Error when restoring a backup from one Docker container to another using pg_dump client

[igallart]

SO: Ubuntu 22.04 (32 GB RAM)

Install last client:
https://www.postgresql.org/download/linux/ubuntu/

Run a docker postgres:16

Backup from docker:
docker exec -t postgres pg_dump -U usr -Fc -Z4 -Od DATABASE > DATABASE.dump

Restore into docker with client:
pg_restore -vvv -U usr -h 127.0.0.1 -j 4 -Od TEST DATABASE.dump

Show errors and fail:
pg_restore: allocating AH for TEST.dump, format 0
pg_restore: attempting to ascertain archive format
pg_restore: conectando a la base de datos para reestablecimiento
pg_restore: asumiendo reestablecimiento de sólo datos
pg_restore: entering restore_toc_entries_prefork
pg_restore: entering restore_toc_entries_parallel
memoria agotada

But the backup is done with pg_dump from client it works (pg_dump from localhost, not docker):
pg_dump -U usr -h 127.0.0.1 -Fc -Z4 -Od DATABASE > DATABASE.dump

[tianon]

How did you install Docker? (memoria agotada is "memory exhausted", right? that seems odd for a machine with 32GiB of RAM 🤔)

[igallart]

Yes, is memory exhausted. Docker is installed how is say:
https://docs.docker.com/engine/install/ubuntu/#install-using-the-repository

[igallart]

Hello, I don't know if it's a mistake, but doing these steps one fails and another one doesn't.

`docker container run -d
--name postgres1
--hostname postgres1
--stop-timeout 20
-e POSTGRES_DB=postgres
-e POSTGRES_PASSWORD=usr
-e POSTGRES_USER=usr
-e POSTGRES_PORT=5432
-e POSTGRES_INITDB_ARGS="--locale=en_US.UTF-8 --lc-collate=C"
-p 5432:5432
--restart unless-stopped
postgres:16

docker exec -it postgres1 psql -U usr -d postgres -c 'CREATE DATABASE "TEST";'
docker exec -it postgres1 psql -U usr -d TEST -c "CREATE TABLE users (id SERIAL PRIMARY KEY,name VARCHAR(50),age INT);"
docker exec -it postgres1 psql -U usr -d TEST -c "INSERT INTO users (name, age) VALUES ('Juan', 25), ('María', 30), ('Carlos', 22);"

docker container run -d
--name postgres2
--hostname postgres1
--stop-timeout 20
-e POSTGRES_DB=postgres
-e POSTGRES_PASSWORD=usr
-e POSTGRES_USER=usr
-e POSTGRES_PORT=5432
-e POSTGRES_INITDB_ARGS="--locale=en_US.UTF-8 --lc-collate=C"
-p 5433:5432
--restart unless-stopped
postgres:16

docker exec -it postgres2 psql -U usr -d postgres -c 'CREATE DATABASE "TEST2";'

Fail:

docker exec -t postgres1 pg_dump -U usr -Fc -Z4 -Od TEST > TEST.dump
pg_restore -vvv -p 5433 -U usr -h 127.0.0.1 -j 4 -Od TEST2 TEST.dump
pg_restore: allocating AH for TEST.dump, format 0
pg_restore: attempting to ascertain archive format
pg_restore: error: no se pudo leer desde el archivo de entrada: fin de archivo

Work:

docker exec -it postgres1 bash
pg_dump -U usr -Fc -Z4 -Od TEST > TEST.dump
exit
docker cp postgres1:/root/TEST.dump .
pg_restore -vvv -p 5433 -U usr -h 127.0.0.1 -Od TEST2 TEST.dump

`

Maybe it's not the postgres client, but the ">" redirection. Is it possible?

libpq5:amd64 16.1-1.pgdg22.04+1
pgadmin4-desktop 8.2
pgadmin4-server 8.2
postgresql-client 16+256.pgdg22.04+1
postgresql-client-16 16.1-1.pgdg22.04+1
postgresql-client-common 256.pgdg22.04+1

[igallart]

I think I found the issue or at least the solution, and it's changing -t to -i in docker exec:

docker exec -i postgres1 pg_dump -U usr -Fc -Z4 -Od TEST > TEST.dump

It now works! Thanks!

[LaurentGoderre]

Ah! Maybe the file was too big for a TTY

[igallart]

From what I could find out, with tty, the resulting file was created with copy instructions from the standard input, whereas with -i, it was only created as a standard dump file.

[tianon]

Ah yep, adding -t turns \n into \r\n:

$ docker run --rm bash echo | hexdump -C
00000000  0a                                                |.|
00000001
$ docker run --rm -t bash echo | hexdump -C
00000000  0d 0a                                             |..|
00000002