opentelemetry: update otel to 0.18.0 (#2303)

## Motivation

Support the latest OpenTelemetry specification.

## Solution

Update `opentelemetry` to the latest `0.18.x` release. Breaking changes
in the metrics spec have removed value recorders and added histograms so
the metrics layer's `value.` prefix has been changed to `histogram.` and
behaves accordingly. Additionally the `PushController` configuration for
the metrics layer has been simplified to accept a `BasicController` that
can act in either push or pull modes. Finally trace sampling in the
sdk's `PreSampledTracer` impl has been updated to match the sampling
logic in open-telemetry/opentelemetry-rust#839.

* Update MSRV to 1.56
* Update examples
* Fix async-trait dep
* Update msrv action

Co-authored-by: Eliza Weisman <eliza@buoyant.io>

.github/workflows/CI.yml

@@ -214,6 +214,7 @@ jobs:
           --exclude=tracing-appender
           --exclude=tracing-examples
           --exclude=tracing-futures
+          --exclude=tracing-opentelemetry
         toolchain: ${{ env.MSRV }}
 
   # TODO: remove this once tracing's MSRV is bumped.

examples/Cargo.toml

@@ -52,8 +52,8 @@ inferno = "0.11.6"
 tempfile = "3"
 
 # opentelemetry example
-opentelemetry = { version = "0.17.0", default-features = false, features = ["trace"] }
-opentelemetry-jaeger = "0.16.0"
+opentelemetry = { version = "0.18.0", default-features = false, features = ["trace"] }
+opentelemetry-jaeger = "0.17.0"
 
 # fmt examples
 snafu = "0.6.10"

examples/examples/opentelemetry.rs

@@ -19,7 +19,7 @@ fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
     // Install an otel pipeline with a simple span processor that exports data one at a time when
     // spans end. See the `install_batch` option on each exporter's pipeline builder to see how to
     // export in batches.
-    let tracer = opentelemetry_jaeger::new_pipeline()
+    let tracer = opentelemetry_jaeger::new_agent_pipeline()
         .with_service_name("report_example")
         .install_simple()?;
     let opentelemetry = tracing_opentelemetry::layer().with_tracer(tracer);

tracing-opentelemetry/Cargo.toml

@@ -17,15 +17,15 @@ categories = [
 keywords = ["tracing", "opentelemetry", "jaeger", "zipkin", "async"]
 license = "MIT"
 edition = "2018"
-rust-version = "1.46.0"
+rust-version = "1.56.0"
 
 [features]
 default = ["tracing-log", "metrics"]
 # Enables support for exporting OpenTelemetry metrics
 metrics = ["opentelemetry/metrics"]
 
 [dependencies]
-opentelemetry = { version = "0.17.0", default-features = false, features = ["trace"] }
+opentelemetry = { version = "0.18.0", default-features = false, features = ["trace"] }
 tracing = { path = "../tracing", version = "0.1.35", default-features = false, features = ["std"] }
 tracing-core = { path = "../tracing-core", version = "0.1.28" }
 tracing-subscriber = { path = "../tracing-subscriber", version = "0.3.0", default-features = false, features = ["registry", "std"] }
@@ -39,7 +39,7 @@ thiserror = { version = "1.0.31", optional = true }
 [dev-dependencies]
 async-trait = "0.1.56"
 criterion = { version = "0.3.6", default-features = false }
-opentelemetry-jaeger = "0.16.0"
+opentelemetry-jaeger = "0.17.0"
 futures-util = { version = "0.3", default-features = false }
 tokio = { version = "1", features = ["full"] }
 tokio-stream = "0.1"
@@ -53,4 +53,4 @@ harness = false
 
 [package.metadata.docs.rs]
 all-features = true
-rustdoc-args = ["--cfg", "docsrs"]
+rustdoc-args = ["--cfg", "docsrs"]

tracing-opentelemetry/README.md

@@ -50,7 +50,7 @@ The crate provides the following types:
 [`tracing`]: https://crates.io/crates/tracing
 [OpenTelemetry]: https://opentelemetry.io/
 
-*Compiler support: [requires `rustc` 1.49+][msrv]*
+*Compiler support: [requires `rustc` 1.56+][msrv]*
 
 [msrv]: #supported-rust-versions
 
@@ -110,7 +110,7 @@ $ firefox http://localhost:16686/
 ## Supported Rust Versions
 
 Tracing Opentelemetry is built against the latest stable release. The minimum
-supported version is 1.46. The current Tracing version is not guaranteed to
+supported version is 1.56. The current Tracing version is not guaranteed to
 build on Rust versions earlier than the minimum supported version.
 
 Tracing follows the same compiler support policies as the rest of the Tokio