Auto merge of #3115 - Turbo87:tracing, r=pietroalbini

Replace `log` and `env_logger` with `tracing` crates

This brings us closer to being able to use structured logging and properly instrumenting some of functions. The change is mostly a drop-in replacement as described by https://docs.rs/tracing/0.1.22/tracing/#for-log-users.

The only difference is the slightly changed log output format:

```
# before
[2020-12-23T21:51:50Z INFO  cargo_registry::app] test23

# after
Dec 23 22:53:48.847  INFO cargo_registry::app: test23
```

This could be massaged by using a custom `FormatEvent` implementation though, if we really need this to be formatted in a specific way. Otherwise there is also a JSON-based output format which might be beneficial in production for real structured logging.

r? `@pietroalbini`

Author: bors

Cargo.lock

@@ -54,7 +54,6 @@ dialoguer = "0.7.1"
 diesel = { version = "1.4.0", features = ["postgres", "serde_json", "chrono", "r2d2"] }
 diesel_full_text_search = "1.0.0"
 dotenv = "0.15"
-env_logger = "0.8"
 failure = "0.1.1"
 flate2 = "1.0"
 futures-channel = { version = "0.3.1", default-features = false }
@@ -69,7 +68,6 @@ indexmap = "1.0.2"
 jemallocator = { version = "0.3", features = ['unprefixed_malloc_on_supported_platforms', 'profiling'] }
 lettre = { version = "0.10.0-alpha.1", default-features = false, features = ["file-transport", "smtp-transport", "native-tls", "hostname", "builder"] }
 license-exprs = "^1.4"
-log = "0.4"
 oauth2 = { version = "3.0.0", default-features = false, features = ["reqwest-010"] }
 parking_lot = "0.11"
 rand = "0.7"
@@ -85,6 +83,8 @@ tar = "0.4.16"
 tempfile = "3"
 tokio = { version = "0.2", default-features = false, features = ["net", "signal", "io-std"]}
 toml = "0.5"
+tracing = "0.1"
+tracing-subscriber = "0.2"
 url = "2.1"
 
 [dev-dependencies]

Cargo.toml

@@ -45,7 +45,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         });
 
     // Initialize logging
-    env_logger::init();
+    tracing_subscriber::fmt::init();
 
     let config = cargo_registry::Config::default();
     let client = Client::new();

src/bin/server.rs

@@ -15,11 +15,11 @@ extern crate derive_deref;
 #[macro_use]
 extern crate diesel;
 #[macro_use]
-extern crate log;
-#[macro_use]
 extern crate serde;
 #[macro_use]
 extern crate serde_json;
+#[macro_use]
+extern crate tracing;
 
 pub use crate::{app::App, config::Config, uploaders::Uploader};
 use std::sync::Arc;

src/lib.rs

@@ -7,11 +7,11 @@ extern crate diesel;
 #[macro_use]
 extern crate lazy_static;
 #[macro_use]
-extern crate log;
-#[macro_use]
 extern crate serde;
 #[macro_use]
 extern crate serde_json;
+#[macro_use]
+extern crate tracing;
 
 use crate::util::{RequestHelper, TestApp};
 use cargo_registry::{

src/tests/all.rs

@@ -48,9 +48,10 @@ use url::Url;
 pub use conduit::{header, StatusCode};
 
 pub fn init_logger() {
-    let _ = env_logger::builder()
-        .format_timestamp(None)
-        .is_test(true)
+    let _ = tracing_subscriber::fmt()
+        .with_env_filter(tracing_subscriber::EnvFilter::from_default_env())
+        .without_time()
+        .with_test_writer()
         .try_init();
 }