remaining backports for tracing-subscriber 0.3

.github/workflows/CI.yml

@@ -6,6 +6,27 @@ on:
     - master
   pull_request: {}
 
+env:
+  # Disable incremental compilation.
+  #
+  # Incremental compilation is useful as part of an edit-build-test-edit cycle,
+  # as it lets the compiler avoid recompiling code that hasn't changed. However,
+  # on CI, we're not making small edits; we're almost always building the entire
+  # project from scratch. Thus, incremental compilation on CI actually
+  # introduces *additional* overhead to support making future builds
+  # faster...but no future builds will ever occur in any given CI environment.
+  #
+  # See https://matklad.github.io/2021/09/04/fast-rust-builds.html#ci-workflow
+  # for details.
+  CARGO_INCREMENTAL: 0
+  # Allow more retries for network requests in cargo (downloading crates) and
+  # rustup (installing toolchains). This should help to reduce flaky CI failures
+  # from transient network timeouts or other issues.
+  CARGO_NET_RETRY: 10
+  RUSTUP_MAX_RETRIES: 10
+  # Don't emit giant backtraces in the CI logs.
+  RUST_BACKTRACE: short
+
 jobs:
   check-msrv:
     # Run `cargo check` on our minimum supported Rust version (1.42.0).
@@ -21,7 +42,24 @@ jobs:
       uses: actions-rs/cargo@v1
       with:
         command: check
-        args: --all
+        args: --all --exclude=tracing-appender
+
+  # TODO: remove this once tracing's MSRV is bumped.
+  check-msrv-appender:
+    # Run `cargo check` on our minimum supported Rust version (1.51.0).
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@main
+    - uses: actions-rs/toolchain@v1
+      with:
+        toolchain: 1.51.0
+        profile: minimal
+        override: true
+    - name: Check
+      uses: actions-rs/cargo@v1
+      with:
+        command: check
+        args: --lib=tracing-appender
 
   check:
     # Run `cargo check` first to ensure that the pushed code at least compiles.

.github/workflows/audit.yml

@@ -1,7 +1,30 @@
 name: Security audit
+
 on:
   schedule:
     - cron: '0 0 * * *'
+
+env:
+  # Disable incremental compilation.
+  #
+  # Incremental compilation is useful as part of an edit-build-test-edit cycle,
+  # as it lets the compiler avoid recompiling code that hasn't changed. However,
+  # on CI, we're not making small edits; we're almost always building the entire
+  # project from scratch. Thus, incremental compilation on CI actually
+  # introduces *additional* overhead to support making future builds
+  # faster...but no future builds will ever occur in any given CI environment.
+  #
+  # See https://matklad.github.io/2021/09/04/fast-rust-builds.html#ci-workflow
+  # for details.
+  CARGO_INCREMENTAL: 0
+  # Allow more retries for network requests in cargo (downloading crates) and
+  # rustup (installing toolchains). This should help to reduce flaky CI failures
+  # from transient network timeouts or other issues.
+  CARGO_NET_RETRY: 10
+  RUSTUP_MAX_RETRIES: 10
+  # Don't emit giant backtraces in the CI logs.
+  RUST_BACKTRACE: short
+
 jobs:
   security_audit:
     runs-on: ubuntu-latest

README.md

@@ -401,6 +401,7 @@ are not maintained by the `tokio` project. These include:
 - [`tracing-tracy`] provides a way to collect [Tracy] profiles in instrumented
   applications.
 - [`tracing-elastic-apm`] provides a layer for reporting traces to [Elastic APM].
+- [`tracing-etw`] provides a layer for emitting Windows [ETW] events.
 
 (if you're the maintainer of a `tracing` ecosystem crate not in this list,
 please let us know!)
@@ -431,6 +432,8 @@ please let us know!)
 [Tracy]: https://github.com/wolfpld/tracy
 [`tracing-elastic-apm`]: https://crates.io/crates/tracing-elastic-apm
 [Elastic APM]: https://www.elastic.co/apm
+[`tracing-etw`]: https://github.com/microsoft/tracing-etw
+[ETW]: https://docs.microsoft.com/en-us/windows/win32/etw/about-event-tracing
 
 **Note:** that some of the ecosystem crates are currently unreleased and
 undergoing active development. They may be less stable than `tracing` and
@@ -444,6 +447,8 @@ Tracing.
 #### Blog Posts
 
 * [Diagnostics with Tracing][tokio-blog-2019-08] on the Tokio blog, August 2019
+* [Production-Grade Logging in Rust Applications][production-logging-2020], November 2020
+* [Custom Logging in Rust using `tracing` and `tracing-subscriber`, part 1][custom-logging-part-1] and [part 2][custom-logging-part-2], October 2021
 
 [tokio-blog-2019-08]: https://tokio.rs/blog/2019-08-tracing/
 
@@ -458,6 +463,9 @@ Tracing.
 [rust-conf-2019-08-slides]: https://www.elizas.website/slides/rustconf-8-2019.pdf
 [rusty-days-2020-08-video]: https://youtu.be/HtKnLiFwHJM
 [rusty-days-2020-08-slides]: https://docs.google.com/presentation/d/1zrxJs7fJgQ29bKfnAll1bYTo9cYZxsCZUwDDtyp5Fak/edit?usp=sharing
+[production-logging-2020]: https://medium.com/better-programming/production-grade-logging-in-rust-applications-2c7fffd108a6
+[custom-logging-part-1]: https://burgers.io/custom-logging-in-rust-using-tracing
+[custom-logging-part-2]: https://burgers.io/custom-logging-in-rust-using-tracing-part-2
 
 Help us expand this list! If you've written or spoken about Tracing, or
 know of resources that aren't listed, please open a pull request adding them.

tracing-appender/Cargo.toml

@@ -21,14 +21,15 @@ edition = "2018"
 
 [dependencies]
 crossbeam-channel = "0.5.0"
-chrono = { version = "0.4.16", default-features = false, features = ["clock", "std"] }
+time = { version = "0.3", default-features = false, features = ["formatting"] }
 
 [dependencies.tracing-subscriber]
 path = "../tracing-subscriber"
 version = "0.2.7"
 default-features = false
-features = ["fmt"]
+features = ["fmt", "std"]
 
 [dev-dependencies]
 tracing = { path = "../tracing", version = "0.1" }
+time = { version = "0.3", default-features = false, features = ["formatting", "parsing"] }
 tempfile = "3"

tracing-appender/README.md

@@ -36,7 +36,7 @@ allows events and spans to be recorded in a non-blocking manner through a
 dedicated logging thread. It also provides a [`RollingFileAppender`][file_appender] 
 that can be used with _or_ without the non-blocking writer.
 
-*Compiler support: [requires `rustc` 1.42+][msrv]*
+*Compiler support: [requires `rustc` 1.51+][msrv]*
 
 [msrv]: #supported-rust-versions
 
@@ -145,17 +145,17 @@ fn main() {
 
 ## Supported Rust Versions
 
-Tracing is built against the latest stable release. The minimum supported
-version is 1.42. The current Tracing version is not guaranteed to build on Rust
-versions earlier than the minimum supported version.
+`tracing-appender` is built against the latest stable release. The minimum supported
+version is 1.51. The current `tracing-appender` 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
 project. The current stable Rust compiler and the three most recent minor
-versions before it will always be supported. For example, if the current stable
-compiler version is 1.45, the minimum supported version will not be increased
-past 1.42, three minor versions prior. Increasing the minimum supported compiler
-version is not considered a semver breaking change as long as doing so complies
-with this policy.
+versions before it will always be supported. For example, if the current
+stable compiler version is 1.45, the minimum supported version will not be
+increased past 1.42, three minor versions prior. Increasing the minimum
+supported compiler version is not considered a semver breaking change as
+long as doing so complies with this policy.
 
 ## License
 

tracing-appender/src/inner.rs

@@ -2,23 +2,23 @@ use std::io::{BufWriter, Write};
 use std::{fs, io};
 
 use crate::rolling::Rotation;
-use chrono::prelude::*;
 use std::fmt::Debug;
 use std::fs::{File, OpenOptions};
 use std::path::Path;
+use time::OffsetDateTime;
 
 #[derive(Debug)]
 pub(crate) struct InnerAppender {
     log_directory: String,
     log_filename_prefix: String,
     writer: BufWriter<File>,
-    next_date: DateTime<Utc>,
+    next_date: Option<OffsetDateTime>,
     rotation: Rotation,
 }
 
 impl io::Write for InnerAppender {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        let now = Utc::now();
+        let now = OffsetDateTime::now_utc();
         self.write_timestamped(buf, now)
     }
 
@@ -32,7 +32,7 @@ impl InnerAppender {
         log_directory: &Path,
         log_filename_prefix: &Path,
         rotation: Rotation,
-        now: DateTime<Utc>,
+        now: OffsetDateTime,
     ) -> io::Result<Self> {
         let log_directory = log_directory.to_str().unwrap();
         let log_filename_prefix = log_filename_prefix.to_str().unwrap();
@@ -49,15 +49,15 @@ impl InnerAppender {
         })
     }
 
-    fn write_timestamped(&mut self, buf: &[u8], date: DateTime<Utc>) -> io::Result<usize> {
+    fn write_timestamped(&mut self, buf: &[u8], date: OffsetDateTime) -> io::Result<usize> {
         // Even if refresh_writer fails, we still have the original writer. Ignore errors
         // and proceed with the write.
         let buf_len = buf.len();
         self.refresh_writer(date);
         self.writer.write_all(buf).map(|_| buf_len)
     }
 
-    fn refresh_writer(&mut self, now: DateTime<Utc>) {
+    fn refresh_writer(&mut self, now: OffsetDateTime) {
         if self.should_rollover(now) {
             let filename = self.rotation.join_date(&self.log_filename_prefix, &now);
 
@@ -75,8 +75,12 @@ impl InnerAppender {
         }
     }
 
-    fn should_rollover(&self, date: DateTime<Utc>) -> bool {
-        date >= self.next_date
+    fn should_rollover(&self, date: OffsetDateTime) -> bool {
+        // the `None` case means that the `InnerAppender` *never* rorates log files.
+        match self.next_date {
+            None => false,
+            Some(next_date) => date >= next_date,
+        }
     }
 }
 

tracing-appender/src/lib.rs

@@ -7,7 +7,7 @@
 //! a dedicated logging thread. It also provides a [`RollingFileAppender`][file_appender] that can
 //! be used with _or_ without the non-blocking writer.
 //!
-//! *Compiler support: [requires `rustc` 1.42+][msrv]*
+//! *Compiler support: [requires `rustc` 1.51+][msrv]*
 //!
 //! [msrv]: #supported-rust-versions
 //! [file_appender]: ./rolling/struct.RollingFileAppender.html
@@ -110,8 +110,8 @@
 //!
 //! ## Supported Rust Versions
 //!
-//! Tracing is built against the latest stable release. The minimum supported
-//! version is 1.42. The current Tracing version is not guaranteed to build on
+//! `tracing-appender` is built against the latest stable release. The minimum supported
+//! version is 1.51. The current `tracing-appender` 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