Access Podman Rest API from Testcontainer

Expose ports with rootless podman

Double check this step when using rootless pod:

$ telnet 8080
Trying ...
telnet: Unable to connect to remote host: No route to host

I have reproduced your environnement and your image, and I didn't found any problems.

PS: it may be something related to firewalld, try to open port 8080.

# firewall-cmd --add-port=8080/tcp --permanent 
# firewall-cmd --reload

Podman in Podman, similar to Docker in Docker?

Assume we would like to run ls / in a docker.io/library/alpine container.

Standard Podman

podman run --rm docker.io/library/alpine ls /

Podman in Podman

Let's run ls / in a docker.io/library/alpine container, but this time we run podman in a quay.io/podman/stable container.

Update June 2021

A GitHub issue comment shows an example of how to run Podman in Podman as a non-root user both on the host and in the outer container. Slightly modified it would look like this:

podman \
  run \
    --rm \
    --security-opt label=disable \
    --user podman \
    quay.io/podman/stable \
      podman \
        run \
          --rm \
          docker.io/library/alpine \
            ls / 

Here is a full example:

$ podman --version
podman version 3.2.1
$ cat /etc/fedora-release 
Fedora release 34 (Thirty Four)
$ uname -r
5.12.11-300.fc34.x86_64
$ podman \
  run \
    --rm \
    --security-opt label=disable \
    --user podman \
    quay.io/podman/stable \
      podman \
        run \
          --rm \
          docker.io/library/alpine \
            ls / 
Trying to pull docker.io/library/alpine:latest...
Getting image source signatures
Copying blob sha256:5843afab387455b37944e709ee8c78d7520df80f8d01cf7f861aae63beeddb6b
Copying config sha256:d4ff818577bc193b309b355b02ebc9220427090057b54a59e73b79bdfe139b83
Writing manifest to image destination
Storing signatures
bin
dev
etc
home
lib
media
mnt
opt
proc
root
run
sbin
srv
sys
tmp
usr
var
$ 

To avoid repeatedly downloading the inner container image,
create a volume

podman volume create mystorage

and add the command-line option
-v mystorage:/home/podman/.local/share/containers:rw
to the outer Podman command. In other words

podman \
  run \
    -v mystorage:/home/podman/.local/share/containers:rw \
    --rm \
    --security-opt label=disable \
    --user podman \
    quay.io/podman/stable \
      podman \
        run \
          --rm \
          docker.io/library/alpine \
            ls / 

Podman in Podman (outdated answer)

(The old outdated answer from Dec 2020. I'll probably remove this when it's clear that the method described here is outdated)

Let's run ls / in a docker.io/library/alpine container, but this time we run podman in a quay.io/podman/stable container.

The command will look like this:

podman \
  run \
    --privileged \
    --rm \
    --ulimit host \
    -v /dev/fuse:/dev/fuse:rw \
    -v ./mycontainers:/var/lib/containers:rw \
    quay.io/podman/stable \
      podman \
        run \
          --rm \
          --user 0 \
          docker.io/library/alpine ls 

(The directory ./mycontainers is here used for container storage)

Here is a full example

$ podman --version
podman version 2.1.1
$ mkdir mycontainers
$ podman run --privileged --rm --ulimit host -v /dev/fuse:/dev/fuse:rw -v ./mycontainers:/var/lib/containers:rw   quay.io/podman/stable podman run --rm --user 0 docker.io/library/alpine ls | head -5
Trying to pull docker.io/library/alpine...
Getting image source signatures
Copying blob sha256:188c0c94c7c576fff0792aca7ec73d67a2f7f4cb3a6e53a84559337260b36964
Copying config sha256:d6e46aa2470df1d32034c6707c8041158b652f38d2a9ae3d7ad7e7532d22ebe0
Writing manifest to image destination
Storing signatures
bin
dev
etc
home
lib
$ podman run --privileged --rm --ulimit host -v /dev/fuse:/dev/fuse:rw -v ./mycontainers:/var/lib/containers:rw  quay.io/podman/stable podman images
REPOSITORY                TAG     IMAGE ID      CREATED     SIZE
docker.io/library/alpine  latest  d6e46aa2470d  4 days ago  5.85 MB

If you would leave out -v ./mycontainers:/var/lib/containers:rw you might see the slightly confusing error message

Error: executable file `ls` not found in $PATH: No such file or directory: OCI runtime command not found error

References:

• How to use Podman inside of a container Red Hat blog post from July 2021.

• discussion.fedoraproject.org (discussion about not found in $PATH)

• github comment (that gives advice about the correct way to run Podman in Podman)

Communication between podman containers without root

The two containers have to be in the same pod or the same network.

Using a pod, it is possible to do the following:

$ podman pod create -n test
$ podman run --rm --pod test python:3 python3 -m http.server

and in another shell:

$ podman run --rm --pod test python:3 curl localhost:8000

How to test repository with junit5 and testcontainers?

The JUnit 5 extension provided by the @Testcontainers annotation scans for any containers declared with the @Container annotation, and then starts and stops the those containers for your tests. Containers as static fields will be shared with all tests, and containers as instance fields will be started and stopped for every test.

If you are using Spring Boot, the easiest way to setup testcontainers for your tests is probably to provide properties in application-test.yml. This will use the datasource JDBC URL to launch the testcontainers container. Refer to Testcontainers JDBC support for more information.

You can also test just the repository layer by using @DataJpaTest instead of @SpringBootTest:

@DataJpaTest
@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
@ActiveProfiles("test")
class CompanyRepositoryTest { }

Your application-test.yml file:

spring:
  datasource:
    url: jdbc:tc:mysql:8.0://hostname/databasename
    driver-class-name: org.testcontainers.jdbc.ContainerDatabaseDriver

In some cases you might also want to use the @TestPropertySource annotation instead:

@DataJpaTest
@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
@TestPropertySource(
    properties = {
        "spring.datasource.url = jdbc:tc:mysql:8.0://hostname/test-database",
        "spring.datasource.driver-class-name = org.testcontainers.jdbc.ContainerDatabaseDriver"
    }
)
class CompanyRepositoryTest { }

Please note that the hostname and test-database are not actually used anywhere.

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