golang filter: add GetProperty (envoyproxy#29355)

* golang filter: add GetProperty (envoyproxy#28595) As we already support getting/setting FilterState, we don't need to implement GetProperty with non-attribute name & SetProperty which actually work on FilterState * remove assertion which is no longer true The assertion is no longer true after envoyproxy@a420821 Solve envoyproxy#28595 (comment) Signed-off-by: spacewander <[email protected]>
ohadvano · Sep 1, 2023 · 951d4ba · 951d4ba
1 parent 9a2f5fc
commit 951d4ba
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Showing 17 changed files with 583 additions and 7 deletions.
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
@@ -250,6 +250,12 @@ updates:
     interval: daily
     time: "06:00"
 
+- package-ecosystem: "gomod"
+  directory: "/contrib/golang/filters/http/test/test_data/property"
+  schedule:
+    interval: daily
+    time: "06:00"
+
 - package-ecosystem: "gomod"
   directory: "/contrib/golang/router/cluster_specifier/test/test_data/simple"
   schedule:

diff --git a/contrib/golang/common/go/api/api.h b/contrib/golang/common/go/api/api.h
@@ -47,6 +47,8 @@ typedef enum { // NOLINT(modernize-use-using)
   CAPIInvalidPhase = -4,
   CAPIValueNotFound = -5,
   CAPIYield = -6,
+  CAPIInternalFailure = -7,
+  CAPISerializationFailure = -8,
 } CAPIStatus;
 
 CAPIStatus envoyGoFilterHttpContinue(void* r, int status);
@@ -82,6 +84,7 @@ void envoyGoConfigHttpFinalize(void* c);
 CAPIStatus envoyGoFilterHttpSetStringFilterState(void* r, void* key, void* value, int state_type,
                                                  int life_span, int stream_sharing);
 CAPIStatus envoyGoFilterHttpGetStringFilterState(void* r, void* key, void* value);
+CAPIStatus envoyGoFilterHttpGetStringProperty(void* r, void* key, void* value, int* rc);
 
 CAPIStatus envoyGoFilterHttpDefineMetric(void* c, uint32_t metric_type, void* name,
                                          void* metric_id);

diff --git a/contrib/golang/common/go/api/capi.go b/contrib/golang/common/go/api/capi.go
@@ -54,6 +54,8 @@ type HttpCAPI interface {
 	HttpSetStringFilterState(r unsafe.Pointer, key string, value string, stateType StateType, lifeSpan LifeSpan, streamSharing StreamSharing)
 	HttpGetStringFilterState(r unsafe.Pointer, key string) string
 
+	HttpGetStringProperty(r unsafe.Pointer, key string) (string, error)
+
 	HttpDefineMetric(c unsafe.Pointer, metricType MetricType, name string) uint32
 	HttpIncrementMetric(c unsafe.Pointer, metricId uint32, offset int64)
 	HttpGetMetric(c unsafe.Pointer, metricId uint32) uint64

diff --git a/contrib/golang/common/go/api/filter.go b/contrib/golang/common/go/api/filter.go
@@ -129,6 +129,9 @@ type StreamInfo interface {
 	FilterState() FilterState
 	// VirtualClusterName returns the name of the virtual cluster which got matched
 	VirtualClusterName() (string, bool)
+
+	// Some fields in stream info can be fetched via GetProperty
+	// For example, startTime() is equal to GetProperty("request.time")
 }
 
 type StreamFilterCallbacks interface {
@@ -144,6 +147,13 @@ type FilterCallbacks interface {
 	RecoverPanic()
 	Log(level LogType, msg string)
 	LogLevel() LogType
+	// GetProperty fetch Envoy attribute and return the value as a string.
+	// The list of attributes can be found in https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/advanced/attributes.
+	// If the fetch succeeded, a string will be returned.
+	// If the value is a timestamp, it is returned as a timestamp string like "2023-07-31T07:21:40.695646+00:00".
+	// If the fetch failed (including the value is not found), an error will be returned.
+	// Currently, fetching requests/response attributes are mostly unsupported.
+	GetProperty(key string) (string, error)
 	// TODO add more for filter callbacks
 }
 

diff --git a/contrib/golang/filters/http/source/BUILD b/contrib/golang/filters/http/source/BUILD
@@ -37,6 +37,18 @@ envoy_cc_library(
         "//source/common/http:headers_lib",
         "//source/common/http:utility_lib",
         "//source/common/http/http1:codec_lib",
+        "//source/common/protobuf:utility_lib",
+        "//source/extensions/filters/common/expr:cel_state_lib",
+        "//source/extensions/filters/common/expr:evaluator_lib",
+        "@com_google_cel_cpp//eval/public:activation",
+        "@com_google_cel_cpp//eval/public:builtin_func_registrar",
+        "@com_google_cel_cpp//eval/public:cel_expr_builder_factory",
+        "@com_google_cel_cpp//eval/public:cel_value",
+        "@com_google_cel_cpp//eval/public:value_export_util",
+        "@com_google_cel_cpp//eval/public/containers:field_access",
+        "@com_google_cel_cpp//eval/public/containers:field_backed_list_impl",
+        "@com_google_cel_cpp//eval/public/containers:field_backed_map_impl",
+        "@com_google_cel_cpp//eval/public/structs:cel_proto_wrapper",
         "@envoy_api//contrib/envoy/extensions/filters/http/golang/v3alpha:pkg_cc_proto",
     ],
 )
@@ -77,6 +89,9 @@ envoy_cc_library(
         "//source/common/http:headers_lib",
         "//source/common/http:utility_lib",
         "//source/common/http/http1:codec_lib",
+        "//source/common/protobuf:utility_lib",
+        "//source/extensions/filters/common/expr:cel_state_lib",
+        "//source/extensions/filters/common/expr:evaluator_lib",
         "@envoy_api//contrib/envoy/extensions/filters/http/golang/v3alpha:pkg_cc_proto",
     ],
 )
diff --git a/contrib/golang/filters/http/source/cgo.cc b/contrib/golang/filters/http/source/cgo.cc
@@ -268,6 +268,15 @@ CAPIStatus envoyGoFilterHttpGetStringFilterState(void* r, void* key, void* value
                                      });
 }
 
+CAPIStatus envoyGoFilterHttpGetStringProperty(void* r, void* key, void* value, int* rc) {
+  return envoyGoFilterHandlerWrapper(
+      r, [key, value, rc](std::shared_ptr<Filter>& filter) -> CAPIStatus {
+        auto key_str = referGoString(key);
+        auto value_str = reinterpret_cast<GoString*>(value);
+        return filter->getStringProperty(key_str, value_str, rc);
+      });
+}
+
 CAPIStatus envoyGoFilterHttpDefineMetric(void* c, uint32_t metric_type, void* name,
                                          void* metric_id) {
   return envoyGoConfigHandlerWrapper(

diff --git a/contrib/golang/filters/http/source/go/pkg/http/capi_impl.go b/contrib/golang/filters/http/source/go/pkg/http/capi_impl.go
@@ -32,6 +32,7 @@ package http
 */
 import "C"
 import (
+	"errors"
 	"reflect"
 	"runtime"
 	"strings"
@@ -61,21 +62,37 @@ const (
 
 type httpCApiImpl struct{}
 
-// Only CAPIOK is expected, otherwise, it means unexpected stage when invoke C API,
+// When the status means unexpected stage when invoke C API,
 // panic here and it will be recover in the Go entry function.
 func handleCApiStatus(status C.CAPIStatus) {
 	switch status {
-	case C.CAPIOK:
-		return
+	case C.CAPIFilterIsGone,
+		C.CAPIFilterIsDestroy,
+		C.CAPINotInGo,
+		C.CAPIInvalidPhase:
+		panic(capiStatusToStr(status))
+	}
+}
+
+func capiStatusToStr(status C.CAPIStatus) string {
+	switch status {
 	case C.CAPIFilterIsGone:
-		panic(errRequestFinished)
+		return errRequestFinished
 	case C.CAPIFilterIsDestroy:
-		panic(errFilterDestroyed)
+		return errFilterDestroyed
 	case C.CAPINotInGo:
-		panic(errNotInGo)
+		return errNotInGo
 	case C.CAPIInvalidPhase:
-		panic(errInvalidPhase)
+		return errInvalidPhase
+	case C.CAPIValueNotFound:
+		return errValueNotFound
+	case C.CAPIInternalFailure:
+		return errInternalFailure
+	case C.CAPISerializationFailure:
+		return errSerializationFailure
 	}
+
+	return "unknown status"
 }
 
 func (c *httpCApiImpl) HttpContinue(r unsafe.Pointer, status uint64) {
@@ -324,6 +341,31 @@ func (c *httpCApiImpl) HttpGetStringFilterState(rr unsafe.Pointer, key string) s
 	return strings.Clone(value)
 }
 
+func (c *httpCApiImpl) HttpGetStringProperty(rr unsafe.Pointer, key string) (string, error) {
+	r := (*httpRequest)(rr)
+	var value string
+	var rc int
+	r.mutex.Lock()
+	defer r.mutex.Unlock()
+	r.sema.Add(1)
+	res := C.envoyGoFilterHttpGetStringProperty(unsafe.Pointer(r.req), unsafe.Pointer(&key),
+		unsafe.Pointer(&value), (*C.int)(unsafe.Pointer(&rc)))
+	if res == C.CAPIYield {
+		atomic.AddInt32(&r.waitingOnEnvoy, 1)
+		r.sema.Wait()
+		res = C.CAPIStatus(rc)
+	} else {
+		r.sema.Done()
+		handleCApiStatus(res)
+	}
+
+	if res == C.CAPIOK {
+		return strings.Clone(value), nil
+	}
+
+	return "", errors.New(capiStatusToStr(res))
+}
+
 func (c *httpCApiImpl) HttpDefineMetric(cfg unsafe.Pointer, metricType api.MetricType, name string) uint32 {
 	var value uint32
 

diff --git a/contrib/golang/filters/http/source/go/pkg/http/filter.go b/contrib/golang/filters/http/source/go/pkg/http/filter.go
@@ -130,6 +130,10 @@ func (r *httpRequest) LogLevel() api.LogType {
 	return cAPI.HttpLogLevel()
 }
 
+func (r *httpRequest) GetProperty(key string) (string, error) {
+	return cAPI.HttpGetStringProperty(unsafe.Pointer(r), key)
+}
+
 func (r *httpRequest) StreamInfo() api.StreamInfo {
 	return &streamInfo{
 		request: r,

diff --git a/contrib/golang/filters/http/source/go/pkg/http/type.go b/contrib/golang/filters/http/source/go/pkg/http/type.go
@@ -31,6 +31,10 @@ const (
 	errFilterDestroyed = "golang filter has been destroyed"
 	errNotInGo         = "not proccessing Go"
 	errInvalidPhase    = "invalid phase, maybe headers/buffer already continued"
+
+	errInternalFailure      = "internal failure"
+	errValueNotFound        = "value not found"
+	errSerializationFailure = "serialization failure"
 )
 
 // api.HeaderMap