Downloading data from WIS2¶
This section provides guidance how to download data from WIS2 Global Services.
WIS2 Global Services include a Global Broker that provides users the ability to subscribe to data (via topics) and download to their local environment / workstation / decision support system from the WIS2 Global Cache.
The pywis-pubsub tool¶
wis2box enables subscribe and data download workflow the WIS2 network, by using the
wis2box-subscribe-download container, inside of which runs the pywis-pubsub tool
pywis-pubsub is a Python package that provides publish, subscription and download capability of data from WIS2 Global Services.
Before starting the
wis2box-subscribe-download container, the default configuration (provided in
must be updated, by defining the URL of the MQTT broker as well as the desired topic(s) to subscribe to.
In addition, the storage path should be updated to specify where downloaded data should be saved to.
# fully qualified URL of broker broker: mqtts://username:password@host:port # whether to run checksum verification when downloading data (default true) verify_data: true # whether to validate broker messages (default true) validate_message: true # list of 1..n topics to subscribe to topics: - 'cache/a/wis2/topic1/#' - 'cache/a/wis2/topic2/#' # storage: filesystem storage: type: fs options: path: /tmp/foo/bar
To start a continuous subscribe and download process, run the
wis2box-subscribe-download container as follows (
-d for detached mode,
--build to ensure changes in
local.yml are built into the container):
docker-compose -f docker.subscribe-download.yml up -d --build
To stop the subscribe and download process, run the following command:
docker-compose -f docker.subscribe-download.yml down
Running pywis-pubsub interactively¶
pywis-pubsub can also be run interactively from inside the wis2box main container as follows:
# login to wis2box main container python3 wis2box-ctl.py login # edit a local configuration by using wis2box-subscribe-download/local.yml as a template vi /data/wis2box/local.yml # connect, and simply display data notifications pywis-pubsub subscribe --config local.yml # connect, and additionally download messages pywis-pubsub subscribe --config local.yml --download # connect, and filter messages by bounding box geometry pywis-pubsub subscribe --config local.yml --bbox=-142,42,-52,84