add pyroscope (#4871)

* pyroscope

* fixup

* add pyroscope target

* fixins

* spellcheck

* rename 'pyroscoped' feature to 'pyroscope'

* build testnet binary with pyroscope feature

* Update Cargo.toml

Co-authored-by: Andronik <write@reusable.software>

* make args a string, resolve using std::net

* fixup

* remove --features pyroscope for testnet builds

Until the panics are fixed in upstream, this is sane.

* chore: bump pyroscope to 0.3.1

Fixes an underflow panic.

* Revert "remove --features pyroscope for testnet builds
"

This reverts commit 57dbdc7aa5f6427aeb1e3dfdfc97071c3a74851e.

* fix: Make sample rate a prime

Co-authored-by: Pierre Besson <pierre.besson@parity.io>
Co-authored-by: Andronik <write@reusable.software>

polkadot/cli/src/cli.rs

@@ -115,7 +115,14 @@ pub struct RunCmd {
 	/// Must be valid socket address, of format `IP:Port`
 	/// commonly `127.0.0.1:6831`.
 	#[clap(long)]
-	pub jaeger_agent: Option<std::net::SocketAddr>,
+	pub jaeger_agent: Option<String>,
+
+	/// Add the destination address to the `pyroscope` agent.
+	///
+	/// Must be valid socket address, of format `IP:Port`
+	/// commonly `127.0.0.1:4040`.
+	#[clap(long)]
+	pub pyroscope_server: Option<String>,
 }
 
 #[allow(missing_docs)]

polkadot/cli/src/command.rs

@@ -20,6 +20,7 @@ use log::info;
 use sc_cli::{Role, RuntimeVersion, SubstrateCli};
 use service::{self, IdentifyVariant};
 use sp_core::crypto::Ss58AddressFormatRegistry;
+use std::net::ToSocketAddrs;
 
 pub use crate::error::Error;
 pub use polkadot_performance_test::PerfCheckError;
@@ -266,7 +267,17 @@ where
 		info!("----------------------------");
 	}
 
-	let jaeger_agent = cli.run.jaeger_agent;
+	let jaeger_agent = if let Some(ref jaeger_agent) = cli.run.jaeger_agent {
+		Some(
+			jaeger_agent
+				.to_socket_addrs()
+				.map_err(Error::AddressResolutionFailure)?
+				.next()
+				.ok_or_else(|| Error::AddressResolutionMissing)?,
+		)
+	} else {
+		None
+	};
 
 	runner.run_node_until_exit(move |config| async move {
 		let role = config.role.clone();
@@ -293,6 +304,31 @@ where
 pub fn run() -> Result<()> {
 	let cli: Cli = Cli::from_args();
 
+	#[cfg(feature = "pyroscope")]
+	let mut pyroscope_agent_maybe = if let Some(ref agent_addr) = cli.run.pyroscope_server {
+		let address = agent_addr
+			.to_socket_addrs()
+			.map_err(Error::AddressResolutionFailure)?
+			.next()
+			.ok_or_else(|| Error::AddressResolutionMissing)?;
+		// The pyroscope agent requires a `http://` prefix, so we just do that.
+		let mut agent = pyro::PyroscopeAgent::builder(
+			"http://".to_owned() + address.to_string().as_str(),
+			"polkadot".to_owned(),
+		)
+		.sample_rate(113)
+		.build()?;
+		agent.start();
+		Some(agent)
+	} else {
+		None
+	};
+
+	#[cfg(not(feature = "pyroscope"))]
+	if cli.run.pyroscope_server.is_some() {
+		return Err(Error::PyroscopeNotCompiledIn)
+	}
+
 	match &cli.subcommand {
 		None => run_node_inner(cli, service::RealOverseerGen, polkadot_node_metrics::logger_hook()),
 		Some(Subcommand::BuildSpec(cmd)) => {
@@ -509,5 +545,10 @@ pub fn run() -> Result<()> {
 		)
 		.into()),
 	}?;
+
+	#[cfg(feature = "pyroscope")]
+	if let Some(mut pyroscope_agent) = pyroscope_agent_maybe.take() {
+		pyroscope_agent.stop();
+	}
 	Ok(())
 }

polkadot/cli/src/error.rs

@@ -31,6 +31,20 @@ pub enum Error {
 	#[error(transparent)]
 	PerfCheck(#[from] polkadot_performance_test::PerfCheckError),
 
+	#[cfg(not(feature = "pyroscope"))]
+	#[error("Binary was not compiled with `--feature=pyroscope`")]
+	PyroscopeNotCompiledIn,
+
+	#[cfg(feature = "pyroscope")]
+	#[error("Failed to connect to pyroscope agent")]
+	PyroscopeError(#[from] pyro::error::PyroscopeError),
+
+	#[error("Failed to resolve provided URL")]
+	AddressResolutionFailure(#[from] std::io::Error),
+
+	#[error("URL did not resolve to anything")]
+	AddressResolutionMissing,
+
 	#[error("Other: {0}")]
 	Other(String),
 }