Release automation phase 1

[jerryxwu]

Currently, our release procedure produces a version tag. Ideally, we want all the final packages (docker etc) built and tested. Since we don't currently own the docker images (we may not own them in the future either), as a first step, we want to achieve the following:

1. Build the deb and rpm packages
2. Run some validate tests on the final packages. Ideally, these validation tests are data-driven like what we have been doing in sql-doctester
3. Publish the packages onto packagecloud

[epgts]

Currently I test binaries manually by following our official installation instructions on CentOS 7 (well, Rocky 8.6 this time) and Ubuntu 20.04 and running a manual smoke test, usually by copying something out of a doc test or pgx test.

For automated testing of binaries, I left a comment at line 21 here: https://github.com/timescale/release-build-scripts/blob/90da47dc17ba5bcf677e6ecfaa85690a83ec9fcb/debian/docker-build-toolkit.sh#L21

What I left out of that comment is moving the post-install run to after we build the deb and install it with dpkg -i. After test passes, remove it again with dpkg -r.

Currently we:

  cargo run --manifest-path tools/post-install/Cargo.toml -- --dir target/release/timescaledb_toolkit-pg${PG_MAJOR}

I mentioned this morning that --dir /usr ought to work but doesn't, but actually I noticed that's not how we do it from tools/build anyway!

So the real fix might be as simple as changing that to

  cargo run --manifest-path tools/post-install/Cargo.toml /bin/pg_config

Possibly we may need to execute other commands from https://docs.timescale.com/timescaledb/latest/how-to-guides/hyperfunctions/install-toolkit/#install-toolkit-on-ubuntu-and-other-debian-based-systems in order for that to work (in particular, possibly /usr/share/postgresql-common/pgdg/apt.postgresql.org.sh and systemctl restart postgresql).