Docker customization

[clarked-msft]

Fix problems with customizing CA and pip.conf from testing in customer environment.

[Copilot]

Pull request overview

Adds a documented and build-time mechanism to customize Docker trust (custom CA certs) and Python package installation behavior (pip.conf) for customer environments.

Changes:

• Copy docker-customization/pip.conf into the builder image as /etc/pip.conf for pip configuration during pip install.
• Copy docker-customization/custom-ca-certificates/ into the system trust anchors and run update-ca-trust during the build.
• Add docs and release notes entry describing the customization workflow.

Reviewed changes

Copilot reviewed 4 out of 6 changed files in this pull request and generated 6 comments.

File	Description
application/single_app/Dockerfile	Uses repo-root docker-customization/ inputs to configure pip and CA trust; adds runtime cert-related env vars.
docker-customization/pip.conf	Placeholder pip config file intended to be customized by deployers/customers.
docs/how-to/docker_customization.md	New how-to documentation for adding custom CA certs and pip.conf.
docs/explanation/release_notes.md	Adds a release note entry for Docker customization fixes.

[Copilot]

The links use absolute site paths like /docker-customization/..., but docker-customization/ lives at the repo root (not under docs/) so these links will likely 404 in the rendered docs site. Consider linking to the GitHub paths (or describe the filesystem paths without markdown links) so readers can actually find the files.

Suggested change

	Add custom certification authorities to [/docker-customization/custom-ca-certificates](/docker-customization/custom-ca-certificates/) and they will be pull in to the system CAs during docker build. Must be in .crt format.
	## Custom pip conf
	Add customization as needed to [/docker-customization/pip.conf](/docker-customization/pip.conf). This will be used during docker build.
	Add custom certification authorities to the `docker-customization/custom-ca-certificates/` directory in the repository root, and they will be pulled into the system CAs during docker build. Must be in `.crt` format.
	## Custom pip conf
	Add customization as needed to the `docker-customization/pip.conf` file in the repository root. This will be used during docker build.

[Copilot]

Grammar: “they will be pull in to the system CAs” should be rephrased (e.g., “they will be pulled into the system trust store”) to read correctly.

Suggested change

	Add custom certification authorities to [/docker-customization/custom-ca-certificates](/docker-customization/custom-ca-certificates/) and they will be pull in to the system CAs during docker build. Must be in .crt format.
	Add custom certification authorities to [/docker-customization/custom-ca-certificates](/docker-customization/custom-ca-certificates/), and they will be pulled into the system trust store during the Docker build. Must be in .crt format.

[Copilot]

Pull request overview

Copilot reviewed 4 out of 6 changed files in this pull request and generated 2 comments.

[Copilot]

This PR adds a new behavior/doc and a release-notes entry under v0.238.024, but application/single_app/config.py still defines VERSION = "0.238.024". If this is intended to ship as a new patch, bump the third segment in config.py and add the release-notes entry under the new version header to keep versioning consistent.

[Bionic711]

Looks good.