The systemd unit templates hardcoded {{ install_dir }}/venv/bin/decnet.
On production hosts enroll_bootstrap.sh creates exactly that path so it
worked. On dev boxes where the operator runs `sudo decnet init` against
a source checkout with a differently-named venv (.venv, .311, .312),
every decnet-*.service looped forever in auto-restart with:
Failed at step EXEC spawning .../venv/bin/decnet: No such file or
directory
Templates now use {{ venv_dir }} as an independent Jinja2 var. `decnet
init` adds --venv-dir (explicit override), otherwise autodetects:
1. $VIRTUAL_ENV (only when inside --install-dir, so a user-home venv
never gets baked into a root-owned unit),
2. {install_dir}/venv (production default; what enroll_bootstrap
creates),
3. {install_dir}/{.venv,.311,.312,.313} (common dev conventions).
Init aborts before any file writes if nothing resolves — an
operator-friendly error beats journalctl spam on every unit restart.
python3-venv doesn't set a persistent system variable — $VIRTUAL_ENV
lives in the activated shell only — so this has to be decided + baked
in at init time; there's no way for systemd to "inherit the current
venv" at unit start.
Test mode (--prefix) skips venv validation so the existing test suite
doesn't need to stub up a venv tree per case.
Distros reserve /opt for different things (some package managers own it
outright), and a DECNET install that wants to live at /srv/decnet or
/usr/local/decnet had to hand-edit 13 service files post-install.
Converts every deploy/decnet-*.service to a .j2 template keyed on
{{ install_dir }}, rendered by `decnet init` at install time. All other
paths (log_dir, state_dir, runtime_dir, user, group) stay standard —
only install_dir varies.
Changes:
- deploy/decnet-*.service → deploy/decnet-*.service.j2 (13 files).
- decnet init gains --install-dir (default /opt/decnet, preserves
existing behaviour byte-for-byte). Validates absolute-path at the
CLI boundary. Threads through useradd --home-dir and the dir-creation
list so the filesystem layout matches the rendered templates.
- _install_units renders via Jinja2 with StrictUndefined (typo → loud
error, not a silent broken unit). SHA over rendered output so
operators with a custom install_dir get idempotent re-runs.
- decnet.target, tmpfiles.d, polkit rule stay static — they don't
reference install paths.
- 4 new tests: custom install_dir renders into units, default remains
/opt/decnet, relative paths rejected, second run with same custom
dir is idempotent.
