added metrics library

.github/workflows/tests.yaml

@@ -86,4 +86,14 @@ jobs:
           toolchain: stable
       - name: Install Protoc
         uses: arduino/setup-protoc@v1     
-      - run: cargo build --features static-files
+      - run: cargo build --features static-files
+  build-with-metrics:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+      - name: Install Protoc
+        uses: arduino/setup-protoc@v1     
+      - run: cargo build --features metrics

Cargo.toml

@@ -8,5 +8,5 @@ members = [
     "my-http-server-signal-r-middleware",
     "static-files-middleware",
     "signal-r-macros",
-    "my-http-server-test",
+    "my-http-server-test", "my-http-metrics",
 ]

my-http-metrics/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "my-http-metrics"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+my-http-server-core = { path = "../my-http-server-core" }
+metrics = "*"
+tokio = { version = "*", features = ["full"] }
+async-trait = "*"
+stopwatch = "*"
+prometheus = "*"

my-http-metrics/src/lib.rs

@@ -0,0 +1,3 @@
+mod middleware;
+
+pub use middleware::*;

my-http-metrics/src/middleware/metrics_middleware.rs

@@ -0,0 +1,79 @@
+use async_trait::async_trait;
+use my_http_server_core::{
+    HttpContext, HttpFailResult, HttpOkResult, HttpOutput, HttpServerMiddleware,
+    HttpServerRequestFlow,
+};
+use stopwatch::Stopwatch;
+
+pub struct MetricsMiddleware;
+
+impl MetricsMiddleware {
+    pub fn new() -> Self {
+        Self {}
+    }
+}
+
+#[async_trait]
+impl HttpServerMiddleware for MetricsMiddleware {
+    async fn handle_request(
+        &self,
+        ctx: &mut HttpContext,
+        get_next: &mut HttpServerRequestFlow,
+    ) -> Result<HttpOkResult, HttpFailResult> {
+        let path = ctx.request.http_path.as_str().to_string();
+
+        if path == "/metrics" {
+            let report = prometheus::TextEncoder::new()
+                .encode_to_string(&prometheus::default_registry().gather());
+
+            match report {
+                Ok(report) => {
+                    let response = HttpOutput::as_text(report).into_ok_result(false);
+                    return response;
+                }
+                Err(err) => {
+                    let response =
+                        HttpOutput::as_text(err.to_string()).into_fail_result(502, false);
+                    return response;
+                }
+            }
+        }
+
+        let mut sw = Stopwatch::start_new();
+        let result = get_next.next(ctx).await;
+        sw.stop();
+
+        let duration = sw.elapsed();
+        let method = ctx.request.method.as_str().to_string();
+        let path = ctx.request.http_path.as_str().to_string();
+        let common_labels = &[("method", method.clone()), ("path", path.clone())];
+
+        let mut has_to_write_metrics = false;
+
+        if let Err(result) = &result {
+            if result.status_code == 404 {
+                has_to_write_metrics = true
+            } else {
+                let failed_labels = &[
+                    ("method", method.clone()),
+                    ("path", path.clone()),
+                    ("status_code", result.status_code.to_string()),
+                ];
+
+                metrics::counter!("failed_request_count", failed_labels).increment(1);
+                metrics::counter!("failed_request_duration_sum", failed_labels).increment(duration.as_millis() as u64);
+                metrics::histogram!("failed_request_duration_nanos", failed_labels).record(duration.as_millis() as f64);
+            }
+        }
+
+        if has_to_write_metrics {
+            return result;
+        }
+
+        metrics::histogram!("request_duration_nanos", common_labels).record(duration.as_millis() as f64);
+        metrics::counter!("request_duration_sum", common_labels).increment(duration.as_millis() as u64);
+        metrics::counter!("request_count", common_labels).increment(1);
+
+        return result;
+    }
+}

my-http-metrics/src/middleware/mod.rs

@@ -0,0 +1,3 @@
+mod metrics_middleware;
+
+pub use metrics_middleware::*;

my-http-server-core/src/http_fail_result.rs

@@ -66,7 +66,7 @@ impl HttpFailResult {
     pub fn as_not_found(text: String, write_telemetry: bool) -> Self {
         Self::new(
             WebContentType::Text,
-            400,
+            404,
             text.into_bytes(),
             write_telemetry,
             false,

my-http-server/Cargo.toml

@@ -14,6 +14,7 @@ full = [
     "signal-r",
     "with-telemetry",
     "static-files",
+    "metrics",
 ]
 controllers = ["my-http-server-controllers"]
 macros = ["my-http-server-macros", "my-http-server-controllers"]
@@ -25,6 +26,7 @@ with-telemetry = [
 ]
 
 static-files = ["static-files-middleware"]
+metrics = ["my-http-metrics"]
 
 
 [dependencies]
@@ -35,3 +37,4 @@ my-http-server-controllers = { optional = true, path = "../my-http-server-contro
 my-http-server-core = { path = "../my-http-server-core" }
 signal-r-macros = { optional = true, path = "../signal-r-macros" }
 static-files-middleware = { path = "../static-files-middleware", optional = true }
+my-http-metrics = { path = "../my-http-metrics", optional = true }

my-http-server/src/lib.rs

@@ -18,3 +18,6 @@ pub mod signal_r {
 pub use static_files_middleware::*;
 
 pub use my_http_server_core::*;
+
+#[cfg(feature = "metrics")]
+pub use my_http_metrics as metrics;