fix(build): add Dockerfile for container build

build/package/Dockerfile

@@ -0,0 +1,18 @@
+FROM golang:alpine AS build
+
+WORKDIR /app
+RUN apk add --no-cache make
+
+# Install dependencies.
+COPY go.* ./
+RUN go mod download
+
+# Copy source files and build application.
+COPY . /app
+ARG VERSION
+RUN VERSION=${VERSION} make -B && mv bin/* /app/bin/netadm
+
+# Create minimal container image.
+FROM alpine AS run
+COPY --from=build /app/bin/netadm /netadm
+CMD [ "/netadm" ]