pglogrepl is a Go package for PostgreSQL logical replication.
pglogrepl uses package github.com/jackc/pgx/v5/pgconn as its underlying PostgreSQL connection.
Proper use of this package requires understanding the underlying PostgreSQL concepts. See https://www.postgresql.org/docs/current/protocol-replication.html.
In example/pglogrepl_demo, there is an example demo program that connects to a database and logs all messages sent over logical replication.
In example/pgphysrepl_demo, there is an example demo program that connects to a database and logs all messages sent over physical replication.
Testing requires a user with replication permission, a database to replicate, access allowed in pg_hba.conf, and
logical replication enabled in postgresql.conf.
Create a database:
create database pglogrepl;
Create a user:
create user pglogrepl with replication password 'secret';
If you're using PostgreSQL 15 or newer grant access to the public schema, just for these tests:
grant all on schema public to pglogrepl;
Add a replication line to your pg_hba.conf:
host replication pglogrepl 127.0.0.1/32 md5
Change the following settings in your postgresql.conf:
wal_level=logical
max_wal_senders=5
max_replication_slots=5
To run the tests set PGLOGREPL_TEST_CONN_STRING environment variable with a replication connection string (URL or DSN).
Since the base backup would request postgres to create a backup tar and stream it, this test cn be disabled with
PGLOGREPL_SKIP_BASE_BACKUP=true
Example:
PGLOGREPL_TEST_CONN_STRING=postgres://pglogrepl:secret@127.0.0.1/pglogrepl?replication=database go test