Bug Info

When mounting a custom .psqlrc configuration file with timing enabled, some SQL queries within the docker-entrypoint.sh do not return the expected values, as they are superseded by the timing strings. For instance, it breaks the script that creates the initial database from working correctly.

For more context, I prefer to mount my custom .psqlrc file for local development, to have my common functions and aliases always ready when I need them.

Proposed solution

From my local testing, it would be enough to add --no-psqlrc flag to the query_runner variable in the docker_process_sql function.

Minimal example

.psqlrc

\set QUIET 1
\timing on
\unset QUIET

docker-compose.yml

version: "3.7"
services:
  database:
    build:
      context: .
    environment:
      POSTGRES_DB: sample
      POSTGRES_PASSWORD: postgres
    ports:
    - 5432:5432
    volumes:
    # Mount psql config file in the system configuration directory.
    - ./.psqlrc:/etc/postgresql-common/psqlrc:ro

I also have a following Dockerfile:

FROM postgres

COPY docker-entrypoint.sh /usr/local/bin/

with custom docker-entrypoint.sh where I modified the function to print extra debug info:

docker_setup_db() {
    local dbAlreadyExists
    dbAlreadyExists="$(
        POSTGRES_DB= docker_process_sql --dbname postgres --set db="$POSTGRES_DB" --tuples-only <<-'EOSQL'
	    SELECT 1 FROM pg_database WHERE datname = :'db' ;
        EOSQL
    )"
    echo "Exists: $dbAlreadyExists"
    if [ -z "$dbAlreadyExists" ]; then
	POSTGRES_DB= docker_process_sql --dbname postgres --set db="$POSTGRES_DB" <<-'EOSQL'
	    CREATE DATABASE :"db" ;
	EOSQL
	echo
    else
        echo "DB already exists"
    fi
}

Log

Building and running the above code with docker compose up will yield following log:

database_1 | 2021-10-23 20:37:19.438 UTC [49] LOG: database system is ready to accept connections
database_1 | done
database_1 | server started
database_1 | Exists:
database_1 | Time: 2.633 ms
database_1 | DB already exists