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Custom configuration

You can override some default properties if your environment requires that.

Configuration locations

The configuration may be loaded from multiple locations. Properties are considered in the following order:

  1. Environment variables
  2. ~/.testcontainers.properties file (a Java properties file, enabled by the properties-config feature) Example locations:
    Linux: /home/myuser/.testcontainers.properties
    Windows: C:/Users/myuser/.testcontainers.properties
    macOS: /Users/myuser/.testcontainers.properties

Docker host resolution

The host is resolved in the following order:

  1. Docker host from the tc.host property in the ~/.testcontainers.properties file.
  2. DOCKER_HOST environment variable.
  3. Docker host from the "docker.host" property in the ~/.testcontainers.properties file.
  4. Else, the default Docker socket will be returned.

Docker authentication

Sometimes the Docker images you use live in a private Docker registry. For that reason, Testcontainers for Rust gives you the ability to read the Docker configuration and retrieve the authentication for a given registry. Configuration is fetched in the following order:

  1. DOCKER_AUTH_CONFIG environment variable, unmarshalling the string value from its JSON representation and using it as the Docker config.
  2. DOCKER_CONFIG environment variable, as an alternative path to the directory containing Docker config.json file.
  3. else it will load the default Docker config file, which lives in the user's home, e.g. ~/.docker/config.json.

bollard, rustls and SSL Cryptography providers

testcontainers uses bollard to interact with the Docker API.

bollard in turn has options provided by rustls to configure its SSL cryptography providers.

The testcontainers feature flags to control this are as follows:

  • ring - use rustls with ring as the cryptography provider (default)
  • aws-lc-rs - use rustls with aws-lc-rs as the cryptography provider
  • ssl - use rustls with a custom cryptography provider configuration - see bollard and rustls documentation for more.

Podman Docker compatibility

Install podman + podman-docker packages for your system.

systemctl --user enable podman.socket
systemctl --user start podman.socket
systemctl --user status podman.socket

export DOCKER_HOST=unix:///run/user/$UID/podman/podman.sock