Header based routing filters

[kostis-codefresh]

When HTTP headers are used, clone all original filters/matches when creating the new route.

Fixes #87

[kostis-codefresh]

@CodiumAI-Agent /improve

[QodoAI-Agent]

PR Code Suggestions ✨

Latest suggestions up to d9f73bc

Category	Suggestion	Impact
Possible issue	Prevent nil-pointer on filter copy Guard against nil elements within httpRouteRule.Filters before calling DeepCopy() to prevent a potential nil-pointer panic. Also preallocate the destination slice to avoid repeated allocations and preserve order deterministically. pkg/plugin/httproute.go [152-157] // Copy filters from original route if httpRouteRule.Filters != nil { + httpHeaderRouteRule.Filters = make([]gatewayv1.HTTPRouteFilter, 0, len(httpRouteRule.Filters)) for i := 0; i < len(httpRouteRule.Filters); i++ { + if httpRouteRule.Filters[i] == nil { + continue + } httpHeaderRouteRule.Filters = append(httpHeaderRouteRule.Filters, *httpRouteRule.Filters[i].DeepCopy()) } } Suggestion importance[1-10]: 6 __ Why: The code copies Filters without guarding against potential nil elements; adding per-element nil checks and preallocating the slice is a safe, low-overhead improvement. Impact is moderate as nil entries may be rare but would cause a panic if present.	Low
	Safely copy gRPC filters Add a nil check for each grpcRouteRule.Filters[i] before dereferencing and preallocate the target slice to avoid panics and extra allocations. This ensures robust copying when filters contain nil entries. pkg/plugin/grpcroute.go [149-153] // Copy filters from original route if grpcRouteRule.Filters != nil { + grpcHeaderRouteRule.Filters = make([]gatewayv1.GRPCRouteFilter, 0, len(grpcRouteRule.Filters)) for i := 0; i < len(grpcRouteRule.Filters); i++ { + if grpcRouteRule.Filters[i] == nil { + continue + } grpcHeaderRouteRule.Filters = append(grpcHeaderRouteRule.Filters, *grpcRouteRule.Filters[i].DeepCopy()) } } Suggestion importance[1-10]: 6 __ Why: Similar to HTTP, copying gRPC filters without checking for nil elements could panic; preallocation and nil checks improve robustness with minimal complexity. Useful but not critical unless nil entries occur.	Low

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Previous suggestions

Suggestions up to commit d9f73bc

Category	Suggestion	Impact
Possible issue	Safely copy HTTP filters Guard against nil pointer dereferences when copying nested filter fields by using safe deep copies and checking inner pointers. Some filter variants may have nil sub-structs, and dereferencing them during deepcopy or later usage can panic. pkg/plugin/httproute.go [152-157] // Copy filters from original route if httpRouteRule.Filters != nil { - for i := 0; i < len(httpRouteRule.Filters); i++ { - httpHeaderRouteRule.Filters = append(httpHeaderRouteRule.Filters, *httpRouteRule.Filters[i].DeepCopy()) + httpHeaderRouteRule.Filters = make([]gatewayv1.HTTPRouteFilter, 0, len(httpRouteRule.Filters)) + for i := range httpRouteRule.Filters { + src := httpRouteRule.Filters[i] + // Use value copy first; then deep copy only when non-nil helper present + copied := src + if src.RequestHeaderModifier != nil { + copied.RequestHeaderModifier = src.RequestHeaderModifier.DeepCopy() + } + if src.ResponseHeaderModifier != nil { + copied.ResponseHeaderModifier = src.ResponseHeaderModifier.DeepCopy() + } + if src.URLRewrite != nil { + copied.URLRewrite = src.URLRewrite.DeepCopy() + } + if src.RequestMirror != nil { + copied.RequestMirror = src.RequestMirror.DeepCopy() + } + httpHeaderRouteRule.Filters = append(httpHeaderRouteRule.Filters, copied) } } Suggestion importance[1-10]: 7 __ Why: The suggestion replaces pointer-dereference-based DeepCopy with defensive field-wise copies, avoiding potential nil dereferences on optional filter sub-structs while preserving semantics. Impact is moderate as it hardens code against panics during filter copying introduced in this PR.	Medium
	Safely copy gRPC filters Prevent potential nil dereferences by defensively copying nested fields within each filter. Some GRPCRouteFilter option structs can be nil; copying them blindly risks panics or unintended shared references. pkg/plugin/grpcroute.go [149-153] // Copy filters from original route if grpcRouteRule.Filters != nil { - for i := 0; i < len(grpcRouteRule.Filters); i++ { - grpcHeaderRouteRule.Filters = append(grpcHeaderRouteRule.Filters, *grpcRouteRule.Filters[i].DeepCopy()) + grpcHeaderRouteRule.Filters = make([]gatewayv1.GRPCRouteFilter, 0, len(grpcRouteRule.Filters)) + for i := range grpcRouteRule.Filters { + src := grpcRouteRule.Filters[i] + copied := src + if src.RequestHeaderModifier != nil { + copied.RequestHeaderModifier = src.RequestHeaderModifier.DeepCopy() + } + if src.ResponseHeaderModifier != nil { + copied.ResponseHeaderModifier = src.ResponseHeaderModifier.DeepCopy() + } + if src.RequestMirror != nil { + copied.RequestMirror = src.RequestMirror.DeepCopy() + } + grpcHeaderRouteRule.Filters = append(grpcHeaderRouteRule.Filters, copied) } } Suggestion importance[1-10]: 7 __ Why: Similar to the HTTP case, this reduces risk of nil pointer panics when copying optional GRPCRoute filter fields by copying conditionally per sub-struct. This improves robustness of new filter-preservation logic without changing behavior.	Medium

[kostis-codefresh]

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