tracing: just control ansi colors with feature flags (#1006)

Now that we have updated the proxy to Rust 1.52.1, we can use the
`resolver = "2"` cargo feature, which results in feature flags enabled
by dev-dependencies *not* enable features in the main build. This lets us
toggle ANSI colors on and off using a dev-dependency without them being
enabled in the primary release build.

Furthermore, all tracing initialization for tests is now instrumented via the
`linkerd-tracing` so that it can be more easily reused.

Closes #997

Author: hawkw

Cargo.lock

@@ -125,18 +125,6 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
-[[package]]
-name = "chrono"
-version = "0.4.19"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "670ad68c9088c2a963aaa298cb369688cf3f9465ce5e2d4ca10e6e0098a1ce73"
-dependencies = [
- "libc",
- "num-integer",
- "num-traits",
- "winapi",
-]
-
 [[package]]
 name = "cmake"
 version = "0.1.45"
@@ -744,12 +732,12 @@ dependencies = [
  "linkerd-app-core",
  "linkerd-app-test",
  "linkerd-io",
+ "linkerd-tracing",
  "thiserror",
  "tokio",
  "tokio-test",
  "tower",
  "tracing",
- "tracing-subscriber",
 ]
 
 [[package]]
@@ -767,6 +755,7 @@ dependencies = [
  "linkerd-app-core",
  "linkerd-app-test",
  "linkerd-metrics",
+ "linkerd-tracing",
  "linkerd2-proxy-api",
  "regex",
  "rustls",
@@ -796,13 +785,13 @@ dependencies = [
  "linkerd-identity",
  "linkerd-io",
  "linkerd-retry",
+ "linkerd-tracing",
  "pin-project",
  "thiserror",
  "tokio",
  "tokio-test",
  "tower",
  "tracing",
- "tracing-subscriber",
 ]
 
 [[package]]
@@ -834,11 +823,11 @@ dependencies = [
  "futures",
  "linkerd-error",
  "linkerd-stack",
+ "linkerd-tracing",
  "parking_lot",
  "tokio",
  "tower",
  "tracing",
- "tracing-subscriber",
 ]
 
 [[package]]
@@ -1154,14 +1143,14 @@ dependencies = [
  "linkerd-proxy-transport",
  "linkerd-stack",
  "linkerd-timeout",
+ "linkerd-tracing",
  "pin-project",
  "rand",
  "thiserror",
  "tokio",
  "tokio-test",
  "tower",
  "tracing",
- "tracing-subscriber",
  "try-lock",
 ]
 
@@ -1324,13 +1313,13 @@ dependencies = [
  "dyn-clone",
  "futures",
  "linkerd-error",
+ "linkerd-tracing",
  "pin-project",
  "tokio",
  "tokio-test",
  "tower",
  "tower-test",
  "tracing",
- "tracing-subscriber",
 ]
 
 [[package]]
@@ -1385,13 +1374,13 @@ dependencies = [
  "linkerd-io",
  "linkerd-proxy-transport",
  "linkerd-stack",
+ "linkerd-tracing",
  "rustls",
  "thiserror",
  "tokio",
  "tokio-rustls",
  "tower",
  "tracing",
- "tracing-subscriber",
  "untrusted",
  "webpki",
 ]
@@ -1595,16 +1584,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "num-integer"
-version = "0.1.44"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d2cc698a63b549a70bc047073d2949cce27cd1c7b0a4a862d08a8031bc2801db"
-dependencies = [
- "autocfg",
- "num-traits",
-]
-
 [[package]]
 name = "num-traits"
 version = "0.2.14"
@@ -2373,12 +2352,11 @@ dependencies = [
 
 [[package]]
 name = "tracing-subscriber"
-version = "0.2.16"
+version = "0.2.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ab8966ac3ca27126141f7999361cc97dd6fb4b71da04c02044fa9045d98bb96"
+checksum = "705096c6f83bf68ea5d357a6aa01829ddbdac531b357b45abeca842938085baa"
 dependencies = [
  "ansi_term",
- "chrono",
  "lazy_static",
  "matchers",
  "parking_lot",

Cargo.toml

@@ -1,4 +1,8 @@
 [workspace]
+# Cargo should not unify feature flags across dev-dependencies and build
+# dependencies. This will be the default behavior in Rust 2021.
+resolver = "2"
+
 members = [
     "hyper-balance",
     "linkerd/addr",