weewx-base-image

Current tested/working version: 4.10.2

Running weewx in docker

Why run weewx in docker

Running applications in docker is trendy nowadays, and often easier than using a traditional installation.

But one the main advantage is that the docker image is self-contained, with all the required dependencies. This is particularly important when planning to deploy weewx on an operating system on which installing all the prerequisites can be challenging (NAS, etc.).

With docker, it is possible to run weewx with the latest python and all its dependencies without having to install anything on the host server.

Issues

Unfortunately, weewx is not exactly docker friendly, and running it in a docker container poses several challenges:

1. extensions and customizations are often deployed in directories that are also containing files provided by weewx (skins for example, or bin/user).
   If weewx is installed inside the container (the weewx binaries are provided as part of the image), ensuring the persistence of the customizations with volumes is tricky: the volumes must contain files coming both from the container and from the customizations. Although this can be done, this makes upgrading much more difficult.

2. if the configuration file is mounted in the container as a volume, some tools will fail to properly update it: wee_extension, for example will throw an error when installing extensions that make changes to the configuration.

3. the default logger is syslog, which is not running by default in containers. This can be worked around in various ways (such as using supervisord to run syslog, changing the weewx logging configuration, etc.), but the default configuration just don’t work.

Solution

A not perfect but good enough solution (there are other possible approaches) to those problems is to:

• persist the entire weewx folder in a volume mapped to a local directory. The docker image only contains the weewx prerequisites: python, etc.
  The main drawback of this approach is that weewx is not updated with the docker image. But this could also be viewed as an advantage, since it is probably better to manually manage a weewx upgrade to avoid breaking things.
  The big advantage is that it becomes very easy to customize weewx, or at least no more difficult than for a traditional installation.

• patch weewx to log to the console by default. Newer versions of weewx might actually provide a fix for the logging issue by default.

using this image

Here is the suggested approach to use this image:

Set up a few variables

• The version of weewx to use.

• The name of the docker container.

• The host path for the weewx folder.

# Example

WEEWX_IMAGE=weewx-image
WEEWX_IMAGE_TAG=v4.10.2
WEEWX_TZ=Europe/Paris
WEEWX_CONTAINER_NAME=weewx
WEEWX_DIR=/share/homes/docker/containers/weewx

Build the image

docker build -t ${WEEWX_IMAGE} .

Running the container

The commands below must be adjusted if needed (the device name in particular).

For testing/troubleshooting

This command can be used to start a new container, and log into it. This is useful when troubleshooting, to test various commands, etc.

mkdir -p ${WEEWX_DIR}

docker run --rm -it --name ${WEEWX_CONTAINER_NAME}_debug \
--volume ${WEEWX_DIR}:/home/weewx \
--device=/dev/ttyUSB0  \
--privileged \
-v /dev/bus/usb:/dev/bus/usb \
-e "TZ=${WEEWX_TZ}" \
${WEEWX_IMAGE}:latest bash

To install weewx

This command calls the script install_weewx.sh, copied inside the container.

To install a specific version of weewx, pass the WEEWX_VERSION environment variable to the container. Otherwise it will default to the version specified in the Dockerfile.

docker run --rm --name ${WEEWX_CONTAINER_NAME}_install \
--volume ${WEEWX_DIR}:/home/weewx \
--device=/dev/ttyUSB0  \
--privileged \
-v /dev/bus/usb:/dev/bus/usb \
-e "TZ=${WEEWX_TZ}" \
${WEEWX_IMAGE}:latest sh -c '${SOURCE_DIR}/scripts/install_weewx.sh'

Note	The same command can be used to upgrade weewx.

Note	Any script can be executed like this, even if it is not included in the image (in this case, it has to be accessible via one of the volumes).

To run weewx

Important

Make sure to pass the correct TZ variable from the very beginning. Updating the variable later can lead to unexpected results.

docker run -d --name ${WEEWX_CONTAINER_NAME} \
--volume ${WEEWX_DIR}:/home/weewx \
--device=/dev/ttyUSB0  \
--privileged \
-v /dev/bus/usb:/dev/bus/usb \
-e "TZ=${WEEWX_TZ}" \
${WEEWX_IMAGE}:latest /home/weewx/bin/weewxd /home/weewx/weewx.conf

To log into the weewx running container:

docker exec -it ${WEEWX_CONTAINER_NAME} bash

Installing extensions

Warning

If the extension has prerequisites, those must be available in the docker image. Complete the Dockerfile with the prerequisites, then rebuilt the image.

The commands below are examples of how to download, then install a few extensions. Simply update the URLs to download different versions of those extensions, or edit the commands to download and install different extensions.

mkdir -p ${WEEWX_DIR}/extensions
cd ${WEEWX_DIR}/extensions

# Install the WS-3000 driver
wget -O weewx-ws3000.tar.gz https://github.com/hublol/ws3000-weewx/archive/refs/tags/weewx-ws3000-0.3.tar.gz
docker exec ${WEEWX_CONTAINER_NAME} /home/weewx/bin/wee_extension --install /home/weewx/extensions/weewx-ws3000.tar.gz
docker exec ${WEEWX_CONTAINER_NAME} /home/weewx/bin/wee_config --list-drivers

# Install the WS-3000 data service
wget -O weewx-ws3000ds.tar.gz https://github.com/hublol/ws3000-weewx-dataservice/archive/refs/tags/weewx-ws3000ds-0.2.tar.gz
docker exec ${WEEWX_CONTAINER_NAME} /home/weewx/bin/wee_extension --install /home/weewx/extensions/weewx-ws3000ds.tar.gz

# Install the belchertown skin
wget -O weewx-belchertown.tar.gz https://github.com/poblabs/weewx-belchertown/releases/download/weewx-belchertown-1.3.1/weewx-belchertown-release.1.3.1.tar.gz
docker exec ${WEEWX_CONTAINER_NAME} /home/weewx/bin/wee_extension --install /home/weewx/extensions/weewx-belchertown.tar.gz

# Install the exfoliation skin
#wget -O weewx-exfoliation.zip https://github.com/matthewwall/weewx-exfoliation/archive/refs/heads/master.zip
# Original skins not working anymore with weewx 4.x and python3,
# use this one instead:
wget -O weewx-exfoliation.zip https://github.com/chaunceygardiner/weewx-exfoliation/archive/refs/heads/master.zip
docker exec ${WEEWX_CONTAINER_NAME} /home/weewx/bin/wee_extension --install /home/weewx/extensions/weewx-exfoliation.zip

# Fix exfoliation (like 228):
sed -i 's/\$get_windspeed_trend(\$trend.windSpeed.formatted/\$get_windspeed_trend(\$trend.windSpeed.raw/' ${WEEWX_DIR}/skins/exfoliation/index.html.tmpl

# Install the MQTT plugin
wget -O weewx-mqtt.zip https://github.com/matthewwall/weewx-mqtt/archive/master.zip
docker exec ${WEEWX_CONTAINER_NAME} /home/weewx/bin/wee_extension --install /home/weewx/extensions/weewx-mqtt.zip

# Install influxdb
wget -O weewx-influx.zip https://github.com/matthewwall/weewx-influx/archive/master.zip
docker exec ${WEEWX_CONTAINER_NAME} /home/weewx/bin/wee_extension --install /home/weewx/extensions/weewx-influx.zip

# List the installed extensions
docker exec ${WEEWX_CONTAINER_NAME} /home/weewx/bin/wee_extension --list

Configuration

It is then possible to configure/customize weewx as desired, as if weewx was running on the host, by editing the files in ${WEEWX_DIR}.

To stop/restart weewx after a change, simply run:

docker stop ${WEEWX_CONTAINER_NAME}
docker start ${WEEWX_CONTAINER_NAME}

It is possible to check the logs with:

docker logs -f ${WEEWX_CONTAINER_NAME}

Docker compose

Assuming that the Dockerfile is located in:
/share/homes/docker/dockerfiles/weewx-base-image

A sample docker-compose section for weewx could look like this:

  weewx:
    build: /share/homes/docker/dockerfiles/weewx-base-image
    image: weewx-image:latest
    hostname: weewx
    container_name: weewx
    command: /home/weewx/bin/weewxd /home/weewx/weewx.conf
    restart: always
    privileged: true
    environment:
      - "TZ=Europe/Paris"
    devices:
      - "/dev/ttyUSB0:/dev/ttyUSB0"
    volumes:
      - ${DOCKER_ROOT}/weewx:/home/weewx
      - /dev/bus/usb:/dev/bus/usb
    networks:
      - proxy
    logging:
      driver: "json-file"
      options:
        max-size: "1m"