adding dockerfile

Dockerfile

@@ -0,0 +1,23 @@
+# Alpine version for the runner contianer
+ARG ALPINE_VERSION=latest
+
+# golang builder image
+FROM golang:1.21-bullseye AS builder
+WORKDIR /build
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -buildvcs=false -pgo=auto -ldflags="-w -s -X 'main.Version=$(git describe --tags)'" -o app . \
+	&& git clone https://github.com/andybalholm/redwood-config.git /tmp/redwood-config
+
+# Final runner image
+FROM alpine:${ALPINE_VERSION} AS runner
+
+# Copy in config & app binary
+COPY --from=builder /build/app /app
+COPY --from=builder /tmp/redwood-config /etc/redwood
+RUN mkdir -p /var/log/redwood
+
+# Expose the default ports from redwood-config
+EXPOSE 6502 6510
+
+# Run the app
+ENTRYPOINT [ "/app" ]