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/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),
 }