comp AP gateway: publish, (un)subscribe/(un)follow, public subscription/following/followers: this patch implements those major features: - `publish` is implemented on virtual pubsub service, thus XMPP entities can now publish to AP using this service - replies to XMPP items are managed - `inReplyTo` is filled when converting XMPP items to AP objects - `follow` and `unfollow` (actually an `undo` activity) are implemented and mapped to XMPP's (un)subscribe. On subscription, AP actor's `outbox` collection is converted to XMPP and put in cache. Subscriptions are always public. - `following` and `followers` collections are mapped to XMPP's Public Pubsub Subscription (which should be XEP-0465, but the XEP is not yet published at the time of commit), in both directions. - new helper methods to check if an URL is local and to get JID from actor ID doc will follow to explain behaviour rel 365

#!/bin/bash

# we first need to wait for PostgreSQL
# cf. https://stackoverflow.com/a/39028690 (thanks!)

RETRIES=5

until psql -c "select 1" > /dev/null 2>&1 || [ $RETRIES -eq 0 ]; do
  echo "Waiting for postgres server, $((RETRIES--)) remaining attempts…"
  sleep 1
done

ori_dir=${PWD}
cd /src/sat_pubsub/db

# PG should be OK, we now initialize the database. If it's already done, it will fail
# with exit code 3
psql -v ON_ERROR_STOP=1 pubsub < pubsub.sql 2>/dev/null
case $? in
    0) printf "database initialized\n" ;;
    3) printf "database already exists\n" ;;
    *) printf "can't initialize database, please check PostgreSQL container parameters\n" >&2
       exit 1
       ;;
esac

cd $ori_dir

exec /home/libervia/libervia_env/bin/twistd -n libervia-pubsub "$@"