fix: hello world deployment liveness probe and match message responses with readme

[biswapanda]

Overview:

• fix deploy yaml: add required backendFramework
• fix messages to match with README doc

nvbug: https://nvbugspro.nvidia.com/bug/5471412
closes: DYN-926

Summary by CodeRabbit

• New Features

  • Deployment now supports selecting vLLM as the backend framework.

• Chores

  • Simplified the Hello World example’s startup and readiness behavior for smoother launches.
  • Standardized the example client’s request payload to produce consistent streaming output.

[biswapanda]

/ok to test b09fc30

[coderabbitai]

Walkthrough

The client request payload in examples/runtime/hello_world/client.py was changed from an index-based string to a fixed string. The deployment YAML adds spec.backendFramework: vllm, adjusts HelloWorldWorker readinessProbe to a no-op command, and removes log piping from the container args.

Changes

Cohort / File(s)	Summary of Changes
Client request payload examples/runtime/hello_world/client.py	Replaced dynamic f-string payload using idx with fixed string "world,sun,moon,star" in client.generate; loop, streaming, backoff, and error handling unchanged.
Deployment spec and probes examples/runtime/hello_world/deploy/hello_world.yaml	Added spec.backendFramework: vllm. Changed HelloWorldWorker readinessProbe exec to exit 0 (bypass check). Updated container args to run python3 hello_world.py without log piping to /tmp/hello_world.log.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• docs: hello_world python binding example #2083 — Touches the same client generate payload pattern in examples/runtime/hello_world/client.py.
• fix: prevent crash looping hello world #2625 — Also modifies the streaming generate call/loop behavior in the same client.
• docs: hello world deploy example #2102 — Updates the same hello_world deployment YAML, including readiness probe behavior and related spec fields.

Poem

A bunny taps the keys—hop, hop, hooray!
The client’s words now fixed, no index in the fray.
A probe that simply nods, “All good!” then away—
Backend whispers: vllm lights the way.
Moon, star, sun—queries at play. 🌙⭐️☀️

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[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (2)

examples/runtime/hello_world/deploy/hello_world.yaml (2)

60-68: Readiness probe always returns success; consider tying readiness to actual process health.

Using exit 0 makes the pod "ready" even when the worker hasn’t started correctly, which can mask startup/config issues. If the worker doesn’t expose a health endpoint (typical for a non-serving worker), a lightweight readiness check that the Python process is running is safer.

Apply this diff to make readiness reflect process availability:

-            - "exit 0"
+            - 'ps -ef | grep -q "[p]ython3 hello_world.py" || exit 1'

Note: if your base image lacks ps, use pgrep -f instead, or drop readiness entirely for the worker if it’s not used for traffic gating.

---

87-87: Log flushing: use unbuffered Python for timely container logs.

Without the previous tee, stdout buffering can delay logs. Running Python unbuffered improves observability.

-            - python3 hello_world.py
+            - python3 -u hello_world.py

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📥 Commits

Reviewing files that changed from the base of the PR and between 7076990 and b09fc30.

📒 Files selected for processing (2)

• examples/runtime/hello_world/client.py (1 hunks)
• examples/runtime/hello_world/deploy/hello_world.yaml (3 hunks)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (1)

• GitHub Check: Build and Test - dynamo

🔇 Additional comments (2)

examples/runtime/hello_world/deploy/hello_world.yaml (1)

9-9: CRD enum “vllm” is valid
Verified that both the GraphDeployment and ComponentDeployment CRDs (operator and Helm charts) list “vllm” exactly as a permitted enum value for backendFramework. No casing or enum mismatches remain—this change can be approved.

examples/runtime/hello_world/client.py (1)

43-43: Static prompt matches README — OK.

Change aligns with the docs and is fine. Keeping idx for error context is still useful even if it’s not in the prompt.

[grahamking]

@biswapanda Could you update the title? I'm not sure what "hello world yaml and messages" means.

The title of the PR becomes the commit message, so it should be something we can read in 3 months and understand what's in the commit.

[biswapanda]

@biswapanda Could you update the title? I'm not sure what "hello world yaml and messages" means.

The title of the PR becomes the commit message, so it should be something we can read in 3 months and understand what's in the commit.

fixed the deployment