conf.sh

#!/bin/bash
set -Eeuo pipefail

# The inner sed finds the line number of the last match for the the regex ^\s*shared_preload_libraries\s*=
# The outer sed, operating on that line alone, extracts the text between single quotes after the equals sign
PREVIOUS_PRELOAD_LIBRARIES=$(sed -nE "$(sed -n '/^\s*shared_preload_libraries\s*=/ =' ${PGDATA}/postgresql.conf | tail -n 1) s/^\s*shared_preload_libraries\s*=\s*'(.*?)'/\1/p" ${PGDATA}/postgresql.conf)

NEW_PRELOAD_LIBRARIES="credcheck,pg_cron,pg_partman_bgw,pg_show_plans,pg_similarity,pg_squeeze,pg_stat_statements,pg_stat_kcache,pg_wait_sampling,pgaudit,pgauditlogtofile,pglogical,pglogical_ticker,pgmemcache,plprofiler,plugin_debugger,postgis-3,set_user,timescaledb"

cat >> ${PGDATA}/postgresql.conf << EOT
listen_addresses = '*'

shared_preload_libraries = '$(echo "$PREVIOUS_PRELOAD_LIBRARIES,$NEW_PRELOAD_LIBRARIES" | sed 's/^,//')'

# pg_cron
cron.database_name = '${PG_CRON_DB:-${POSTGRES_DB:-${POSTGRES_USER:-postgres}}}'

# pg_partman
pg_partman_bgw.dbname = '${PG_PARTMAN_DB:-${POSTGRES_DB:-${POSTGRES_USER:-postgres}}}'

# MobilityDB recomendation
max_locks_per_transaction = 128
timescaledb.telemetry_level = off

# pglogical
wal_level = 'logical'
max_worker_processes = 10   # one per database needed on provider node
                            # one per node needed on subscriber node
max_replication_slots = 10  # one per node needed on provider node
max_wal_senders = 10        # one per node needed on provider node
track_commit_timestamp = on # needed for last/first update wins conflict resolution
EOT