Configuration

Container runtime access

Testcontainers for PHP uses Docker APIs under the hood, so your test process must be able to reach a Docker-compatible daemon.

• Local socket: unix:///var/run/docker.sock
• Remote daemon: configure DOCKER_HOST

Environment variables

DOCKER_HOST

Defines where the Docker API is available.
Examples:

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export DOCKER_HOST=tcp://127.0.0.1:2375
export DOCKER_HOST=unix:///var/run/docker.sock

TESTCONTAINERS_HOST_OVERRIDE

Overrides the host address returned by Testcontainers when your tests need a custom endpoint:

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export TESTCONTAINERS_HOST_OVERRIDE=127.0.0.1

Running inside containers

If your tests run inside another container:

• Mount the Docker socket.
• Ensure network routing from test container to started containers is valid.
• Set host overrides when needed for your CI/network topology.

For startup and connectivity failures, see troubleshooting.