylo/gohoarder-frontend:{{ .Version }}-amd64
+      - ghcr.io/lukaszraczylo/gohoarder-frontend:{{ .Version }}-arm64
+  - name_template: ghcr.io/lukaszraczylo/gohoarder-frontend:latest
+    image_templates:
+      - ghcr.io/lukaszraczylo/gohoarder-frontend:latest-amd64
+      - ghcr.io/lukaszraczylo/gohoarder-frontend:latest-arm64
+
+  - name_template: ghcr.io/lukaszraczylo/gohoarder-scanner:{{ .Version }}
+    image_templates:
+      - ghcr.io/lukaszraczylo/gohoarder-scanner:{{ .Version }}-amd64
+      - ghcr.io/lukaszraczylo/gohoarder-scanner:{{ .Version }}-arm64
+  - name_template: ghcr.io/lukaszraczylo/gohoarder-scanner:latest
+    image_templates:
+      - ghcr.io/lukaszraczylo/gohoarder-scanner:latest-amd64
+      - ghcr.io/lukaszraczylo/gohoarder-scanner:latest-arm64
+
+  - name_template: ghcr.io/lukaszraczylo/gohoarder-gateway:{{ .Version }}
+    image_templates:
+      - ghcr.io/lukaszraczylo/gohoarder-gateway:{{ .Version }}-amd64
+      - ghcr.io/lukaszraczylo/gohoarder-gateway:{{ .Version }}-arm64
+  - name_template: ghcr.io/lukaszraczylo/gohoarder-gateway:latest
+    image_templates:
+      - ghcr.io/lukaszraczylo/gohoarder-gateway:latest-amd64
+      - ghcr.io/lukaszraczylo/gohoarder-gateway:latest-arm64
+
+  - name_template: ghcr.io/lukaszraczylo/gohoarder-migrate:{{ .Version }}
+    image_templates:
+      - ghcr.io/lukaszraczylo/gohoarder-migrate:{{ .Version }}-amd64
+      - ghcr.io/lukaszraczylo/gohoarder-migrate:{{ .Version }}-arm64
+  - name_template: ghcr.io/lukaszraczylo/gohoarder-migrate:latest
+    image_templates:
+      - ghcr.io/lukaszraczylo/gohoarder-migrate:latest-amd64
+      - ghcr.io/lukaszraczylo/gohoarder-migrate:latest-arm64

Dockerfile.migrate

@@ -1,25 +1,61 @@
 # Migration Engine - Database Migration Tool
+# Multi-stage build to compile with CGO support
+ARG TARGETOS=linux
+ARG TARGETARCH=amd64
+
+# Build stage
+FROM --platform=$TARGETOS/$TARGETARCH golang:1.23-alpine AS builder
+
+# Install build dependencies for CGO
+RUN apk add --no-cache \
+    gcc \
+    g++ \
+    musl-dev \
+    sqlite-dev \
+    git
+
+WORKDIR /build
+
+# Copy go mod files
+COPY go.mod go.sum ./
+RUN go mod download
+
+# Copy source code
+COPY . .
+
+# Build with CGO enabled
 ARG TARGETOS
 ARG TARGETARCH
+ARG VERSION=dev
+ARG GIT_COMMIT=unknown
+ARG BUILD_TIME=unknown
 
+RUN CGO_ENABLED=1 GOOS=$TARGETOS GOARCH=$TARGETARCH \
+    go build -ldflags="-s -w \
+    -X main.Version=${VERSION} \
+    -X main.GitCommit=${GIT_COMMIT} \
+    -X main.BuildTime=${BUILD_TIME}" \
+    -o migrate ./cmd/migrate
+
+# Runtime stage
 FROM alpine:latest
 
-# Install runtime dependencies
+# Install runtime dependencies (including CGO/SQLite dependencies)
 RUN apk add --no-cache \
     ca-certificates \
     postgresql-client \
     mysql-client \
     busybox-extras \
+    sqlite-libs \
+    musl \
     && update-ca-certificates
 
 # Create non-root user
 RUN addgroup -g 1000 gohoarder && \
     adduser -D -u 1000 -G gohoarder gohoarder
 
-# Copy binary (from platform-specific path)
-ARG TARGETOS
-ARG TARGETARCH
-COPY ${TARGETOS}/${TARGETARCH}/migrate /usr/local/bin/migrate
+# Copy binary from builder
+COPY --from=builder /build/migrate /usr/local/bin/migrate
 RUN chmod +x /usr/local/bin/migrate
 
 WORKDIR /app

Dockerfile.scanner

@@ -1,10 +1,46 @@
 # Scanning Engine - Background Scanner Worker
+# Multi-stage build to compile with CGO support
+ARG TARGETOS=linux
+ARG TARGETARCH=amd64
+
+# Build stage
+FROM --platform=$TARGETOS/$TARGETARCH golang:1.23-alpine AS builder
+
+# Install build dependencies for CGO
+RUN apk add --no-cache \
+    gcc \
+    g++ \
+    musl-dev \
+    sqlite-dev \
+    git
+
+WORKDIR /build
+
+# Copy go mod files
+COPY go.mod go.sum ./
+RUN go mod download
+
+# Copy source code
+COPY . .
+
+# Build with CGO enabled
 ARG TARGETOS
 ARG TARGETARCH
+ARG VERSION=dev
+ARG GIT_COMMIT=unknown
+ARG BUILD_TIME=unknown
 
+RUN CGO_ENABLED=1 GOOS=$TARGETOS GOARCH=$TARGETARCH \
+    go build -ldflags="-s -w \
+    -X github.com/lukaszraczylo/gohoarder/internal/version.Version=${VERSION} \
+    -X github.com/lukaszraczylo/gohoarder/internal/version.GitCommit=${GIT_COMMIT} \
+    -X github.com/lukaszraczylo/gohoarder/internal/version.BuildTime=${BUILD_TIME}" \
+    -o gohoarder ./cmd/gohoarder
+
+# Runtime stage
 FROM alpine:latest
 
-# Install scanning tools and runtime dependencies
+# Install scanning tools and runtime dependencies (including CGO/SQLite dependencies)
 RUN apk add --no-cache \
     ca-certificates \
     tzdata \
@@ -12,6 +48,8 @@ RUN apk add --no-cache \
     curl \
     wget \
     bash \
+    sqlite-libs \
+    musl \
     && update-ca-certificates
 
 # Install Trivy for container scanning
@@ -37,10 +75,8 @@ RUN mkdir -p /var/cache/gohoarder \
                  /var/lib/gohoarder \
                  /var/lib/trivy
 
-# Copy binary (from platform-specific path)
-ARG TARGETOS
-ARG TARGETARCH
-COPY ${TARGETOS}/${TARGETARCH}/gohoarder /usr/local/bin/gohoarder
+# Copy binary from builder
+COPY --from=builder /build/gohoarder /usr/local/bin/gohoarder
 RUN chmod +x /usr/local/bin/gohoarder
 
 # Copy example config

Dockerfile.server

@@ -1,13 +1,51 @@
 # Application Engine - GoHoarder Server
+# Multi-stage build to compile with CGO support
+ARG TARGETOS=linux
+ARG TARGETARCH=amd64
+
+# Build stage
+FROM --platform=$TARGETOS/$TARGETARCH golang:1.23-alpine AS builder
+
+# Install build dependencies for CGO
+RUN apk add --no-cache \
+    gcc \
+    g++ \
+    musl-dev \
+    sqlite-dev \
+    git
+
+WORKDIR /build
+
+# Copy go mod files
+COPY go.mod go.sum ./
+RUN go mod download
+
+# Copy source code
+COPY . .
+
+# Build with CGO enabled
 ARG TARGETOS
 ARG TARGETARCH
+ARG VERSION=dev
+ARG GIT_COMMIT=unknown
+ARG BUILD_TIME=unknown
 
+RUN CGO_ENABLED=1 GOOS=$TARGETOS GOARCH=$TARGETARCH \
+    go build -ldflags="-s -w \
+    -X github.com/lukaszraczylo/gohoarder/internal/version.Version=${VERSION} \
+    -X github.com/lukaszraczylo/gohoarder/internal/version.GitCommit=${GIT_COMMIT} \
+    -X github.com/lukaszraczylo/gohoarder/internal/version.BuildTime=${BUILD_TIME}" \
+    -o gohoarder ./cmd/gohoarder
+
+# Runtime stage
 FROM alpine:latest
 
-# Install runtime dependencies
+# Install runtime dependencies (including CGO/SQLite dependencies)
 RUN apk add --no-cache \
     ca-certificates \
     tzdata \
+    sqlite-libs \
+    musl \
     && update-ca-certificates
 
 # Create non-root user
@@ -24,10 +62,8 @@ RUN mkdir -p /var/cache/gohoarder \
     chmod -R 750 /var/cache/gohoarder \
                  /var/lib/gohoarder
 
-# Copy binary (from platform-specific path)
-ARG TARGETOS
-ARG TARGETARCH
-COPY ${TARGETOS}/${TARGETARCH}/gohoarder /usr/local/bin/gohoarder
+# Copy binary from builder
+COPY --from=builder /build/gohoarder /usr/local/bin/gohoarder
 RUN chmod +x /usr/local/bin/gohoarder
 
 # Copy example config