Docker mcp gateway starts in WSL2, but calling docker tool fails with docker-entrypoint.sh: exec: line 61: : Permission denied

[agolanov]

Environment

• Windows 11
• Docker Desktop with WSL2 integration enabled
• WSL2 distro: Ubuntu
• Docker MCP launched from inside WSL2
• Docker CLI plugin available inside WSL
• Docker mcp version = v0.40.1

What works

• DOCKER_MCP_IN_CONTAINER=1 docker mcp server ls
• DOCKER_MCP_IN_CONTAINER=1 docker mcp gateway run --servers docker
• MCP initialize succeeds
• tools/list succeeds

Configuration
The MCP client uses:

• command: docker
• args: ["mcp", "gateway", "run", "--servers", "docker"]
• env:
  • DOCKER_MCP_IN_CONTAINER=1

Observed behavior
The MCP gateway starts successfully, but calling the exported docker tool fails.

Example log output:

• Calling tool docker with arguments: {"command":"ps"}
• Running container docker:cli@sha256:067c301efe497cd5d174d468b7b3422a485ae4aca8f7ec1ffd4655c9fa383af2 with args [run --rm -i --init --security-opt no-new-privileges --cpus 1 --memory 2Gb --pull never -l docker-mcp=true -l docker-mcp-tool-type=mcp -l docker-mcp-name=docker -l docker-mcp-transport=stdio -v /var/run/docker.sock:/var/run/docker.sock docker:cli@sha256:067c301efe497cd5d174d468b7b3422a485ae4aca8f7ec1ffd4655c9fa383af2 ]
• /usr/local/bin/docker-entrypoint.sh: exec: line 61: : Permission denied

Actual result

• gateway process starts
• Docker MCP handshake succeeds
• tool invocation fails
• MCP returns an error result

Expected result
Calling the exported docker tool should execute the requested Docker CLI operation, for example ps.

Notes

• Without DOCKER_MCP_IN_CONTAINER=1, some Docker MCP CLI commands inside WSL2 report Docker Desktop is not running
• With DOCKER_MCP_IN_CONTAINER=1, gateway startup works
• The failure seems to happen specifically at tool execution time
• From the logs, it looks like the docker:cli container starts, but no executable command is actually passed into the container, so this may be an argv/tool-invocation bug rather than a WSL startup issue