feat: Support Google structured logging format (#118)

Co-authored-by: tison <[email protected]>

Author: fiadliel

.github/workflows/ci.yml

@@ -84,6 +84,7 @@ jobs:
           cargo run --no-default-features --example simple_stdout
           cargo run --features="json" --example json_stdout
           cargo run --features="json,rolling-file" --example rolling_file
+          cargo run --features="fastrace/enable,google_structured_log" --example google_structured_log
           cargo run --features="fastrace/enable" --example fastrace
 
   required:

Cargo.lock

@@ -36,8 +36,9 @@ default = []
 
 colored = ["dep:colored"]
 fastrace = ["dep:fastrace"]
+google_structured_log = ["internal-serde", "dep:serde_json"]
 journald = ["dep:libc"]
-json = ["dep:serde_json", "dep:serde", "jiff/serde"]
+json = ["internal-serde", "dep:serde_json"]
 native-tls = ["dep:native-tls", "fasyslog?/native-tls"]
 non-blocking = ["dep:crossbeam-channel"]
 opentelemetry = [
@@ -48,6 +49,9 @@ opentelemetry = [
 rolling-file = ["non-blocking"]
 syslog = ["non-blocking", "dep:fasyslog"]
 
+# Internal features - not intended for directly public use
+internal-serde = ["dep:serde", "log/kv_serde", "jiff/serde"]
+
 [dependencies]
 anyhow = { version = "1.0" }
 env_filter = { version = "0.1.1" }
@@ -125,4 +129,10 @@ required-features = ["journald"]
 doc-scrape-examples = true
 name = "fastrace"
 path = "examples/fastrace.rs"
-required-features = ["fastrace", "fastrace/enable"]
+required-features = ["fastrace/enable"]
+
+[[example]]
+doc-scrape-examples = true
+name = "google_structured_log"
+path = "examples/google_structured_log.rs"
+required-features = ["fastrace/enable", "google_structured_log"]

Cargo.toml

@@ -0,0 +1,72 @@
+// Copyright 2024 FastLabs Developers
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use fastrace::collector::Config;
+use fastrace::collector::ConsoleReporter;
+use fastrace::collector::SpanContext;
+use fastrace::prelude::SpanId;
+use fastrace::prelude::TraceId;
+use fastrace::Span;
+use logforth::append;
+use logforth::diagnostic;
+use logforth::layout::GoogleStructuredLogLayout;
+use serde::Serialize;
+
+#[derive(Serialize)]
+struct NestedStructuredValue {
+    c: String,
+    d: bool,
+}
+
+#[derive(Serialize)]
+struct MyStructuredValue {
+    a: i32,
+    b: NestedStructuredValue,
+}
+
+fn main() {
+    logforth::builder()
+        .dispatch(|d| {
+            d.diagnostic(diagnostic::FastraceDiagnostic::default())
+                .append(
+                    append::Stdout::default().with_layout(
+                        GoogleStructuredLogLayout::default()
+                            .trace_project_id("project-id")
+                            .label_keys(["label1"]),
+                    ),
+                )
+        })
+        .apply();
+
+    fastrace::set_reporter(ConsoleReporter, Config::default());
+
+    {
+        let root = Span::root("root", SpanContext::new(TraceId::random(), SpanId(0)));
+        let _g = root.set_local_parent();
+
+        let structured_value = MyStructuredValue {
+            a: 1,
+            b: NestedStructuredValue {
+                c: "Hello".into(),
+                d: true,
+            },
+        };
+
+        log::info!(
+            label1 = "this is a label value",
+            notLabel:serde = structured_value;
+            "Hello label value!",
+        );
+    }
+}