`withExposedPorts` not working on postgres container

[romandecker]

Expected Behaviour

I would expect that

const postgresContainer = await new PostgreSqlContainer()
    .withReuse()
    .withExposedPorts({
      container: 5432,
      host: 54321,
    })
    .start()

leads to postgresContainer.getPort() to always return 54321

Actual Behaviour
postgresContainer.getPort() actually returns a randomly allocated port each time.

The automatic setting of an available port is nice, but it would be great if the withExposedPorts example given here actually worked as advertised for the postgres container. Yes, it's not recommended, but it can still be useful if you want to inspect your database at a known port after a failed test.

[cristianrgreco]

This test passes for me:

it("should bind to specified host port", async () => {
  const container = await new PostgreSqlContainer()
    .withReuse()  // passes with or without this
    .withExposedPorts({
      host: 54321,
      container: 5432,
    })
    .start();

  expect(container.getPort()).toEqual(54321);

  const client = new Client({
    host: container.getHost(),
    port: container.getPort(),
    database: container.getDatabase(),
    user: container.getUsername(),
    password: container.getPassword(),
  });
  await client.connect();

  const result = await client.query("SELECT 1");
  expect(result.rows[0]).toEqual({ "?column?": 1 });

  await client.end();
  await container.stop();
});

So I guess it's an issue with your environment. I'm going to guess that Docker or whatever container runtime you're using (the issue template exists for a reason) is binding to whatever available port it can find because 54321 isn't available.

[romandecker]

You are correct 🤦

terribly sorry for the inconvenience.