Add Dockerfile for Linux and Windows builds

Dockerfile

@@ -0,0 +1,27 @@
+FROM ubuntu:focal
+
+ENV TZ=Etc/UTC
+ENV TERM=xterm
+ENV APPIMAGE_EXTRACT_AND_RUN=1
+ARG DEBIAN_FRONTEND=noninteractive
+ARG NPCAP_VERSION=1.13
+
+RUN apt-get update
+RUN apt-get install -y build-essential pkg-config git zip wget file
+RUN apt-get install -y g++-mingw-w64-i686
+RUN apt-get install -y libpcap-dev libnl-3-dev libnl-route-3-dev
+
+RUN mkdir -p /usr/src
+WORKDIR /usr/src
+
+ADD "https://api.github.com/repos/jclehner/nmrpflash/commits?per_page=1" latest_commit
+RUN git clone https://github.com/jclehner/nmrpflash
+
+WORKDIR /usr/src/nmrpflash
+RUN wget -O npcap-sdk.zip https://npcap.com/dist/npcap-sdk-${NPCAP_VERSION}.zip
+RUN unzip npcap-sdk.zip -d Npcap
+
+RUN make release/linux-appimage
+RUN make clean
+RUN make MINGW=i686-w64-mingw32- release release/win32
+

Makefile

@@ -114,3 +114,10 @@ release: clean nmrpflash$(SUFFIX)
 
 nmrpflash.ico: nmrpflash.svg
 	convert -background transparent -define icon:auto-resize=256,64,48,32,16 $< $@
+
+build-release-with-docker:
+	docker build -t nmrpflash .
+	docker create --name dummy nmrpflash
+	docker cp dummy:/usr/src/nmrpflash/nmrpflash-$(VERSION)-linux-$(ARCH).zip .
+	docker cp dummy:/usr/src/nmrpflash/nmrpflash-$(VERSION)-win32.zip .
+	docker rm -f dummy