feat(flags): more flags production-readiness (#26998)

.github/workflows/rust-docker-build.yml

@@ -33,6 +33,8 @@ jobs:
                       dockerfile: ./rust/Dockerfile
                     - image: cymbal
                       dockerfile: ./rust/Dockerfile
+                    - image: feature-flags
+                      dockerfile: ./rust/Dockerfile
                     - image: batch-import-worker
                       dockerfile: ./rust/Dockerfile
         runs-on: depot-ubuntu-22.04-4
@@ -52,7 +54,7 @@ jobs:
             hook-worker_digest: ${{ steps.digest.outputs.hook-worker_digest }}
             hook-migrator_digest: ${{ steps.digest.outputs.hook-migrator_digest }}
             cymbal_digest: ${{ steps.digest.outputs.cymbal_digest }}
-
+            feature-flags_digest: ${{ steps.digest.outputs.feature-flags_digest }}
         defaults:
             run:
                 working-directory: rust
@@ -145,6 +147,10 @@ jobs:
                       values:
                           image:
                               sha: '${{ needs.build.outputs.property-defs-rs_digest }}'
+                    - release: feature-flags
+                      values:
+                          image:
+                              sha: '${{ needs.build.outputs.feature-flags_digest }}'
                     - release: batch-import-worker
                       values:
                           image:

docker-compose.base.yml

@@ -29,6 +29,11 @@ services:
                         path /capture*
                     }
 
+                    @flags {
+                        path /flags
+                        path /flags*
+                    }
+
                     handle @capture {
                         reverse_proxy capture:3000
                     }
@@ -37,6 +42,10 @@ services:
                         reverse_proxy replay-capture:3000
                     }
 
+                    handle @flags {
+                        reverse_proxy feature-flags:3001
+                    }
+
                     handle {
                         reverse_proxy web:8000
                     }
@@ -197,6 +206,24 @@ services:
             SKIP_READS: 'false'
             FILTER_MODE: 'opt-out'
 
+    feature-flags:
+        image: ghcr.io/posthog/posthog/feature-flags:master
+        build:
+            context: rust/
+            args:
+                BIN: feature-flags
+        restart: on-failure
+        volumes:
+            - ./share:/share
+        environment:
+            WRITE_DATABASE_URL: 'postgres://posthog:posthog@db:5432/posthog'
+            READ_DATABASE_URL: 'postgres://posthog:posthog@db:5432/posthog'
+            MAXMIND_DB_PATH: '/share/GeoLite2-City.mmdb'
+            REDIS_URL: 'redis://redis:6379/'
+            ADDRESS: '0.0.0.0:3001'
+            SKIP_WRITES: 'false'
+            SKIP_READS: 'false'
+
     plugins:
         command: ./bin/plugin-server --no-restart-loop
         restart: on-failure

docker-compose.dev-full.yml

@@ -18,6 +18,7 @@ services:
         depends_on:
             - replay-capture
             - capture
+            - feature-flags
             - web
     db:
         extends:
@@ -150,6 +151,14 @@ services:
         depends_on:
             - kafka
 
+    feature-flags:
+        extends:
+            file: docker-compose.base.yml
+            service: feature-flags
+        depends_on:
+            - redis
+            - db
+
     plugins:
         extends:
             file: docker-compose.base.yml

docker-compose.dev.yml

@@ -17,6 +17,7 @@ services:
         depends_on:
             - replay-capture
             - capture
+            - feature-flags
         extra_hosts:
             - 'web:host-gateway'
     db:
@@ -153,6 +154,14 @@ services:
         depends_on:
             - kafka
 
+    feature-flags:
+        extends:
+            file: docker-compose.base.yml
+            service: feature-flags
+        depends_on:
+            - redis
+            - db
+
     livestream:
         extends:
             file: docker-compose.base.yml

posthog/middleware.py

@@ -51,6 +51,7 @@
     "s",
     "static",
     "_health",
+    "flags",
 ]
 
 if DEBUG:
@@ -66,7 +67,7 @@
     "samesite": "Strict",
 }
 
-cookie_api_paths_to_ignore = {"e", "s", "capture", "batch", "decide", "api", "track"}
+cookie_api_paths_to_ignore = {"e", "s", "capture", "batch", "decide", "api", "track", "flags"}
 
 
 class AllowIPMiddleware:

rust/feature-flags/Cargo.toml

@@ -10,6 +10,7 @@ anyhow = { workspace = true }
 async-trait = { workspace = true }
 axum = { workspace = true }
 axum-client-ip = { workspace = true }
+chrono = { workspace = true }
 envconfig = { workspace = true }
 tokio = { workspace = true }
 tracing = { workspace = true }
@@ -29,6 +30,7 @@ serde-pickle = { version = "1.1.1"}
 sha1 = "0.10.6"
 regex = "1.10.4"
 maxminddb = "0.17"
+metrics = { workspace = true }
 sqlx = { workspace = true }
 uuid = { workspace = true }
 base64.workspace = true
@@ -38,6 +40,7 @@ strum = { version = "0.26", features = ["derive"] }
 health = { path = "../common/health" }
 common-metrics = { path = "../common/metrics" }
 tower = { workspace = true }
+tower-http = { workspace = true }
 derive_builder = "0.20.1"
 petgraph = "0.6.5"
 moka = { workspace = true }

rust/feature-flags/src/api/endpoint.rs

@@ -2,8 +2,8 @@ use std::net::IpAddr;
 
 use crate::{
     api::errors::FlagError,
-    api::handler::{process_request, FlagsQueryParams, RequestContext},
-    api::types::FlagsResponse,
+    api::request_handler::{process_request, FlagsQueryParams, RequestContext},
+    api::types::{FlagsOptionsResponse, FlagsResponse, FlagsResponseCode},
     router,
 };
 // TODO: stream this instead
@@ -53,6 +53,12 @@ pub async fn flags(
     Ok(Json(process_request(context).await?))
 }
 
+pub async fn options() -> Result<Json<FlagsOptionsResponse>, FlagError> {
+    Ok(Json(FlagsOptionsResponse {
+        status: FlagsResponseCode::Ok,
+    }))
+}
+
 fn record_request_metadata(
     headers: &HeaderMap,
     method: &Method,

rust/feature-flags/src/api/errors.rs

@@ -13,6 +13,8 @@ pub enum ClientFacingError {
     Unauthorized(String),
     #[error("Rate limited")]
     RateLimited,
+    #[error("billing limit reached")]
+    BillingLimit,
     #[error("Service unavailable")]
     ServiceUnavailable,
 }
@@ -67,6 +69,7 @@ impl IntoResponse for FlagError {
             FlagError::ClientFacing(err) => match err {
                 ClientFacingError::BadRequest(msg) => (StatusCode::BAD_REQUEST, msg),
                 ClientFacingError::Unauthorized(msg) => (StatusCode::UNAUTHORIZED, msg),
+                ClientFacingError::BillingLimit => (StatusCode::PAYMENT_REQUIRED, "Billing limit reached. Please upgrade your plan.".to_string()),
                 ClientFacingError::RateLimited => (StatusCode::TOO_MANY_REQUESTS, "Rate limit exceeded. Please reduce your request frequency and try again later.".to_string()),
                 ClientFacingError::ServiceUnavailable => (StatusCode::SERVICE_UNAVAILABLE, "Service is currently unavailable. Please try again later.".to_string()),
             },
@@ -176,7 +179,7 @@ impl From<CustomRedisError> for FlagError {
         match e {
             CustomRedisError::NotFound => FlagError::TokenValidationError,
             CustomRedisError::PickleError(e) => {
-                tracing::error!("failed to fetch data: {}", e);
+                tracing::error!("failed to fetch data from redis: {}", e);
                 FlagError::RedisDataParsingError
             }
             CustomRedisError::Timeout(_) => FlagError::TimeoutError,

rust/feature-flags/src/api/mod.rs

@@ -1,4 +1,5 @@
 pub mod endpoint;
 pub mod errors;
-pub mod handler;
+pub mod request_handler;
+pub mod test_endpoint;
 pub mod types;