[Bug]: MalformedChunkCodingException since Update to 1.21.4/2.0.3

Module

Core

Testcontainers version

1.21.4, 2.0.3

Using the latest Testcontainers version?

Yes

Host OS

Windows

Host Arch

X64

Docker version

Client:                                                                      
 Version:           29.0.2-rd                                                
 API version:       1.51 (downgraded from 1.52)                              
 Go version:        go1.25.4                                                 
 Git commit:        5a2d7eb                                                  
 Built:             Tue Nov 18 23:34:16 2025                                 
 OS/Arch:           windows/amd64                                            
 Context:           default                                                  
                                                                             
Server:                                                                      
 Engine:                                                                     
  Version:          28.3.3                                                   
  API version:      1.51 (minimum version 1.24)                              
  Go version:       go1.24.8                                                 
  Git commit:       bea959c7b793b32a893820b97c4eadc7c87fabb0                 
  Built:            Sun Oct 12 08:01:14 2025                                 
  OS/Arch:          linux/amd64                                              
  Experimental:     false                                                    
 containerd:                                                                 
  Version:          v2.1.5                                                   
  GitCommit:        fcd43222d6b07379a4be9786bda52438f0dd16a1                 
 runc:                                                                       
  Version:          1.3.3                                                    
  GitCommit:        d842d7719497cc3b774fd71620278ac9e17710e0                 
 docker-init:                                                                
  Version:          0.19.0                                                   
  GitCommit:

What happened?

Hi,

I described the problem in a comment in #11254 but given the nature of it, I think it warrants its own issue ticket.

Since updating to Testcontainers 1.21.4/2.0.3 we are occasionally encountering an exception:

NpipeSocketClientProviderStrategy: failed with exception RuntimeException (com.github.dockerjava.zerodep.shaded.org.apache.hc.core5.http.MalformedChunkCodingException: Bad chunk header: ). Root cause MalformedChunkCodingException (Bad chunk header: )

I can reproduce it with something simple as the following code. For some reason it becomes more probable when running in debug mode.

try ( final PostgreSQLContainer<?> container = new PostgreSQLContainer<>( "postgres:14" ) ) {
  container.start( );
}

I use a custom policy to make sure that the image is always pulled.

public final class PullAlwaysPolicy implements ImagePullPolicy {

	@Override
	public boolean shouldPull( final DockerImageName imageName ) {
		return true;
	}

} 

Thank you and best regards

Nils

Relevant log output

Feb. 02, 2026 10:17:54 AM org.testcontainers.images.PullPolicy defaultPolicy
INFORMATION: Found configured Image Pull Policy: class com.example.demo.PullAlwaysPolicy
Feb. 02, 2026 10:17:54 AM org.testcontainers.images.PullPolicy defaultPolicy
INFORMATION: Image pull policy will be performed by: com.example.demo.PullAlwaysPolicy@5d76b067
Feb. 02, 2026 10:17:54 AM org.testcontainers.utility.ImageNameSubstitutor instance
INFORMATION: Image name substitution will be performed by: DefaultImageNameSubstitutor (composite of 'ConfigurationFileImageNameSubstitutor' and 'PrefixingImageNameSubstitutor')
Feb. 02, 2026 10:17:54 AM org.testcontainers.DockerClientFactory getOrInitializeStrategy
INFORMATION: Testcontainers version: 2.0.3
Feb. 02, 2026 10:17:54 AM org.testcontainers.dockerclient.DockerClientProviderStrategy lambda$loadConfiguredStrategy$9
INFORMATION: Loaded org.testcontainers.dockerclient.NpipeSocketClientProviderStrategy from ~/.testcontainers.properties, will try it first
Feb. 02, 2026 10:17:55 AM org.testcontainers.dockerclient.DockerMachineClientProviderStrategy isApplicable
INFORMATION: docker-machine executable was not found on PATH ([REDACTED])
Feb. 02, 2026 10:17:55 AM org.testcontainers.dockerclient.DockerClientProviderStrategy lambda$getFirstValidStrategy$7
SCHWERWIEGEND: Could not find a valid Docker environment. Please check configuration. Attempted configurations were:
	NpipeSocketClientProviderStrategy: failed with exception RuntimeException (com.github.dockerjava.zerodep.shaded.org.apache.hc.core5.http.MalformedChunkCodingException: Bad chunk header: ). Root cause MalformedChunkCodingException (Bad chunk header: )As no valid configuration was found, execution cannot continue.
See https://java.testcontainers.org/on_failure.html for more details.
Exception in thread "main" java.lang.IllegalStateException: Could not find a valid Docker environment. Please see logs and check configuration
	at org.testcontainers.dockerclient.DockerClientProviderStrategy.lambda$getFirstValidStrategy$7(DockerClientProviderStrategy.java:274)
	at java.base/java.util.Optional.orElseThrow(Optional.java:403)
	at org.testcontainers.dockerclient.DockerClientProviderStrategy.getFirstValidStrategy(DockerClientProviderStrategy.java:265)
	at org.testcontainers.DockerClientFactory.getOrInitializeStrategy(DockerClientFactory.java:154)
	at org.testcontainers.DockerClientFactory.client(DockerClientFactory.java:196)
	at org.testcontainers.DockerClientFactory$1.getDockerClient(DockerClientFactory.java:108)
	at com.github.dockerjava.api.DockerClientDelegate.authConfig(DockerClientDelegate.java:109)
	at org.testcontainers.containers.GenericContainer.start(GenericContainer.java:316)
	at com.example.demo.Main.main(Main.java:9)

Additional Information

No response

Inizia riproducendo il malfunzionamento con PostgreSQLContainer, PullAlwaysPolicy e la configurazione Docker su Windows segnalata. Leggi DockerClientProviderStrategy e NpipeSocketClientProviderStrategy intorno al controllo dell’ambiente che fallisce e analizza il percorso di MalformedChunkCodingException. Il lavoro è completato quando la configurazione segnalata riesce ad avviare il container senza l’errore MalformedChunkCodingException.