feat(mcp): add a parameterized 'onboard' prompt - #4021
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The server advertised prompts capability but registered none. Add the first: 'onboard', a multi-step workflow driving an agent end-to-end from an empty directory to a deployed, invocable Function. The eight steps map onto existing tools and resources: version (with a kubectl-context check), func://languages, create, run + invoke --target local + run_stop, registry elicitation, deploy + describe, invoke --target remote, and a summary read back out of tool output rather than out of what was requested. All four arguments (language, template, registry, cluster) are optional. Supplied values are rendered into the prompt and marked as decided; omitted ones render as an explicit instruction to ask the user at the relevant step, since neither a language nor a registry has a sane default. template defaults to http and cluster to local. Values are normalized (case, whitespace) and validated, with "cloudevent" resolving to the "cloudevents" template that actually exists on disk; the registry keeps its case, being an image reference prefix. Unrecognized values are rejected rather than rendered, so the agent is never sent off to run a command that cannot succeed. The prompt body is an embedded text/template, mirroring how the server's instructions are embedded. In read-only mode the registry, deploy and remote-invoke steps are omitted rather than handed to an agent that would be refused, and the user is told to restart with FUNC_ENABLE_MCP_WRITE=true.
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[APPROVALNOTIFIER] This PR is NOT APPROVED This pull-request has been approved by: Ankitsinghsisodya The full list of commands accepted by this bot can be found here. DetailsNeeds approval from an approver in each of these files:Approvers can indicate their approval by writing |
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The onboard prompt ran its local run and invoke before asking for a registry, on the theory that proving the Function works should not require one. It does: the default builder is pack, so a local run builds a container image, and naming that image needs a registry. Without one the build fails with "registry required" — for exactly the first-time user the prompt exists to serve, at a step the prompt forbids skipping past. Registry configuration is now step 4 and the local run step 5, which passes the gathered registry to run. Read-only mode omitted the registry step along with deploy and the remote invoke, yet still rendered "ask the user in step 5" in the parameters table, asked for a registry in the summary, and closed by telling the user to re-run deploy, which read-only refuses. The registry step is no longer omitted — a local build has to name an image whether or not it is ever pushed — and the remaining deploy-dependent text is now conditional. Language and template were validated against hardcoded lists. Which runtimes and templates exist depends on the installed binary and on any repositories added with the repository_add tool this same server exposes, so those lists rejected legitimate values outright. Only cluster is validated now, being prompt-internal and never passed to func; the rest are trimmed and passed through with their case intact, since a fold would corrupt the very repository-supplied names the lists used to reject. The agent is still told to check them against func://languages and func://templates. The deploy step named go and python as the host builder's runtimes. It now branches on oci.IsSupported, leaving pkg/oci the only place that list lives. Also: drop step 3's question about a Function name, there being no name argument to carry it (the name is the directory basename); drop the instruction to cd, which nothing depends on now that every tool call takes an absolute path; and assert table values in tests through a padding-insensitive match, so realigning the markdown cannot fail the build. Relates to knative#3737
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onboardMCP prompt that walks an agent from an empty directory to a deployed, invocable Function. The server advertised the prompts capability but registered none; this is the first.version,func://languages,create, localrun/invoke/run_stop, registry setup,deploy+describe, remoteinvoke, summary.language,template,registry,cluster) are optional; omitted ones render as an instruction to ask the user at the relevant step.templatedefaults tohttp,clustertolocal. Unrecognized values are rejected.pkg/mcp/prompts.gomirroring the existing resource helpers, and document the prompt in the server's agent instructions.The prompt body is an embedded
text/template(pkg/mcp/prompts_onboard.md), mirroring how the server's instructions are embedded./kind enhancement
Relates to #3737
Release Note
Docs