Run

alias d=docker
alias dc=docker-compose
dc up -d

Things to try out

dc exec -T -upostgres pub psql <<EOF
insert into foo values
(1),
(2);
EOF

# here, sub MUST be able to connect to pub
dc exec -upostgres sub psql -c "CREATE SUBSCRIPTION mysub CONNECTION 'dbname=postgres host=pub user=postgres password=password' PUBLICATION mypub;"
dc exec -upostgres sub psql -c "SELECT * FROM foo"

publisher goes away

dc stop pub

note the error messages in dc logs -f sub:

could not connect to the publisher: could not translate host name "pub" to address: Temporary failure in name resolution

but subscriber can still query the old data

dc exec -upostgres sub psql -c "SELECT * FROM foo"

then publisher comes back

dc start pub

subscriber goes away

dc stop sub

publisher keeps writing

dc exec -T -upostgres pub psql <<EOF
insert into foo values
(3),
(4);
EOF

sub comes back

dc start sub
dc exec -upostgres sub psql -c "SELECT * FROM foo"

Cleanup

dc down
d volume rm $(d volume ls -qf label=de.felixhummel.project=postgres-logical-replication)