no way to map container port to different host port

[Bill]

docker -p 8003:5432 will expose container port 5432 on host port 8003.

This is extremely valuable when running parallel tests. It lets us avoid port conflicts.

I see no straightforward way to accomplish this with testcontainers.

Container.withExposedPorts(Integer... ports) takes a port array and maps each container port in the array, to the corresponding port on the host.

I expected to find a method with this signature something like this:

Container.withExposedPorts(Map<Integer,Integer> mappings)

Or maybe even:

Container.withExposedPortMappings(Integer... mappings)

…that would take the flattened mapping.

[bsideup]

It lets us avoid port conflicts.

TestContainers doesn't allow you (publically) to use a non-random port. When you call withExposedPorts(5432) it will use -p 5432, it means that the port will be random by default.

Then you just use getMappedPort(5432)

https://www.testcontainers.org/usage/generic_containers.html#accessing-a-container-from-tests

[Bill]

Thank you!!

[NickEm]

BTW, guys there is a possibility to specify host port as well. F.e:

int hostPort = 6380;
int containerExposedPort = 6379;
Consumer<CreateContainerCmd> cmd = e -> e.withPortBindings(new PortBinding(Ports.Binding.bindPort(hostPort), new ExposedPort(containerExposedPort)));

GenericContainer redisContainer = new GenericContainer("redis:4.0.10")
                    .withExposedPorts(containerExposedPort)
                    .withCreateContainerCmdModifier(cmd);

[ocker-docker-gummi-klokker]

import org.testcontainers.containers.GenericContainer
import org.testcontainers.containers.FixedHostPortGenericContainer

Use GenericContainer container = new GenericContainer("name") when working with random ports.

Use GenericContainer container = new FixedHostPortGenericContainer("name") when working
with fixed ports, and then do container.withFixedExposedPort(hostPort, containerPort)

[kiview]

While this works, we strongly advise against using fixed ports, since this will automatically lead to integrated tests (which are an anti pattern).

The definition of integrated tests based on this Spotify blog post:

A test that will pass or fail based on the correctness of another system.

[ocker-docker-gummi-klokker]

I understand and totally agree.
All our automated tests use random ports, but we have a single local acceptance test (disabled in our CI environment) which for good reasons use fixed ports.
In special situations, it is convenient to be able to use fixed ports.

[stahloss]

How do I bind the random host port to my @SpringBootTest Spring Data property? For instance: spring.data.mongodb.port=xxxxx.

Would be nice if I could do something like spring.data.mongodb.port=${testcontainers.host.port}.

Now I need to use the FixedHostPortGenericContainer, because I havent figured a way around this yet.

[bsideup]

@D0rmouse please look at our Spring Boot Example

[callamd]

While this works, we strongly advise against using fixed ports, since this will automatically lead to integrated tests (which are an anti pattern).

The definition of integrated tests based on this Spotify blog post:

A test that will pass or fail based on the correctness of another system.

Tenuous

[andrejpetras]

While this works, we strongly advise against using fixed ports, since this will automatically lead to integrated tests (which are an anti pattern).

The definition of integrated tests based on this Spotify blog post:

A test that will pass or fail based on the correctness of another system.

Could you please make the method withFixedExposedPort public in the GenericContainer?
I believe the developers should have the option to decide what they need.

Currently we need to do workaround for example for the PostgreSQLContainer and we are building the library around the testcontainers.

[thergbway]

As far as I see there are some ways to create fixed port bindings for single containers but there is no any way to make fixed port binding for DockerComposeContainer. In our case we want a fixed exposed port for debug the java application we are testing. The target of out tests is one single service of started docker-compose environment.
How to make fixed exposed ports for DockerComposeContainer?

[bsideup]

We do not recommend using fixed ports, even with single containers.

For debugging, consider using the approach described in the following blogpost:
https://bsideup.github.io/posts/debugging_containers/

[bsideup]

@andrejpetras

even if we expose withFixedExposedPort it won't work in some environments (like running a build inside a container, or even Travis). It is protected for a good reason, and there are other ways of doing this (e.g. by proxying, see my previous comment on this issue)