Switch back to cross-build (#10)

If you do not wish to cross build on your local, you can comment out the
cross-build lines and run.

Hacky way of making it easy to run on ARM

Just prefix any make command with 'arm'. Eg. `make arm shell'.
Don't commit the modified Makefile.

Update Readme

Dockerfile

@@ -1,7 +1,7 @@
 FROM hypriot/rpi-node:8
 MAINTAINER ViViDboarder <vividboarder@gmail.com>
 
-RUN cross-build-start || true
+RUN [ "cross-build-start" ]
 
 ENV LANG en_US.UTF-8
 ENV LC_ALL en_US.UTF-8
@@ -34,7 +34,7 @@ RUN [ -s npm-shrinkwrap.json ] || rm npm-shrinkwrap.json
 
 RUN npm install
 
-RUN cross-build-end || true
+RUN [ "cross-build-end" ]
 
 EXPOSE 5353 51826
 

Makefile

@@ -3,13 +3,16 @@ DOCKER_TAG ?= rpi-homebridge
 DOCKER_TAG_DEV ?= $(DOCKER_TAG)-dev
 HOMEBRIDGE_USER ?= root
 
+.PHONY: default
 default: build
 
 # Default target to build the image
+.PHONY: build
 build:
 	docker build -t $(DOCKER_TAG_DEV) .
 
 # Target to build and run and subsequently remove image
+.PHONY: run
 run: build
 	docker run --net=host --rm \
 		-p "51826:51826" \
@@ -18,31 +21,44 @@ run: build
 		$(DOCKER_TAG_DEV)
 
 # Target to drop into an interractive shell
+.PHONY: shell
 shell: build
 	docker run --net=host --rm \
 		-p "51826:51826" \
 		-v "$(shell pwd)/config.json:/$(HOMEBRIDGE_USER)/.homebridge/config.json" \
 		-v "$(shell pwd)/plugins.txt:/$(HOMEBRIDGE_USER)/.homebridge/plugins.txt" \
+		$(shell grep -q '^RUN.*cross-build-start' Dockerfile && echo '-v "/usr/bin/qemu-arm-static:/usr/bin/qemu-arm-static"') \
 		-it $(DOCKER_TAG_DEV) \
 		bash
 
 # Tags dev image so it can be pushed
+.PHONY: tag
 tag: build
 	docker tag $(DOCKER_TAG_DEV) $(DOCKER_REPO)/$(DOCKER_TAG)
 
 # Pushes tagged image to docker hub
+.PHONY: push
 push: tag
 	docker push $(DOCKER_REPO)/$(DOCKER_TAG)
 
 
 # Clears shrinkwrap so next build will install latest version of everything
+.PHONY: unshrinkwrap
 unshrinkwrap:
 	rm ./npm-shrinkwrap.json
 	touch ./npm-shrinkwrap.json
 
 # Generates a new shrinkwrap from installed node modules
+.PHONY: shrinkwrap
 shrinkwrap: build
 	docker run --rm \
 		-v "$(shell pwd)/npm-shrinkwrap.json:/homebridge/npm-shrinkwrap-volume.json" \
+		$(shell grep -q '^RUN.*cross-build-start' Dockerfile && echo '-v "/usr/bin/qemu-arm-static:/usr/bin/qemu-arm-static"') \
 		$(DOCKER_TAG_DEV) \
 		bash -c "npm shrinkwrap && cat npm-shrinkwrap.json > npm-shrinkwrap-volume.json"
+
+# Converts Dockerfile so that it can compile on ARM
+.PHONY: arm
+arm:
+	cat Dockerfile | sed '/^RUN.*cross-build-/s/^/# /' > Dockerfile.arm
+	mv Dockerfile.arm Dockerfile

README.md

@@ -29,12 +29,35 @@ docker-compose up
 If you want a little more control, you can use any of the make targets:
 
 ```
-make build  # builds a new image
-make run    # builds and runs container using same parameters as compose
-make shell  # builds and runs an interractive container
-make tag    # tags image to be pushed to docker hub
-make push   # pushes image to docker hub
+make build          # builds a new image
+make run            # builds and runs container using same parameters as compose
+make shell          # builds and runs an interractive container
+make tag            # tags image to be pushed to docker hub
+make push           # pushes image to docker hub
+make unshrinkwrap   # clears npm-shrinkwrap.json so the next build will use latest
+make shrinkwrap     # generates npm-shrinkwrap.json to pin versions
+make arm            # modifies Dockerfile for building against arm
 ```
 
+## Multi-arch
+This project is capable of being compiled on arm or cross-built on an x86 machine. There is some trickiness involved in this, so here's the description broken down by platform. High level, the `cross-build-start` cannot be present when building on arm. When running the built image, a non-arm system needs to have `qemu-arm-static` mounted as a volume. The `Makefile` tries to automate this a bit.
+
+### arm (Raspberry Pi)
+The default is to support building on Docker Hub and not a Raspberry Pi. Unfortunately, `cross-build-start` will fail to run on an arm machine.
+
+To build or shrinkwrap, just add `arm` to your make command. Eg. `make arm build shrinkwrap`. This will modify the `Dockerfile` to comment out the cross-build commands. If contributing changes back upstream, do not commit this change!
+
+### Linux x86
+Building can be done by directly running `make build`. If you want to run image, you need to install `qemu qemu-user qemu-user-static`. After that you should be able to run `make shrinkwrap or make shell`.
+
+### macOS
+Docker for Mac actually supports running arm binaries. So that's cool! To make things simple, you should follow the arm instructions.
+
+## Development
+Follow the instructions above for how to run on your architechture. Also, be sure to not commit commented out `cross-build-*` lines as those are necessary for Docker Hub to build.
+
+### Bumping version numbers
+This is most easily done by updating `package.json` and then running `make unshrinkwrap shrinkwrap`. That should force a reinstallation of all node packages and then provide you with an updated `npm-shrinkwrap.json` file to commit.
+
 ## Issues?
 Feel free to report any issues you're having getting this to run on [Github](https://github.com/ViViDboarder/docker-rpi-homebridge/issues)