Handle SIGTERM to enable graceful script shutdown when a container is stopped. This currently only matters for the InfluxDB scripts, and only when they run in a loop, since if the script is hard-terminated, it won't flush out any queued data points to the InfluxDB server. This also required changing the entrypoint script to exec python instead of running it as a child process of the shell running entrypoint.sh, since Docker will only deliver SIGTERM to the parent process it started directly.
Also, add -t 30 to the default Docker command to match the script default behavior prior to the changes in 46f65a6214
Add an interval timing loop for all the grpc scripts that did not already have one. Organized some of the code into functions in order to facilitate this, which caused some problems with local variables vs global ones, so moved the script code into a proper main() function. Which didn't really solve the access to globals issue, so also moved the mutable state into a class instance.
The interval timer should be relatively robust against time drift due to the loop function running time and/or OS scheduler delay, but is far from perfect.
Retry logic is now in place for both InfluxDB scripts. Retry for dishStatusInflux.py is slightly changed in that a failed write to InfluxDB server will be retried on every interval, rather than waiting for another batch full of data points to write, but this only happens once there is at least a full batch (currently 6) of data points pending. This new behavior matches how the autocommit functionality on SeriesHelper works.
Changed the default behavior of dishStatusInflux.py to not loop, in order to match the other scripts. To get the old behavior, add a '-t 30' option to the command line.
Closes#9
The README instructions @neurocis added for the Docker container recommend this name, and I like that better than dishstats, so now it's the default.
"dish" can be useful to differentiate between the Starlink user terminal (dish) and the Starlink router, both of which expose gRPC services for polling status information, but that's more applicable to the measurement name (AKA series_name) and a hypothetical database that contained both would be more appropriately labelled "Starlink".
SSL/TLS support for InfluxDB and MQTT scripts
Copy the command line option handling into the status scripts to facilitate this. Also copy the setting from env from dishStatusInflux_cron.py.
Better error handling for failures while writing to the data backend. Error printing verbosity is now a bit inconsistent, but I'll address that separately.
Still to be done is dishStatusInflux_cron.py, pending a decision on what to do with that script, given that dishStatusInflux.py can now be run in one-shot mode.
This is related to issue #2.
Unlike the status info scripts, these include support for setting host and database parameters via command line options. Still to be added is support for HTTPS/SSL.
Add a get_id function to the grpc parser module, so it can be used for tagging purposes.
Minor cleanups in some of the other scripts to make them consistent with the newly added scripts.
