Also listen for http requests and serve metrics

Use axum to listen for http requests to respond with the metrics.

Cargo.lock

@@ -38,6 +38,17 @@ version = "1.0.57"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08f9b8508dccb7687a1d6c4ce66b2b0ecef467c94667de27d8d7fe1f8d2a9cdc"
 
+[[package]]
+name = "async-trait"
+version = "0.1.53"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed6aa3524a2dfcf9fe180c51eae2b58738348d819517ceadf95789c51fff7600"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "atty"
 version = "0.2.14"
@@ -55,12 +66,63 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
+[[package]]
+name = "axum"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f523b4e98ba6897ae90994bc18423d9877c54f9047b06a00ddc8122a957b1c70"
+dependencies = [
+ "async-trait",
+ "axum-core",
+ "bitflags",
+ "bytes",
+ "futures-util",
+ "http",
+ "http-body",
+ "hyper",
+ "itoa",
+ "matchit",
+ "memchr",
+ "mime",
+ "percent-encoding",
+ "pin-project-lite",
+ "serde",
+ "serde_json",
+ "serde_urlencoded",
+ "sync_wrapper",
+ "tokio",
+ "tower",
+ "tower-http",
+ "tower-layer",
+ "tower-service",
+]
+
+[[package]]
+name = "axum-core"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3ddbd16eabff8b45f21b98671fddcc93daaa7ac4c84f8473693437226040de5"
+dependencies = [
+ "async-trait",
+ "bytes",
+ "futures-util",
+ "http",
+ "http-body",
+ "mime",
+]
+
 [[package]]
 name = "bitflags"
 version = "1.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
+[[package]]
+name = "bytes"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4872d67bab6358e59559027aa3b9157c53d9358c51423c17554809a8858e0f8"
+
 [[package]]
 name = "cc"
 version = "1.0.73"
@@ -86,6 +148,61 @@ dependencies = [
  "termcolor",
 ]
 
+[[package]]
+name = "fnv"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
+
+[[package]]
+name = "form_urlencoded"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5fc25a87fa4fd2094bffb06925852034d90a17f0d1e05197d4956d3555752191"
+dependencies = [
+ "matches",
+ "percent-encoding",
+]
+
+[[package]]
+name = "futures-channel"
+version = "0.3.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3083ce4b914124575708913bca19bfe887522d6e2e6d0952943f5eac4a74010"
+dependencies = [
+ "futures-core",
+]
+
+[[package]]
+name = "futures-core"
+version = "0.3.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c09fd04b7e4073ac7156a9539b57a484a8ea920f79c7c675d05d289ab6110d3"
+
+[[package]]
+name = "futures-sink"
+version = "0.3.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "21163e139fa306126e6eedaf49ecdb4588f939600f0b1e770f4205ee4b7fa868"
+
+[[package]]
+name = "futures-task"
+version = "0.3.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57c66a976bf5909d801bbef33416c41372779507e7a6b3a5e25e4749c58f776a"
+
+[[package]]
+name = "futures-util"
+version = "0.3.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8b7abd5d659d9b90c8cba917f6ec750a74e2dc23902ef9cd4cc8c8b22e6036a"
+dependencies = [
+ "futures-core",
+ "futures-task",
+ "pin-project-lite",
+ "pin-utils",
+]
+
 [[package]]
 name = "hermit-abi"
 version = "0.1.19"
@@ -95,12 +212,87 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "http"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "31f4c6746584866f0feabcc69893c5b51beef3831656a968ed7ae254cdc4fd03"
+dependencies = [
+ "bytes",
+ "fnv",
+ "itoa",
+]
+
+[[package]]
+name = "http-body"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ff4f84919677303da5f147645dbea6b1881f368d03ac84e1dc09031ebd7b2c6"
+dependencies = [
+ "bytes",
+ "http",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "http-range-header"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0bfe8eed0a9285ef776bb792479ea3834e8b94e13d615c2f66d03dd50a435a29"
+
+[[package]]
+name = "httparse"
+version = "1.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6330e8a36bd8c859f3fa6d9382911fbb7147ec39807f63b923933a247240b9ba"
+
+[[package]]
+name = "httpdate"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4a1e36c821dbe04574f602848a19f742f4fb3c98d40449f11bcad18d6b17421"
+
 [[package]]
 name = "humantime"
 version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
 
+[[package]]
+name = "hyper"
+version = "0.14.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b26ae0a80afebe130861d90abf98e3814a4f28a4c6ffeb5ab8ebb2be311e0ef2"
+dependencies = [
+ "bytes",
+ "futures-channel",
+ "futures-core",
+ "futures-util",
+ "http",
+ "http-body",
+ "httparse",
+ "httpdate",
+ "itoa",
+ "pin-project-lite",
+ "socket2",
+ "tokio",
+ "tower-service",
+ "tracing",
+ "want",
+]
+
+[[package]]
+name = "itoa"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1aab8fc367588b89dcee83ab0fd66b72b50b72fa1904d7095045ace2b0c81c35"
+
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+
 [[package]]
 name = "libc"
 version = "0.2.124"
@@ -154,6 +346,18 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "matches"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a3e378b66a060d48947b590737b30a1be76706c8dd7b8ba0f2fe3989c68a853f"
+
+[[package]]
+name = "matchit"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73cbba799671b762df5a175adf59ce145165747bb891505c43d09aefbbf38beb"
+
 [[package]]
 name = "memchr"
 version = "2.4.1"
@@ -174,12 +378,42 @@ name = "mightyohm-gc-exporter"
 version = "0.1.0-dev"
 dependencies = [
  "anyhow",
+ "axum",
  "env_logger",
  "log",
  "serialport",
  "tokio",
 ]
 
+[[package]]
+name = "mime"
+version = "0.3.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a60c7ce501c71e03a9c9c0d35b861413ae925bd979cc7a4e30d060069aaac8d"
+
+[[package]]
+name = "mio"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "52da4364ffb0e4fe33a9841a98a3f3014fb964045ce4f7a45a398243c8d6b0c9"
+dependencies = [
+ "libc",
+ "log",
+ "miow",
+ "ntapi",
+ "wasi",
+ "winapi",
+]
+
+[[package]]
+name = "miow"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9f1c5b025cda876f66ef43a113f91ebc9f4ccef34843000e0adf6ebbab84e21"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "nix"
 version = "0.23.1"
@@ -193,6 +427,15 @@ dependencies = [
  "memoffset",
 ]
 
+[[package]]
+name = "ntapi"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c28774a7fd2fbb4f0babd8237ce554b73af68021b5f695a3cebd6c59bac0980f"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "num_cpus"
 version = "1.13.1"
@@ -203,12 +446,44 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "percent-encoding"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d4fd5641d01c8f18a23da7b6fe29298ff4b55afcccdf78973b24cf3175fee32e"
+
+[[package]]
+name = "pin-project"
+version = "1.0.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "58ad3879ad3baf4e44784bc6a718a8698867bb991f8ce24d1bcbe2cfb4c3a75e"
+dependencies = [
+ "pin-project-internal",
+]
+
+[[package]]
+name = "pin-project-internal"
+version = "1.0.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "744b6f092ba29c3650faf274db506afd39944f48420f6c86b17cfe0ee1cb36bb"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "pin-project-lite"
 version = "0.2.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e280fbe77cc62c91527259e9442153f4688736748d24660126286329742b4c6c"
 
+[[package]]
+name = "pin-utils"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
+
 [[package]]
 name = "pkg-config"
 version = "0.3.25"
@@ -250,6 +525,41 @@ version = "0.6.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
 
+[[package]]
+name = "ryu"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73b4b750c782965c211b42f022f59af1fbceabdd026623714f104152f1ec149f"
+
+[[package]]
+name = "serde"
+version = "1.0.136"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ce31e24b01e1e524df96f1c2fdd054405f8d7376249a5110886fb4b658484789"
+
+[[package]]
+name = "serde_json"
+version = "1.0.79"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e8d9fa5c3b304765ce1fd9c4c8a3de2c8db365a5b91be52f186efc675681d95"
+dependencies = [
+ "itoa",
+ "ryu",
+ "serde",
+]
+
+[[package]]
+name = "serde_urlencoded"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3491c14715ca2294c4d6a88f15e84739788c1d030eed8c110436aafdaa2f3fd"
+dependencies = [
+ "form_urlencoded",
+ "itoa",
+ "ryu",
+ "serde",
+]
+
 [[package]]
 name = "serialport"
 version = "4.1.0"
@@ -267,6 +577,16 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "socket2"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "66d72b759436ae32898a2af0a14218dbf55efde3feeb170eb623637db85ee1e0"
+dependencies = [
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "syn"
 version = "1.0.91"
@@ -278,6 +598,12 @@ dependencies = [
  "unicode-xid",
 ]
 
+[[package]]
+name = "sync_wrapper"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "20518fe4a4c9acf048008599e464deb21beeae3d3578418951a189c235a7a9a8"
+
 [[package]]
 name = "termcolor"
 version = "1.1.3"
@@ -293,9 +619,13 @@ version = "1.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2af73ac49756f3f7c01172e34a23e5d0216f6c32333757c2c61feb2bbff5a5ee"
 dependencies = [
+ "libc",
+ "mio",
  "num_cpus",
  "pin-project-lite",
+ "socket2",
  "tokio-macros",
+ "winapi",
 ]
 
 [[package]]
@@ -309,12 +639,116 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "tokio-util"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0edfdeb067411dba2044da6d1cb2df793dd35add7888d73c16e3381ded401764"
+dependencies = [
+ "bytes",
+ "futures-core",
+ "futures-sink",
+ "pin-project-lite",
+ "tokio",
+]
+
+[[package]]
+name = "tower"
+version = "0.4.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a89fd63ad6adf737582df5db40d286574513c69a11dac5214dc3b5603d6713e"
+dependencies = [
+ "futures-core",
+ "futures-util",
+ "pin-project",
+ "pin-project-lite",
+ "tokio",
+ "tokio-util",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
+[[package]]
+name = "tower-http"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aba3f3efabf7fb41fae8534fc20a817013dd1c12cb45441efb6c82e6556b4cd8"
+dependencies = [
+ "bitflags",
+ "bytes",
+ "futures-core",
+ "futures-util",
+ "http",
+ "http-body",
+ "http-range-header",
+ "pin-project-lite",
+ "tower",
+ "tower-layer",
+ "tower-service",
+]
+
+[[package]]
+name = "tower-layer"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "343bc9466d3fe6b0f960ef45960509f84480bf4fd96f92901afe7ff3df9d3a62"
+
+[[package]]
+name = "tower-service"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "360dfd1d6d30e05fda32ace2c8c70e9c0a9da713275777f5a4dbb8a1893930c6"
+
+[[package]]
+name = "tracing"
+version = "0.1.34"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d0ecdcb44a79f0fe9844f0c4f33a342cbcbb5117de8001e6ba0dc2351327d09"
+dependencies = [
+ "cfg-if",
+ "log",
+ "pin-project-lite",
+ "tracing-core",
+]
+
+[[package]]
+name = "tracing-core"
+version = "0.1.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f54c8ca710e81886d498c2fd3331b56c93aa248d49de2222ad2742247c60072f"
+dependencies = [
+ "lazy_static",
+]
+
+[[package]]
+name = "try-lock"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59547bce71d9c38b83d9c0e92b6066c4253371f15005def0c30d9657f50c7642"
+
 [[package]]
 name = "unicode-xid"
 version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
 
+[[package]]
+name = "want"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ce8a968cb1cd110d136ff8b819a556d6fb6d919363c61534f6860c7eb172ba0"
+dependencies = [
+ "log",
+ "try-lock",
+]
+
+[[package]]
+name = "wasi"
+version = "0.11.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
+
 [[package]]
 name = "winapi"
 version = "0.3.9"

Cargo.toml

@@ -14,3 +14,4 @@ serialport = "4.1"
 log = "0.4"
 env_logger = "0.9"
 tokio = { version = "1.17", features = ["rt-multi-thread", "macros"] }
+axum = "0.5"

src/main.rs

@@ -1,7 +1,9 @@
 use anyhow::{bail, Error, Result};
-use log::{debug, trace};
+use axum::{extract::Extension, routing::get, Router, Server};
+use log::{debug, info, trace};
 use std::{
     io::{BufRead, BufReader},
+    net::SocketAddr,
     str::FromStr,
     sync::{
         atomic::{AtomicU32, AtomicUsize, Ordering},
@@ -21,6 +23,11 @@ impl AtomicF32 {
         let as_u32 = value.to_bits();
         self.storage.store(as_u32, ordering);
     }
+
+    fn load(&self, ordering: Ordering) -> f32 {
+        let as_u32 = self.storage.load(ordering);
+        f32::from_bits(as_u32)
+    }
 }
 
 #[derive(Debug)]
@@ -99,6 +106,39 @@ async fn listen_serial(metrics: Arc<Metrics>) -> Result<()> {
     }
 }
 
+#[allow(clippy::unused_async)]
+async fn get_metrics(Extension(metrics): Extension<Arc<Metrics>>) -> String {
+    format!(
+        r"# HELP mightyohm_gc_cps Counts per second.
+# TYPE mightyohm_gc_cps gauge
+mightyohm_gc_cps {}
+# HELP mightyohm_gc_cpm Counts per minute.
+# TYPE mightyohm_gc_cpm gauge
+mightyohm_gc_cpm {}
+# HELP mightyohm_gc_radiation Ionizing Radiation in μSv/h.
+# TYPE mightyohm_gc_radiation gauge
+mightyohm_gc_radiation {}
+# HELP mightyohm_gc_mode Data acquisition mode (0 = Slow, 1 = Fast, 2 = Inst).
+# TYPE mightyohm_gc_mode gauge
+mightyohm_gc_mode {}
+",
+        metrics.cps.load(Ordering::Relaxed),
+        metrics.cpm.load(Ordering::Relaxed),
+        metrics.radiation.load(Ordering::Relaxed),
+        metrics.mode.load(Ordering::Relaxed)
+    )
+}
+
+async fn listen_http(metrics: Arc<Metrics>) -> Result<()> {
+    let app = Router::new()
+        .route("/metrics", get(get_metrics))
+        .layer(Extension(metrics));
+    let addr = SocketAddr::from(([0, 0, 0, 0], 9111));
+    info!("Listening on 0.0.0.0:9111");
+
+    Ok(Server::bind(&addr).serve(app.into_make_service()).await?)
+}
+
 async fn flatten<T>(handle: JoinHandle<Result<T>>) -> Result<T>
 where
     T: Send,
@@ -115,7 +155,10 @@ async fn main() -> Result<()> {
     env_logger::init();
     let metrics = Arc::new(Metrics::default());
 
-    try_join!(flatten(spawn(listen_serial(Arc::clone(&metrics)))))?;
+    try_join!(
+        flatten(spawn(listen_serial(Arc::clone(&metrics)))),
+        flatten(spawn(listen_http(Arc::clone(&metrics))))
+    )?;
 
     Ok(())
 }