feat(gateway): add optional openapi-to-mcp sidecar by jarvis9443 · Pull Request #279 · api7/api7-helm-chart

jarvis9443 · 2026-04-17T04:02:08Z

Summary

The OpenAPI-to-MCP server has been extracted from the gateway image into a standalone image (api7/openapi-to-mcp). This PR adds an optional sidecar deployment for it under openapiToMcp in the gateway chart.

Changes

charts/gateway/values.yaml: new openapiToMcp block (enabled: false, image api7/openapi-to-mcp:0.0.1-beta, port 3000, empty resources).
charts/gateway/templates/_pod.tpl: render the sidecar container when openapiToMcp.enabled is true. Shares the pod network namespace so the gateway plugin reaches it on 127.0.0.1:<port>.
charts/gateway/README.md: regenerated via make helm-docs.

Notes

The upstream server binds to 127.0.0.1 inside the container, so httpGet/tcpSocket probes from kubelet would fail. The template uses an exec probe that runs a small node -e script against 127.0.0.1:$SSE_PORT/health.
Default is enabled: false. Users running the openapi-to-mcp or mcp-tools-acl plugins must flip this to true after upgrading to a gateway image that no longer bundles the server.

Verification

helm lint charts/gateway                    # passes
helm template t charts/gateway              # no openapi-to-mcp container
helm template t charts/gateway --set openapiToMcp.enabled=true   # container rendered

Summary by CodeRabbit

New Features
- Optional OpenAPI-to-MCP sidecar with enable/disable toggle, configurable image, port, and resource requests/limits.
- Built-in readiness and liveness checks for the sidecar.
- Deployment-time validation to ensure the sidecar port matches the gateway plugin port.
Documentation
- Updated Helm chart values and README with sidecar configuration and usage guidance.

The OpenAPI-to-MCP service has been moved out of the gateway image into a standalone image (api7/openapi-to-mcp). This chart now optionally deploys it as a sidecar in the gateway pod when the openapi-to-mcp / mcp-tools-acl plugins are in use. - Disabled by default; enable via openapiToMcp.enabled=true. - Shares the pod network namespace with the gateway so the plugin can continue to reach it on 127.0.0.1:<port>. - Uses exec-based probes because the upstream server binds to 127.0.0.1 inside the container. - Existing users of the openapi-to-mcp / mcp-tools-acl plugins must set openapiToMcp.enabled=true after upgrading.

coderabbitai · 2026-04-17T04:02:16Z

📝 Walkthrough

Walkthrough

Adds Helm values and README documentation for an optional OpenAPI-to-MCP sidecar and updates the gateway pod template to conditionally inject that sidecar (image, port, env, probes, resources) with template-time validation that the sidecar port matches gateway plugin attributes.

Changes

Cohort / File(s)	Summary
Helm values & docs `charts/gateway/values.yaml`, `charts/gateway/README.md`	Add `openapiToMcp` values: `enabled`, `image.{repository,tag,pullPolicy}`, `port`, and `resources`; document that `openapiToMcp.port` must match `plugin_attr.openapi-to-mcp` (plugin attribute port).
Pod template `charts/gateway/templates/_pod.tpl`	Conditionally inject an `openapi-to-mcp` container when `.Values.openapiToMcp.enabled` is true; configure image/pullPolicy, set `SSE_PORT` from `.Values.openapiToMcp.port`, expose TCP port `http`, add HTTP readiness/liveness probes on `/health`, apply `.Values.openapiToMcp.resources`, and perform template-time `fail` if the configured port is missing or mismatched with `pluginAttrs["openapi-to-mcp"].port`.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

🚥 Pre-merge checks | ✅ 3 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
E2e Test Quality Review	⚠️ Warning	PR lacks E2E tests for the new OpenAPI-to-MCP sidecar container feature in the Helm chart.	Implement E2E tests validating sidecar deployment, port binding, health probes, and resource limits across enabled/disabled scenarios.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The pull request title accurately describes the main change: adding an optional openapi-to-mcp sidecar to the gateway chart. It is concise, specific, and directly reflects the primary objective of the changeset.
Security Check	✅ Passed	OpenAPI-to-MCP sidecar container includes proper environment variable injection, port binding to localhost, health probes, and no hardcoded secrets.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

Create PR with unit tests
Commit unit tests in branch feat/openapi-to-mcp-sidecar

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coderabbitai

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@charts/gateway/templates/_pod.tpl`:
- Around line 231-273: The template currently wires the sidecar to
.Values.openapiToMcp.port but doesn't validate equality with
pluginAttrs["openapi-to-mcp"].port, allowing silent runtime breakage; add a Helm
template guard at the top of the openapi-to-mcp block that compares
.Values.openapiToMcp.port with index .Values.pluginAttrs "openapi-to-mcp" .port
and calls fail(...) if they differ so the chart rendering fails fast; locate the
openapiToMcp block in _pod.tpl and add the eq check using Helm's eq/if or ne and
fail to produce a clear error message referencing both .Values.openapiToMcp.port
and pluginAttrs["openapi-to-mcp"].port.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

Push a commit to this branch (recommended)
Create a new PR with the fixes

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: aef03d22-ecda-46e0-b474-8f58bef58637

📥 Commits

Reviewing files that changed from the base of the PR and between 8e20c00 and 0b1232a.

📒 Files selected for processing (3)

charts/gateway/README.md
charts/gateway/templates/_pod.tpl
charts/gateway/values.yaml

OpenAPI2MCP image now binds to 0.0.0.0 by default (via SSE_HOST) in api7/OpenAPI2MCP#40, so we can drop the awkward exec+node probe.

coderabbitai

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@charts/gateway/templates/_pod.tpl`:
- Around line 232-235: The template currently skips validation when
pluginAttrs.openapi-to-mcp.port is missing; change the logic in the block using
$mcpAttr and the hasKey check so you always validate port alignment: retrieve
pluginPort from (index $mcpAttr "port") using a default/sentinel and then
compare int(pluginPort) to int(.Values.openapiToMcp.port), and if pluginPort is
absent fail when .Values.openapiToMcp.port does not equal the plugin’s expected
default port; update the fail message in the same block to reference
.Values.openapiToMcp.port and the plugin port value so a mismatch is caught even
when pluginAttrs omits the port.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

Push a commit to this branch (recommended)
Create a new PR with the fixes

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: cbd830d4-0bfc-4a74-ba64-9769da0a5de8

📥 Commits

Reviewing files that changed from the base of the PR and between 6a074fb and 9ac8a14.

📒 Files selected for processing (1)

charts/gateway/templates/_pod.tpl

coderabbitai

🧹 Nitpick comments (1)

charts/gateway/templates/_pod.tpl (1)

232-235: Prefer merged plugin attrs over raw .Values.pluginAttrs to avoid default drift.

This works, but using the merged helper output as the source of truth will reduce maintenance risk if base plugin defaults change later.

♻️ Proposed refactor

-    {{- $mcpAttr := (index .Values.pluginAttrs "openapi-to-mcp" | default dict) -}}
+    {{- $pluginAttrs := (include "apisix.pluginAttrs" . | fromYaml) -}}
+    {{- $mcpAttr := (index $pluginAttrs "openapi-to-mcp" | default dict) -}}
     {{- $pluginMcpPort := (index $mcpAttr "port" | default 3000 | int) -}}

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@charts/gateway/templates/_pod.tpl` around lines 232 - 235, The comparison is
reading raw .Values.pluginAttrs via $mcpAttr but should use the chart's merged
plugin-attrs helper output to avoid default-drift; replace the lookup currently
using (index .Values.pluginAttrs "openapi-to-mcp") with the merged-plugin-attrs
variable or helper used elsewhere (e.g., the template variable that holds merged
plugin attrs, such as $mergedPluginAttrs or the include/tuple helper that
returns merged attrs), then use (index $mergedPluginAttrs "openapi-to-mcp" |
default dict) to compute $mcpAttr and keep the rest of the check against
.Values.openapiToMcp.port unchanged so plugin defaults remain authoritative.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@charts/gateway/templates/_pod.tpl`:
- Around line 232-235: The comparison is reading raw .Values.pluginAttrs via
$mcpAttr but should use the chart's merged plugin-attrs helper output to avoid
default-drift; replace the lookup currently using (index .Values.pluginAttrs
"openapi-to-mcp") with the merged-plugin-attrs variable or helper used elsewhere
(e.g., the template variable that holds merged plugin attrs, such as
$mergedPluginAttrs or the include/tuple helper that returns merged attrs), then
use (index $mergedPluginAttrs "openapi-to-mcp" | default dict) to compute
$mcpAttr and keep the rest of the check against .Values.openapiToMcp.port
unchanged so plugin defaults remain authoritative.

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 061002d3-fc4e-4416-843f-959c88e3bca3

📥 Commits

Reviewing files that changed from the base of the PR and between 9ac8a14 and 5cb6415.

📒 Files selected for processing (1)

charts/gateway/templates/_pod.tpl

jarvis9443 marked this pull request as ready for review April 17, 2026 05:00

coderabbitai bot reviewed Apr 17, 2026

View reviewed changes

Comment thread charts/gateway/templates/_pod.tpl

feat: fail fast on sidecar/plugin port mismatch

6a074fb

nic-6443 reviewed Apr 17, 2026

View reviewed changes

Comment thread charts/gateway/templates/_pod.tpl Outdated

chore(gateway): use httpGet probe for openapi-to-mcp sidecar

9ac8a14

OpenAPI2MCP image now binds to 0.0.0.0 by default (via SSE_HOST) in api7/OpenAPI2MCP#40, so we can drop the awkward exec+node probe.

coderabbitai bot reviewed Apr 17, 2026

View reviewed changes

Comment thread charts/gateway/templates/_pod.tpl

fix(gateway): validate port mismatch even when pluginAttrs omitted

5cb6415

coderabbitai bot reviewed Apr 17, 2026

View reviewed changes

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feat(gateway): add optional openapi-to-mcp sidecar#279

feat(gateway): add optional openapi-to-mcp sidecar#279
jarvis9443 wants to merge 4 commits intomainfrom
feat/openapi-to-mcp-sidecar

jarvis9443 commented Apr 17, 2026 •

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jarvis9443 commented Apr 17, 2026 •

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