TZ updates with read only file system about tzdata

[lau]

Hi. A new version has just been released (0.5.15). See the updated README. If you have a read only file system you can put an .ets file with the newest data available in the configured data_dir.

Yes it would be possible to use auto update via the internet and not save the new data to file. That could potentially be added as a config option. However it would mean that the if Tzdata restarts it would go back to the old version on the read only file system. Potentially going back and forth between an old and new version.

May I ask what sort of application is it that is connected to the internet but has no writeable disk space?

[tomciopp]

The application handles electronic medical records. It is shipped in a docker container with no access to a mounted disk. This allows us to avoid a series of attack vectors that most normal web apps don't consider protecting against. A package arbitrarily writing files is just something we can't condone. It can only write to a database that is not connected to the public internet.

[lau]

One problem with getting updates and not writing to disk is that upon restarts it would go back to an old version from disk. So you could cycle back and forth between old and new versions. If you don't want the library to write to disk you could write your own code that puts .ets files in a location you specify in the config and then trigger loading of the new database from that file.