Lab 2.2 — Prompt to Production

You have a Dev Space, an in-cluster LLM, and a short AGENTS.md. Three OpenCode sessions take you from an empty tree to a live Fortune Cookie app, then through a real change — still no Ansible, no local Docker, no public LLM.

Estimated time: 35 minutes
Persona: Developer
What you build: A Fortune Cookie web application in Go — generated, built with Tekton, deployed via your own Argo CD instance, then updated

OpenCode reads AGENTS.md before every prompt. You do not repeat platform rules — describe what you want. The LLM knows the Dockerfile template and the git, ephemeral Git, and oc deploy phases.

Step 1: Open the Project and Launch OpenCode

Dev Spaces already cloned the template — it is in ${PROJECT_SOURCE}. The template sets APP_NAME=fortune-cookie.

cd ${PROJECT_SOURCE}
echo "APP_NAME=$APP_NAME"
ls
Expected
APP_NAME=fortune-cookie
AGENTS.md  deploy/  devfile.yaml  gitops/  opencode.json  pipeline/
opencode
Phase What it does Duration

Git

Create a personal repo on ephemeral Git, commit, and push

~30s

Image

oc apply -k pipeline/base + Tekton PipelineRun

3–5 min

GitOps

Point image: at the build, apply gitops/base, create the Argo CD Application

2–3 min
Prompt to production

Session 1: Plan

Press Tab until the TUI shows plan, then paste. Stay in this session — do not start a new one (Ctrl+N).

Fortune Cookie in Go: GET / is HTML with a random fortune from at least 10 hard-coded messages.

Review the plan. Adjust if needed. The plan is the context for the next prompt.

Session 2: Build and Deploy

Press Tab to build in the same session.

Implement the plan.

OpenCode writes the files, compiles, then ships from AGENTS.md. When it is done it should print the app route and the Argo CD console URL. The Argo CD Application must live in ${APP_NAME}-dev (never default).

Checkpoint — the app is live

APP_NAME="${APP_NAME:-fortune-cookie}"

APP_ROUTE=$(oc get route $APP_NAME -n ${APP_NAME}-dev \
  -o jsonpath='{.spec.host}' 2>/dev/null)
ARGOCD_ROUTE=$(oc get route argocd-server -n ${APP_NAME}-dev \
  -o jsonpath='{.spec.host}' 2>/dev/null)

echo "================================================"
echo " App:    https://${APP_ROUTE}"
echo " ArgoCD: https://${ARGOCD_ROUTE}"
echo "================================================"

oc get application $APP_NAME -n ${APP_NAME}-dev \
  -o jsonpath='{.status.sync.status} / {.status.health.status}' && echo

curl -sk https://${APP_ROUTE}/healthz

Expected:

{"status":"ok"}

Open both URLs in your browser:

  • The app URL shows a random fortune cookie message

  • The Argo CD console shows your fortune-cookie Application in Synced / Healthy — your Argo CD instance, scoped to your project

The model wrote the code; the running app serves a slice of strings.

Session 3: Ship a change

Close the GitOps loop: change the app, push, watch Tekton rebuild, roll the deployment. Still no hand-written kubectl apply for the app.

Start a new OpenCode session in ${PROJECT_SOURCE}. Press Tab to build:

Add 10 more fortunes and show the message in a styled card with 🥠. Then ship it.

Wait for OpenCode to confirm the PipelineRun succeeded.

You can watch the build in the OpenShift console: Pipelines → PipelineRuns in the fortune-cookie-build namespace.

APP_NAME="${APP_NAME:-fortune-cookie}"

oc get application $APP_NAME -n ${APP_NAME}-dev \
  -o jsonpath='{.status.sync.status} / {.status.health.status}' && echo

oc rollout status deployment/$APP_NAME -n ${APP_NAME}-dev --timeout=120s

ROUTE=$(oc get route $APP_NAME -n ${APP_NAME}-dev -o jsonpath='{.spec.host}')
echo "https://${ROUTE}"
curl -sk https://${ROUTE}/healthz
Expected
Synced / Healthy

Open the URL — you should see the cookie emoji 🥠 and the new fortunes.

Step Platform action

git push

Updated code on your personal Git repo

Tekton PipelineRun

git-clone + buildah, image to the internal registry

oc rollout restart

Pods pull ${APP_NAME}:latest

➡️ Move on to Lab 2.3: Audit with OpenCode.