Port mapping for ipv4 & ipv6 can cause different ports to be mapped and getMappedPort function will return wrong portΒ #750
Description
Expected Behaviour
I want to get a predictable port number and host,
the problem seems to be in this file - https://github.com/testcontainers/testcontainers-node/blob/main/packages/testcontainers/src/utils/bound-ports.ts
method - resolveHostPortBinding
line - return hostPortBindings[0].hostPort;
Actual Behaviour
We have tests that are running in parallel and it was quite hard to identify that issue, because locally on mac os everything is fine, but on latest ubuntu the problem auto assigning port appear
testcontainers/testcontainers-dotnet#825 - same issue for .net
So what happening:
- Starting a redis container (doesn't matter which one, it just an example)
- withExposedPorts(6389) - let docker to auto assign host port
- calling getMappedPort function -> may return ipv4 or ipv6 port, depends on your luck
Testcontainer Logs
...
Steps to Reproduce
- In this environment ubuntu 22
- With this config.
- Run '...'
const container = await new GenericContainer(
`${options.imageName}:${options.imageTag}`,
)
.withExposedPorts(6379)
.start();
// eslint-disable-next-line no-console
console.timeEnd(`start redis`);
const redisConfig = {
port: container.getMappedPort(6379),
host: 'localhost',
} satisfies RedisStartedConfig;- Run docker ps, and see that there are 2 ports actually
Environment Information
- Operating System: ubuntu
- Docker Version: 24+
- Node version: 20+
- Testcontainers version: 10.8.1
we temporary fixed it by retrieving ipv4 port from the docker inspect info:
import { StartedTestContainer } from 'testcontainers/build/test-container';
export function retrievePortFromBinding(
container: StartedTestContainer,
sourcePort: number,
): number {
return Number.parseInt(
// eslint-disable-next-line @typescript-eslint/no-explicit-any
(container as never as any).inspectResult.NetworkSettings.Ports[
`${sourcePort}/tcp`
].find((p: { HostIp: string; HostPort: string }) => p.HostIp === '0.0.0.0')
.HostPort,
);
}