feat: preliminary implementation of traffic routing

Author: saicaca

core/route/base/headers.go

@@ -0,0 +1,12 @@
+package base
+
+type Headers struct {
+	Request  *HeaderOperations
+	Response *HeaderOperations
+}
+
+type HeaderOperations struct {
+	Set    map[string]string
+	Add    map[string]string
+	Remove []string
+}

core/route/base/http_match_request.go

@@ -0,0 +1,27 @@
+package base
+
+type HTTPMatchRequest struct {
+	Name        string
+	Headers     map[string]*StringMatch
+	Uri         *StringMatch
+	Scheme      *StringMatch
+	Authority   *StringMatch
+	Method      *StringMatch
+	Port        *int
+	QueryParams map[string]*StringMatch
+}
+
+// TODO
+func (h *HTTPMatchRequest) IsMatch(context *TrafficContext) bool {
+	if !h.Method.IsMatch(context.MethodName) {
+		return false
+	}
+
+	for key, match := range h.Headers {
+		if v, ok := context.Headers[key]; ok && !match.IsMatch(v) {
+			return false
+		}
+	}
+
+	return true
+}

core/route/base/http_route.go

@@ -0,0 +1,16 @@
+package base
+
+type HTTPRoute struct {
+	Name  string
+	Match []*HTTPMatchRequest
+	Route []*HTTPRouteDestination
+}
+
+func (h *HTTPRoute) IsMatch(context *TrafficContext) bool {
+	for _, match := range h.Match {
+		if match.IsMatch(context) {
+			return true
+		}
+	}
+	return false
+}

core/route/base/http_route_destination.go

@@ -0,0 +1,20 @@
+package base
+
+import "fmt"
+
+type HTTPRouteDestination struct {
+	Weight      int
+	Destination *Destination
+	Headers     Headers // TODO modifies headers
+}
+
+func (H HTTPRouteDestination) String() string {
+	return fmt.Sprintf("{Weight: %v, Destination: %+v}\n", H.Weight, H.Destination)
+}
+
+type Destination struct {
+	Host     string
+	Subset   string
+	Port     uint32
+	Fallback *HTTPRouteDestination
+}

core/route/base/instance.go

@@ -0,0 +1,9 @@
+package base
+
+type Instance struct {
+	AppName        string
+	Host           string
+	Port           int
+	Metadata       map[string]string
+	TargetInstance interface{}
+}

core/route/base/string_match.go

@@ -0,0 +1,25 @@
+package base
+
+import "regexp"
+
+type StringMatch struct {
+	Exact  string
+	Prefix string
+	Regex  string
+}
+
+func (s *StringMatch) IsMatch(input string) bool {
+	if input == "" {
+		return false
+	}
+
+	if s.Exact != "" {
+		return input == s.Exact
+	} else if s.Prefix != "" {
+		return len(input) >= len(s.Prefix) && input[:len(s.Prefix)] == s.Prefix
+	} else if s.Regex != "" {
+		matched, _ := regexp.MatchString(s.Regex, input)
+		return matched
+	}
+	return true
+}

core/route/base/traffic_context.go

@@ -0,0 +1,13 @@
+package base
+
+type TrafficContext struct {
+	Path        string
+	ServiceName string
+	Group       string
+	Version     string
+	MethodName  string
+	ParamTypes  []string
+	Args        []interface{}
+	Headers     map[string]string
+	Baggage     map[string]string
+}

core/route/base/traffic_policy.go

@@ -0,0 +1,5 @@
+package base
+
+type TrafficPolicy struct {
+	LoadBalancer string
+}

core/route/base/traffic_router.go

@@ -0,0 +1,11 @@
+package base
+
+type TrafficRouter struct {
+	Host []string
+	Http []*HTTPRoute
+}
+
+type Fallback struct {
+	Host   string
+	Subset string
+}

core/route/base/virtual_workload.go

@@ -0,0 +1,12 @@
+package base
+
+type VirtualWorkload struct {
+	Host          string
+	trafficPolicy *TrafficPolicy
+	Subsets       []*Subset
+}
+
+type Subset struct {
+	Name   string
+	Labels map[string]string
+}