Added support for setting tracer tags via the configuration (#284)

Signed-off-by: Tobias Stadler <[email protected]>

Co-authored-by: Yuri Shkuro <[email protected]>

src/jaegertracing/Config.h

@@ -68,14 +68,21 @@ class Config {
         const auto baggageRestrictionsNode = configYAML["baggage_restrictions"];
         const auto baggageRestrictions =
             baggage::RestrictionsConfig::parse(baggageRestrictionsNode);
+
+        std::vector<Tag> tags;
+        const auto node = configYAML["tags"];
+        for(YAML::const_iterator it = node.begin(); it != node.end(); ++it) {
+            tags.emplace_back(it->first.as<std::string>(), it->second.as<std::string>());
+        }
+
         return Config(disabled,
                       traceId128Bit,
                       sampler,
                       reporter,
                       headers,
                       baggageRestrictions,
                       serviceName,
-                      std::vector<Tag>(),
+                      tags,
                       propagationFormat);
     }
 

src/jaegertracing/ConfigTest.cpp

@@ -107,6 +107,21 @@ propagation_format: w3c
     }
 }
 
+TEST(Config, testTags)
+{
+    {
+        constexpr auto kConfigYAML = R"cfg(
+tags:
+  foo: bar
+)cfg";
+        const auto config = Config::parse(YAML::Load(kConfigYAML));
+
+        std::vector<Tag> expectedTags;
+        expectedTags.emplace_back("foo", std::string("bar"));
+        ASSERT_EQ(expectedTags, config.tags());
+    }
+}
+
 #endif  // JAEGERTRACING_WITH_YAML_CPP
 
 TEST(Config, testFromEnv)