Laredo

Quick Start

Quick Start

Get Laredo running with a PostgreSQL source and an in-memory target in under 5 minutes.

Prerequisites

  • Go 1.23+
  • PostgreSQL 14+ with wal_level = logical

Install

go install github.com/zourzouvillys/laredo/cmd/laredo-server@latest
go install github.com/zourzouvillys/laredo/cmd/laredo@latest

Configure PostgreSQL

Ensure logical replication is enabled:

ALTER SYSTEM SET wal_level = logical;
-- Restart PostgreSQL after this change

Create a test table:

CREATE TABLE public.config_document (
  id BIGSERIAL PRIMARY KEY,
  instance_id TEXT NOT NULL,
  key TEXT NOT NULL,
  data JSONB,
  created_at TIMESTAMPTZ DEFAULT now(),
  updated_at TIMESTAMPTZ
);

INSERT INTO public.config_document (instance_id, key, data)
VALUES
  ('inst_abc', 'settings/default', '{"theme": "dark"}'),
  ('inst_abc', 'settings/notifications', '{"email": true}'),
  ('inst_xyz', 'settings/default', '{"theme": "light"}');

Write a minimal config

Create laredo.conf:

sources {
  pg_main {
    type = postgresql
    connection = "postgresql://user:pass@localhost:5432/mydb"
    slot_mode = ephemeral
  }
}

tables = [
  {
    source = pg_main
    schema = public
    table = config_document
    targets = [
      {
        type = indexed-memory
        lookup_fields = [instance_id, key]
      }
    ]
  }
]

Start the server

laredo-server --config laredo.conf

Query the data

In another terminal:

# Check status
laredo status

# Look up a row
laredo query public.config_document inst_abc settings/default

# Watch for changes
laredo watch public.config_document

Now insert or update a row in PostgreSQL — you'll see it appear in the watch stream immediately.

Next steps