fix and test mcptoolconfig for vmcp

[yrobla]

Add proper reconciliation, dynamic updates and overrides support Add tests to validate it

Large PR Justification

This is an atomic PR, that captured some bugs and needs for improvement, and also added relevant tests.

[codecov]

Codecov Report

❌ Patch coverage is 97.05882% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 56.50%. Comparing base (0c0d907) to head (dabba77).

Files with missing lines	Patch %	Lines
cmd/thv-operator/pkg/vmcpconfig/converter.go	97.05%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2891      +/-   ##
==========================================
+ Coverage   56.36%   56.50%   +0.14%     
==========================================
  Files         323      323              
  Lines       31764    31816      +52     
==========================================
+ Hits        17904    17978      +74     
+ Misses      12331    12308      -23     
- Partials     1529     1530       +1     

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[Copilot]

Pull request overview

This PR adds proper MCPToolConfig reconciliation, dynamic updates, and override support for VirtualMCPServer, along with comprehensive e2e tests to validate the functionality.

Key changes:

• Added MCPToolConfig reference resolution in the VirtualMCPServer converter with proper filter and override merging
• Implemented watch-based reconciliation to trigger VirtualMCPServer updates when referenced MCPToolConfigs change
• Added comprehensive e2e tests covering filtering, overrides, and dynamic configuration updates

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
test/e2e/thv-operator/virtualmcp/virtualmcp_toolconfig_test.go	New e2e tests for MCPToolConfig filtering, overrides, and dynamic updates
cmd/thv-operator/pkg/vmcpconfig/converter.go	Extended converter to resolve MCPToolConfig references and merge filters/overrides with precedence rules
cmd/thv-operator/pkg/vmcpconfig/converter_test.go	Updated test helper to pass required k8sClient parameter to converter
cmd/thv-operator/controllers/virtualmcpserver_vmcpconfig_test.go	Updated test to create fake k8s client for converter initialization
cmd/thv-operator/controllers/virtualmcpserver_vmcpconfig.go	Updated to pass k8sClient to converter constructor
cmd/thv-operator/controllers/virtualmcpserver_podtemplatespec_reconcile_test.go	Updated test calls to include workloadNames parameter
cmd/thv-operator/controllers/virtualmcpserver_controller.go	Updated function call to include workloadNames parameter and added MCPToolConfig watch

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[github-actions]

Large PR Detected

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## Large PR Justification

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[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

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Large PR justification has been provided. Thank you!

[github-actions]

✅ Large PR justification has been provided. The size review has been dismissed and this PR can now proceed with normal review.

[jhrozek]

PR Review: MCPToolConfig Support for VirtualMCPServer

Overall, this is a solid implementation with excellent test coverage. I have a few observations about error handling patterns and code organization that are worth considering.

Error Handling: Fails Open vs Fails Closed

In applyToolConfigRef (converter.go:337-341), the error handling logs the failure but continues with an empty/incomplete configuration. This is different from how OIDC resolution handles errors (lines 135-138), which fails closed by returning an error.

Concern: If a user explicitly references an MCPToolConfig that doesn't exist (typo, not yet created, deleted), the VirtualMCPServer will deploy with no tool filtering applied instead of failing. This could be a security concern if tool filtering was intended to restrict exposed tools.

Question: Was this intentional to allow graceful degradation, or should this fail closed like OIDC resolution to ensure explicit configuration errors are caught?

// OIDC resolution (fails closed):
return nil, fmt.Errorf("OIDC resolution failed for type %q: %w", ...)

// MCPToolConfig resolution (fails open):
ctxLogger.Error(err, "failed to resolve MCPToolConfig reference", ...)
return  // continues without config

Unreachable Code (converter.go:344-346)

The nil check if resolvedConfig == nil appears unreachable. Looking at resolveMCPToolConfig (lines 407-421), it either returns (toolConfig, nil) on success or (nil, error) on failure - it never returns (nil, nil).

If this is intentional defensive coding, consider adding a comment explaining the reasoning.

Minor: Method Receiver Pattern (converter.go:353, 363, 386)

The methods mergeToolConfigFilter, mergeToolConfigOverrides, and applyInlineOverrides use (*Converter) receiver but don't access any Converter fields - they're pure functions operating only on their parameters.

Question: Would it be cleaner to make these package-level functions, or use a value receiver (Converter) to signal they're stateless? This is a minor stylistic point.

---

Summary:

• 3 observations/questions noted
• No blocking issues identified
• Test coverage is comprehensive

[jhrozek]

PR Review: MCPToolConfig Support for VirtualMCPServer

Overall, this is a solid implementation with excellent test coverage. I have a few observations about error handling patterns and code organization that are worth considering.

Error Handling: Fails Open vs Fails Closed

In applyToolConfigRef (converter.go:337-341), the error handling logs the failure but continues with an empty/incomplete configuration. This is different from how OIDC resolution handles errors (lines 135-138), which fails closed by returning an error.

Concern: If a user explicitly references an MCPToolConfig that doesn't exist (typo, not yet created, deleted), the VirtualMCPServer will deploy with no tool filtering applied instead of failing. This could be a security concern if tool filtering was intended to restrict exposed tools.

Question: Was this intentional to allow graceful degradation, or should this fail closed like OIDC resolution to ensure explicit configuration errors are caught?

// OIDC resolution (fails closed):
return nil, fmt.Errorf("OIDC resolution failed for type %q: %w", ...)

// MCPToolConfig resolution (fails open):
ctxLogger.Error(err, "failed to resolve MCPToolConfig reference", ...)
return  // continues without config

Unreachable Code (converter.go:344-346)

The nil check if resolvedConfig == nil appears unreachable. Looking at resolveMCPToolConfig (lines 407-421), it either returns (toolConfig, nil) on success or (nil, error) on failure - it never returns (nil, nil).

If this is intentional defensive coding, consider adding a comment explaining the reasoning.

Minor: Method Receiver Pattern (converter.go:353, 363, 386)

The methods mergeToolConfigFilter, mergeToolConfigOverrides, and applyInlineOverrides use (*Converter) receiver but don't access any Converter fields - they're pure functions operating only on their parameters.

Question: Would it be cleaner to make these package-level functions, or use a value receiver (Converter) to signal they're stateless? This is a minor stylistic point.

---

Summary:

• 3 observations/questions noted
• No blocking issues identified
• Test coverage is comprehensive

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated no new comments.

---

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[yrobla]

PR Review: MCPToolConfig Support for VirtualMCPServer

Overall, this is a solid implementation with excellent test coverage. I have a few observations about error handling patterns and code organization that are worth considering.

Error Handling: Fails Open vs Fails Closed

In applyToolConfigRef (converter.go:337-341), the error handling logs the failure but continues with an empty/incomplete configuration. This is different from how OIDC resolution handles errors (lines 135-138), which fails closed by returning an error.

Concern: If a user explicitly references an MCPToolConfig that doesn't exist (typo, not yet created, deleted), the VirtualMCPServer will deploy with no tool filtering applied instead of failing. This could be a security concern if tool filtering was intended to restrict exposed tools.

Question: Was this intentional to allow graceful degradation, or should this fail closed like OIDC resolution to ensure explicit configuration errors are caught?

// OIDC resolution (fails closed):
return nil, fmt.Errorf("OIDC resolution failed for type %q: %w", ...)

// MCPToolConfig resolution (fails open):
ctxLogger.Error(err, "failed to resolve MCPToolConfig reference", ...)
return  // continues without config

Unreachable Code (converter.go:344-346)

The nil check if resolvedConfig == nil appears unreachable. Looking at resolveMCPToolConfig (lines 407-421), it either returns (toolConfig, nil) on success or (nil, error) on failure - it never returns (nil, nil).

If this is intentional defensive coding, consider adding a comment explaining the reasoning.

Minor: Method Receiver Pattern (converter.go:353, 363, 386)

The methods mergeToolConfigFilter, mergeToolConfigOverrides, and applyInlineOverrides use (*Converter) receiver but don't access any Converter fields - they're pure functions operating only on their parameters.

Question: Would it be cleaner to make these package-level functions, or use a value receiver (Converter) to signal they're stateless? This is a minor stylistic point.

Summary:

• 3 observations/questions noted
• No blocking issues identified
• Test coverage is comprehensive

please review again