func SentinelClientMiddleware()

in pkg/adapters/kratos/client.go [40:95]
54 lines of code
10 McCabe index (conditional complexity)

func SentinelClientMiddleware(opts ...Option) middleware.Middleware {
	options := newOptions(opts)
	return func(src middleware.Handler) middleware.Handler {
		return func(ctx context.Context, req interface{}) (interface{}, error) {
			if !options.EnableOutlier(ctx) {
				resourceName := options.ResourceExtract(ctx, req)
				entry, blockErr := sentinel.Entry(
					resourceName,
					sentinel.WithResourceType(base.ResTypeRPC),
					sentinel.WithTrafficType(base.Outbound),
				)
				if blockErr != nil {
					return options.BlockFallback(ctx, req, blockErr)
				}
				defer entry.Exit()
				resp, err := src(ctx, req)
				if err != nil {
					sentinel.TraceError(entry, err)
				}
				return resp, err
			} else { // returns new client middleware specifically for outlier ejection.
				resourceName := ServiceNameExtract(ctx)
				slotChain := sentinel.BuildDefaultSlotChain()
				slotChain.AddRuleCheckSlot(outlier.DefaultSlot)
				slotChain.AddStatSlot(outlier.DefaultMetricStatSlot)
				entry, _ := sentinel.Entry(
					resourceName,
					sentinel.WithResourceType(base.ResTypeRPC),
					sentinel.WithTrafficType(base.Outbound),
					sentinel.WithSlotChain(slotChain),
				)
				defer entry.Exit()

				if v, ok := metadata.FromClientContext(ctx); ok {
					filterNodes := entry.Context().FilterNodes()
					for _, node := range filterNodes {
						v.Add(filterNodesKey, node)
					}
					halfNodes := entry.Context().HalfOpenNodes()
					for _, node := range halfNodes {
						v.Add(halfNodesKey, node)
					}
				}

				res, err := src(ctx, req)
				if p, ok := selector.FromPeerContext(ctx); ok && p.Node != nil {
					sentinel.TraceCallee(entry, p.Node.Address())
					if err != nil {
						sentinel.TraceError(entry, err)
					}
				}
				return res, err
			}
		}
	}
}