HOWTO: Release a signed docker image
Jul 03 2017
1 minute read

HOWTO: Release a signed docker image

First, install notary from one of the released versions.

Then, you need to build a new image with a specific tag, lets say you are building an image called maxking/mailman-web and you decide to sign the testing tag:

$ docker build --disable-cotent-trust=false -t maxking/mailman-web:latest . 

The above command will build the image and then ask you to initialize a few keys if you haven’t yet created the keys. There will be in total three keys,

  • one root key which will be kept offline and is the main source of trust for all your notary repositories. Use a secure passphrase for this one.
  • one target key which will correspond to the specific repository that you will be signing, docker.io/maxking/mailman-web in this case
  • one snapshot key which is….

So, after you are done with building the images, you can now push the image to Docker Hub along with the signature to notary.docker.io which is the default notary server.

$ docker push --disable-content-trust=false maxking/mailman-web:testing

From a different client, to pull the images and verify the signature run the following command:

$ docker pull --disable-content-trust=false maxking/mailman-web:testing

This command will fail if either the signature verification process doesn’t succeed because either the signature is not correct or not present.


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