Add Docker Image CI workflow

[marekdkropiewnicki-dotcom]

Why:

Closes:

What's being changed (if available, include any code snippets, screenshots, or gifs):

Check off the following:

• A subject matter expert (SME) has reviewed the technical accuracy of the content in this PR. In most cases, the author can be the SME. Open source contributions may require an SME review from GitHub staff.
• The changes in this PR meet the docs fundamentals that are required for all content.
• All CI checks are passing and the changes look good in the review environment.

[github-actions]

👋 Hey there spelunker. It looks like you've modified some files that we can't accept as contributions:

• .github/workflows/docker-image.yml

You'll need to revert all of the files you changed that match that list using GitHub Desktop or git checkout origin/main <file name>. Once you get those files reverted, we can continue with the review process.

The complete list of files we can't accept are:

• .devcontainer/**
• .github/**
• data/reusables/rai/**
• Dockerfile*
• src/**
• package*.json
• content/actions/how-tos/security-for-github-actions/security-hardening-your-deployments/**

We also can't accept contributions to files in the content directory with frontmatter contentType: rai.

[github-actions]

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[Copilot]

Pull request overview

Adds a new GitHub Actions workflow intended to build the repository’s Docker image on pushes and pull requests targeting main.

Changes:

• Introduces .github/workflows/docker-image.yml to run docker build in CI.
• Checks out the repository and builds the root Dockerfile image.

[Copilot]

steps: is incorrectly indented: the list items (- uses, - name) need to be indented under steps:. As written, this workflow will fail YAML parsing / the steps key will not contain the step list, so the job won’t run.

Suggested change

	- uses: actions/checkout@v4
	- name: Build the Docker image
	run: docker build . --file Dockerfile --tag my-image-name:$(date +%s)
	- uses: actions/checkout@v4
	- name: Build the Docker image
	run: docker build . --file Dockerfile --tag my-image-name:$(date +%s)

[Copilot]

This workflow uses actions/checkout@v4, but this repo’s workflows generally pin actions/checkout to a specific commit SHA (e.g. 8e8c483... # v6.0.1) to reduce supply-chain risk. Please update to the pinned SHA/version used elsewhere in .github/workflows/.

Suggested change

	- uses: actions/checkout@v4
	- uses: actions/checkout@8e8c483e0f71c1f5f6bbf3c5c8ec0e5c0eb0f3f8 # v6.0.1

[Copilot]

For consistency with other workflows in this repo and to reduce risk/noise, add an explicit minimal permissions: block (e.g. contents: read) and gate the job with if: github.repository == 'github/docs-internal' || github.repository == 'github/docs' so forks don’t run this workflow by default.

Suggested change

	jobs:
	build:
	permissions:
	contents: read
	jobs:
	build:
	if: github.repository == 'github/docs-internal' || github.repository == 'github/docs'