[workshop] Add node: Control Network Access with the Firewall

workshop/31-control-network-access.md

@@ -0,0 +1,98 @@
+<!-- page-journey: all -->
+<!-- page-adventure: advanced -->
+<!--
+<research-metadata>
+  <focus>Network allowlists — controlling which domains an agentic workflow can reach with the `network:` frontmatter key</focus>
+  <sources>
+    <source>https://github.github.com/gh-aw/reference/network/</source>
+    <source>https://github.github.com/gh-aw/reference/sandbox/</source>
+  </sources>
+  <rationale>Steps 17, 24, and 25 mention `network.allowed` and the firewall in passing, but no step teaches learners to set an allowlist deliberately. Enterprise learners behind proxies and security teams reviewing workflows need a hands-on step that starts from default access, adds one domain, and reads the blocked-request evidence in an audit.</rationale>
+</research-metadata>
+-->
+
+# Control Network Access with the Firewall
+
+> _Decide exactly which websites your agent can talk to, so a surprise request never leaves your workflow._
+
+## :dart: What You'll Do
+
+You'll add a `network:` section to one of your workflows so the agent can reach only the domains you name. Then you'll run it and confirm that a request to an unlisted domain is blocked. When you finish, you'll be able to hand your security team a precise allowlist.
+
+## :clipboard: Before You Start
+
+- A compiled workflow from [Step 7](07-your-first-workflow.md) in your Codespace
+- Familiarity with reading a run summary from [Step 8b](08b-interpret-your-run.md)
+
+## Steps
+
+### Understand the default
+
+Agentic workflows run behind a [firewall](https://github.github.com/gh-aw/reference/network/). By default the agent can reach a small set of trusted infrastructure domains, such as the ones needed for its AI engine and GitHub. Everything else is blocked. The `network:` key in your frontmatter widens or narrows that list.
+
+### Ask your agent to add an allowlist
+
+Start your AI agent in the Codespace terminal:
+
+```bash
+gh copilot
+```
+
+Then pass it this prompt:
+
+```prompt
+/agentic-workflows Update my daily-status workflow so it can only reach github.com and api.github.com, and nothing else.
+```
+
+### Review the frontmatter
+
+The agent should produce a section like this one. Ecosystem names such as `defaults` expand to a curated domain list, and plain domains are matched exactly.
+
+```yaml
+---
+on:
+  workflow_dispatch:
+permissions:
+  contents: read
+engine: copilot
+network:
+  allowed:
+    - defaults
+    - contoso.com
+---
+
+# Network demo
+
+Summarize the repository, then try to fetch https://example.org and report what happened.
+```
+
+> [!NOTE]
+> Setting `network: {}` blocks all outbound access beyond what the engine itself needs. Use it for workflows that only read repository data.
+
+### Recompile and run
+
+Compile in the terminal, then commit both files:
+
+```bash
+gh aw compile
+```
+
+Dispatch the workflow from the **Actions** tab on GitHub.com, as you did in [Step 8](08-run-your-workflow.md).
+
+### Find the blocked request
+
+Open the finished run and read the firewall section of the summary. The request to `example.org` should appear as blocked. If you want the full report, follow the audit walkthrough in [Step 25](25-audit-and-observability.md).
+
+> [!TIP]
+> When a legitimate request is blocked, copy that domain from the report into `network.allowed`, recompile, and run again. Add one domain at a time so the list stays reviewable.
+
+## :white_check_mark: Checkpoint
+
+- [ ] Your workflow has a `network:` section listing only the domains it needs
+- [ ] `gh aw compile` succeeded and you committed the `.md` and `.lock.yml` files
+- [ ] A run showed the request to an unlisted domain as blocked
+- [ ] You can explain why `defaults` plus a short list is easier to review than a long one
+
+<!-- journey: all -->
+Want to choose another branch from the workshop hub? Return to [What's Next? Keep Exploring](14-next-steps.md).
+<!-- /journey -->

workshop/README.md

@@ -42,6 +42,7 @@ A hands-on workshop that takes you from zero to a fully automated, AI-powered wo
 | 28 | [Orchestrate Multiple Agentic Workflows](28-orchestrate-workflows.md) |
 | 29 | [Teach Your Agent Domain Knowledge with Skills](29-skills-and-domain-knowledge.md) |
 | 30 | [Preview Your Workflow's Writes with Staged Mode](30-preview-with-staged-mode.md) |
+| 31 | [Control Network Access with the Firewall](31-control-network-access.md) |
 
 ## Optional Side Quests