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LLeMbas/deploy/install.sh
T
Jaroslav Beneš 0c438a6333 A version somebody can read, instead of a sha nobody can
Updates follow a channel now. `stable` is the newest vX.Y.Z tag; `edge` is the
branch tip, which is what this did before. Stable is the default, because a
branch tip is not a release -- following one means deploying whatever was pushed
five minutes ago, possibly mid-feature, which is right for whoever builds this
and wrong for whoever runs it. The page can now say "running 1.0.0, 1.1.0
available" rather than showing two shas and leaving somebody to guess.

Read with git plumbing and never a forge API, for three reasons in the order
they bite. It would need a token on the deployment host -- a credential that can
reach the repository, sitting on a box, to answer a read-only question about
version numbers. It would tie this to one forge, so a fork on GitHub gets
nothing. And it breaks: checked against the Gitea this is developed on, `tea
whoami` works and `tea releases list` returns a 500 from a server-side panic
about token scopes, so a page resting on that endpoint would have shipped
already broken.

Release notes still travel, inside the annotated tag object, which
`git for-each-ref` reads with no API anywhere.

Two details that are only obvious after getting them wrong. A tag with a suffix
is not a release: git's version sort puts v1.1.0-rc1 *above* v1.1.0, so
accepting one would step a stable host onto a candidate on the strength of a
hyphen. And `--sort=-v:refname` rather than a lexical sort, which puts v1.9.0
above v1.10.0 and does it silently the first time a project reaches ten of
anything -- there is a test.

What is running is `git describe --tags --always`, so it reads "1.0.0" at a tag,
"1.0.0-7-gd4f56d" seven commits past one, and a bare sha before the first
release ever exists. That last case is what `--always` is for. When it lands
exactly on a tag whose name disagrees with __version__, the page says so: a tag
cut before the version bump names a release nobody can identify afterwards, and
the check costs no subprocess because both facts are already in hand.

update.sh resolves the channel the same way and detaches at the tag rather than
resetting -- a `reset --hard <tag>` while on main would move the local branch to
it, which is a rewrite of a ref nobody asked to rewrite. A host with no tags
falls back to the branch and says so, which is every host until the release.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-06 20:42:03 +02:00

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#!/usr/bin/env bash
# Install LLeMbas as a system service behind nginx with a self-signed cert.
#
# Creates a dedicated service user, a virtualenv, a systemd unit and an nginx
# vhost. Idempotent: safe to re-run. To deploy new code afterwards use
# update.sh, which is what a `git push` should be followed by.
#
# Everything is configurable from the environment:
#
# SITE_HOST=chat.example ./deploy/install.sh # vhost name
# APP_PORT=8080 # loopback port
# PREFIX=/srv/lembas # install root
# HOME_DIR=/home/lembas # service user's home
# REPO_URL=... # defaults to this checkout's origin
#
# PREFIX defaults to a bind mount of HOME_DIR rather than living directly under
# /srv, because on many machines the root filesystem is small and the venv plus
# database belong on the larger /home volume. Set PREFIX=HOME_DIR to skip that.
set -euo pipefail
HERE="$(dirname "$(readlink -f "$0")")"
SITE_HOST="${SITE_HOST:-lembas.local}"
APP_PORT="${APP_PORT:-8080}"
SERVICE_USER="${SERVICE_USER:-lembas}"
HOME_DIR="${HOME_DIR:-/home/lembas}"
PREFIX="${PREFIX:-/srv/lembas}"
BRANCH="${LEMBAS_BRANCH:-main}"
# Which channel this host follows: `stable` (the newest release tag) or `edge`
# (the branch tip). Stable by default, because a branch tip is not a release --
# following one means deploying whatever was pushed five minutes ago, which is
# right for whoever builds this and wrong for whoever runs it.
CHANNEL="${LEMBAS_CHANNEL:-stable}"
# Whether to install the units that let the web interface update this host.
# Off, and off on a re-run that does not ask for it: it grants anybody who can
# administer the web UI the ability to deploy the branch, as root. See the
# "Updating from the web interface" section of deploy/README.md.
INSTALL_UPDATE_HELPER="${INSTALL_UPDATE_HELPER:-0}"
# Default to wherever this checkout came from, so a fork deploys itself.
REPO_URL="${REPO_URL:-$(git -C "$HERE" remote get-url origin 2>/dev/null || true)}"
APP="$PREFIX/app"
VENV="$PREFIX/venv"
ENV_FILE="$PREFIX/lembas.env"
if [[ -z "$REPO_URL" ]]; then
echo "Could not determine REPO_URL. Set it explicitly." >&2
exit 1
fi
echo "== plan =="
echo " host : https://$SITE_HOST -> 127.0.0.1:$APP_PORT"
echo " user : $SERVICE_USER ($HOME_DIR)"
echo " prefix : $PREFIX"
echo " repo : $REPO_URL ($BRANCH, $CHANNEL channel)"
if [[ "$INSTALL_UPDATE_HELPER" == "1" ]]; then
echo " updates : web interface may deploy $BRANCH as root (helper units)"
else
echo " updates : by hand only ($PREFIX/app/deploy/update.sh)"
fi
echo "== service user =="
# --system: no ageing, no mail spool. Home under /home, not /var/lib, so the
# venv and database sit on the larger volume.
if ! getent passwd "$SERVICE_USER" >/dev/null; then
sudo useradd --system --create-home --home-dir "$HOME_DIR" \
--shell /usr/bin/nologin --comment "LLeMbas" "$SERVICE_USER"
else
echo " user $SERVICE_USER already exists"
fi
sudo chmod 755 "$HOME_DIR"
if [[ "$PREFIX" != "$HOME_DIR" ]]; then
echo "== $PREFIX bind-mount onto $HOME_DIR =="
sudo mkdir -p "$PREFIX"
grep -q "^$HOME_DIR[[:space:]]" /etc/fstab \
|| echo "$HOME_DIR $PREFIX none bind 0 0" | sudo tee -a /etc/fstab >/dev/null
sudo systemctl daemon-reload
mountpoint -q "$PREFIX" || sudo mount "$PREFIX"
fi
echo "== checkout =="
if [[ ! -d "$APP/.git" ]]; then
sudo -u "$SERVICE_USER" git clone --branch "$BRANCH" "$REPO_URL" "$APP"
else
echo " already cloned; use update.sh to pull"
fi
echo "== virtualenv =="
if [[ ! -x "$VENV/bin/python" ]]; then
sudo -u "$SERVICE_USER" python -m venv "$VENV"
fi
sudo -u "$SERVICE_USER" "$VENV/bin/pip" install --quiet --upgrade pip
# The extras a deployment gets. `search` because DuckDuckGo is the default web
# search provider and is meant to need no setup; `ssh` because agent chats reach
# their machine over it and a deployment without it offers the feature with an
# install hint instead. Listed here AND in update.sh -- an extra added to only
# one of them means existing deployments silently miss it.
LEMBAS_EXTRAS="${LEMBAS_EXTRAS:-search,ssh}"
sudo -u "$SERVICE_USER" "$VENV/bin/pip" install --quiet -e "$APP[$LEMBAS_EXTRAS]"
echo "== environment =="
# Generated once and never regenerated: rotating LEMBAS_SECRET_KEY signs every
# user out AND makes the stored upstream API keys unreadable.
if [[ ! -f "$ENV_FILE" ]]; then
KEY=$("$VENV/bin/python" -c "import secrets; print(secrets.token_urlsafe(48))")
sudo tee "$ENV_FILE" >/dev/null <<EOF
# LLeMbas service environment. Generated by deploy/install.sh.
# LEMBAS_SECRET_KEY signs sessions and encrypts stored API keys.
# Changing it signs everyone out and makes stored API keys unreadable.
LEMBAS_SECRET_KEY=$KEY
LEMBAS_DATA_DIR=$PREFIX/data
# Loopback only: reachable through the nginx vhost, never directly.
LEMBAS_HOST=127.0.0.1
LEMBAS_PORT=$APP_PORT
LEMBAS_LOG_LEVEL=info
LEMBAS_ALLOW_SIGNUP=true
LEMBAS_DEFAULT_THEME=moria
# Which branch /admin/updates compares against. Deployment configuration, not
# an instance setting: it decides what code runs here, and a value a web
# administrator could edit would turn "you may deploy the branch" into "you may
# deploy anything".
LEMBAS_UPDATE_BRANCH=$BRANCH
# stable follows the newest release tag; edge follows the branch tip.
LEMBAS_UPDATE_CHANNEL=$CHANNEL
EOF
sudo chown "$SERVICE_USER:$SERVICE_USER" "$ENV_FILE"
sudo chmod 600 "$ENV_FILE"
echo " generated $ENV_FILE"
else
echo " $ENV_FILE exists, keeping it (and its secret key)"
fi
sudo install -d -o "$SERVICE_USER" -g "$SERVICE_USER" -m 750 "$PREFIX/data"
echo "== systemd unit =="
sed -e "s|__PREFIX__|$PREFIX|g" -e "s|__SERVICE_USER__|$SERVICE_USER|g" \
"$HERE/lembas.service" | sudo tee /etc/systemd/system/lembas.service >/dev/null
# Which version of the template this host is running. update.sh compares
# against it and says so when the template moves on, because the installed
# unit usually grows host-specific lines and cannot simply be overwritten.
sha256sum "$HERE/lembas.service" | cut -d' ' -f1 | sudo tee "$PREFIX/.unit-applied" >/dev/null
sudo systemctl daemon-reload
echo "== update helper =="
# Two units and a marker. The marker is what the web interface reads to decide
# whether to offer the button at all -- a file rather than `systemctl
# is-enabled`, because that would be a subprocess on every page render to answer
# a question that changes once.
UPDATE_MARKER="$PREFIX/data/.update-helper"
if [[ "$INSTALL_UPDATE_HELPER" == "1" ]]; then
for unit in lembas-update.path lembas-update.service; do
sed -e "s|__PREFIX__|$PREFIX|g" \
-e "s|__SERVICE_USER__|$SERVICE_USER|g" \
-e "s|__UPDATE_BRANCH__|$BRANCH|g" \
-e "s|__UPDATE_CHANNEL__|$CHANNEL|g" \
"$HERE/$unit" | sudo tee "/etc/systemd/system/$unit" >/dev/null
done
sudo systemctl daemon-reload
sudo systemctl enable --now lembas-update.path
sudo touch "$UPDATE_MARKER"
sudo chown "$SERVICE_USER:$SERVICE_USER" "$UPDATE_MARKER"
echo " installed. The web interface can now deploy the $CHANNEL channel and restart."
else
# Removed rather than left, so turning it off is re-running without the flag
# rather than remembering three commands. The button then says so and prints
# the manual one, which is the honest degradation.
sudo systemctl disable --now lembas-update.path 2>/dev/null || true
sudo rm -f /etc/systemd/system/lembas-update.path \
/etc/systemd/system/lembas-update.service "$UPDATE_MARKER"
sudo systemctl daemon-reload
echo " not installed (INSTALL_UPDATE_HELPER=1 to allow updating from the web UI)"
fi
echo "== self-signed cert for $SITE_HOST =="
sudo mkdir -p /etc/nginx/ssl
if [[ ! -f "/etc/nginx/ssl/$SITE_HOST.crt" ]]; then
sudo openssl req -x509 -newkey rsa:2048 -nodes \
-keyout "/etc/nginx/ssl/$SITE_HOST.key" -out "/etc/nginx/ssl/$SITE_HOST.crt" \
-days 3650 -subj "/CN=$SITE_HOST" -addext "subjectAltName=DNS:$SITE_HOST"
sudo chmod 600 "/etc/nginx/ssl/$SITE_HOST.key"
sudo chmod 644 "/etc/nginx/ssl/$SITE_HOST.crt"
fi
echo "== nginx vhost =="
sed -e "s|__SITE_HOST__|$SITE_HOST|g" -e "s|__APP_PORT__|$APP_PORT|g" \
"$HERE/nginx-vhost.conf" | sudo tee "/etc/nginx/conf.d/$SITE_HOST.conf" >/dev/null
sudo nginx -t
sudo systemctl reload nginx
# What this host was installed with, so update.sh can name the vhost it should
# be comparing against and print a command that actually runs. Without it the
# drift check below could only say "something changed somewhere".
printf 'SITE_HOST=%s\nAPP_PORT=%s\n' "$SITE_HOST" "$APP_PORT" \
| sudo tee "$PREFIX/.deploy-env" >/dev/null
sha256sum "$HERE/nginx-vhost.conf" | cut -d' ' -f1 \
| sudo tee "$PREFIX/.vhost-applied" >/dev/null
echo "== local name resolution =="
# Only useful when the LAN's DNS does not already answer for this name.
if ! getent hosts "$SITE_HOST" >/dev/null; then
printf '127.0.0.1\t%s\n::1\t\t%s\n' "$SITE_HOST" "$SITE_HOST" | sudo tee -a /etc/hosts >/dev/null
echo " added $SITE_HOST to /etc/hosts"
else
echo " $SITE_HOST already resolves"
fi
echo "== enable service =="
sudo systemctl enable --now lembas
sleep 2
sudo systemctl --no-pager --lines=0 status lembas || true
echo
echo "LLeMbas is up at https://$SITE_HOST (self-signed cert; accept the warning)"
echo "Create the first account -- it becomes the administrator."