Files
attune/crates/api/src/routes/agent.rs
2026-03-21 10:05:02 -05:00

483 lines
16 KiB
Rust

//! Agent binary download endpoints
//!
//! Provides endpoints for downloading the attune-agent binary for injection
//! into arbitrary containers. This supports deployments where shared Docker
//! volumes are impractical (Kubernetes, ECS, remote Docker hosts).
use axum::{
body::Body,
extract::{Query, State},
http::{header, HeaderMap, StatusCode},
response::IntoResponse,
routing::get,
Json, Router,
};
use serde::{Deserialize, Serialize};
use std::sync::Arc;
use subtle::ConstantTimeEq;
use tokio::fs;
use tokio_util::io::ReaderStream;
use utoipa::{IntoParams, ToSchema};
use crate::state::AppState;
/// Query parameters for the binary download endpoint
#[derive(Debug, Deserialize, IntoParams)]
pub struct BinaryDownloadParams {
/// Target architecture (x86_64, aarch64). Defaults to x86_64.
#[param(example = "x86_64")]
pub arch: Option<String>,
/// Optional bootstrap token for authentication
pub token: Option<String>,
}
/// Agent binary metadata
#[derive(Debug, Serialize, ToSchema)]
pub struct AgentBinaryInfo {
/// Available architectures
pub architectures: Vec<AgentArchInfo>,
/// Agent version (from build)
pub version: String,
}
/// Per-architecture binary info
#[derive(Debug, Serialize, ToSchema)]
pub struct AgentArchInfo {
/// Architecture name
pub arch: String,
/// Binary size in bytes
pub size_bytes: u64,
/// Whether this binary is available
pub available: bool,
}
/// Validate that the architecture name is safe (no path traversal) and normalize it.
fn validate_arch(arch: &str) -> Result<&str, (StatusCode, Json<serde_json::Value>)> {
match arch {
"x86_64" | "aarch64" => Ok(arch),
// Accept arm64 as an alias for aarch64
"arm64" => Ok("aarch64"),
_ => Err((
StatusCode::BAD_REQUEST,
Json(serde_json::json!({
"error": "Invalid architecture",
"message": format!("Unsupported architecture '{}'. Supported: x86_64, aarch64", arch),
})),
)),
}
}
/// Validate bootstrap token if configured.
///
/// If the agent config has a `bootstrap_token` set, the request must provide it
/// via the `X-Agent-Token` header or the `token` query parameter. If no token
/// is configured, access is unrestricted.
fn validate_token(
config: &attune_common::config::Config,
headers: &HeaderMap,
query_token: &Option<String>,
) -> Result<(), (StatusCode, Json<serde_json::Value>)> {
let expected_token = config
.agent
.as_ref()
.and_then(|ac| ac.bootstrap_token.as_ref());
let expected_token = match expected_token {
Some(t) => t,
None => {
use std::sync::Once;
static WARN_ONCE: Once = Once::new();
WARN_ONCE.call_once(|| {
tracing::warn!(
"Agent binary download endpoint has no bootstrap_token configured. \
Anyone with network access to the API can download the agent binary. \
Set agent.bootstrap_token in config to restrict access."
);
});
return Ok(());
}
};
// Check X-Agent-Token header first, then query param
let provided_token = headers
.get("x-agent-token")
.and_then(|v| v.to_str().ok())
.map(|s| s.to_string())
.or_else(|| query_token.clone());
match provided_token {
Some(ref t) if bool::from(t.as_bytes().ct_eq(expected_token.as_bytes())) => Ok(()),
Some(_) => Err((
StatusCode::UNAUTHORIZED,
Json(serde_json::json!({
"error": "Invalid token",
"message": "The provided bootstrap token is invalid",
})),
)),
None => Err((
StatusCode::UNAUTHORIZED,
Json(serde_json::json!({
"error": "Token required",
"message": "A bootstrap token is required. Provide via X-Agent-Token header or token query parameter.",
})),
)),
}
}
/// Download the agent binary
///
/// Returns the statically-linked attune-agent binary for the requested architecture.
/// The binary can be injected into any container to turn it into an Attune worker.
#[utoipa::path(
get,
path = "/api/v1/agent/binary",
params(BinaryDownloadParams),
responses(
(status = 200, description = "Agent binary", content_type = "application/octet-stream"),
(status = 400, description = "Invalid architecture"),
(status = 401, description = "Invalid or missing bootstrap token"),
(status = 404, description = "Agent binary not found"),
(status = 503, description = "Agent binary distribution not configured"),
),
tag = "agent"
)]
pub async fn download_agent_binary(
State(state): State<Arc<AppState>>,
headers: HeaderMap,
Query(params): Query<BinaryDownloadParams>,
) -> Result<impl IntoResponse, (StatusCode, Json<serde_json::Value>)> {
// Validate bootstrap token if configured
validate_token(&state.config, &headers, &params.token)?;
let agent_config = state.config.agent.as_ref().ok_or_else(|| {
(
StatusCode::SERVICE_UNAVAILABLE,
Json(serde_json::json!({
"error": "Not configured",
"message": "Agent binary distribution is not configured. Set agent.binary_dir in config.",
})),
)
})?;
let arch = params.arch.as_deref().unwrap_or("x86_64");
let arch = validate_arch(arch)?;
let binary_dir = std::path::Path::new(&agent_config.binary_dir);
// Try arch-specific binary first, then fall back to generic name.
// IMPORTANT: The generic `attune-agent` binary is only safe to serve for
// x86_64 requests, because the current build pipeline produces an
// x86_64-unknown-linux-musl binary. Serving it for aarch64/arm64 would
// give the caller an incompatible executable (exec format error).
let arch_specific = binary_dir.join(format!("attune-agent-{}", arch));
let generic = binary_dir.join("attune-agent");
let binary_path = if arch_specific.exists() {
arch_specific
} else if arch == "x86_64" && generic.exists() {
tracing::debug!(
"Arch-specific binary not found at {:?}, falling back to generic {:?} (safe for x86_64)",
arch_specific,
generic
);
generic
} else {
tracing::warn!(
"Agent binary not found. Checked: {:?} and {:?}",
arch_specific,
generic
);
return Err((
StatusCode::NOT_FOUND,
Json(serde_json::json!({
"error": "Not found",
"message": format!(
"Agent binary not found for architecture '{}'. Ensure the agent binary is built and placed in '{}'.",
arch,
agent_config.binary_dir
),
})),
));
};
// Get file metadata for Content-Length
let metadata = fs::metadata(&binary_path).await.map_err(|e| {
tracing::error!(
"Failed to read agent binary metadata at {:?}: {}",
binary_path,
e
);
(
StatusCode::INTERNAL_SERVER_ERROR,
Json(serde_json::json!({
"error": "Internal error",
"message": "Failed to read agent binary",
})),
)
})?;
// Open file for streaming
let file = fs::File::open(&binary_path).await.map_err(|e| {
tracing::error!("Failed to open agent binary at {:?}: {}", binary_path, e);
(
StatusCode::INTERNAL_SERVER_ERROR,
Json(serde_json::json!({
"error": "Internal error",
"message": "Failed to open agent binary",
})),
)
})?;
let stream = ReaderStream::new(file);
let body = Body::from_stream(stream);
let headers_response = [
(header::CONTENT_TYPE, "application/octet-stream".to_string()),
(
header::CONTENT_DISPOSITION,
"attachment; filename=\"attune-agent\"".to_string(),
),
(header::CONTENT_LENGTH, metadata.len().to_string()),
(header::CACHE_CONTROL, "public, max-age=3600".to_string()),
];
tracing::info!(
arch = arch,
size_bytes = metadata.len(),
path = ?binary_path,
"Serving agent binary download"
);
Ok((headers_response, body))
}
/// Get agent binary metadata
///
/// Returns information about available agent binaries, including
/// supported architectures and binary sizes.
#[utoipa::path(
get,
path = "/api/v1/agent/info",
responses(
(status = 200, description = "Agent binary info", body = AgentBinaryInfo),
(status = 503, description = "Agent binary distribution not configured"),
),
tag = "agent"
)]
pub async fn agent_info(
State(state): State<Arc<AppState>>,
) -> Result<impl IntoResponse, (StatusCode, Json<serde_json::Value>)> {
let agent_config = state.config.agent.as_ref().ok_or_else(|| {
(
StatusCode::SERVICE_UNAVAILABLE,
Json(serde_json::json!({
"error": "Not configured",
"message": "Agent binary distribution is not configured.",
})),
)
})?;
let binary_dir = std::path::Path::new(&agent_config.binary_dir);
let architectures = ["x86_64", "aarch64"];
let mut arch_infos = Vec::new();
for arch in &architectures {
let arch_specific = binary_dir.join(format!("attune-agent-{}", arch));
let generic = binary_dir.join("attune-agent");
// Only fall back to the generic binary for x86_64, since the build
// pipeline currently produces x86_64-only generic binaries.
let (available, size_bytes) = if arch_specific.exists() {
match fs::metadata(&arch_specific).await {
Ok(m) => (true, m.len()),
Err(_) => (false, 0),
}
} else if *arch == "x86_64" && generic.exists() {
match fs::metadata(&generic).await {
Ok(m) => (true, m.len()),
Err(_) => (false, 0),
}
} else {
(false, 0)
};
arch_infos.push(AgentArchInfo {
arch: arch.to_string(),
size_bytes,
available,
});
}
Ok(Json(AgentBinaryInfo {
architectures: arch_infos,
version: env!("CARGO_PKG_VERSION").to_string(),
}))
}
/// Create agent routes
pub fn routes() -> Router<Arc<AppState>> {
Router::new()
.route("/agent/binary", get(download_agent_binary))
.route("/agent/info", get(agent_info))
}
#[cfg(test)]
mod tests {
use super::*;
use attune_common::config::AgentConfig;
use axum::http::{HeaderMap, HeaderValue};
// ── validate_arch tests ─────────────────────────────────────────
#[test]
fn test_validate_arch_valid_x86_64() {
let result = validate_arch("x86_64");
assert!(result.is_ok());
assert_eq!(result.unwrap(), "x86_64");
}
#[test]
fn test_validate_arch_valid_aarch64() {
let result = validate_arch("aarch64");
assert!(result.is_ok());
assert_eq!(result.unwrap(), "aarch64");
}
#[test]
fn test_validate_arch_arm64_alias() {
// "arm64" is an alias for "aarch64"
let result = validate_arch("arm64");
assert!(result.is_ok());
assert_eq!(result.unwrap(), "aarch64");
}
#[test]
fn test_validate_arch_invalid() {
let result = validate_arch("mips");
assert!(result.is_err());
let (status, body) = result.unwrap_err();
assert_eq!(status, StatusCode::BAD_REQUEST);
assert_eq!(body.0["error"], "Invalid architecture");
}
// ── validate_token tests ────────────────────────────────────────
/// Helper: build a minimal Config with the given agent config.
/// Only the `agent` field is relevant for `validate_token`.
fn test_config(agent: Option<AgentConfig>) -> attune_common::config::Config {
let manifest_dir = std::env::var("CARGO_MANIFEST_DIR").unwrap_or_else(|_| ".".to_string());
let config_path = format!("{}/../../config.test.yaml", manifest_dir);
let mut config = attune_common::config::Config::load_from_file(&config_path)
.expect("Failed to load test config");
config.agent = agent;
config
}
#[test]
fn test_validate_token_no_config() {
// When no agent config is set at all, no token is required.
let config = test_config(None);
let headers = HeaderMap::new();
let query_token = None;
let result = validate_token(&config, &headers, &query_token);
assert!(result.is_ok());
}
#[test]
fn test_validate_token_no_bootstrap_token_configured() {
// Agent config exists but bootstrap_token is None → no token required.
let config = test_config(Some(AgentConfig {
binary_dir: "/tmp/test".to_string(),
bootstrap_token: None,
}));
let headers = HeaderMap::new();
let query_token = None;
let result = validate_token(&config, &headers, &query_token);
assert!(result.is_ok());
}
#[test]
fn test_validate_token_valid_from_header() {
let config = test_config(Some(AgentConfig {
binary_dir: "/tmp/test".to_string(),
bootstrap_token: Some("s3cret-bootstrap".to_string()),
}));
let mut headers = HeaderMap::new();
headers.insert(
"x-agent-token",
HeaderValue::from_static("s3cret-bootstrap"),
);
let query_token = None;
let result = validate_token(&config, &headers, &query_token);
assert!(result.is_ok());
}
#[test]
fn test_validate_token_valid_from_query() {
let config = test_config(Some(AgentConfig {
binary_dir: "/tmp/test".to_string(),
bootstrap_token: Some("s3cret-bootstrap".to_string()),
}));
let headers = HeaderMap::new();
let query_token = Some("s3cret-bootstrap".to_string());
let result = validate_token(&config, &headers, &query_token);
assert!(result.is_ok());
}
#[test]
fn test_validate_token_invalid() {
let config = test_config(Some(AgentConfig {
binary_dir: "/tmp/test".to_string(),
bootstrap_token: Some("correct-token".to_string()),
}));
let mut headers = HeaderMap::new();
headers.insert("x-agent-token", HeaderValue::from_static("wrong-token"));
let query_token = None;
let result = validate_token(&config, &headers, &query_token);
assert!(result.is_err());
let (status, body) = result.unwrap_err();
assert_eq!(status, StatusCode::UNAUTHORIZED);
assert_eq!(body.0["error"], "Invalid token");
}
#[test]
fn test_validate_token_missing_when_required() {
// bootstrap_token is configured but caller provides nothing.
let config = test_config(Some(AgentConfig {
binary_dir: "/tmp/test".to_string(),
bootstrap_token: Some("required-token".to_string()),
}));
let headers = HeaderMap::new();
let query_token = None;
let result = validate_token(&config, &headers, &query_token);
assert!(result.is_err());
let (status, body) = result.unwrap_err();
assert_eq!(status, StatusCode::UNAUTHORIZED);
assert_eq!(body.0["error"], "Token required");
}
#[test]
fn test_validate_token_header_takes_precedence_over_query() {
// When both header and query provide a token, the header value is
// checked first (it appears first in the or_else chain). Provide a
// valid token in the header and an invalid one in the query — should
// succeed because the header matches.
let config = test_config(Some(AgentConfig {
binary_dir: "/tmp/test".to_string(),
bootstrap_token: Some("the-real-token".to_string()),
}));
let mut headers = HeaderMap::new();
headers.insert("x-agent-token", HeaderValue::from_static("the-real-token"));
let query_token = Some("wrong-token".to_string());
let result = validate_token(&config, &headers, &query_token);
assert!(result.is_ok());
}
}