These functions improve usability and take all the proper steps to
set restoring on/off (and stop/start background workers in the process)
and to set the license key via a function rather than a guc modification.
Currently the view displays the current edition, expiry date, and
whether the license is expired. We're not displaying the license key
itself in the view as it can get rather long, and get be read via SHOW.
We also do not display the license's ID since that is for internal use.
So as to reduce the amount of logspam users receive, restrict printing license info
to the following:
1. On CREATE EXTENSION
a. in the notice, print the license expiration time, if any
b. if the license is expired additionally print that
c. else if the license will expire within a week print an addional warning
2. On the first usage of a TSL function, print if the license is expired or will
be expired within a week
This commit adds support for dynamically loaded submodules to timescaledb
as well an initial license-key implementation in the tsl subdirectory.
Dynamically loaded modules allow our users to determine which licenses they
wish to use for their version of timescaledb; if they wish to only use
Apache-Licensed code, they do not load the Timescale-Licensed submodule. Calls
from the Apache-Licensed code into the Timescale-Licensed submodule are
handled via dynamicaly-set function pointers; see tsl/src/Readme.module.md for
more details.
This commit also adds code for license keys for the ApacheOnly, Community, and
Enterprise editions. The license key determines which features are enabled,
and controls loading the submodule: when a license key that requires the
sub-module is installed, the module is automatically loaded.
Currently the ApacheOnly and Community license-keys are hardcoded to be
"ApacheOnly" and "Community" respectively. The first version of the enterprise
license-key is described in tsl/src/Readme.module.md
