json: ser/de bytes as base64 strings not an array of bytes

Author: adriangb

opentelemetry-otlp/tests/integration_test/expected/traces.json

@@ -57,6 +57,12 @@
                   "value": {
                     "stringValue": "yes"
                   }
+                },
+                {
+                  "key": "data",
+                  "value": {
+                    "bytesValue": "gICA"
+                  }
                 }
               ],
               "events": [

opentelemetry-proto/Cargo.toml

@@ -45,7 +45,7 @@ testing = ["opentelemetry/testing"]
 
 # add ons
 with-schemars = ["schemars"]
-with-serde = ["serde", "hex"]
+with-serde = ["serde", "hex", "base64"]
 populate-logs-event-name = []
 
 [dependencies]
@@ -56,6 +56,7 @@ opentelemetry_sdk = { version = "0.27", default-features = false, path = "../ope
 schemars = { version = "0.8", optional = true }
 serde = { workspace = true, optional = true, features = ["serde_derive"] }
 hex = { version = "0.4.3", optional = true }
+base64 = { version = "0.22.1", optional = true }
 
 [dev-dependencies]
 opentelemetry = { features = ["testing"], path = "../opentelemetry" }

opentelemetry-proto/src/proto.rs

@@ -56,6 +56,11 @@ pub(crate) mod serializers {
                 map.serialize_entry("intValue", &i.to_string());
                 map.end()
             }
+            Some(Value::BytesValue(b)) => {
+                let mut map = serializer.serialize_map(Some(1))?;
+                map.serialize_entry("bytesValue", &base64::encode(b));
+                map.end()
+            }
             Some(value) => value.serialize(serializer),
             None => serializer.serialize_none(),
         }
@@ -127,8 +132,10 @@ pub(crate) mod serializers {
                             value = Some(any_value::Value::KvlistValue(kv));
                         }
                         "bytesValue" => {
-                            let bytes = map.next_value()?;
-                            value = Some(any_value::Value::BytesValue(bytes));
+                            let base64: String = map.next_value()?;
+                            let decoded = base64::decode(base64.as_bytes())
+                                .map_err(|e| de::Error::custom(e))?;
+                            value = Some(any_value::Value::BytesValue(decoded));
                         }
                         _ => {
                             //skip unknown keys, and handle error later.
@@ -182,6 +189,17 @@ pub(crate) mod serializers {
         let s: String = Deserialize::deserialize(deserializer)?;
         s.parse::<i64>().map_err(de::Error::custom)
     }
+
+    pub fn serialize_vec_u8_as_base64_string<S: Serializer>(v: &Vec<u8>, s: S) -> Result<S::Ok, S::Error> {
+        let base64 = base64::encode(v);
+        String::serialize(&base64, s)
+    }
+
+    pub fn deserialize_base64_string_to_vec_u8<'de, D: Deserializer<'de>>(d: D) -> Result<Vec<u8>, D::Error> {
+        let base64 = String::deserialize(d)?;
+        base64::decode(base64.as_bytes())
+            .map_err(|e| serde::de::Error::custom(e))
+    }
 }
 
 #[cfg(feature = "gen-tonic-messages")]