#!/bin/sh

: ${postgres_max_connections:='128'}
: ${postgres_shared_buffers:="$(( memsize  / 2 ))"}
: ${postgres_work_mem:="$(( memsize / 4 / ${postgres_max_connections} ))"}
: ${postgres_maintenance_work_mem:="$(( memsize / 20 ))"}
: ${postgres_temp_buffers:="$((32 * 1024 * 1024))"}
: ${postgres_effective_cache_size:="$(( memsize * 3 / 4 ))"}

postgres_user=postgres
postgres_home=/var/db/postgres
postgres_data_dir="${postgres_home}/data${postgres_version}"
postgres_tls_cert="${postgres_home}/postgres.crt"
postgres_tls_key="${postgres_home}/postgres.key"
postgres_keytab="${keytab_dir}/postgres.keytab"

psql(){
  command psql --quiet --no-align --echo-all --tuples-only --no-password --username=postgres --dbname=postgres "$@"
}

pkg install -y postgresql${postgresql_version}-server

# Create ZFS dataset for postgresql data.
create_dataset \
  -o "mountpoint=${postgres_home}" \
  -o recordsize=16k \
  -o primarycache=metadata \
  -o atime=off \
  "${state_dataset}/postgres"
install_directory -m 0755 -o "$postgres_user" -g "$postgres_user" "$postgres_home"

# Initialize the database.
sysrc -v postgresql_enable=YES
[ -d "${postgres_data_dir}" ] || service postgresql initdb

# Create service principal and keytab.
add_principal -nokey -x "containerdn=${services_basedn}" "postgres/${fqdn}"

ktadd -k "$postgres_keytab" "postgres/${fqdn}"
chgrp "$postgres_user" "$postgres_keytab"
chmod 640 "$postgres_keytab"

postgres_uid=$(id -u "$postgres_user")
install_directory -o "$postgres_user" -m 0700 "/var/krb5/user/${postgres_uid}"
ln -snfv "$postgres_keytab" "/var/krb5/user/${postgres_uid}/keytab"

# Create postgresql PAM service.
install_template -m 0644 /etc/pam.d/postgresql

# Copy TLS certificate for postgres.
install_certificate     -m 0644 -o root -g "$postgres_user" postgres "$postgres_tls_cert"
install_certificate_key -m 0640 -o root -g "$postgres_user" postgres "$postgres_tls_key"

# Generate postgresql configuration.
install_template -m 0600 -o "$postgres_user" -g "$postgres_user" \
  "${postgres_data_dir}/postgresql.conf"                         \
  "${postgres_data_dir}/pg_hba.conf"
install_file -m 0600 -o "$postgres_user" -g "$postgres_user" \
  "${postgres_data_dir}/pg_ident.conf"

# The postgresql rc script seems to hold onto open descriptors, which causes
# the parent boxconf SSH process to never close.
echo 'Restarting postgresql.'
service postgresql restart > /dev/null 2>&1 < /dev/null

# Create boxconf admin user.
psql -c "DO
\$$
BEGIN
  IF NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname = '${boxconf_user}') THEN
    CREATE ROLE \"${boxconf_user}\" WITH LOGIN SUPERUSER;
  END IF;
END
\$$"