tracing: add OpenCensus agent exporter support to OpenCensus driver.

api/bazel/repository_locations.bzl

@@ -4,8 +4,8 @@ BAZEL_SKYLIB_SHA256 = "2ef429f5d7ce7111263289644d233707dba35e39696377ebab8b0bc70
 GOGOPROTO_RELEASE = "1.2.1"
 GOGOPROTO_SHA256 = "99e423905ba8921e86817607a5294ffeedb66fdd4a85efce5eb2848f715fdb3a"
 
-OPENCENSUS_PROTO_RELEASE = "0.2.1"
-OPENCENSUS_PROTO_SHA256 = "bfcefa6093fc2ecdf5c9effea86e6982d0d6f9a5178b17fcf73a62e0f3fb43d0"
+OPENCENSUS_PROTO_GIT_SHA = "26aa36c099c2041b432cf3cc8a26c5fb858d218b"  # Jul 23, 2019
+OPENCENSUS_PROTO_SHA256 = "a63bcc8655140b6273cabf91dd84c8e3d8ea98ab2727555e7cf1c13cae5367db"
 
 PGV_GIT_SHA = "2feaabb13a5d697b80fcb938c0ce37b24c9381ee"  # Jul 26, 2018
 PGV_SHA256 = "ddefe3dcbb25d68a2e5dfea67d19c060959c2aecc782802bd4c1a5811d44dd45"
@@ -46,8 +46,8 @@ REPOSITORY_LOCATIONS = dict(
     ),
     opencensus_proto = dict(
         sha256 = OPENCENSUS_PROTO_SHA256,
-        strip_prefix = "opencensus-proto-" + OPENCENSUS_PROTO_RELEASE + "/src",
-        urls = ["https://github.com/census-instrumentation/opencensus-proto/archive/v" + OPENCENSUS_PROTO_RELEASE + ".tar.gz"],
+        strip_prefix = "opencensus-proto-" + OPENCENSUS_PROTO_GIT_SHA + "/src",
+        urls = ["https://github.com/census-instrumentation/opencensus-proto/archive/" + OPENCENSUS_PROTO_GIT_SHA + ".tar.gz"],
     ),
     kafka_source = dict(
         sha256 = KAFKA_SOURCE_SHA,

api/envoy/config/trace/v2/trace.proto

@@ -136,6 +136,13 @@ message OpenCensusConfig {
   // The URL to Zipkin, e.g. "http://127.0.0.1:9411/api/v2/spans"
   string zipkin_url = 6;
 
+  // Enables the OpenCensus Agent exporter if set to true. The address must also
+  // be set.
+  bool ocagent_exporter_enabled = 11;
+
+  // The address of the OpenCensus Agent, if its exporter is enabled.
+  string ocagent_address = 12;
+
   reserved 7; // Formerly zipkin_service_name.
 
   enum TraceContext {

bazel/repositories.bzl

@@ -147,6 +147,7 @@ def envoy_dependencies(skip_targets = []):
     _com_google_googletest()
     _com_google_protobuf()
     _io_opencensus_cpp()
+    _grpc_java()
     _com_github_curl()
     _com_github_envoyproxy_sqlparser()
     _com_googlesource_quiche()
@@ -549,6 +550,10 @@ def _io_opencensus_cpp():
         name = "opencensus_trace_trace_context",
         actual = "@io_opencensus_cpp//opencensus/trace:trace_context",
     )
+    native.bind(
+        name = "opencensus_exporter_ocagent",
+        actual = "@io_opencensus_cpp//opencensus/exporters/trace/ocagent:ocagent_exporter",
+    )
     native.bind(
         name = "opencensus_exporter_stdout",
         actual = "@io_opencensus_cpp//opencensus/exporters/trace/stdout:stdout_exporter",
@@ -562,6 +567,14 @@ def _io_opencensus_cpp():
         actual = "@io_opencensus_cpp//opencensus/exporters/trace/zipkin:zipkin_exporter",
     )
 
+def _grpc_java():
+    # Used by @io_opencensus_proto.
+    location = REPOSITORY_LOCATIONS["grpc_java"]
+    http_archive(
+        name = "grpc_java",
+        **location
+    )
+
 def _com_github_curl():
     # Used by OpenCensus Zipkin exporter.
     location = REPOSITORY_LOCATIONS["com_github_curl"]

bazel/repository_locations.bzl

@@ -232,10 +232,15 @@ REPOSITORY_LOCATIONS = dict(
         urls = ["https://files.pythonhosted.org/packages/b3/b2/238e2590826bfdd113244a40d9d3eb26918bd798fc187e2360a8367068db/six-1.10.0.tar.gz"],
     ),
     io_opencensus_cpp = dict(
-        sha256 = "8d6016e47c2e19e7acbadb6f905b8c422748c64299d71101ac8f28151677e195",
-        strip_prefix = "opencensus-cpp-cad0d03ff3474cf14389fc249e16847ab7b6895f",
-        # 2019-07-31
-        urls = ["https://github.com/census-instrumentation/opencensus-cpp/archive/cad0d03ff3474cf14389fc249e16847ab7b6895f.tar.gz"],
+        sha256 = "b5fcc36a994a4ecb6e53c901e33579ed1ac238cff9975807db760918a15f43ff",
+        strip_prefix = "opencensus-cpp-8058a1b8efe6a63bd18673abc51223917d12d45d",
+        # 2019-08-22
+        urls = ["https://github.com/census-instrumentation/opencensus-cpp/archive/8058a1b8efe6a63bd18673abc51223917d12d45d.tar.gz"],
+    ),
+    grpc_java = dict(
+        sha256 = "9618a6f4ec0f2bdb77d9b6e01865af9796f370e63e1352210798bacfc99ccdac",
+        strip_prefix = "grpc-java-1.23.0",
+        urls = ["https://github.com/grpc/grpc-java/archive/v1.23.0.tar.gz"],
     ),
     com_github_curl = dict(
         sha256 = "4376ac72b95572fb6c4fbffefb97c7ea0dd083e1974c0e44cd7e49396f454839",

source/extensions/tracers/opencensus/BUILD

@@ -32,6 +32,7 @@ envoy_cc_library(
         "opencensus_trace_cloud_trace_context",
         "opencensus_trace_grpc_trace_bin",
         "opencensus_trace_trace_context",
+        "opencensus_exporter_ocagent",
         "opencensus_exporter_stdout",
         "opencensus_exporter_stackdriver",
         "opencensus_exporter_zipkin",

source/extensions/tracers/opencensus/opencensus_tracer_impl.cc

@@ -8,6 +8,7 @@
 
 #include "absl/strings/str_cat.h"
 #include "google/devtools/cloudtrace/v2/tracing.grpc.pb.h"
+#include "opencensus/exporters/trace/ocagent/ocagent_exporter.h"
 #include "opencensus/exporters/trace/stackdriver/stackdriver_exporter.h"
 #include "opencensus/exporters/trace/stdout/stdout_exporter.h"
 #include "opencensus/exporters/trace/zipkin/zipkin_exporter.h"
@@ -257,6 +258,11 @@ Driver::Driver(const envoy::config::trace::v2::OpenCensusConfig& oc_config,
     opts.service_name = local_info_.clusterName();
     ::opencensus::exporters::trace::ZipkinExporter::Register(opts);
   }
+  if (oc_config.ocagent_exporter_enabled()) {
+    ::opencensus::exporters::trace::OcAgentOptions opts;
+    opts.address = oc_config.ocagent_address();
+    ::opencensus::exporters::trace::OcAgentExporter::Register(std::move(opts));
+  }
 }
 
 void Driver::applyTraceConfig(const opencensus::proto::trace::v1::TraceConfig& config) {

test/extensions/tracers/opencensus/config_test.cc

@@ -50,6 +50,8 @@ TEST(OpenCensusTracerConfigTest, OpenCensusHttpTracerWithTypedConfig) {
       stackdriver_project_id: test_project_id
       zipkin_exporter_enabled: true
       zipkin_url: http://127.0.0.1:9411/api/v2/spans
+      ocagent_exporter_enabled: true
+      ocagent_address: 127.0.0.1:55678
       incoming_trace_context: b3
       incoming_trace_context: trace_context
       incoming_trace_context: grpc_trace_bin