opentelemetry: Add extension to link spans

.github/workflows/CI.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        rust: [stable, 1.40.0]
+        rust: [stable, 1.42.0]
     steps:
     - uses: actions/checkout@main
     - uses: actions-rs/toolchain@v1
@@ -24,30 +24,9 @@ jobs:
       uses: actions-rs/cargo@v1
       with:
         command: check
-        args: --all --bins --examples --tests --benches
-
-  cache-cargo-hack:
-    runs-on: ubuntu-latest
-    steps:
-    - name: Fetch latest release version of cargo-hack
-      run: |
-        mkdir -p .github/caching
-        curl -sL https://api.github.com/repos/taiki-e/cargo-hack/releases/latest | jq -r '.name' > .github/caching/cargo-hack.lock
-    - name: Cache cargo-hack/bin
-      id: cache-cargo-hack
-      uses: actions/cache@v1
-      with:
-        path: ${{ runner.tool_cache }}/cargo-hack/bin
-        key: cargo-hack-bin-${{ hashFiles('.github/caching/cargo-hack.lock') }}
-    - name: Install cargo-hack
-      if: "steps.cache-cargo-hack.outputs.cache-hit != 'true'"
-      uses: actions-rs/cargo@v1
-      with:
-        command: install
-        args: --root ${{ runner.tool_cache }}/cargo-hack --force cargo-hack
+        args: --all --bins --tests --benches
 
   cargo-hack:
-    needs: cache-cargo-hack
     runs-on: ubuntu-latest
     strategy:
       matrix:
@@ -73,19 +52,9 @@ jobs:
         toolchain: stable
         profile: minimal
         override: true
-    - name: Fetch latest release version of cargo-hack
+    - name: Install cargo-hack
       run: |
-        mkdir -p .github/caching
-        curl -sL https://api.github.com/repos/taiki-e/cargo-hack/releases/latest | jq -r '.name' > .github/caching/cargo-hack.lock
-    - name: Restore cargo-hack/bin
-      uses: actions/cache@v1
-      with:
-        path: ${{ runner.tool_cache }}/cargo-hack/bin
-        key: cargo-hack-bin-${{ hashFiles('.github/caching/cargo-hack.lock') }}
-    - run: echo "::add-path::${{ runner.tool_cache }}/cargo-hack/bin"
-    # if `cargo-hack` somehow doesn't exist after loading it from the cache,
-    # make *sure* it's there.
-    - run: cargo hack --help || { cargo install --force cargo-hack; }
+        curl -LsSf https://github.com/taiki-e/cargo-hack/releases/latest/download/cargo-hack-x86_64-unknown-linux-gnu.tar.gz | tar xzf - -C ~/.cargo/bin
     - name: cargo hack check
       working-directory: ${{ matrix.subcrate }}
       run: cargo hack check --feature-powerset --no-dev-deps
@@ -145,7 +114,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        rust: [stable, beta, nightly, 1.40.0]
+        rust: [stable, beta, nightly]
     steps:
     - uses: actions/checkout@main
     - uses: actions-rs/toolchain@v1
@@ -159,6 +128,32 @@ jobs:
         command: test
         args: --all
 
+  test-msrv:
+    # Test against the minimum supported Rust version
+    needs: check
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@main
+    - uses: actions-rs/toolchain@v1
+      with:
+        toolchain: 1.42.0
+        profile: minimal
+        override: true
+    # We can't use `cargo test --all`, as that will also compile the examples.
+    # We don't guarantee the examples will work on the MSRV, because they have
+    # external dependencies which may not comply with our MSRV policy, but don't
+    # actually impact users on our MSRV.
+    - name: Run tests
+      uses: actions-rs/cargo@v1
+      with:
+        command: test
+        args: --workspace --lib --tests
+    - name: Run doctests
+      uses: actions-rs/cargo@v1
+      with:
+        command: test
+        args: --workspace --doc
+
   test-build-wasm:
     needs: check
     runs-on: ubuntu-latest
@@ -282,26 +277,3 @@ jobs:
       with:
         token: ${{ secrets.GITHUB_TOKEN }}
         args: --all --bins --examples --tests --benches -- -D warnings
-
-  cargo-audit:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@main
-    - name: Fetch latest release version of cargo-audit
-      run: |
-        mkdir -p .github/caching
-        cargo search cargo-audit | grep '^cargo-audit' | awk '{gsub(/"/,"",$3); print $3}' > .github/caching/cargo-audit.lock
-    - name: Cache cargo-audit/bin
-      id: cache-cargo-audit
-      uses: actions/cache@v1
-      with:
-        path: ${{ runner.tool_cache }}/cargo-audit/bin
-        key: cargo-audit-bin-${{ hashFiles('.github/caching/cargo-audit.lock') }}
-    - name: Install cargo-audit
-      if: "steps.cache-cargo-audit.outputs.cache-hit != 'true'"
-      uses: actions-rs/cargo@v1
-      with:
-        command: install
-        args: --root ${{ runner.tool_cache }}/cargo-audit --force cargo-audit
-    - run: echo "::add-path::${{ runner.tool_cache }}/cargo-audit/bin"
-    - run: cargo audit

.github/workflows/audit.yml

@@ -0,0 +1,14 @@
+name: Security audit
+on:
+  push:
+    paths:
+      - '**/Cargo.toml'
+      - '**/Cargo.lock'
+jobs:
+  security_audit:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions-rs/audit-check@v1
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}

README.md

@@ -169,7 +169,7 @@ pub fn shave_all(yaks: usize) -> usize {
 
         if let Err(ref error) = res {
             // Like spans, events can also use the field initialization shorthand.
-            // In this instance, `yak` is the field being initalized.
+            // In this instance, `yak` is the field being initialized.
             error!(yak, error = error.as_ref(), "failed to shave yak!");
         } else {
             yaks_shaved += 1;
@@ -192,7 +192,7 @@ set the default later.
 
 ### In Asynchronous Code
 
-To trace `async fn`s, the preferred method is using the [`#[instrument]`] attribute:
+To trace `async fn`s, the preferred method is using the [`#[instrument]`][instrument] attribute:
 
 ```rust
 use tracing::{info, instrument};
@@ -244,19 +244,19 @@ my_future
 `Future::instrument` attaches a span to the future, ensuring that the span's lifetime
 is as long as the future's.
 
-Under the hood, the `#[instrument]` macro performs same the explicit span
+Under the hood, the [`#[instrument]`][instrument] macro performs same the explicit span
 attachment that `Future::instrument` does.
 
 [std-future]: https://doc.rust-lang.org/stable/std/future/trait.Future.html
 [`tracing-futures`]: https://docs.rs/tracing-futures
-[closing]: https://docs.rs/tracing/latest/span/index.html#closing-spans
+[closing]: https://docs.rs/tracing/latest/tracing/span/index.html#closing-spans
 [`Future::instrument`]: https://docs.rs/tracing/latest/tracing/trait.Instrument.html#method.instrument
-[`#[instrument]`]: https://docs.rs/tracing/0.1.11/tracing/attr.instrument.html
+[instrument]: https://docs.rs/tracing/0.1.11/tracing/attr.instrument.html
 
 ## Supported Rust Versions
 
 Tracing is built against the latest stable release. The minimum supported
-version is 1.40. The current Tracing version is not guaranteed to build on Rust
+version is 1.42. 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
@@ -399,6 +399,7 @@ are not maintained by the `tokio` project. These include:
 - [`diesel-tracing`] provides integration with [`diesel`] database connections.
 - [`tracing-tracy`] provides a way to collect [Tracy] profiles in instrumented
   applications.
+- [`tracing-elastic-apm`] provides a layer for reporting traces to [Elastic APM].
 
 (if you're the maintainer of a `tracing` ecosystem crate not in this list,
 please let us know!)
@@ -426,6 +427,8 @@ please let us know!)
 [`diesel-tracing`]: https://crates.io/crates/diesel-tracing
 [`tracing-tracy`]: https://crates.io/crates/tracing-tracy
 [Tracy]: https://github.com/wolfpld/tracy
+[`tracing-elastic-apm`]: https://crates.io/crates/tracing-elastic-apm
+[Elastic APM]: https://www.elastic.co/apm
 
 **Note:** that some of the ecosystem crates are currently unreleased and
 undergoing active development. They may be less stable than `tracing` and

examples/Cargo.toml

@@ -10,24 +10,25 @@ default = []
 [dev-dependencies]
 
 # tracing crates
-tracing = { path = "../tracing", version = "0.1"}
-tracing-core = { path = "../tracing-core", version = "0.1"}
+tracing = { path = "../tracing", version = "0.1" }
+tracing-core = { path = "../tracing-core", version = "0.1" }
 tracing-error = { path = "../tracing-error" }
 tracing-flame = { path = "../tracing-flame" }
 tracing-tower = { version = "0.1.0", path = "../tracing-tower" }
-tracing-subscriber = { path = "../tracing-subscriber", version = "0.2.12", features = ["json", "chrono"] }
+tracing-subscriber = { path = "../tracing-subscriber", version = "0.2.13", features = ["json", "chrono"] }
 tracing-futures = { version = "0.2.1", path = "../tracing-futures", features = ["futures-01"] }
-tracing-attributes =  { path = "../tracing-attributes", version = "0.1.2"}
+tracing-attributes = { path = "../tracing-attributes", version = "0.1.2" }
 tracing-log = { path = "../tracing-log", version = "0.1.1", features = ["env_logger"] }
 tracing-serde = { path = "../tracing-serde" }
 tracing-opentelemetry = { path = "../tracing-opentelemetry" }
 tracing-journald = { path = "../tracing-journald" }
+tracing-appender = { path = "../tracing-appender", version = "0.1.2" }
 
 # serde example
 serde_json = "1.0"
 
 futures = "0.3"
-tokio = { version = "0.2.12", features = ["full"] }
+tokio = { version = "0.2.13", features = ["full"] }
 
 # env-logger example
 env_logger = "0.7"
@@ -52,5 +53,5 @@ inferno = "0.10.0"
 tempdir = "0.3.7"
 
 # opentelemetry example
-opentelemetry = { version = "0.8", default-features = false, features = ["trace"] }
-opentelemetry-jaeger = "0.7"
+opentelemetry = { version = "0.15", default-features = false, features = ["trace"] }
+opentelemetry-jaeger = "0.14"

examples/README.md

@@ -24,6 +24,8 @@ This directory contains a collection of examples that demonstrate the use of the
     fields on spans and events.
   + `fmt-custom-event`: Demonstrates overriding how the `fmt` subscriber formats
     events.
+  + `fmt-multiple-writers.rs`: demonstrates how `fmt::Layer` can write
+    to multiple destinations (in this instance, stdout and a file) simultaneously.
   + `subscriber-filter`: Demonstrates the `tracing-subscriber::filter` module,
     which provides a layer which adds configurable filtering to a subscriber
     implementation.

examples/examples/fmt-json.rs

@@ -0,0 +1,21 @@
+#![deny(rust_2018_idioms)]
+#[path = "fmt/yak_shave.rs"]
+mod yak_shave;
+
+fn main() {
+    tracing_subscriber::fmt()
+        .json()
+        .with_max_level(tracing::Level::TRACE)
+        .with_current_span(false)
+        .init();
+
+    let number_of_yaks = 3;
+    // this creates a new event, outside of any spans.
+    tracing::info!(number_of_yaks, "preparing to shave yaks");
+
+    let number_shaved = yak_shave::shave_all(number_of_yaks);
+    tracing::info!(
+        all_yaks_shaved = number_shaved == number_of_yaks,
+        "yak shaving completed"
+    );
+}

examples/examples/fmt-multiple-writers.rs

@@ -0,0 +1,32 @@
+//! An example demonstrating how `fmt::Layer` can write to multiple
+//! destinations (in this instance, `stdout` and a file) simultaneously.
+
+#[path = "fmt/yak_shave.rs"]
+mod yak_shave;
+
+use std::io;
+use tempdir::TempDir;
+use tracing_subscriber::{fmt, layer::SubscriberExt, EnvFilter};
+
+fn main() {
+    let dir = TempDir::new("directory").expect("Failed to create tempdir");
+
+    let file_appender = tracing_appender::rolling::hourly(dir, "example.log");
+    let (non_blocking, _guard) = tracing_appender::non_blocking(file_appender);
+
+    let subscriber = tracing_subscriber::registry()
+        .with(EnvFilter::from_default_env().add_directive(tracing::Level::TRACE.into()))
+        .with(fmt::Layer::new().with_writer(io::stdout))
+        .with(fmt::Layer::new().with_writer(non_blocking));
+    tracing::subscriber::set_global_default(subscriber).expect("Unable to set a global collector");
+
+    let number_of_yaks = 3;
+    // this creates a new event, outside of any spans.
+    tracing::info!(number_of_yaks, "preparing to shave yaks");
+
+    let number_shaved = yak_shave::shave_all(number_of_yaks);
+    tracing::info!(
+        all_yaks_shaved = number_shaved == number_of_yaks,
+        "yak shaving completed."
+    );
+}

examples/examples/fmt-pretty.rs

@@ -0,0 +1,23 @@
+#![deny(rust_2018_idioms)]
+#[path = "fmt/yak_shave.rs"]
+mod yak_shave;
+
+fn main() {
+    tracing_subscriber::fmt()
+        .pretty()
+        .with_thread_names(true)
+        // enable everything
+        .with_max_level(tracing::Level::TRACE)
+        // sets this to be the default, global collector for this application.
+        .init();
+
+    let number_of_yaks = 3;
+    // this creates a new event, outside of any spans.
+    tracing::info!(number_of_yaks, "preparing to shave yaks");
+
+    let number_shaved = yak_shave::shave_all(number_of_yaks);
+    tracing::info!(
+        all_yaks_shaved = number_shaved == number_of_yaks,
+        "yak shaving completed"
+    );
+}

examples/examples/fmt.rs

@@ -1,23 +1,20 @@
 #![deny(rust_2018_idioms)]
-use tracing::{info, Level};
-
 #[path = "fmt/yak_shave.rs"]
 mod yak_shave;
 
 fn main() {
     tracing_subscriber::fmt()
-        // all spans/events with a level higher than DEBUG (e.g, info, warn, etc.)
-        // will be written to stdout.
-        .with_max_level(Level::DEBUG)
-        // sets this to be the default, global subscriber for this application.
+        // enable everything
+        .with_max_level(tracing::Level::TRACE)
+        // sets this to be the default, global collector for this application.
         .init();
 
     let number_of_yaks = 3;
     // this creates a new event, outside of any spans.
-    info!(number_of_yaks, "preparing to shave yaks");
+    tracing::info!(number_of_yaks, "preparing to shave yaks");
 
     let number_shaved = yak_shave::shave_all(number_of_yaks);
-    info!(
+    tracing::info!(
         all_yaks_shaved = number_shaved == number_of_yaks,
         "yak shaving completed."
     );