refactor(proxy/http): create `linkerd-http-version` crate (#3379)

* feat(proxy/http): create `linkerd-http-version` crate

this outlines the http version type into its own crate.

reëxports are added to make this a backwards compatible change, i.e. no
changes to the public api of `linkerd-proxy-http` are performed here.

Signed-off-by: katelyn martin <kate@buoyant.io>

* docs(http/version): doc comments

this adds some brief documentation comments to the crate.

Signed-off-by: katelyn martin <kate@buoyant.io>

---------

Signed-off-by: katelyn martin <kate@buoyant.io>

Cargo.lock

@@ -1797,6 +1797,14 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "linkerd-http-version"
+version = "0.1.0"
+dependencies = [
+ "http",
+ "thiserror",
+]
+
 [[package]]
 name = "linkerd-identity"
 version = "0.1.0"
@@ -2158,6 +2166,7 @@ dependencies = [
  "linkerd-http-classify",
  "linkerd-http-executor",
  "linkerd-http-h2",
+ "linkerd-http-version",
  "linkerd-io",
  "linkerd-proxy-balance",
  "linkerd-stack",

Cargo.toml

@@ -33,6 +33,7 @@ members = [
     "linkerd/http/prom",
     "linkerd/http/retry",
     "linkerd/http/route",
+    "linkerd/http/version",
     "linkerd/identity",
     "linkerd/idle-cache",
     "linkerd/io",

linkerd/http/version/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "linkerd-http-version"
+version = "0.1.0"
+authors = ["Linkerd Developers <cncf-linkerd-dev@lists.cncf.io>"]
+license = "Apache-2.0"
+edition = "2021"
+publish = false
+description = """
+HTTP version types.
+"""
+
+[dependencies]
+http = "0.2"
+thiserror = "1"

linkerd/http/version/src/lib.rs

@@ -1,11 +1,19 @@
+//! HTTP version types.
+//!
+//! See [`Version`].
+
 use thiserror::Error;
 
+/// HTTP protocol version.
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub enum Version {
+    /// HTTP/1
     Http1,
+    /// HTTP/2
     H2,
 }
 
+/// An unsupported HTTP version error.
 #[derive(Debug, Error)]
 #[error("unsupported HTTP version {:?}", self.0)]
 pub struct Unsupported(http::Version);

linkerd/proxy/http/Cargo.toml

@@ -42,9 +42,10 @@ linkerd-detect = { path = "../../detect" }
 linkerd-duplex = { path = "../../duplex" }
 linkerd-error = { path = "../../error" }
 linkerd-http-box = { path = "../../http/box" }
+linkerd-http-classify = { path = "../../http/classify" }
 linkerd-http-executor = { path = "../../http/executor" }
 linkerd-http-h2 = { path = "../../http/h2" }
-linkerd-http-classify = { path = "../../http/classify" }
+linkerd-http-version = { path = "../../http/version" }
 linkerd-io = { path = "../../io" }
 linkerd-proxy-balance = { path = "../balance" }
 linkerd-stack = { path = "../../stack" }

linkerd/proxy/http/src/lib.rs

@@ -23,7 +23,6 @@ pub mod stream_timeouts;
 pub mod strip_header;
 pub mod timeout;
 pub mod upgrade;
-pub mod version;
 
 pub use self::{
     balance::NewBalance,
@@ -41,7 +40,6 @@ pub use self::{
     stream_timeouts::{EnforceTimeouts, StreamTimeouts},
     strip_header::StripHeader,
     timeout::{NewTimeout, ResponseTimeout, ResponseTimeoutError},
-    version::Version,
 };
 pub use http::{
     header::{self, HeaderMap, HeaderName, HeaderValue},
@@ -50,6 +48,7 @@ pub use http::{
 pub use hyper::body::HttpBody;
 pub use linkerd_http_box::{BoxBody, BoxRequest, BoxResponse, EraseResponse};
 pub use linkerd_http_executor::TracingExecutor;
+pub use linkerd_http_version::{self as version, Version};
 
 #[derive(Clone, Debug)]
 pub struct HeaderPair(pub HeaderName, pub HeaderValue);