You can override some default properties if your environment requires that.
The configuration will be loaded from multiple locations. Properties are considered in the following order:
- Environment variables
.testcontainers.propertiesin user's home folder. Example locations:
testcontainers.propertieson the classpath.
Note that when using environment variables, configuration property names should be set in upper
case with underscore separators, preceded by
TESTCONTAINERS_ - e.g.
testcontainers.properties file may exist within the local codebase (e.g. within the
src/test/resources directory) or within library dependencies that you may have.
Any such configuration files will have their contents merged.
If any keys conflict, the value will be taken on the basis of the first value found in:
- 'local' classpath (i.e. where the URL of the file on the classpath begins with
- other classpath locations (i.e. JAR files) - considered in alphabetical order of path to provide deterministic ordering.
Disabling the startup checks
checks.disable = [true|false]
Before running any containers Testcontainers will perform a set of startup checks to ensure that your environment is configured correctly. Usually they look like this:
ℹ︎ Checking the system... ✔ Docker version should be at least 1.6.0 ✔ Docker environment should have more than 2GB free disk space ✔ File should be mountable ✔ A port exposed by a docker container should be accessible
$HOME/.testcontainers.propertiesto completely disable them.
This approach is discouraged and deprecated, but is documented for completeness. Overriding individual image names via configuration may be removed in 2021. See Image Name Substitution for other strategies for substituting image names to pull from other registries.
Testcontainers uses public Docker images to perform different actions like startup checks, VNC recording and others.
Some companies disallow the usage of Docker Hub, but you can override
*.image properties with your own images from your private registry to workaround that.
ryuk.container.image = testcontainers/ryuk:0.3.2 Performs fail-safe cleanup of containers, and always required (unless Ryuk is disabled)
tinyimage.container.image = alpine:3.14
Used to check whether images can be pulled at startup, and always required (unless startup checks are disabled)
sshd.container.image = testcontainers/sshd:1.0.0
Required if exposing host ports to containers
vncrecorder.container.image = testcontainers/vnc-recorder:1.1.0 Used by VNC recorder in Testcontainers' Selenium integration
socat.container.image = alpine/socat
compose.container.image = docker/compose:1.8.0
Required if using Docker Compose
kafka.container.image = confluentinc/cp-kafka
Used by KafkaContainer
localstack.container.image = localstack/localstack
Used by LocalStack
pulsar.container.image = apachepulsar/pulsar:2.2.0
Used by Apache Pulsar
Customizing Ryuk resource reaper
ryuk.container.image = testcontainers/ryuk:0.3.2 The resource reaper is responsible for container removal and automatic cleanup of dead containers at JVM shutdown
ryuk.container.privileged = false In some environments ryuk must be started in privileged mode to work properly (--privileged flag)
Ryuk must be started as a privileged container.
If your environment already implements automatic cleanup of containers after the execution, but does not allow starting privileged containers, you can turn off the Ryuk container by setting
TESTCONTAINERS_RYUK_DISABLED environment variable to
Note that Testcontainers will continue doing the cleanup at JVM's shutdown, unless you
kill -9 your JVM process.
Customizing image pull behaviour
pull.pause.timeout = 30 By default Testcontainers will abort the pull of an image if the pull appears stalled (no data transferred) for longer than this duration (in seconds).
Customizing Docker host detection
Testcontainers will attempt to detect the Docker environment and configure everything to work automatically.
However, sometimes customization is required. Testcontainers will respect the following environment variables:
DOCKER_HOST = unix:///var/run/docker.sock
See Docker environment variables
Path to Docker's socket. Used by Ryuk, Docker Compose, and a few other containers that need to perform Docker actions.
Docker's host on which ports are exposed.
For advanced users, the Docker host connection can be configured via configuration in
Note that these settings require use of the
EnvironmentAndSystemPropertyClientProviderStrategy. The example below
docker.client.strategy=org.testcontainers.dockerclient.EnvironmentAndSystemPropertyClientProviderStrategy docker.host=tcp\://my.docker.host\:1234 # Equivalent to the DOCKER_HOST environment variable. Colons should be escaped. docker.tls.verify=1 # Equivalent to the DOCKER_TLS_VERIFY environment variable docker.cert.path=/some/path # Equivalent to the DOCKER_CERT_PATH environment variable