Add Prometheus /metrics endpoint for ClamAV monitoring

docker/Dockerfile

@@ -0,0 +1,34 @@
+FROM golang:1.22-alpine AS builder
+
+WORKDIR /app
+
+COPY go.mod go.sum ./
+RUN go mod download
+COPY ./*.go ./
+RUN CGO_ENABLED=0 GOOS=linux go build -o clamdproxy .
+
+FROM alpine:latest
+
+# Define build arguments with default values
+ARG LISTEN_ADDR="0.0.0.0:3315"
+ARG BACKEND_ADDR="clamav:3310"
+ARG LOG_LEVEL="debug"
+ARG METRICS_ADDR="0.0.0.0:2112"
+
+# Create environment variables from the ARGs
+ENV LISTEN_ADDR=${LISTEN_ADDR}
+ENV BACKEND_ADDR=${BACKEND_ADDR}
+ENV LOG_LEVEL=${LOG_LEVEL}
+ENV METRICS_ADDR=${METRICS_ADDR}
+
+RUN apk --no-cache add ca-certificates
+WORKDIR /app
+COPY --from=builder /app/clamdproxy /app/
+
+# Create a startup script
+RUN echo '#!/bin/sh' > /app/start.sh && \
+    echo 'exec /app/clamdproxy --listen "$LISTEN_ADDR" --backend "$BACKEND_ADDR" --log-level "$LOG_LEVEL" --metrics "$METRICS_ADDR"' >> /app/start.sh && \
+    chmod +x /app/start.sh
+
+EXPOSE 3315 2112
+ENTRYPOINT ["/app/start.sh"]

docker/docker-compose.yml

@@ -0,0 +1,71 @@
+version: '3.8'
+
+services:
+  clamav:
+    image: mkodockx/docker-clamav:alpine
+    container_name: clamav-docker
+    ports:
+      - "3310:3310"
+    volumes:
+      - ./testfiles:/scan
+      - clamav_data:/var/lib/clamav
+    restart: unless-stopped
+    healthcheck:
+      test: ["CMD", "./check.sh"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 120s
+    networks:
+      - clam-net
+  clamdproxy:
+    build:
+      context: ../ 
+      dockerfile: docker/Dockerfile
+    container_name: clamdproxy
+    ports:
+      - "3315:3315"
+      - "2112:2112"
+    depends_on:
+      clamav:
+        condition: service_healthy
+    restart: unless-stopped
+    networks:
+      - clam-net
+
+  prometheus:
+    image: prom/prometheus:latest
+    ports:
+      - "9090:9090"
+    volumes:
+      - ./prometheus.yml:/etc/prometheus/prometheus.yml
+      - prometheus_data:/prometheus
+    command:
+      - '--config.file=/etc/prometheus/prometheus.yml'
+      - '--storage.tsdb.path=/prometheus'
+      - '--storage.tsdb.retention.time=15d'
+    networks:
+      - clam-net
+
+  grafana:
+    image: grafana/grafana:latest
+    ports:
+      - "3001:3000"
+    environment:
+      - GF_SECURITY_ADMIN_PASSWORD=admin
+      - GF_SECURITY_ADMIN_USER=admin
+    volumes:
+      - grafana_data:/var/lib/grafana
+    depends_on:
+      - prometheus
+    networks:
+      - clam-net
+
+volumes:
+  clamav_data:
+  prometheus_data:
+  grafana_data:
+
+networks:
+  clam-net:
+    driver: bridge

docker/docker.md

@@ -0,0 +1,62 @@
+# Docker Build and Run Guide
+
+This guide explains how to build and run the ClamdProxy Docker container with custom configuration.
+
+## Building the Docker Image
+
+You can build the ClamdProxy Docker image using the following command:
+
+```bash
+docker build -t clamdproxy \
+  --build-arg LISTEN_ADDR=0.0.0.0:3315 \
+  --build-arg BACKEND_ADDR=docker.for.mac.localhost:3310 \
+  --build-arg LOG_LEVEL=debug \
+  --build-arg METRICS_ADDR=0.0.0.0:2112 \
+  -f docker/Dockerfile .
+```
+
+### Build Arguments
+
+The Dockerfile supports the following build arguments:
+
+| Argument | Description | Default Value |
+|----------|-------------|---------------|
+| `LISTEN_ADDR` | Address and port for ClamdProxy to listen on | `0.0.0.0:3315` |
+| `BACKEND_ADDR` | Address and port of the clamd backend | `clamav:3310` |
+| `LOG_LEVEL` | Logging level (debug, info, warn, error) | `debug` |
+| `METRICS_ADDR` | Address and port for exposing Prometheus metrics | `0.0.0.0:2112` |
+
+## Running the Container
+
+After building the image, you can run the container with:
+
+```bash
+docker run -p 3315:3315 -p 2112:2112 \
+  -e LISTEN_ADDR=0.0.0.0:3315 \
+  -e BACKEND_ADDR=docker.for.mac.localhost:3310 \
+  -e LOG_LEVEL=debug \
+  -e METRICS_ADDR=0.0.0.0:2112 \
+  clamdproxy
+```
+
+### Environment Variables
+
+The container uses the following environment variables:
+
+| Variable | Description | Default Value |
+|----------|-------------|---------------|
+| `LISTEN_ADDR` | Address and port for ClamdProxy to listen on | Value from build arg |
+| `BACKEND_ADDR` | Address and port of the clamd backend | Value from build arg |
+| `LOG_LEVEL` | Logging level (debug, info, warn, error) | Value from build arg |
+| `METRICS_ADDR` | Address and port for exposing Prometheus metrics | Value from build arg |
+
+## Notes for macOS Users
+
+When running Docker on macOS, use `docker.for.mac.localhost` to connect to clamD services running on your host machine. This is why the example uses `docker.for.mac.localhost:3310` as the backend address.
+
+## Ports
+
+- The proxy service listens on port 3315 (or as configured)
+- Metrics are exposed on port 2112 (or as configured)
+
+Make sure to map these ports correctly when running the container.