Can you share a docker service between steps?

Mark McLaren

Imagine I had a pipeline where step 1 created a Docker image and step 2 deployed it to a container registry.

I appreciate I could create a Docker image with both Java and Azure CLI installed and use that in one step but I'm interested if I could do it without that.

Without the "caches" sections, it doesn't look like the docker service in the example below keeps the image after the step has completed.

pipelines: 
  default: 
  - step: 
      image: adoptopenjdk/openjdk11
      services: 
        - docker 
      # caches: 
      # - docker
      script: 
        - docker pull docker/whalesay 
        - docker images 
   - step: 
       image: microsoft/azure-cli
       services: 
         - docker 
       # caches:
       # - docker 
       script: 
       - docker images

The whalesay image downloaded in step 1 is no longer in docker at the beginning of step 2.

If I add "caches" sections. It does seem to keep the downloaded docker image but the repository and tag details disappear?

"docker images" output from step 1:

REPOSITORY TAG IMAGE ID CREATED SIZE

docker/whalesay latest 6b362a9f73eb 4 years ago 247MB

"docker images" output from step 2:

REPOSITORY TAG IMAGE ID CREATED SIZE

<none> <none> 6b362a9f73eb 4 years ago 247MB

 

Steven Vaccarella

Hi Mark,

The only way to share information between steps is using caches or artifacts (or an external service like an artifact repository). The recommended way to build and deploy a docker image is to do it all in a single step.

If you don't want to use a single image that includes all the required dependencies then another option is to use a "docker run" command to perform one of the operations. For example you can deploy using a "docker run" command within your script (based on an image that contains the azure cli).

Another option is to use a pipe such as https://bitbucket.org/microsoft/azure-cli-run/src/master/ to perform the deploy (the pipe actually just uses "docker run" under the hood).