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fix(container): stop every vLLM sidecar inference request failing in the runtime image - #14731
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…code EngineCore encodes its messages as msgpack arrays ordered by field position, and the Rust EngineCore client inside `vllm-rs` decodes them strictly against its own field count. vLLM-Omni's `vllm.general_plugins` entry point appends three fields to `vllm.v1.engine.EngineCoreOutput`, and vLLM auto-loads every entry point in that group unless `VLLM_PLUGINS` names an allowlist. The vLLM runtime image installs vLLM-Omni and also puts `vllm-rs` on `PATH`, so the headless EngineCore workers that `vllm-rs serve` manages emit 19-position elements while `vllm-rs` expects 16. Every real inference request through the vLLM native-gRPC sidecar then fails to decode. Replace the bare `vllm-rs` symlink with a wrapper at the same `PATH` location. It sets `VLLM_PLUGINS` to the render-time allowlist of plugins the Rust decoder tolerates, defers to a caller that already exported `VLLM_PLUGINS`, and execs the packaged binary resolved exactly as the symlink resolved it. A global `ENV VLLM_PLUGINS` would also suppress the plugin in the Python omni workers, which is what its entry point exists to serve; the wrapper scopes the allowlist to the one process family that cannot tolerate the patch. Record the bound in the sidecar's runtime-compatibility notes, including that a caller invoking the binary by its in-package path bypasses the wrapper and must set `VLLM_PLUGINS` itself. Signed-off-by: svc-glamr@nvidia.com <svc-glamr@nvidia.com>
The wrapper installed on PATH allowlists only `modelexpress`, but the template comment, the comment inside the generated wrapper, and the new README paragraph all described it as allowing every plugin the Rust EngineCore decoder tolerates. vLLM ships two `vllm.general_plugins` entry points of its own, `lora_filesystem_resolver` and `lora_hf_hub_resolver`, which the decoder does tolerate and which the allowlist silently drops. Keep the allowlist minimal and make the prose match it: name what it excludes, record that `VLLM_PLUGINS` is the shared gate for the other `vllm.*_plugins` groups, and note that an image built without ModelExpress renders an allowlist that admits nothing. Also stop `lib/sidecar/vllm/README.md` describing the PATH entry as a symlink, which it has not been since the wrapper replaced it. Signed-off-by: svc-glamr@nvidia.com <svc-glamr@nvidia.com>
Signed-off-by: svc-glamr@nvidia.com <svc-glamr@nvidia.com>
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Included review availability: Your plan provides up to 12 included reviews per hour; 4 remain after this review. WalkthroughThe vLLM runtime template configures optional plugins and generates an executable ChangesvLLM plugin runtime
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The `vllm-rs` wrapper pins VLLM_PLUGINS to an allowlist so an auto-loaded plugin cannot extend EngineCoreOutput and break the positional msgpack decoder. Only the images that install vLLM-Omni carry such a plugin, and the dev and local-dev targets skip that install along with ModelExpress. Emitting the allowlist there filtered out every plugin that used to load by default, including vLLM's own LoRA resolvers and anything installed into the image afterwards, and named a modelexpress entry point those targets never install. Render the allowlist only for the targets that install vLLM-Omni; dev and local-dev link the binary onto PATH directly and leave VLLM_PLUGINS unset. The shell branches on a rendered flag, matching vllm_rs_required, because a Jinja block tag inside the backslash-continued RUN would end it early. Signed-off-by: svc-glamr@nvidia.com <svc-glamr@nvidia.com>
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Repair round 1 — head Finding addressed. The Change. Checks run. All hooks pass. The template was rendered for all nine |
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Signed-off-by: GLAMR <svc-glamr@nvidia.com>
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/ok to test 876683c |
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…0c6d2a Signed-off-by: GLAMR <svc-glamr@nvidia.com>
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@alec-flowers The merge from current |
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Inline comments:
In `@container/templates/vllm_runtime.Dockerfile`:
- Around line 537-558: Update the wrapper generated in the vllm_rs_allowlist
branch so an explicitly defined but empty VLLM_PLUGINS value is preserved.
Replace the current fallback expansion with logic that applies vllm_rs_plugins
only when VLLM_PLUGINS is unset, before executing vllm-rs.
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container/templates/vllm_runtime.Dockerfilelib/sidecar/vllm/README.md
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@alec-flowers The CodeRabbit finding is fixed and all lightweight checks are green on |
Revert 6974aef. The original shell expansion already preserves explicitly empty VLLM_PLUGINS values. Signed-off-by: Julien Darve <jdarve@NVIDIA.com>
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/ok to test 4c51dd3 |
…6d2a Signed-off-by: GLAMR <svc-glamr@nvidia.com>
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Source issue: DYN-4414.
Summary
On the Dynamo vLLM runtime image, every inference request through the native-gRPC vLLM sidecar fails. The engine logs
messagepack decode failed ... array had incorrect length, expected 16, the sidecar's health flips toNotServing, and the worker stays broken until it restarts.The cause is a third package, not version skew between
vllmandvllm-rs. EngineCore encodes each message as a msgpack array ordered by field position, and vLLM-Omni, which this image installs, appends three fields tovllm.v1.engine.EngineCoreOutput. vLLM auto-loads everyvllm.general_pluginsentry point unlessVLLM_PLUGINSnames an allowlist, so vLLM-Omni also reaches the engine processesvllm-rs servemanages, where the strict Rust decoder rejects every output as the wrong length.Details:
container/templates/vllm_runtime.Dockerfilenow putsvllm-rsonPATHas a small wrapper on the targets that install vLLM-Omni. The wrapper setsVLLM_PLUGINSto a render-time allowlist, thenexecs the binary out of the installedvllmpackage, so it stays at that package's revision. The allowlist ismodelexpresswhen the image installs ModelExpress and empty otherwise; an exportedVLLM_PLUGINSstill wins.The
devandlocal-devtargets skip the vLLM-Omni and ModelExpress installs, so they have no plugin to exclude and nothing to allow. They keep the plain symlink and leaveVLLM_PLUGINSunset, which preserves vLLM's default discovery for its own entry points and for anything installed into a dev image afterwards. The shell picks between the two on a rendered flag, the same way the existingvllm_rs_requiredcheck works, because a Jinja block tag inside the backslash-continuedRUNwould end the command early.lib/sidecar/vllm/README.mdrecords the failure mode, what the allowlist leaves out, which images set it, and how to setVLLM_PLUGINSwhen calling the binary by its in-package path.Where should the reviewer start?
The
RUNblock that installsvllm-rsincontainer/templates/vllm_runtime.Dockerfile, then the new paragraphs under "Runtime compatibility" inlib/sidecar/vllm/README.md.Validation
pre-commit run --files container/templates/vllm_runtime.Dockerfile lib/sidecar/vllm/README.mdpasses.The template renders for every supported combination, and the resulting
vllm-rsblock is valid POSIX shell in each one:All nine render, and
sh -naccepts the rendered block in each. Running that block against a stub binary givesVLLM_PLUGINS=modelexpressfor a runtime image with ModelExpress, an emptyVLLM_PLUGINSfor one without, and an unsetVLLM_PLUGINSplus a symlink fordevandlocal-dev; an exportedVLLM_PLUGINSoverrides all three.Building the image needs a Docker daemon, so that runs in the
vllm-buildjob in CI.Related Issues
Linear: DYN-4414
Summary by CodeRabbit
New Features
vllm-rscommand with controlled plugin loading and environment variable overrides.Documentation