Remove serialize feature (open-telemetry#738)

Removes non-spec serialization support to reduce public API surface
area.

Author: jtescher

.github/workflows/ci.yml

@@ -72,7 +72,7 @@ jobs:
         override: true
     - name: Run tests
       run: cargo --version &&
-        cargo test --verbose --manifest-path=opentelemetry/Cargo.toml --features trace,metrics,serialize,rt-tokio,testing &&
+        cargo test --verbose --manifest-path=opentelemetry/Cargo.toml --features trace,metrics,rt-tokio,testing &&
         cargo test --manifest-path=opentelemetry-jaeger/Cargo.toml --features rt-tokio &&
         cargo test --manifest-path=opentelemetry-zipkin/Cargo.toml
   cargo-deny:

examples/basic-otlp-http/Cargo.toml

@@ -5,6 +5,6 @@ edition = "2018"
 publish = false
 
 [dependencies]
-opentelemetry = { path = "../../opentelemetry", features = ["rt-tokio", "metrics", "serialize"] }
+opentelemetry = { path = "../../opentelemetry", features = ["rt-tokio", "metrics"] }
 opentelemetry-otlp = { path = "../../opentelemetry-otlp", features = ["http-proto", "reqwest-client"] }
 tokio = { version = "1.0", features = ["full"] }

examples/basic-otlp-with-selector/Cargo.toml

@@ -7,7 +7,7 @@ publish = false
 [dependencies]
 futures-util = { version = "0.3", default-features = false, features = ["std"] }
 lazy_static = "1.4"
-opentelemetry = { path = "../../opentelemetry", features = ["rt-tokio", "metrics", "serialize"] }
+opentelemetry = { path = "../../opentelemetry", features = ["rt-tokio", "metrics"] }
 opentelemetry-otlp = { path = "../../opentelemetry-otlp", features = ["tonic", "metrics"] }
 serde_json = "1.0"
 tokio = { version = "1.0", features = ["full"] }

examples/basic-otlp/Cargo.toml

@@ -7,7 +7,7 @@ publish = false
 [dependencies]
 futures-util = { version = "0.3", default-features = false, features = ["std"] }
 lazy_static = "1.4"
-opentelemetry = { path = "../../opentelemetry", features = ["rt-tokio", "metrics", "serialize"] }
+opentelemetry = { path = "../../opentelemetry", features = ["rt-tokio", "metrics"] }
 opentelemetry-otlp = { path = "../../opentelemetry-otlp", features = ["tonic", "metrics"] }
 serde_json = "1.0"
 tokio = { version = "1.0", features = ["full"] }

examples/basic/Cargo.toml

@@ -7,8 +7,7 @@ publish = false
 [dependencies]
 futures-util = { version = "0.3", default-features = false, features = ["std"] }
 lazy_static = "1.4"
-opentelemetry = { path = "../../opentelemetry", features = ["serialize", "rt-tokio", "metrics"] }
+opentelemetry = { path = "../../opentelemetry", features = ["rt-tokio", "metrics"] }
 opentelemetry-jaeger = { path = "../../opentelemetry-jaeger", features = ["rt-tokio"] }
-serde_json = "1.0"
 thrift = "0.13"
 tokio = { version = "1.0", features = ["full"] }

examples/basic/src/main.rs

@@ -6,7 +6,7 @@ use opentelemetry::sdk::{metrics::PushController, trace as sdktrace, Resource};
 use opentelemetry::trace::TraceError;
 use opentelemetry::{
     baggage::BaggageExt,
-    metrics::{MetricsError, ObserverResult},
+    metrics::ObserverResult,
     trace::{TraceContextExt, Tracer},
     Context, Key, KeyValue,
 };
@@ -29,13 +29,7 @@ fn delayed_interval(duration: Duration) -> impl Stream<Item = tokio::time::Insta
 }
 
 fn init_meter() -> PushController {
-    opentelemetry::sdk::export::metrics::stdout(tokio::spawn, delayed_interval)
-        .with_formatter(|batch| {
-            serde_json::to_value(batch)
-                .map(|value| value.to_string())
-                .map_err(|err| MetricsError::Other(err.to_string()))
-        })
-        .init()
+    opentelemetry::sdk::export::metrics::stdout(tokio::spawn, delayed_interval).init()
 }
 
 const FOO_KEY: Key = Key::from_static_str("ex.com/foo");

examples/dynatrace/Cargo.toml

@@ -8,7 +8,7 @@ publish = false
 futures = "0.3"
 http = "0.2"
 lazy_static = "1.4"
-opentelemetry = { path = "../../opentelemetry", default-features = false, features = ["trace", "serialize"] }
+opentelemetry = { path = "../../opentelemetry", default-features = false, features = ["trace"] }
 opentelemetry-dynatrace = { path = "../../opentelemetry-dynatrace" }
 opentelemetry-http = { path = "../../opentelemetry-http", default-features = false }
 opentelemetry-otlp = { path = "../../opentelemetry-otlp", default-features = false, features = ["http-proto", "reqwest-client"] }

examples/external-otlp-grpcio-async-std/Cargo.toml

@@ -7,10 +7,7 @@ publish = false
 [dependencies]
 async-std = { version = "1.9.0", features = ["attributes"] }
 env_logger = "0.8.2"
-opentelemetry = { path = "../../opentelemetry", features = [
-    "rt-async-std",
-    "serialize"
-] }
+opentelemetry = { path = "../../opentelemetry", features = ["rt-async-std"] }
 opentelemetry-otlp = { path = "../../opentelemetry-otlp", features = [
     "grpc-sys",
     "trace",

examples/external-otlp-tonic-tokio/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2018"
 publish = false
 
 [dependencies]
-opentelemetry = { path = "../../opentelemetry", features = ["rt-tokio", "metrics", "serialize"] }
+opentelemetry = { path = "../../opentelemetry", features = ["rt-tokio", "metrics"] }
 opentelemetry-otlp = { path = "../../opentelemetry-otlp", features = ["tonic", "tls", "tls-roots"] }
 serde_json = "1.0"
 tokio = { version = "1.0", features = ["full"] }

opentelemetry-api/Cargo.toml

@@ -9,7 +9,6 @@ futures-channel = "0.3"
 futures-util = { version = "0.3", default-features = false, features = ["std", "sink"] }
 lazy_static = "1.4"
 pin-project = { version = "1.0.2", optional = true }
-serde = { version = "1.0", features = ["derive", "rc"], optional = true }
 thiserror = "1"
 tokio-stream = { version = "0.1", optional = true }
 
@@ -24,5 +23,4 @@ js-sys = "0.3"
 default = ["trace"]
 trace = ["pin-project"]
 metrics = ["fnv"]
-serialize = ["serde"]
 testing = ["trace"]