Docker.DotNet JSON parsing fails with Docker 29.x - "0x00 is an invalid start of a property name"

[thomhurst]

When using Testcontainers with Docker daemon version 29.x (e.g., 29.1.3), operations like ExecAsync() and image pulling fail with JSON parsing errors:

JsonException: '0x00' is invalid after a single JSON value. Expected end of data.

or

JsonReaderException: '0x00' is an invalid start of a property name. Expected a '"'.

Root Cause:

The Docker API in version 29.x appears to return responses with embedded null bytes or a different wire format that Docker.DotNet (the library Testcontainers uses internally) doesn't handle correctly. The parsing happens in
Docker.DotNet.JsonSerializer.TryParseJson().

Affected Operations:

• Container exec (DockerContainerOperations.ExecAsync)
• Image pulling (DockerImageOperations.CreateAsync)

Environment:

• Docker: 29.1.3
• Testcontainers.Kafka
• OS: Ubuntu 24.04 / WSL2

[HofmeisterAn]

Could you please check if you're experiencing the issue with the latest release (4.0.2)? It's also part of the TC develop branch: testcontainers/testcontainers-dotnet#1665.