Nomad's periodic block includes a "time_zone" parameter which lets
operators set the time zone at which the next launch interval is
checked against. For this to work, Nomad needs to use the
"time.LoadLocation" which in-turn can use multiple TZ data sources.
When using the Docker image to trigger Nomad job registrations, it
currently does not have access to any TZ data, meaning it is only
aware of UTC. Adding the tzdata package contents to the release
image provides the required data for this to work.
It would have also been possible to set the "-tags" build tag when
releasing Nomad which would embed a copy of the timezone database
in the code. We decided against using the build tag approach as it
is a subtle way that we could introduce bugs that are very
difficult to track down and we prefer the commit approach.
