A purpose-built proxy for the Linkerd service mesh. Written in Rust.
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Scott Fleener 7343c72948
feat(tracing): Allow trace collector to be unmeshed
The proxy currently treats the trace collector endpoint as a control plane component, mostly to prevent a circular dependency in the service stack. This means that we've had to manually supply a mesh identity in the form of a service account name, usually through an extension's injector.

However, this isn't strictly required as the control plane stack works just fine when the endpoint is unmeshed. This is realistically only useful for the trace collector which don't benefit much from being meshed, so this change only allows the collector to omit a mesh identity.

Signed-off-by: Scott Fleener <scott@buoyant.io>
2025-06-06 10:53:50 -04:00
.checksec build(deps): Update rustls and ring (#2735) 2024-02-21 16:03:35 -08:00
.devcontainer chore(dev): introduce copilot instructions (#3873) 2025-04-21 12:24:34 -04:00
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docs chore(deps): bump DavidAnson/markdownlint-cli2-action (#3923) 2025-05-22 13:16:37 -07:00
hyper-balance chore(deps)!: upgrade to hyper 1.x (#3504) 2025-03-21 12:53:11 -04:00
linkerd feat(tracing): Allow trace collector to be unmeshed 2025-06-06 10:53:50 -04:00
linkerd2-proxy chore(deps): define `tracing` workspace dependency (#3834) 2025-05-12 16:00:34 -04:00
opencensus-proto chore(deps)!: upgrade to hyper 1.x (#3504) 2025-03-21 12:53:11 -04:00
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.clippy.toml clippy: Disallow lock and instant types from `std` (#1458) 2022-02-02 11:59:03 -08:00
.codecov.yml ci: Fixup codecov config (#2545) 2023-12-03 11:53:02 -08:00
.dockerignore Add proxy_build_info metric (#600) 2020-07-24 09:19:40 -07:00
.gitattributes Update to linkerd2-proxy-api v0.5 and tonic v0.7 (#1596) 2022-04-11 11:29:33 -07:00
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Cargo.lock build(deps): bump hyper-util from 0.1.13 to 0.1.14 (#3948) 2025-06-05 06:51:50 -07:00
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Dockerfile chore: bump dev from v44 to v45 (#3496) 2025-01-06 13:27:49 -05:00
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LICENSE Introducing Conduit, the ultralight service mesh 2017-12-05 00:24:55 +00:00
MAINTAINERS.md ci: Lint markdown files (#1707) 2022-05-25 11:46:19 -07:00
README.md chore(deps): bump DavidAnson/markdownlint-cli2-action (#3923) 2025-05-22 13:16:37 -07:00
deny.toml feat(meshtls): Add aws-lc-rs as optional rustls backend (#3883) 2025-04-28 08:38:40 -04:00
justfile fix(ci): work around broken `linkerd install --crds` (#3828) 2025-03-31 14:55:09 +00:00
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README.md

The Linkerd Proxy

linkerd2

GitHub license Slack Status

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 Mutual TLS;
  • An on-demand diagnostic tap API.

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 using cargo
  • just test -- Runs unit and integration tests on your local system using cargo
  • just 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:

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 can be found in the docs/reports/ directory.

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.