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chio_envoy_ext_authz/
lib.rs

1//! Chio adapter for Envoy's [`ext_authz`][ext-authz] gRPC filter.
2//!
3//! This crate implements `envoy.service.auth.v3.Authorization/Check` as a thin
4//! shim that translates each Envoy `CheckRequest` into an Chio
5//! [`translate::ToolCallRequest`], hands it to an [`EnvoyKernel`] implementation,
6//! and maps the returned [`translate::Verdict`] onto a compliant
7//! `CheckResponse`.
8//!
9//! The crate deliberately keeps its dependency surface small so the adapter
10//! can be linked into any Envoy-fronted service without pulling in the rest
11//! of the Chio substrate. The [`EnvoyKernel`] trait exists precisely so real
12//! deployments can plug `chio-kernel` (or `chio-http-core`'s `HttpAuthority`)
13//! into this service without this crate depending on them. A doc example is
14//! sketched below.
15//!
16//! # Example wiring
17//!
18//! ```ignore
19//! use chio_envoy_ext_authz::{
20//!     proto::envoy::service::auth::v3::authorization_server::AuthorizationServer,
21//!     translate::{ToolCallRequest, Verdict},
22//!     ChioExtAuthzService, EnvoyKernel, KernelError,
23//! };
24//! use async_trait::async_trait;
25//!
26//! struct MyKernel;
27//!
28//! #[async_trait]
29//! impl EnvoyKernel for MyKernel {
30//!     async fn evaluate(
31//!         &self,
32//!         request: ToolCallRequest,
33//!     ) -> Result<Verdict, KernelError> {
34//!         // Delegate to chio-kernel / HttpAuthority / custom policy here.
35//!         Ok(Verdict::Allow)
36//!     }
37//! }
38//!
39//! #[tokio::main]
40//! async fn main() -> Result<(), Box<dyn std::error::Error>> {
41//!     let svc = ChioExtAuthzService::new(MyKernel);
42//!     tonic::transport::Server::builder()
43//!         .add_service(AuthorizationServer::new(svc))
44//!         .serve("0.0.0.0:9091".parse()?)
45//!         .await?;
46//!     Ok(())
47//! }
48//! ```
49//!
50//! [ext-authz]: https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_filters/ext_authz_filter
51
52#![deny(missing_docs)]
53
54pub mod error;
55pub mod service;
56pub mod translate;
57
58pub use error::{KernelError, TranslateError};
59pub use service::{ChioExtAuthzService, EnvoyKernel};
60pub use translate::{
61    check_request_to_tool_call, AuthMethod, CallerIdentity, HttpMethod, ToolCallRequest, Verdict,
62    ENVOY_SERVER_ID,
63};
64
65/// Generated protobuf bindings for the vendored Envoy ext_authz v3 service.
66///
67/// The module tree mirrors the `.proto` package hierarchy so downstream code
68/// can address each message by its fully qualified protobuf name.
69pub mod proto {
70    /// Envoy API protobuf modules. Only the messages required by ext_authz
71    /// are vendored; see each `.proto` for the upstream source.
72    pub mod envoy {
73        /// `envoy.service` generated modules.
74        pub mod service {
75            /// `envoy.service.auth` generated modules.
76            pub mod auth {
77                /// `envoy.service.auth.v3` generated module.
78                pub mod v3 {
79                    #![allow(missing_docs)]
80                    tonic::include_proto!("envoy.service.auth.v3");
81                }
82            }
83        }
84
85        /// `envoy.config` generated modules.
86        pub mod config {
87            /// `envoy.config.core` generated modules.
88            pub mod core {
89                /// `envoy.config.core.v3` generated module.
90                pub mod v3 {
91                    #![allow(missing_docs)]
92                    tonic::include_proto!("envoy.config.core.v3");
93                }
94            }
95        }
96
97        /// `envoy.type` generated modules. The `type` module name is escaped
98        /// because `type` is a Rust keyword.
99        pub mod r#type {
100            /// `envoy.type.v3` generated module.
101            pub mod v3 {
102                #![allow(missing_docs)]
103                tonic::include_proto!("envoy.r#type.v3");
104            }
105        }
106    }
107
108    /// `google.rpc` generated modules.
109    pub mod google {
110        /// `google.rpc` generated module.
111        pub mod rpc {
112            #![allow(missing_docs)]
113            tonic::include_proto!("google.rpc");
114        }
115    }
116}