Docker container version of kplex

.github/workflows/container.yml

@@ -0,0 +1,43 @@
+name: Docker Builds
+
+on: [workflow_dispatch]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+
+    - name: Set up QEMU
+      uses: docker/setup-qemu-action@v1
+
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v1
+
+    - name: Cache Docker layers
+      uses: actions/cache@v2
+      with:
+        path: /tmp/.buildx-cache
+        key: ${{ runner.os }}-buildx-${{ github.sha }}
+        restore-keys: |
+          ${{ runner.os }}-buildx-
+
+    - name: Log in to GHCR
+      if: github.event_name != 'pull_request'
+      uses: docker/login-action@v1
+      with:
+        registry: ghcr.io
+        username: ${{ github.repository_owner }}
+        password: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: Build and push to ghcr
+      uses: docker/build-push-action@v2
+      with:
+        context: .
+        file: ./Dockerfile
+        platforms: linux/amd64,linux/386,linux/arm64,linux/arm/v6,linux/arm/v7
+        push: ${{ github.event_name != 'pull_request' }}
+        tags: |
+          ghcr.io/bklofas/kplex:latest
+

Dockerfile

@@ -0,0 +1,21 @@
+FROM debian:stretch-slim
+LABEL "name"="kplex" \
+  "description"="A multiplexer for various nmea 0183 interfaces"
+
+ENV APP=/usr/src/app
+
+WORKDIR $APP
+
+COPY . $APP
+
+RUN apt-get update && apt-get install -y \
+  make \
+  build-essential \
+  pkg-config \
+  && make \ 
+  && apt-get remove -y make build-essential pkg-config \
+  && apt-get autoremove -y \
+  && rm -rf /var/lib/apt/lists/*
+
+CMD $APP/kplex
+

README

@@ -56,10 +56,82 @@ the serial ports (normally "dialout" on modern debian-based systems).
 
 The configuration file the .deb installation installs in /etc/kplex.conf
 actually does nothing (all directives are commented out).  Read the instructions
-in this README file for how to create a confiuration file.  A quick start
+in this README file for how to create a configuration file.  A quick start
 example which bridges between a tcp server and a 38400 baud serial-to-usb
 connection is commented out in this example file.
 
+Docker
+------
+kplex can now run in a Docker container. There are no dependencies to install, 
+and nothing to build. The final image size is about 55 to 75 MB depending on 
+the host architecture.
+
+Two options for obtaining the container: Either download and run a pre-built 
+container, or build the container locally.
+
+Just to test things out on a pre-built container: 
+docker run -it --rm --network=host -v /home/user/kplex.conf:/etc/kplex.conf:ro ghcr.io/bklofas/kplex:latest
+
+* This downloads a pre-built container from the Github container registry.
+* Architectures supported are i386, amd64, arm32v6, arm32v7, and arm64. Tested 
+  on amd64, arm32v7, and arm64. arm packages run on all RaspberryPi flavors. Your 
+  client will automatically download the appropriate architecture.
+* --network=host: Allows the container to talk to the internet, if you are 
+  sending the packets to an online service.
+* -v /home/user/kplex.conf:/etc/kplex.conf:ro  This mounts kplex.conf (from your 
+  home directory) into the container's /etc folder (read-only), when the container is started. 
+  kplex looks in /etc for configuration files during startup.
+* To add command-line options, add ./kplex [OPTIONS] on the end.
+* Ctrl-C to kill the container.
+* Using the --rm flag will delete the container when you kill it. Otherwise, 
+  it will stay around until you prune.
+
+For a more permanent setup, run the container in the background:
+docker run -d --name kplex --restart=unless-stopped --log-driver=local --network=host -v ~/kplex.conf:/etc/kplex.conf:ro ghcr.io/bklofas/kplex:latest ./kplex -d 4
+
+* -d: Start this container in daemon/background mode.
+* --name: Name this anything you want.
+* --restart=unless-stopped: Automatically restart the container if something 
+  happens (reboot, USB problem), unless you have manually stopped the container.
+* --log-driver=local: By default, docker uses the json log driver which may fill 
+  up your harddrive, depending on how busy your station is. local log driver 
+  defaults to 100MB of saved logs, and automatically rotates them.
+* ./kplex -d 4: Debug command line options. Optional if all the configuration
+  is in the kplex.conf file.
+* After you make any edits to kplex.conf, reload the container with "docker 
+  restart kplex".
+* If you want to bring real serial devices into the container, add 
+  "--device=/dev/ttyS0" to the command line
+* For USB-serial devices, you could use "--device=/dev/ttyUSB0" or similar, but
+  it's probably better to specify the USB devices by ID. Look in /dev/serial/by-id,
+  and add "--device=/dev/serial/by-id/usb-Prolific_Tech..." or similar. This will
+  ensure the same device is used across reboots. Use the same path in the kplex.conf
+  file. For example:
+  [serial]
+  filename=/dev/ttyS0   or /dev/ttyUSB0   or /dev/serial/by-id/usb-Prolific_Tech....
+  direction=in
+  baud=4800
+* View the startup messages (if any) and output with "docker logs --follow kplex".
+* Stop the container with "docker stop kplex".
+
+Building the container:
+
+Clone the repository with "git clone https://github.com/stripydog/kplex.git", then 
+from that folder "docker build -t kplex:1.0 ."
+
+Or, build the container without cloning the repository:
+"docker build https://github.com/stripydog/kplex.git"
+
+Other tips and tricks:
+
+* If you have this [file] STDOUT directive in your kplex.conf file, you can see 
+  the individual AIS packets with "docker logs --follow kplex".
+  [file]
+  filename=-
+  direction=out
+
+
+
 Invocation:
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