Expose Image Pull Policy on Containers

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Is there an existing issue for this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe the problem.

Currently if you reference the container via a mutable tag (e.g. redis:latest), then docker will only pull the latest version of that tag if one doesn't exist locally. This could mean that your latest tag is many versions behind if you haven't explicitly done a docker pull redis:latest to refresh your local version.

Docker Compose and Kubernetes expose Image Pull Policies that can be used to configure this behavior, it would be nice if Aspire exposes the same.

This functionality is available through --pull on docker container create. Alternatively it can be implemented by explicitly running docker pull before creating the container image

Describe the solution you'd like

From a user perspective, I imagine this being a WithImagePullPolicy extension method on IResourceBuilder

container
    .WithImagePullPolicy(ImagePullPolicy.Always) // Always | Missing (default) | Never

The naming of the method and arguments matching what are used by Kubernetes & docker for this same capability:

• Docker Compose: https://docs.docker.com/reference/compose-file/services/#pull_policy
• Kubernetes: https://kubernetes.io/docs/concepts/containers/images/#image-pull-policy

Additional context

We're looking to create a number of internal components re-distributing our production services as ContainerResources via shared nuget packages. These services follow a trunk based CD model and could be released several times a day - because of this we want our aspire component to reference a mutable container tag (e.g. latest or production) and not have to update the version number in our nuget package every release, and then get all consumers to )

In our early days of rolling this out, we've already encountered a couple of issues at this point which we root causes as being caused by the consumer having an ancient version of the container that they used for some ad-hoc testing 1-2 years ago! Having the ability to set an image pull policy to always would greatly help.