Conftest is available for Windows, macOS and Linux on the releases page.

On Linux and macOS you can download as follows:

LATEST_VERSION=$(wget -O - "" | grep '"tag_name":' | sed -E 's/.*"([^"]+)".*/\1/' | cut -c 2-)
wget "${LATEST_VERSION}/conftest_${LATEST_VERSION}_${SYSTEM}_${ARCH}.tar.gz"
tar xzf conftest_${LATEST_VERSION}_${SYSTEM}_${ARCH}.tar.gz
sudo mv conftest /usr/local/bin


Install with Homebrew on macOS or Linux:

brew install conftest


You can also install using Scoop on Windows:

scoop install conftest


Conftest Docker images are also available. Simply mount your configuration and policy at /project and specify the relevant command like so:

$ docker run --rm -v $(pwd):/project openpolicyagent/conftest test deployment.yaml
FAIL - deployment.yaml - Containers must not run as root in Deployment hello-kubernetes

1 test, 0 passed, 0 warnings, 1 failure, 0 exceptions

NOTE: The instrumenta/conftest image is deprecated and will no longer be updated. Please use the openpolicyagent/conftest image.

From Source

If you have a working Go environment, you can install conftest from source. It will be installed to your configured $GOPATH/bin folder.

CGO_ENABLED=0 go install