[SOLVED] How to check if an image is already present locally

How to check if an image is already present locally

I am using the docker-java Maven library, and I would like to know if there is a way to check if an image has already been pulled or is present locally before pulling it if necessary, with only the image name. Currently, I have to pull the image everytime I execute it to ensure it is present locally, which is not nice.

Solution

If you need to do it in Java, you can use the inspectImageCmd method of the com.github.dockerjava.api.DockerClient interface. Then check the returned InspectImageResponse response object. Something like this:

String imageId = ...;
InspectImageResponse response = dockerClient.inspectImageCmd(imageid).exec();

docker-java is just a wrapper for the Docker REST API and the inspect command is the equivalent of the GET http request to /images/{imageid}/json. See section 3.2 Images in Docker Engine API.