acton-service 0.21.4

Production-ready Rust backend framework with type-enforced API versioning
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333

//! Redis-backed rate limiting middleware
//!
//! Provides distributed rate limiting with per-route configuration support.
//! Uses Redis for shared state across multiple service instances.

#[cfg(feature = "cache")]
use deadpool_redis::Pool as RedisPool;
#[cfg(feature = "cache")]
use std::ops::DerefMut;
use std::sync::Arc;

use axum::{
    body::Body,
    extract::{Request, State},
    middleware::Next,
    response::Response,
};

#[cfg(feature = "cache")]
use axum::http::{header::HeaderValue, HeaderName};

use crate::{config::RateLimitConfig, error::Error};

#[cfg(feature = "cache")]
use crate::middleware::Claims;

use super::route_matcher::CompiledRoutePatterns;

#[cfg(feature = "cache")]
use super::route_matcher::normalize_path;

#[cfg(feature = "cache")]
use tracing::{debug, warn};

/// Rate limiting middleware state
///
/// Provides Redis-backed distributed rate limiting with support for:
/// - Global per-user and per-client limits
/// - Per-route rate limit overrides
/// - Automatic path normalization for dynamic segments
#[derive(Clone)]
pub struct RateLimit {
    #[cfg_attr(not(feature = "cache"), allow(dead_code))]
    config: RateLimitConfig,
    #[cfg_attr(not(feature = "cache"), allow(dead_code))]
    route_patterns: Arc<CompiledRoutePatterns>,
    #[cfg(feature = "cache")]
    redis_pool: Option<RedisPool>,
}

/// Rate limit check result containing limit info for response headers
#[cfg(feature = "cache")]
struct RateLimitResult {
    /// Maximum requests allowed in window
    limit: u32,
    /// Current request count (after this request)
    count: u32,
    /// Seconds until window resets
    reset_secs: u64,
}

impl RateLimit {
    /// Create a new rate limiting middleware with Redis backend
    #[cfg(feature = "cache")]
    pub fn new(config: RateLimitConfig, redis_pool: RedisPool) -> Self {
        let route_patterns = CompiledRoutePatterns::compile(&config.routes);
        Self {
            config,
            route_patterns: Arc::new(route_patterns),
            redis_pool: Some(redis_pool),
        }
    }

    /// Create a new rate limiting middleware without Redis (for testing)
    #[cfg(not(feature = "cache"))]
    pub fn new(config: RateLimitConfig) -> Self {
        let route_patterns = CompiledRoutePatterns::compile(&config.routes);
        Self {
            config,
            route_patterns: Arc::new(route_patterns),
        }
    }

    /// Middleware function to enforce rate limits
    ///
    /// Checks rate limits in the following order:
    /// 1. Per-route limits (if configured for the request path)
    /// 2. Global per-user limits (if JWT claims present)
    /// 3. Global per-client limits (if client token)
    pub async fn middleware(
        #[cfg_attr(not(feature = "cache"), allow(unused_variables))] State(rate_limit): State<Self>,
        request: Request<Body>,
        next: Next,
    ) -> Result<Response, Error> {
        #[cfg(feature = "cache")]
        {
            let method = request.method().as_str();
            let path = request.uri().path();
            let claims = request.extensions().get::<Claims>().cloned();

            // Check rate limit and get result for headers
            let result = rate_limit
                .check_rate_limit_with_route(method, path, claims.as_ref())
                .await?;

            // Run the request
            let mut response = next.run(request).await;

            // Add rate limit headers to response
            Self::add_rate_limit_headers(&mut response, &result);

            Ok(response)
        }

        #[cfg(not(feature = "cache"))]
        Ok(next.run(request).await)
    }

    /// Check rate limit considering per-route configuration
    #[cfg(feature = "cache")]
    async fn check_rate_limit_with_route(
        &self,
        method: &str,
        path: &str,
        claims: Option<&Claims>,
    ) -> Result<RateLimitResult, Error> {
        let normalized_path = normalize_path(path);

        // Check if there's a route-specific rate limit
        if let Some(route_config) = self.route_patterns.match_route(method, &normalized_path) {
            debug!(
                "Using per-route rate limit for {} {}: {} rpm",
                method, normalized_path, route_config.requests_per_minute
            );

            let key = if route_config.per_user {
                // Per-user route limit
                if let Some(claims) = claims {
                    format!("route:{}:user:{}", normalized_path, claims.sub)
                } else {
                    // No claims, use global route limit
                    format!("route:{}:global", normalized_path)
                }
            } else {
                // Global route limit (shared across all users)
                format!("route:{}:global", normalized_path)
            };

            return self
                .check_and_increment(
                    &key,
                    route_config.requests_per_minute,
                    self.config.window_secs,
                )
                .await;
        }

        // Fall back to global user/client limits
        if let Some(claims) = claims {
            let (key, limit) = if claims.is_user() {
                (
                    format!("ratelimit:user:{}", claims.sub),
                    self.config.per_user_rpm,
                )
            } else if claims.is_client() {
                (
                    format!("ratelimit:client:{}", claims.sub),
                    self.config.per_client_rpm,
                )
            } else {
                // Default to user limit
                (
                    format!("ratelimit:unknown:{}", claims.sub),
                    self.config.per_user_rpm,
                )
            };

            return self
                .check_and_increment(&key, limit, self.config.window_secs)
                .await;
        }

        // No claims and no route-specific limit - allow the request
        // In production, you might want to add IP-based limiting here
        warn!("Rate limit middleware called without JWT claims and no route-specific limit");
        Ok(RateLimitResult {
            limit: self.config.per_user_rpm,
            count: 0,
            reset_secs: self.config.window_secs,
        })
    }

    /// Check and increment rate limit counter in Redis
    #[cfg(feature = "cache")]
    async fn check_and_increment(
        &self,
        key: &str,
        limit: u32,
        window_secs: u64,
    ) -> Result<RateLimitResult, Error> {
        let redis_pool = self
            .redis_pool
            .as_ref()
            .ok_or_else(|| Error::Internal("Redis pool not configured".to_string()))?;

        let mut conn = redis_pool.get().await.map_err(|e| {
            let redis_err = redis::RedisError::from((
                redis::ErrorKind::IoError,
                "Failed to get Redis connection",
                e.to_string(),
            ));
            Error::Redis(Box::new(redis_err))
        })?;

        // Use INCR and EXPIRE for simple rate limiting
        // In production, you might want to use a more sophisticated algorithm (sliding window, token bucket)
        let count: u32 = redis::cmd("INCR")
            .arg(key)
            .query_async(conn.deref_mut())
            .await?;

        // Set expiration on first request
        if count == 1 {
            let _: () = redis::cmd("EXPIRE")
                .arg(key)
                .arg(window_secs as i64)
                .query_async(conn.deref_mut())
                .await?;
        }

        // Get TTL for reset time
        let ttl: i64 = redis::cmd("TTL")
            .arg(key)
            .query_async(conn.deref_mut())
            .await
            .unwrap_or(window_secs as i64);

        let reset_secs = if ttl > 0 { ttl as u64 } else { window_secs };

        // Check if limit exceeded
        if count > limit {
            warn!(
                "Rate limit exceeded for {}: {} requests (limit: {})",
                key, count, limit
            );
            return Err(Error::RateLimitExceeded);
        }

        Ok(RateLimitResult {
            limit,
            count,
            reset_secs,
        })
    }

    /// Add rate limit headers to response
    #[cfg(feature = "cache")]
    fn add_rate_limit_headers(response: &mut Response, result: &RateLimitResult) {
        let headers = response.headers_mut();

        // Standard rate limit headers
        if let Ok(value) = HeaderValue::from_str(&result.limit.to_string()) {
            headers.insert(HeaderName::from_static("x-ratelimit-limit"), value);
        }

        let remaining = result.limit.saturating_sub(result.count);
        if let Ok(value) = HeaderValue::from_str(&remaining.to_string()) {
            headers.insert(HeaderName::from_static("x-ratelimit-remaining"), value);
        }

        // Calculate reset timestamp
        let reset_timestamp = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .map(|d| d.as_secs() + result.reset_secs)
            .unwrap_or(0);

        if let Ok(value) = HeaderValue::from_str(&reset_timestamp.to_string()) {
            headers.insert(HeaderName::from_static("x-ratelimit-reset"), value);
        }
    }
}

#[cfg(test)]
mod tests {
    #[cfg(not(feature = "cache"))]
    use super::{RateLimit, RateLimitConfig};

    #[test]
    fn test_rate_limit_creation() {
        #[cfg(not(feature = "cache"))]
        {
            let config = RateLimitConfig {
                per_user_rpm: 200,
                per_client_rpm: 1000,
                window_secs: 60,
                routes: std::collections::HashMap::new(),
            };
            let _rate_limit = RateLimit::new(config);
        }

        // With cache feature, we would need a Redis pool
    }

    #[test]
    fn test_rate_limit_with_routes() {
        #[cfg(not(feature = "cache"))]
        {
            use crate::config::RouteRateLimitConfig;
            use std::collections::HashMap;

            let mut routes = HashMap::new();
            routes.insert(
                "/api/v1/heavy".to_string(),
                RouteRateLimitConfig {
                    requests_per_minute: 10,
                    burst_size: 2,
                    per_user: true,
                },
            );

            let config = RateLimitConfig {
                per_user_rpm: 200,
                per_client_rpm: 1000,
                window_secs: 60,
                routes,
            };
            let rate_limit = RateLimit::new(config);

            // Verify route patterns were compiled
            assert!(!rate_limit.route_patterns.is_empty());
        }
    }
}