From 5e24bb06a7a3c331ec0f19d676a6cb7cb95a788a Mon Sep 17 00:00:00 2001
From: "Aode (lion)" <asonix@asonix.dog>
Date: Sat, 18 Sep 2021 13:40:47 -0500
Subject: [PATCH] Support exporting metrics to Opentelemetry

---
 .env          |   1 +
 Cargo.lock    | 414 ++++++++++++++++++++++++++++++++++++++++++++++++++
 Cargo.toml    |   3 +
 src/config.rs |   8 +
 src/main.rs   |  21 ++-
 5 files changed, 445 insertions(+), 2 deletions(-)

diff --git a/.env b/.env
index 6535b40..c007da1 100644
--- a/.env
+++ b/.env
@@ -1,3 +1,4 @@
 HOSTNAME=localhost:8079
 PORT=8079
 RESTRICTED_MODE=true
+# OPENTELEMETRY_URL=http://localhost:4317
diff --git a/Cargo.lock b/Cargo.lock
index b8521ae..e13f51c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -326,6 +326,27 @@ dependencies = [
  "event-listener",
 ]
 
+[[package]]
+name = "async-stream"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "171374e7e3b2504e0e5236e3b59260560f9fe94bfe9ac39ba5e4e929c5590625"
+dependencies = [
+ "async-stream-impl",
+ "futures-core",
+]
+
+[[package]]
+name = "async-stream-impl"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "648ed8c8d2ce5409ccd57453d9d1b214b342a0d69376a6feda1fd6cae3299308"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "async-trait"
 version = "0.1.51"
@@ -607,6 +628,16 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "crossbeam-channel"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06ed27e177f16d65f0f0c22a213e17c696ace5dd64b14258b52f9417ccb52db4"
+dependencies = [
+ "cfg-if",
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "crossbeam-epoch"
 version = "0.9.5"
@@ -712,6 +743,12 @@ version = "0.4.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "31586bda1b136406162e381a3185a506cdfc1631708dd40cba2f6628d8634499"
 
+[[package]]
+name = "fixedbitset"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37ab347416e802de484e4d03c7316c48f1ecb56574dfd4a46a80f173ce1de04d"
+
 [[package]]
 name = "fnv"
 version = "1.0.7"
@@ -754,12 +791,54 @@ dependencies = [
  "new_debug_unreachable",
 ]
 
+[[package]]
+name = "futures"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a12aa0eb539080d55c3f2d45a67c3b58b6b0773c1a3ca2dfec66d58c97fd66ca"
+dependencies = [
+ "futures-channel",
+ "futures-core",
+ "futures-executor",
+ "futures-io",
+ "futures-sink",
+ "futures-task",
+ "futures-util",
+]
+
+[[package]]
+name = "futures-channel"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5da6ba8c3bb3c165d3c7319fc1cc8304facf1fb8db99c5de877183c08a273888"
+dependencies = [
+ "futures-core",
+ "futures-sink",
+]
+
 [[package]]
 name = "futures-core"
 version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "88d1c26957f23603395cd326b0ffe64124b818f4449552f960d815cfba83a53d"
 
+[[package]]
+name = "futures-executor"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "45025be030969d763025784f7f355043dc6bc74093e4ecc5000ca4dc50d8745c"
+dependencies = [
+ "futures-core",
+ "futures-task",
+ "futures-util",
+]
+
+[[package]]
+name = "futures-io"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "522de2a0fe3e380f1bc577ba0474108faf3f6b18321dbf60b3b9c39a75073377"
+
 [[package]]
 name = "futures-macro"
 version = "0.3.17"
@@ -792,10 +871,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "36568465210a3a6ee45e1f165136d68671471a501e632e9a98d96872222b5481"
 dependencies = [
  "autocfg 1.0.1",
+ "futures-channel",
  "futures-core",
+ "futures-io",
  "futures-macro",
  "futures-sink",
  "futures-task",
+ "memchr",
  "pin-project-lite",
  "pin-utils",
  "proc-macro-hack",
@@ -915,6 +997,17 @@ dependencies = [
  "itoa",
 ]
 
+[[package]]
+name = "http-body"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "399c583b2979440c60be0821a6199eca73bc3c8dcd9d070d75ac726e2c6186e5"
+dependencies = [
+ "bytes",
+ "http",
+ "pin-project-lite",
+]
+
 [[package]]
 name = "http-signature-normalization"
 version = "0.5.4"
@@ -949,6 +1042,48 @@ version = "1.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "acd94fdbe1d4ff688b67b04eee2e17bd50995534a61539e45adfefb45e5e5503"
 
+[[package]]
+name = "httpdate"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6456b8a6c8f33fee7d958fcd1b60d55b11940a79e63ae87013e6d22e26034440"
+
+[[package]]
+name = "hyper"
+version = "0.14.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "15d1cfb9e4f68655fa04c01f59edb405b6074a0f7118ea881e5026e4a1cd8593"
+dependencies = [
+ "bytes",
+ "futures-channel",
+ "futures-core",
+ "futures-util",
+ "h2",
+ "http",
+ "http-body",
+ "httparse",
+ "httpdate",
+ "itoa",
+ "pin-project-lite",
+ "socket2",
+ "tokio",
+ "tower-service",
+ "tracing",
+ "want",
+]
+
+[[package]]
+name = "hyper-timeout"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbb958482e8c7be4bc3cf272a766a2b0bf1a6755e7a6ae777f017a31d11b13b1"
+dependencies = [
+ "hyper",
+ "pin-project-lite",
+ "tokio",
+ "tokio-io-timeout",
+]
+
 [[package]]
 name = "idna"
 version = "0.2.3"
@@ -1196,6 +1331,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "multimap"
+version = "0.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5ce46fe64a9d73be07dcbe690a38ce1b293be448fd8ce1e6c1b8062c9f72c6a"
+
 [[package]]
 name = "new_debug_unreachable"
 version = "1.0.4"
@@ -1349,6 +1490,42 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "624a8340c38c1b80fd549087862da4ba43e08858af025b236e509b6649fc13d5"
 
+[[package]]
+name = "opentelemetry"
+version = "0.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e1cf9b1c4e9a6c4de793c632496fa490bdc0e1eea73f0c91394f7b6990935d22"
+dependencies = [
+ "async-trait",
+ "crossbeam-channel",
+ "futures",
+ "js-sys",
+ "lazy_static",
+ "percent-encoding",
+ "pin-project",
+ "rand 0.8.4",
+ "thiserror",
+ "tokio",
+ "tokio-stream",
+]
+
+[[package]]
+name = "opentelemetry-otlp"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f19d4b43842433c420c548c985d158f5628bba5b518e0be64627926d19889992"
+dependencies = [
+ "async-trait",
+ "futures",
+ "http",
+ "opentelemetry",
+ "prost",
+ "thiserror",
+ "tokio",
+ "tonic",
+ "tonic-build",
+]
+
 [[package]]
 name = "parking_lot"
 version = "0.11.2"
@@ -1404,6 +1581,16 @@ dependencies = [
  "ucd-trie",
 ]
 
+[[package]]
+name = "petgraph"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "467d164a6de56270bd7c4d070df81d07beace25012d5103ced4e9ff08d6afdb7"
+dependencies = [
+ "fixedbitset",
+ "indexmap",
+]
+
 [[package]]
 name = "phf"
 version = "0.8.0"
@@ -1555,6 +1742,57 @@ dependencies = [
  "unicode-xid",
 ]
 
+[[package]]
+name = "prost"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "de5e2533f59d08fcf364fd374ebda0692a70bd6d7e66ef97f306f45c6c5d8020"
+dependencies = [
+ "bytes",
+ "prost-derive",
+]
+
+[[package]]
+name = "prost-build"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "355f634b43cdd80724ee7848f95770e7e70eefa6dcf14fea676216573b8fd603"
+dependencies = [
+ "bytes",
+ "heck",
+ "itertools",
+ "log",
+ "multimap",
+ "petgraph",
+ "prost",
+ "prost-types",
+ "tempfile",
+ "which",
+]
+
+[[package]]
+name = "prost-derive"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "600d2f334aa05acb02a755e217ef1ab6dea4d51b58b7846588b747edec04efba"
+dependencies = [
+ "anyhow",
+ "itertools",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "prost-types"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "603bbd6394701d13f3f25aada59c7de9d35a6a5887cfc156181234a44002771b"
+dependencies = [
+ "bytes",
+ "prost",
+]
+
 [[package]]
 name = "quote"
 version = "1.0.9"
@@ -1719,6 +1957,8 @@ dependencies = [
  "http-signature-normalization-actix",
  "lru",
  "mime",
+ "opentelemetry",
+ "opentelemetry-otlp",
  "rand 0.8.4",
  "rsa",
  "rsa-magic-public-key",
@@ -1734,10 +1974,20 @@ dependencies = [
  "tracing-error",
  "tracing-futures",
  "tracing-log",
+ "tracing-opentelemetry",
  "tracing-subscriber",
  "uuid",
 ]
 
+[[package]]
+name = "remove_dir_all"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3acd125665422973a33ac9d3dd2df85edad0f4ae9b00dafb1a05e43a9f5ef8e7"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "ring"
 version = "0.16.20"
@@ -2232,6 +2482,20 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "55937e1799185b12863d447f42597ed69d9928686b8d88a1df17376a097d8369"
 
+[[package]]
+name = "tempfile"
+version = "3.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dac1c663cfc93810f88aed9b8941d48cabf856a1b111c29a40439018d870eb22"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "rand 0.8.4",
+ "redox_syscall",
+ "remove_dir_all",
+ "winapi",
+]
+
 [[package]]
 name = "tendril"
 version = "0.4.2"
@@ -2356,13 +2620,36 @@ dependencies = [
  "libc",
  "memchr",
  "mio",
+ "num_cpus",
  "once_cell",
  "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
+ "tokio-macros",
  "winapi",
 ]
 
+[[package]]
+name = "tokio-io-timeout"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90c49f106be240de154571dd31fbe48acb10ba6c6dd6f6517ad603abffa42de9"
+dependencies = [
+ "pin-project-lite",
+ "tokio",
+]
+
+[[package]]
+name = "tokio-macros"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "54473be61f4ebe4efd09cec9bd5d16fa51d70ea0192213d754d2d500457db110"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "tokio-rustls"
 version = "0.22.0"
@@ -2374,6 +2661,17 @@ dependencies = [
  "webpki",
 ]
 
+[[package]]
+name = "tokio-stream"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b2f3f698253f03119ac0102beaa64f67a67e08074d03a22d18784104543727f"
+dependencies = [
+ "futures-core",
+ "pin-project-lite",
+ "tokio",
+]
+
 [[package]]
 name = "tokio-util"
 version = "0.6.8"
@@ -2397,6 +2695,81 @@ dependencies = [
  "serde 1.0.130",
 ]
 
+[[package]]
+name = "tonic"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "796c5e1cd49905e65dd8e700d4cb1dffcbfdb4fc9d017de08c1a537afd83627c"
+dependencies = [
+ "async-stream",
+ "async-trait",
+ "base64",
+ "bytes",
+ "futures-core",
+ "futures-util",
+ "h2",
+ "http",
+ "http-body",
+ "hyper",
+ "hyper-timeout",
+ "percent-encoding",
+ "pin-project",
+ "prost",
+ "prost-derive",
+ "tokio",
+ "tokio-stream",
+ "tokio-util",
+ "tower",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+ "tracing-futures",
+]
+
+[[package]]
+name = "tonic-build"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "12b52d07035516c2b74337d2ac7746075e7dcae7643816c1b12c5ff8a7484c08"
+dependencies = [
+ "proc-macro2",
+ "prost-build",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "tower"
+version = "0.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f60422bc7fefa2f3ec70359b8ff1caff59d785877eb70595904605bcc412470f"
+dependencies = [
+ "futures-core",
+ "futures-util",
+ "indexmap",
+ "pin-project",
+ "rand 0.8.4",
+ "slab",
+ "tokio",
+ "tokio-stream",
+ "tokio-util",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
+[[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 = "0.1.28"
@@ -2404,6 +2777,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "84f96e095c0c82419687c20ddf5cb3eadb61f4e1405923c9dc8e53a1adacbda8"
 dependencies = [
  "cfg-if",
+ "log",
  "pin-project-lite",
  "tracing-attributes",
  "tracing-core",
@@ -2471,6 +2845,19 @@ dependencies = [
  "tracing-core",
 ]
 
+[[package]]
+name = "tracing-opentelemetry"
+version = "0.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "599f388ecb26b28d9c1b2e4437ae019a7b336018b45ed911458cd9ebf91129f6"
+dependencies = [
+ "opentelemetry",
+ "tracing",
+ "tracing-core",
+ "tracing-log",
+ "tracing-subscriber",
+]
+
 [[package]]
 name = "tracing-serde"
 version = "0.1.2"
@@ -2503,6 +2890,12 @@ dependencies = [
  "tracing-serde",
 ]
 
+[[package]]
+name = "try-lock"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59547bce71d9c38b83d9c0e92b6066c4253371f15005def0c30d9657f50c7642"
+
 [[package]]
 name = "typenum"
 version = "1.14.0"
@@ -2595,6 +2988,16 @@ version = "0.9.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5fecdca9a5291cc2b8dcf7dc02453fee791a280f3743cb0905f8822ae463b3fe"
 
+[[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 = "0.9.0+wasi-snapshot-preview1"
@@ -2690,6 +3093,17 @@ dependencies = [
  "webpki",
 ]
 
+[[package]]
+name = "which"
+version = "4.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ea187a8ef279bc014ec368c27a920da2024d2a711109bfbe3440585d5cf27ad9"
+dependencies = [
+ "either",
+ "lazy_static",
+ "libc",
+]
+
 [[package]]
 name = "winapi"
 version = "0.3.9"
diff --git a/Cargo.toml b/Cargo.toml
index 54fd99f..79bb515 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -30,6 +30,8 @@ dotenv = "0.15.0"
 futures-util = "0.3.17"
 lru = "0.6.0"
 mime = "0.3.16"
+opentelemetry = { version = "0.16", features = ["rt-tokio-current-thread"] }
+opentelemetry-otlp = "0.9"
 rand = "0.8"
 rsa = "0.5"
 rsa-magic-public-key = "0.4.0"
@@ -43,6 +45,7 @@ tracing = "0.1"
 tracing-error = "0.1"
 tracing-futures = "0.2"
 tracing-log = "0.1"
+tracing-opentelemetry = "0.15"
 tracing-subscriber = { version = "0.2", features = ["ansi", "fmt"] }
 uuid = { version = "0.8", features = ["v4", "serde"] }
 
diff --git a/src/config.rs b/src/config.rs
index 14751ae..5b617fd 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -23,6 +23,7 @@ pub(crate) struct ParsedConfig {
     publish_blocks: bool,
     sled_path: PathBuf,
     source_repo: Url,
+    opentelemetry_url: Option<Url>,
 }
 
 #[derive(Clone, Debug)]
@@ -37,6 +38,7 @@ pub struct Config {
     base_uri: Url,
     sled_path: PathBuf,
     source_repo: Url,
+    opentelemetry_url: Option<Url>,
 }
 
 pub enum UrlKind {
@@ -66,6 +68,7 @@ impl Config {
             .set_default("publish_blocks", false)?
             .set_default("sled_path", "./sled/db-0-34")?
             .set_default("source_repo", "https://git.asonix.dog/asonix/relay")?
+            .set_default("opentelemetry_url", None as Option<&str>)?
             .merge(Environment::new())?;
 
         let config: ParsedConfig = config.try_into()?;
@@ -84,6 +87,7 @@ impl Config {
             base_uri,
             sled_path: config.sled_path,
             source_repo: config.source_repo,
+            opentelemetry_url: config.opentelemetry_url,
         })
     }
 
@@ -152,6 +156,10 @@ impl Config {
         &self.source_repo
     }
 
+    pub(crate) fn opentelemetry_url(&self) -> Option<&Url> {
+        self.opentelemetry_url.as_ref()
+    }
+
     pub(crate) fn generate_url(&self, kind: UrlKind) -> Url {
         let mut url = self.base_uri.clone();
 
diff --git a/src/main.rs b/src/main.rs
index 7b5fd3a..ead6f50 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,5 @@
 use actix_web::{web, App, HttpServer};
+use opentelemetry_otlp::WithExportConfig;
 use tracing_actix_web::TracingLogger;
 use tracing_error::ErrorLayer;
 use tracing_log::LogTracer;
@@ -29,6 +30,8 @@ use self::{
 async fn main() -> Result<(), anyhow::Error> {
     dotenv::dotenv().ok();
 
+    let config = Config::build()?;
+
     LogTracer::init()?;
 
     let env_filter = EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new("info"));
@@ -42,9 +45,23 @@ async fn main() -> Result<(), anyhow::Error> {
         .with(ErrorLayer::default())
         .with(format_layer);
 
-    tracing::subscriber::set_global_default(subscriber)?;
+    if let Some(url) = config.opentelemetry_url() {
+        let tracer = opentelemetry_otlp::new_pipeline()
+            .tracing()
+            .with_exporter(
+                opentelemetry_otlp::new_exporter()
+                    .tonic()
+                    .with_endpoint(url.as_str()),
+            )
+            .install_batch(opentelemetry::runtime::TokioCurrentThread)?;
 
-    let config = Config::build()?;
+        let otel_layer = tracing_opentelemetry::layer().with_tracer(tracer);
+
+        let subscriber = subscriber.with(otel_layer);
+        tracing::subscriber::set_global_default(subscriber)?;
+    } else {
+        tracing::subscriber::set_global_default(subscriber)?;
+    }
 
     let db = Db::build(&config)?;