c7918cfb1f
Currently, when the outbound proxy makes a direct connection prefixed with a `TransportHeader` in order to send HTTP traffic, it will always send a `SessionProtocol` hint with the HTTP version as part of the header. This instructs the inbound proxy to use that protocol, even if the target port has a ServerPolicy that marks that port as opaque, which can result in incorrect handling of that connection. See linkerd/linkerd2#9888 for details. In order to prevent this, linkerd/linkerd2-proxy-api#197 adds a new `ProtocolHint` value to the protobuf endpoint metadata message. This will allow the Destination controller to explicitly indicate to the outbound proxy that a given endpoint is known to handle all connections to a port as an opaque TCP stream, and that the proxy should not perform a protocol upgrade or send a `SessionProtocol` in the transport header. This branch updates the proxy to handle this new hint value, and adds tests that the outbound proxy behaves as expected. Along with linkerd/linkerd2#10301, this will fix linkerd/linkerd2#9888. I opened a new PR for this change rather than attempting to rebase my previous PR #2209, as it felt a bit easier to start with a new branch and just make the changes that were still relevant. Therefore, this closes #2209. |
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| .github | ||
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| hyper-balance | ||
| linkerd | ||
| linkerd2-proxy | ||
| opencensus-proto | ||
| tools | ||
| .clippy.toml | ||
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| CONTRIBUTING.md | ||
| Cargo.lock | ||
| Cargo.toml | ||
| DCO | ||
| Dockerfile | ||
| GOVERNANCE.md | ||
| LICENSE | ||
| MAINTAINERS.md | ||
| README.md | ||
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README.md
The Linkerd Proxy
This repo contains the transparent proxy component of Linkerd2. While the Linkerd2 proxy is heavily influenced by the Linkerd 1.X proxy, it comprises an entirely new codebase implemented in the Rust programming language.
This proxy's features include:
- Transparent, zero-config proxying for HTTP, HTTP/2, and arbitrary TCP protocols.
- Automatic Prometheus metrics export for HTTP and TCP traffic;
- Transparent, zero-config WebSocket proxying;
- Automatic, latency-aware, layer-7 load balancing;
- Automatic layer-4 load balancing for non-HTTP traffic;
- Automatic TLS (experimental);
- An on-demand diagnostic
tapAPI.
This proxy is primarily intended to run on Linux in containerized environments like Kubernetes, though it may also work on other Unix-like systems (like macOS).
The proxy supports service discovery via DNS and the linkerd2
Destination gRPC API.
The Linkerd project is hosted by the Cloud Native Computing Foundation (CNCF).
Building the project
We use just-cargo which provide a thin wrapper around just and
cargo.
We recommend that you use the included Dev Container to avoid setting
up the complex development environment by hand.
Just
A justfile is provided to automate most build tasks. It provides
the following recipes:
just build-- Compiles the proxy on your local system usingcargojust test-- Runs unit and integration tests on your local system usingcargojust docker-- Builds a Docker container image that can be used for testing.
Cargo
Usually, Cargo, Rust's package manager, is used to build and test this project. If you don't have Cargo installed, we suggest getting it via https://rustup.rs/.
Devcontainer
A Devcontainer is provided for use with Visual Studio Code. It includes all of the tooling needed to build and test the proxy.
Repository Structure
This project is broken into many small libraries, or crates, so that components may be compiled & tested independently. The following crate targets are especially important:
linkerd2-proxycontains the proxy executable;linkerd2-app-integrationcontains the proxy's integration tests;linkerd2-appbundles thelinkerd2-app-inboundandlinkerd2-app-outboundcrates so that they may be run by the executable or integration tests.
Code of conduct
This project is for everyone. We ask that our users and contributors take a few minutes to review our code of conduct.
Security
We test our code by way of fuzzing and this is described in FUZZING.md.
A third party security audit focused on fuzzing Linkerd2-proxy was performed by Ada Logics in 2021. The full report is available here.
License
linkerd2-proxy is copyright 2018 the linkerd2-proxy authors. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use these files except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.