Node-RED-Docker
This project describes some of the many ways Node-RED can be run under Docker. Some basic familiarity with Docker and the Docker Command Line is assumed.
This project also provides the build for the nodered/node-red-docker
container on DockerHub.
To run this directly in docker at it's simplest just run
docker run -it -p 1880:1880 --name mynodered nodered/node-red-docker
Let's dissect that command...
docker run - run this container... and build locally if necessary first.
-it - attach a terminal session so we can see what is going on
-p 1880:1880 - connect local port 1880 to the exposed internal port 1880
--name mynodered - give this machine a friendly local name
nodered/node-red-docker - the image to base it on - currently Node-RED v0.14.5
Running that command should give a terminal window with a running instance of Node-RED
Welcome to Node-RED
===================
8 Apr 12:13:44 - [info] Node-RED version: v0.14.5
8 Apr 12:13:44 - [info] Node.js version: v4.4.7
.... etc
You can then browse to http://{host-ip}:1880 to get the familiar Node-RED desktop.
The advantage of doing this is that by giving it a name we can manipulate it more easily, and by fixing the host port we know we are on familiar ground. (Of course this does mean we can only run one instance at a time... but one step at a time folks...)
If we are happy with what we see we can detach the terminal with Ctrl-p``Ctrl-q - the container will keep running in the background.
To reattach to the terminal (to see logging) run:
$ docker attach mynodered
If you need to restart the container (e.g. after a reboot or restart of the Docker daemon)
$ docker start mynodered
and stop it again when required
$ docker stop mynodered
Note : this Dockerfile is configured to store the flows.json file and any extra nodes you install "outside" of the container. We do this so that you may rebuild the underlying container without permanently losing all of your customisations.
Container Layout
This repository contains Dockerfiles to build different Node-RED Docker images.
- latest - uses official Node.JS v4 base image.
- slim uses Alpine Linux base image.
- rpi uses RPi-compatible base image.
Using Alpine Linux reduces the built image size (~100MB vs ~700MB) but removes standard dependencies that are required for native module compilation. If you want to add modules with native dependencies, use the standard image or extend the slim image with the missing packages.
Build these images with the following command...
$ docker build -f <version>/Dockerfile -t mynodered:<version> .
package.json
The package.json is a metafile that downloads and installs the required version
of Node-RED and any other npms you wish to install at build time. During the
Docker build process, the dependencies are installed under /usr/src/node-red.
The main sections to modify are
"dependencies": {
"node-red": "0.14.x", <-- set the version of Node-RED here
"node-red-node-rbe": "*" <-- add any extra npm packages here
},
This is where you can pre-define any extra nodes you want installed every time by default, and then
"scripts" : {
"start": "node-red -v $FLOWS"
},
This is the command that starts Node-RED when the container is run.
startup
Node-RED is started using NPM start from this /usr/src/node-red, with the --userDir
parameter pointing to the /data directory on the container.
The flows configuration file is set using an environment parameter (FLOWS), which defaults to 'flows.json'. This can be changed at runtime using the following command-line flag.
$ docker run -it -p 1880:1880 -e FLOWS=my_flows.json nodered/node-red-docker
Node.js runtime arguments can be passed to the container using an environment parameter (NODE_OPTIONS). For example, to fix the heap size used by the Node.js garbage collector you would use the following command.
$ docker run -it -p 1880:1880 -e NODE_OPTIONS="--max_old_space_size=128" nodered/node-red-docker
Adding Nodes
Installing extra Node-RED nodes into an instance running with Docker can be achieved by manually installing those nodes into the container, using the cli or running npm commands within a container shell, or mounting a host directory with those nodes as a data volume.
Node-RED Admin Tool
Using the administration tool, with port forwarding on the container to the host system, extra nodes can be installed without leaving the host system.
$ npm install -g node-red-admin
$ node-red-admin install node-red-node-openwhisk
This tool assumes Node-RED is available at the following address
http://localhost:1880.
Refreshing the browser page should now reveal the newly added node in the palette.
Container Shell
$ docker exec -it mynodered /bin/bash
Will give a command line inside the container - where you can then run the npm install command you wish - e.g.
$ cd /data
$ npm install node-red-node-smooth
node-red-node-smooth@0.0.3 node_modules/node-red-node-smooth
$ exit
$ docker stop mynodered
$ docker start mynodered
Refreshing the browser page should now reveal the newly added node in the palette.
Host Directory As Volume
Running a Node-RED container with a host directory mounted as the data volume,
you can manually run npm install within your host directory. Files created in
the host directory will automatically appear in the container's file system.
This command mounts the host's node-red directory, containing the user's configuration and installed nodes, as the user configuration directory inside the container.
$ docker run -it -p 1880:1880 -v ~/.node-red:/data --name mynodered nodered/node-red-docker
Having file permissions issues after mounting a host directory?
Docker maps the internal container uuid to 1000 on the host system. If you are running as a user with a different uuid, e.g. the second user added on a system, the container user account won't be able to read files on the host system. Fix this by using the --run $USER flag. See here for more details.
Adding extra nodes to the container can be accomplished by running npm install locally.
$ cd ~/.node-red
$ npm install node-red-node-smooth
node-red-node-smooth@0.0.3 node_modules/node-red-node-smooth
$ docker stop mynodered
$ docker start mynodered
Note : Modules with a native dependencies will be compiled on the host machine's architecture. These modules will not work inside the Node-RED container unless the architecture matches the container's base image. For native modules, it is recommended to install using a local shell or update the project's package.json and re-build.
Building Custom Image
Creating a new Docker image, using the public Node-RED images as the base image, allows you to install extra nodes during the build process.
This Dockerfile builds a custom Node-RED image with the flightaware module installed from NPM.
FROM nodered/node-red-docker
RUN npm install node-red-contrib-flightaware
Alternatively, you can modify the package.json in this repository and re-build the images from scratch. This will also allow you to modify the version of Node-RED that is installed. See below for more details...
Managing User Data
Once you have customised the Node-RED instance running with Docker, we need to ensure these modifications are not lost if the container is destroyed. Managing this user data can be handed by persisting container state into a new image or using named data volumes to handle move this data outside the container.
Saving Changes As Custom Image
Modifications to files within the live container, e.g. manually adding nodes or creating flows, do not exist outside the lifetime of the container. If that container instance is destroyed, these changes will be lost.
Docker allows you to the current state of a container to a new image. This means you can persist your changes as a new image that can be shared on other systems.
$ docker commit mynodered custom-node-red-docker
If we destroy the mynodered container, the instance can be recovered by
spawning a new container using the custom-node-red-docker image.
Using Named Data Volumes
Docker supports using data volumes to store persistent or shared data outside the container. Files and directories within data volumes exist outside of the lifecycle of containers, i.e. the files still exist after removing the container.
Node-RED uses the /data directory to store user configuration data.
Mounting a data volume inside the container at this directory path means user configuration data can be saved outside of the container and even shared between container instances.
Let's create a new named data volume to persist our user data and run a new container using this volume.
$ docker volume create --name node_red_user_data
$ docker volume ls
DRIVER VOLUME NAME
local node_red_user_data
$ docker run -it -p 1880:1880 -v node_red_user_data:/data --name mynodered nodered/node-red-docker
Using Node-RED to create and deploy some sample flows, we can now destroy the container and start a new instance without losing our user data.
$ docker rm mynodered
$ docker run -it -p 1880:1880 -v node_red_user_data:/data --name mynodered nodered/node-red-docker
Updating
Updating the base container image is as simple as
$ docker pull nodered/node-red-docker
$ docker stop mynodered
$ docker start mynodered
Running headless
The barest minimum we need to just run Node-RED is
$ docker run -d -p 1880 nodered/node-red-docker
This will create a local running instance of a machine - that will have some docker id number and be running on a random port... to find out run
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
4bbeb39dc8dc nodered/node-red-docker:latest "npm start" 4 seconds ago Up 4 seconds 0.0.0.0:49154->1880/tcp furious_yalow
$
You can now point a browser to the host machine on the tcp port reported back, so in the example
above browse to http://{host ip}:49154
Linking Containers
You can link containers "internally" within the docker runtime by using the --link option.
For example I have a simple MQTT broker container available as
docker run -it --name mybroker nodered/node-red-docker
(no need to expose the port 1883 globally unless you want to... as we do magic below)
Then run nodered docker - but this time with a link parameter (name:alias)
docker run -it -p 1880:1880 --name mynodered --link mybroker:broker nodered/node-red-docker
the magic here being the --link that inserts a entry into the node-red instance
hosts file called broker that links to the mybroker instance.... but we do
expose the 1880 port so we can use an external browser to do the node-red editing.
Then a simple flow like below should work - using the alias broker we just set up a second ago.
[{"id":"190c0df7.e6f3f2","type":"mqtt-broker","broker":"broker","port":"1883","clientid":""},{"id":"37963300.c869cc","type":"mqtt in","name":"","topic":"test","broker":"190c0df7.e6f3f2","x":226,"y":244,"z":"f34f9922.0cb068","wires":[["802d92f9.7fd27"]]},{"id":"edad4162.1252c","type":"mqtt out","name":"","topic":"test","qos":"","retain":"","broker":"190c0df7.e6f3f2","x":453,"y":135,"z":"f34f9922.0cb068","wires":[]},{"id":"13d1cf31.ec2e31","type":"inject","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"x":226,"y":157,"z":"f34f9922.0cb068","wires":[["edad4162.1252c"]]},{"id":"802d92f9.7fd27","type":"debug","name":"","active":true,"console":"false","complete":"false","x":441,"y":261,"z":"f34f9922.0cb068","wires":[]}]
This way the internal broker is not exposed outside of the docker host - of course
you may add -p 1883:1883 etc to the broker run command if you want to see it...
Issues
Here is a list of common issues users have reported with possible solutions.
User Permission Errors
If you are seeing permission denied errors opening files or accessing host devices, try running the container as the root user.
docker run -it -p 1880:1880 --name mynodered --user=root nodered/node-red-docker
References:
Accessing Host Devices
If you want to access a device from the host inside the container, e.g. serial port, use the following command-line flag to pass access through.
docker run -it -p 1880:1880 --name mynodered --device=/dev/ttyACM0 nodered/node-red-docker
References: node-red#15
Setting Timezone
If you want to modify the default timezone, use the TZ environment variable with the relevant timezone.
docker run -it -p 1880:1880 --name mynodered -e TZ="Europe/London" nodered/node-red-docker
References: https://groups.google.com/forum/#!topic/node-red/ieo5IVFAo2o