chore: update Rust toolchain to 1.52.1 (#1005)

This branch updates the Rust toolchain to 1.52.1. This includes a [major
bugfix][1] for an issue effecting incremental compilation. Additionally,
Rust 1.51 enabled the `resolver = "2"` feature in Cargo.toml, which can
be used to fix the feature flagging issues with tracing in a more
principled way than the current solution.

A *very* large amount of new lints were added since Rust 1.49.0; in
particular:

* clippy now warns when an `Into` impl could be a `From` impl, because
  `From` impls provide `Into` impls for free, but the reverse is not
  the case
* panic messages must now *always* be `format_args!`
* exact comparisons of floating-point numbers (rather than within an
  error margin) now produce a warning

This branch also fixes all the new warnings.

[1]: https://blog.rust-lang.org/2021/05/10/Rust-1.52.1.html

Signed-off-by: Eliza Weisman <eliza@buoyant.io>

Author: hawkw

.github/actions/package/Dockerfile

@@ -1,4 +1,4 @@
-ARG BASE_IMAGE=rust:1.49.0-buster
+ARG BASE_IMAGE=rust:1.52.1-buster
 FROM $BASE_IMAGE
 WORKDIR /linkerd
 RUN apt-get update && \

.github/workflows/rust.yml

@@ -11,7 +11,7 @@ jobs:
     timeout-minutes: 5
     runs-on: ubuntu-latest
     container:
-      image: docker://rust:1.49.0-buster
+      image: docker://rust:1.52.1-buster
     steps:
       - uses: actions/checkout@v2
       - run: rustup component add rustfmt
@@ -37,7 +37,7 @@ jobs:
     timeout-minutes: 5
     runs-on: ubuntu-latest
     container:
-      image: docker://rust:1.49.0-buster
+      image: docker://rust:1.52.1-buster
     steps:
       - uses: actions/checkout@v2
       - run: rustup component add clippy
@@ -47,7 +47,7 @@ jobs:
     timeout-minutes: 20
     runs-on: ubuntu-latest
     container:
-      image: docker://rust:1.49.0-buster
+      image: docker://rust:1.52.1-buster
     steps:
       - uses: actions/checkout@v2
       # Iterate through all subcrates to ensure each compiles indpendently.
@@ -57,7 +57,7 @@ jobs:
     timeout-minutes: 40
     runs-on: ubuntu-latest
     container:
-      image: docker://rust:1.49.0-buster
+      image: docker://rust:1.52.1-buster
     steps:
       - uses: actions/checkout@v2
       - run: rustup toolchain add nightly

Dockerfile

@@ -17,7 +17,7 @@
 #     :; docker buildx build . --load
 
 # Please make changes via update-rust-version.sh
-ARG RUST_IMAGE=rust:1.49.0-buster
+ARG RUST_IMAGE=rust:1.52.1-buster
 
 # Use an arbitrary ~recent edge release image to get the proxy
 # identity-initializing and linkerd-await wrappers.
@@ -41,7 +41,7 @@ RUN --mount=type=cache,target=/var/lib/apt/lists \
 WORKDIR /usr/src/linkerd2-proxy
 COPY . .
 RUN --mount=type=cache,target=target \
-  --mount=type=cache,from=rust:1.49.0-buster,source=/usr/local/cargo,target=/usr/local/cargo \
+  --mount=type=cache,from=rust:1.52.1-buster,source=/usr/local/cargo,target=/usr/local/cargo \
   mkdir -p /out && \
   if [ -n "$PROXY_UNOPTIMIZED" ]; then \
   (cd linkerd2-proxy && /usr/bin/time -v cargo build --locked --features="$PROXY_FEATURES") && \

hyper-balance/src/lib.rs

@@ -1,4 +1,5 @@
 #![deny(warnings, rust_2018_idioms)]
+#![allow(clippy::inconsistent_struct_constructor)]
 
 use hyper::body::HttpBody;
 use pin_project::pin_project;

linkerd/addr/src/lib.rs

@@ -1,4 +1,5 @@
 #![deny(warnings, rust_2018_idioms)]
+#![allow(clippy::inconsistent_struct_constructor)]
 use linkerd_dns_name::Name;
 use std::{
     fmt,

linkerd/app/core/src/addr_match.rs

@@ -68,15 +68,15 @@ impl From<NameMatch> for AddrMatch {
     }
 }
 
-impl Into<IpMatch> for AddrMatch {
-    fn into(self) -> IpMatch {
-        self.nets
+impl From<AddrMatch> for IpMatch {
+    fn from(addrs: AddrMatch) -> Self {
+        addrs.nets
     }
 }
 
-impl Into<NameMatch> for AddrMatch {
-    fn into(self) -> NameMatch {
-        self.names
+impl From<AddrMatch> for NameMatch {
+    fn from(addrs: AddrMatch) -> Self {
+        addrs.names
     }
 }
 

linkerd/app/core/src/classify.rs

@@ -215,10 +215,12 @@ fn h2_error(err: &Error) -> String {
 
 impl Class {
     pub(super) fn is_failure(&self) -> bool {
-        matches!(self,
+        matches!(
+            self,
             Class::Default(SuccessOrFailure::Failure)
-            | Class::Grpc(SuccessOrFailure::Failure, _)
-            | Class::Stream(SuccessOrFailure::Failure, _))
+                | Class::Grpc(SuccessOrFailure::Failure, _)
+                | Class::Stream(SuccessOrFailure::Failure, _)
+        )
     }
 }
 

linkerd/app/core/src/lib.rs

@@ -8,6 +8,7 @@
 //! - Metric labeling
 
 #![deny(warnings, rust_2018_idioms)]
+#![allow(clippy::inconsistent_struct_constructor)]
 
 pub use linkerd_addr::{self as addr, Addr, NameAddr};
 pub use linkerd_cache as cache;

linkerd/app/gateway/src/lib.rs

@@ -1,4 +1,5 @@
 #![deny(warnings, rust_2018_idioms)]
+#![allow(clippy::inconsistent_struct_constructor)]
 
 mod gateway;
 #[cfg(test)]

linkerd/app/inbound/src/direct.rs

@@ -247,8 +247,8 @@ impl svc::Param<tls::LocalId> for WithTransportHeaderAlpn {
 
 // === impl RefusedNoHeader ===
 
-impl Into<Error> for RefusedNoHeader {
-    fn into(self) -> Error {
+impl From<RefusedNoHeader> for Error {
+    fn from(_: RefusedNoHeader) -> Error {
         Error::from(io::Error::new(
             io::ErrorKind::ConnectionRefused,
             "Non-transport-header connection refused",