[Bug]: bash shell required for InternalCommandPortListeningCheck

[longliveenduro]

Module

Core

Testcontainers version

1.17.6

Using the latest Testcontainers version?

Yes

Host OS

Ubutntu

Host Arch

x86

Docker version

Client: Docker Engine - Community
 Version:           23.0.1
 API version:       1.42
 Go version:        go1.19.5
 Git commit:        a5ee5b1
 Built:             Thu Feb  9 19:46:56 2023
 OS/Arch:           linux/amd64
 Context:           default

Server: Docker Engine - Community
 Engine:
  Version:          23.0.1
  API version:      1.42 (minimum version 1.12)
  Go version:       go1.19.5
  Git commit:       bc3805a
  Built:            Thu Feb  9 19:46:56 2023
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.6.18
  GitCommit:        2456e983eb9e37e47538f59ea18f2043c9a73640
 runc:
  Version:          1.1.4
  GitCommit:        v1.1.4-0-g5fd4c4d
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

What happened?

I try to create a docker compose test and it spins up correctly. My base image is alpine which has no bash.

Then I get a

19:12:35.916 [testcontainers-wait-0] WARN  org.testcontainers.containers.wait.internal.InternalCommandPortListeningCheck - An exception while executing the internal check: Container.ExecResult(exitCode=137, stdout=, stderr=/bin/sh: /bin/bash: not found
``

### Relevant log output

```shell
19:12:35.916 [testcontainers-wait-0] WARN  org.testcontainers.containers.wait.internal.InternalCommandPortListeningCheck - An exception while executing the internal check: Container.ExecResult(exitCode=137, stdout=, stderr=/bin/sh: /bin/bash: not found

Additional Information

No response

[longliveenduro]

If I check

testcontainers-java/core/src/main/java/org/testcontainers/containers/wait/internal/InternalCommandPortListeningCheck.java

Line 35 in 000cba7

command.append(String.format("/bin/bash -c '</dev/tcp/localhost/%d'", internalPort));

I see there a bash -c ...

Is this intended?

[leonard84]

I just run into this problem when trying to run a busybox image, which doesn't have bash installed.
#2195 seems to be related.

Turns out, that it was a red-herring in my case, although it the command failed it wasn't the actual problem.

[perlun]

Hi @leonard84 and @longliveenduro, I'm the author of #2195. The idea is this:

testcontainers-java/core/src/main/java/org/testcontainers/containers/wait/internal/InternalCommandPortListeningCheck.java

Lines 30 to 36 in 000cba7

	command.append(" (");
	command.append(String.format("grep -i ':0*%x' /proc/net/tcp*", internalPort));
	command.append(" || ");
	command.append(String.format("nc -vz -w 1 localhost %d", internalPort));
	command.append(" || ");
	command.append(String.format("/bin/bash -c '</dev/tcp/localhost/%d'", internalPort));
	command.append(")");

• First try grepping in /proc/net/tcp*
• If there are no matches, try nc -vz -w 1 localhost %d
• If that also fails, as a final step, try /bin/bash -c '</dev/tcp/localhost/%d'

The /dev/tcp/localhost/<port> is a bashism, so this check really cannot be performed without bash. But the first check (grep -i ':0*%x' /proc/net/tcp*) should normally work if the port is listening in the container.

[furstenheim-goodnotes]

Is it possible to optionally disable this check? I'm using spicedb which uses chainguard it doesn't even have sh.

Then the check always fails and I'm never able to reuse the image