Bug: postgres container expects English log line to ensure started #695
Description
Describe the bug
When starting a Postgres Testcontainer, the implementation expects a log line like the latter to ensure its properly started
.*database system is ready to accept connections.*
In case you have a custom Postgres image (e.g. with lang/locales changed) this log line might not appear as expected.
To Reproduce
FROM postgres:16
RUN locale-gen de_AT.utf8 \
&& localedef -i de_AT -c -f UTF-8 -A /usr/share/locale/locale.alias de_AT.UTF-8
ENV LANG=de_AT.utf8use the dockerfile above, and the log lines are more like
2024-09-03 15:35:48.551 UTC [1] LOG: erwarte Verbindungen auf IPv4-Adresse »0.0.0.0«, Port 5432
2024-09-03 15:35:48.551 UTC [1] LOG: erwarte Verbindungen auf IPv6-Adresse »::«, Port 5432
2024-09-03 15:35:48.554 UTC [1] LOG: erwarte Verbindungen auf Unix-Socket »/var/run/postgresql/.s.PGSQL.5432«
2024-09-03 15:35:48.557 UTC [63] LOG: Datenbanksystem wurde am 2024-09-03 15:35:48 UTC heruntergefahren
2024-09-03 15:35:48.561 UTC [1] LOG: Datenbanksystem ist bereit, um Verbindungen anzunehmen
I think that using pg_isready is sufficient - so changing the code of PostgresContainer to
@wait_container_is_ready()
def _connect(self) -> None:
# postgres itself logs these messages to the standard error stream:
#
# $ /opt/homebrew/opt/postgresql@14/bin/postgres -D /opt/homebrew/var/postgresql@14 \
# > | grep -o -a -m 1 -h 'database system is ready to accept connections'
# 2024-08-03 00:13:02.799 EDT [70226] LOG: starting PostgreSQL 14.11 (Homebrew) ....
# 2024-08-03 00:13:02.804 EDT [70226] LOG: listening on IPv4 address "127.0.0.1", port 5432
# ...
# ^C2024-08-03 00:13:04.226 EDT [70226] LOG: received fast shutdown request
# ...
#
# $ /opt/homebrew/opt/postgresql@14/bin/postgres -D /opt/homebrew/var/postgresql@14 2>&1 \
# > | grep -o -a -m 1 -h 'database system is ready to accept connections'
# database system is ready to accept connections
#
# and the setup script inside docker library postgres
# uses pg_ctl:
# https://github.com/docker-library/postgres/blob/66da3846b40396249936938ee17e9684e6968a57/16/alpine3.20/docker-entrypoint.sh#L261-L282
# which prints logs to stdout:
# https://www.postgresql.org/docs/current/app-pg-ctl.html#:~:text=the%20server%27s%20standard%20output%20and%20standard%20error%20are%20sent%20to%20pg_ctl%27s%20standard%20output
#
# so we must wait for both the setup and real startup:
predicate_streams_and = True
# as the wait for logs is commented out, we can start all kinds of containers (even non English ones)
#wait_for_logs(
# self,
# ".*database system is ready to accept connections.*",
# c.max_tries,
# c.sleep_time,
# predicate_streams_and=predicate_streams_and,
# #
#)
count = 0
while count < c.max_tries:
status, _ = self.exec(f"pg_isready -hlocalhost -p{self.port} -U{self.username}")
if status == 0:
return
sleep(c.sleep_time)
count += 1
raise RuntimeError("Postgres could not get into a ready state")
works like a charm.