chore: feature cleanup (#1236)

* chore: feature cleanup

* trim down features

* remove extra features

* fix formatting

Author: chris-olszewski

crates/client/Cargo.toml

@@ -52,6 +52,7 @@ rand = "0.10"
 [dependencies.temporalio-common]
 path = "../common"
 version = "0.3"
+default-features = false
 
 [dev-dependencies]
 assert_matches = "1"

crates/common/Cargo.toml

@@ -14,7 +14,7 @@ exclude = ["protos/*/.github/*"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [features]
-history_builders = ["rand"]
+history_builders = ["dep:rand"]
 otel = ["dep:opentelemetry", "dep:opentelemetry_sdk", "dep:opentelemetry-otlp"]
 prometheus = [
   "dep:prometheus",
@@ -26,12 +26,8 @@ prometheus = [
 envconfig = ["dep:toml", "dep:dirs"]
 serde_serialize = []
 test-utilities = ["history_builders"]
-core-based-sdk = [
-  "prometheus",
-  "envconfig",
-  "dep:ringbuf",
-  "dep:futures-channel",
-]
+core-telemetry-bridge = ["dep:ringbuf", "dep:futures-channel"]
+core-based-sdk = ["core-telemetry-bridge", "prometheus", "envconfig"]
 
 [dependencies]
 anyhow = "1.0"
@@ -85,7 +81,10 @@ tokio = { version = "1.47", default-features = false, features = [
   "rt",
 ], optional = true }
 toml = { version = "1.0", optional = true }
-tonic = { workspace = true, default-features = false, features = ["transport", "codegen"] }
+tonic = { workspace = true, default-features = false, features = [
+  "transport",
+  "codegen",
+] }
 tonic-prost = { workspace = true }
 tracing = "0.1"
 # TODO [rust-sdk-branch]: Is it reasonable to make this optional?

crates/common/src/telemetry.rs

@@ -3,7 +3,7 @@
 /// Metric instrument types and the [`CoreMeter`] trait.
 pub mod metrics;
 
-#[cfg(feature = "core-based-sdk")]
+#[cfg(feature = "core-telemetry-bridge")]
 mod log_export;
 #[cfg(feature = "otel")]
 mod otel;
@@ -31,10 +31,10 @@ use tracing::{Level, Subscriber};
 use tracing_subscriber::{EnvFilter, Layer, layer::SubscriberExt};
 use url::Url;
 
-#[cfg(feature = "core-based-sdk")]
+#[cfg(feature = "core-telemetry-bridge")]
 use crate::telemetry::log_export::CoreLogConsumerLayer;
 
-#[cfg(feature = "core-based-sdk")]
+#[cfg(feature = "core-telemetry-bridge")]
 pub use log_export::{CoreLogBuffer, CoreLogBufferedConsumer, CoreLogStreamConsumer};
 #[cfg(feature = "otel")]
 pub use otel::build_otlp_metric_exporter;
@@ -200,13 +200,13 @@ pub enum Logger {
         /// An [EnvFilter](https://docs.rs/tracing-subscriber/latest/tracing_subscriber/struct.EnvFilter.html) filter string.
         filter: String,
     },
-    #[cfg(feature = "core-based-sdk")]
+    #[cfg(feature = "core-telemetry-bridge")]
     /// Forward logs to Lang - collectable with `fetch_global_buffered_logs`.
     Forward {
         /// An [EnvFilter](https://docs.rs/tracing-subscriber/latest/tracing_subscriber/struct.EnvFilter.html) filter string.
         filter: String,
     },
-    #[cfg(feature = "core-based-sdk")]
+    #[cfg(feature = "core-telemetry-bridge")]
     /// Push logs to Lang. Can be used with
     /// temporalio_sdk_core::telemetry::log_export::CoreLogBufferedConsumer to buffer.
     Push {
@@ -277,7 +277,7 @@ pub trait CoreLogConsumer: Send + Sync + Debug {
     fn on_log(&self, log: CoreLog);
 }
 
-#[cfg(feature = "core-based-sdk")]
+#[cfg(feature = "core-telemetry-bridge")]
 const FORWARD_LOG_BUFFER_SIZE: usize = 2048;
 
 /// Help you construct an [EnvFilter] compatible filter string which will forward all core module
@@ -291,7 +291,7 @@ pub fn construct_filter_string(core_level: Level, other_level: Level) -> String
 /// Holds initialized tracing/metrics exporters, etc
 pub struct TelemetryInstance {
     metric_prefix: String,
-    #[cfg(feature = "core-based-sdk")]
+    #[cfg(feature = "core-telemetry-bridge")]
     logs_out: Option<parking_lot::Mutex<CoreLogBuffer>>,
     metrics: Option<Arc<dyn CoreMeter + 'static>>,
     /// The tracing subscriber which is associated with this telemetry instance. May be `None` if
@@ -372,7 +372,7 @@ pub fn remove_trace_subscriber_for_current_thread() {
     SUB_GUARD.take();
 }
 
-#[cfg(feature = "core-based-sdk")]
+#[cfg(feature = "core-telemetry-bridge")]
 impl CoreTelemetry for TelemetryInstance {
     fn fetch_buffered_logs(&self) -> Vec<CoreLog> {
         if let Some(logs_out) = self.logs_out.as_ref() {
@@ -390,13 +390,13 @@ impl CoreTelemetry for TelemetryInstance {
 ///
 /// See [TelemetryOptions] docs for more on configuration.
 pub fn telemetry_init(opts: TelemetryOptions) -> Result<TelemetryInstance, anyhow::Error> {
-    #[cfg(feature = "core-based-sdk")]
+    #[cfg(feature = "core-telemetry-bridge")]
     let mut logs_out = None;
 
     // Tracing subscriber layers =========
     let mut console_pretty_layer = None;
     let mut console_compact_layer = None;
-    #[cfg(feature = "core-based-sdk")]
+    #[cfg(feature = "core-telemetry-bridge")]
     let mut forward_layer = None;
     // ===================================
 
@@ -431,14 +431,14 @@ pub fn telemetry_init(opts: TelemetryOptions) -> Result<TelemetryInstance, anyho
                         )
                     }
                 }
-                #[cfg(feature = "core-based-sdk")]
+                #[cfg(feature = "core-telemetry-bridge")]
                 Logger::Forward { filter } => {
                     let (export_layer, lo) =
                         CoreLogConsumerLayer::new_buffered(FORWARD_LOG_BUFFER_SIZE);
                     logs_out = Some(parking_lot::Mutex::new(lo));
                     forward_layer = Some(export_layer.with_filter(EnvFilter::new(filter)));
                 }
-                #[cfg(feature = "core-based-sdk")]
+                #[cfg(feature = "core-telemetry-bridge")]
                 Logger::Push { filter, consumer } => {
                     forward_layer = Some(
                         CoreLogConsumerLayer::new(consumer).with_filter(EnvFilter::new(filter)),
@@ -448,7 +448,7 @@ pub fn telemetry_init(opts: TelemetryOptions) -> Result<TelemetryInstance, anyho
             let reg = tracing_subscriber::registry()
                 .with(console_pretty_layer)
                 .with(console_compact_layer);
-            #[cfg(feature = "core-based-sdk")]
+            #[cfg(feature = "core-telemetry-bridge")]
             let reg = reg.with(forward_layer);
 
             Arc::new(reg) as Arc<dyn Subscriber + Send + Sync>
@@ -457,7 +457,7 @@ pub fn telemetry_init(opts: TelemetryOptions) -> Result<TelemetryInstance, anyho
 
     Ok(TelemetryInstance {
         metric_prefix: opts.metric_prefix,
-        #[cfg(feature = "core-based-sdk")]
+        #[cfg(feature = "core-telemetry-bridge")]
         logs_out,
         metrics: opts.metrics,
         trace_subscriber: tracing_sub,

crates/common/src/telemetry/metrics.rs

@@ -11,7 +11,7 @@ use std::{
     time::Duration,
 };
 
-#[cfg(feature = "core-based-sdk")]
+#[cfg(feature = "core-telemetry-bridge")]
 pub mod core;
 
 /// The string name (which may be prefixed) for this metric
@@ -377,10 +377,10 @@ pub enum MetricAttributes {
         labels: Arc<OrderedPromLabelSet>,
     },
     /// Buffered attributes used by core-based SDKs for deferred metric initialization.
-    #[cfg(feature = "core-based-sdk")]
+    #[cfg(feature = "core-telemetry-bridge")]
     Buffer(core::BufferAttributes),
     /// Dynamic attributes backed by a lang-side custom implementation.
-    #[cfg(feature = "core-based-sdk")]
+    #[cfg(feature = "core-telemetry-bridge")]
     Dynamic(Arc<dyn core::CustomMetricAttributes>),
     /// No-op attributes that store labels but do not record.
     NoOp(Arc<HashMap<String, String>>),

crates/sdk-core/Cargo.toml

@@ -10,12 +10,15 @@ repository = "https://github.com/temporalio/sdk-rust"
 keywords = ["temporal", "workflow"]
 categories = ["development-tools"]
 exclude = ["machine_coverage/*"]
-rust-version = "1.88.0" # due to cargo msrv find
+# due to cargo msrv find
+rust-version = "1.88.0"
 
 [lib]
 
 [features]
-default = []
+default = ["envconfig", "prometheus"]
+envconfig = ["temporalio-client/envconfig", "temporalio-common/envconfig"]
+prometheus = ["temporalio-common/prometheus"]
 otel = [
   "dep:opentelemetry",
   "dep:opentelemetry_sdk",
@@ -95,7 +98,12 @@ tokio = { version = "1.47", default-features = false, features = [
 ] }
 tokio-util = { version = "0.7", features = ["io", "io-util"] }
 tokio-stream = { version = "0.1", default-features = false }
-tonic = { workspace = true, default-features = false, features = ["tls-ring", "tls-native-roots", "transport", "codegen"] }
+tonic = { workspace = true, default-features = false, features = [
+  "tls-ring",
+  "tls-native-roots",
+  "transport",
+  "codegen",
+] }
 tracing = "0.1"
 url = "2.5"
 uuid = { version = "1.18", default-features = false, features = ["v4"] }
@@ -110,11 +118,13 @@ zip = { version = "8.4", optional = true, default-features = false, features = [
 [dependencies.temporalio-common]
 path = "../common"
 version = "0.3"
-features = ["core-based-sdk", "history_builders", "test-utilities"]
+default-features = false
+features = ["core-telemetry-bridge", "history_builders"]
 
 [dependencies.temporalio-client]
 path = "../client"
 version = "0.3"
+default-features = false
 features = ["core-based-sdk"]
 
 [dependencies.temporalio-macros]
@@ -139,6 +149,9 @@ hyper-util = { version = "0.1", features = [
 rstest = "0.26"
 semver = "1.0"
 temporalio-sdk = { path = "../sdk" }
+temporalio-common = { path = "../common", version = "0.3", default-features = false, features = [
+  "test-utilities",
+] }
 tokio = { version = "1.47", default-features = false, features = [
   "rt",
   "rt-multi-thread",

crates/sdk/Cargo.toml

@@ -46,10 +46,12 @@ default-features = false
 [dependencies.temporalio-common]
 path = "../common"
 version = "0.3"
+default-features = false
 
 [dependencies.temporalio-client]
 path = "../client"
 version = "0.3"
+default-features = false
 
 [dependencies.temporalio-macros]
 path = "../macros"
@@ -60,9 +62,11 @@ futures = "0.3"
 rstest = "0.26"
 
 [features]
-default = []
-antithesis_assertions = ["temporalio-sdk-core/antithesis_assertions"]
-examples = ["serde/derive", "dep:serde_json"]
+default = ["envconfig", "prometheus"]
+envconfig = ["temporalio-sdk-core/envconfig"]
+prometheus = ["temporalio-sdk-core/prometheus"]
+otel = ["temporalio-sdk-core/otel"]
+examples = ["serde/derive", "dep:serde_json", "envconfig"]
 
 [dependencies.serde_json]
 version = "1"

crates/sdk/README.md

@@ -107,6 +107,22 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 }
 ```
 
+## Crate Features
+
+The SDK enables a few convenience integrations by default. Users who want a smaller dependency
+graph can disable defaults and opt back into the integrations they use:
+
+```toml
+temporalio-sdk = { version = "0.3", default-features = false, features = ["envconfig"] }
+```
+
+- `envconfig` - enabled by default. Adds `ClientOptions::load_from_config` and related helpers for
+  loading connection settings from environment variables and `temporal.toml` files.
+- `prometheus` - enabled by default. Adds the Prometheus metrics exporter in
+  `temporalio_common::telemetry` for serving SDK metrics from a HTTP endpoint.
+- `otel` - optional. Adds the OpenTelemetry metrics exporter in `temporalio_common::telemetry` for
+  sending SDK metrics to an OpenTelemetry collector.
+
 ## Workflows in detail
 
 Workflows are the core abstraction in Temporal. They are defined as structs with associated methods: