mbtaylor/plotserv repository overview

⁠STILTS plot server

This image consists of the uk.ac.starlink.ttools.server.PlotServlet servlet running inside Tomcat. This enables web applications to embed into HTML stilts⁠/topcat⁠-like plots that are interactive, i.e. can be navigated using the mouse.

Some minimal runtime configuration will be required:

• Tomcat's default port 8080 is used, so you have to publish this on the host machine.

• When constructing a plot, table files are referenced as pathnames. So you should make your table files (FITS is a good choice) available somewhere in the filesystem by mounting them.

• When generating plots the servlet uses a disk cache in /tmp to cache initial images and prepared coordinate data. It will use as much cache as is available and clear it out when it gets full. So it's a good idea to limit the amount of space in the /tmp area, which is easy using a tmpfs mount. If you instead use a bind mount and share/reuse it between instances you can retain the cached data between runs.

Here is a suggested invocation:

docker run \
    -p 8080:8080 \
    --mount type=bind,src=/my/data/directory,dst=/data,readonly \
    --mount type=tmpfs,dst=/tmp,tmpfs-size=2G \
    -d mbtaylor/plotserv

Then you can make plots with stilts parameters like

in=/data/cat.fits

See the root URL of the running service for more information about what this is for and how to use it.

There are other ways to run the plotting service; you can just run

java -jar stilts.jar server [port=<number>]

from the command line, or deploy the PlotServlet in your own Tomcat container with a custom web.xml. Those methods currently offer less tidy/secure data file access, but that should be improved in future releases.

See http://www.starlink.ac.uk/stilts/⁠, especiall http://www.starlink.ac.uk/stilts/sun256/PlotServlet.html⁠.