feat(wasi-observe): A WASI Observe host component

Signed-off-by: Caleb Schoepp <caleb.schoepp@fermyon.com>

Author: calebschoepp

Cargo.lock

@@ -86,6 +86,7 @@ openssl = { version = "0.10" }
 anyhow = { workspace = true, features = ["backtrace"] }
 conformance = { path = "tests/conformance-tests" }
 conformance-tests = { workspace = true }
+fake-opentelemetry-collector = "0.21.1"
 hex = "0.4"
 http-body-util = { workspace = true }
 hyper = { workspace = true }

Cargo.toml

@@ -9,6 +9,7 @@ anyhow = { workspace = true }
 lru = "0.12"
 serde = { workspace = true }
 spin-core = { path = "../core" }
+spin-factor-observe = { path = "../factor-observe" }
 spin-factors = { path = "../factors" }
 spin-locked-app = { path = "../locked-app" }
 spin-world = { path = "../world" }

crates/factor-key-value/Cargo.toml

@@ -1,6 +1,7 @@
 use anyhow::{Context, Result};
 use spin_core::{async_trait, wasmtime::component::Resource};
-use spin_world::v2::key_value;
+use spin_factor_observe::ObserveContext;
+use spin_world::{v2::key_value, wasi::observe};
 use std::{collections::HashSet, sync::Arc};
 use table::Table;
 use tracing::{instrument, Level};
@@ -36,22 +37,25 @@ pub struct KeyValueDispatch {
     allowed_stores: HashSet<String>,
     manager: Arc<dyn StoreManager>,
     stores: Table<Arc<dyn Store>>,
+    observe_context: Option<ObserveContext>,
 }
 
 impl KeyValueDispatch {
     pub fn new(allowed_stores: HashSet<String>, manager: Arc<dyn StoreManager>) -> Self {
-        Self::new_with_capacity(allowed_stores, manager, DEFAULT_STORE_TABLE_CAPACITY)
+        Self::new_with_capacity(allowed_stores, manager, DEFAULT_STORE_TABLE_CAPACITY, None)
     }
 
     pub fn new_with_capacity(
         allowed_stores: HashSet<String>,
         manager: Arc<dyn StoreManager>,
         capacity: u32,
+        observe_context: Option<ObserveContext>,
     ) -> Self {
         Self {
             allowed_stores,
             manager,
             stores: Table::new(capacity),
+            observe_context,
         }
     }
 
@@ -71,6 +75,9 @@ impl key_value::Host for KeyValueDispatch {}
 impl key_value::HostStore for KeyValueDispatch {
     #[instrument(name = "spin_key_value.open", skip(self), err(level = Level::INFO), fields(otel.kind = "client", kv.backend=self.manager.summary(&name).unwrap_or("unknown".to_string())))]
     async fn open(&mut self, name: String) -> Result<Result<Resource<key_value::Store>, Error>> {
+        if let Some(observe_context) = self.observe_context.as_ref() {
+            observe_context.reparent_tracing_span()
+        }
         Ok(async {
             if self.allowed_stores.contains(&name) {
                 let store = self
@@ -91,6 +98,9 @@ impl key_value::HostStore for KeyValueDispatch {
         store: Resource<key_value::Store>,
         key: String,
     ) -> Result<Result<Option<Vec<u8>>, Error>> {
+        if let Some(observe_context) = self.observe_context.as_ref() {
+            observe_context.reparent_tracing_span()
+        }
         let store = self.get_store(store)?;
         Ok(store.get(&key).await)
     }
@@ -102,6 +112,9 @@ impl key_value::HostStore for KeyValueDispatch {
         key: String,
         value: Vec<u8>,
     ) -> Result<Result<(), Error>> {
+        if let Some(observe_context) = self.observe_context.as_ref() {
+            observe_context.reparent_tracing_span()
+        }
         let store = self.get_store(store)?;
         Ok(store.set(&key, &value).await)
     }
@@ -112,6 +125,9 @@ impl key_value::HostStore for KeyValueDispatch {
         store: Resource<key_value::Store>,
         key: String,
     ) -> Result<Result<(), Error>> {
+        if let Some(observe_context) = self.observe_context.as_ref() {
+            observe_context.reparent_tracing_span()
+        }
         let store = self.get_store(store)?;
         Ok(store.delete(&key).await)
     }
@@ -122,6 +138,9 @@ impl key_value::HostStore for KeyValueDispatch {
         store: Resource<key_value::Store>,
         key: String,
     ) -> Result<Result<bool, Error>> {
+        if let Some(observe_context) = self.observe_context.as_ref() {
+            observe_context.reparent_tracing_span()
+        }
         let store = self.get_store(store)?;
         Ok(store.exists(&key).await)
     }
@@ -131,6 +150,9 @@ impl key_value::HostStore for KeyValueDispatch {
         &mut self,
         store: Resource<key_value::Store>,
     ) -> Result<Result<Vec<String>, Error>> {
+        if let Some(observe_context) = self.observe_context.as_ref() {
+            observe_context.reparent_tracing_span()
+        }
         let store = self.get_store(store)?;
         Ok(store.get_keys().await)
     }

crates/factor-key-value/src/host.rs

@@ -8,6 +8,7 @@ use std::{
 };
 
 use anyhow::ensure;
+use spin_factor_observe::ObserveContext;
 use spin_factors::{
     ConfigureAppContext, Factor, FactorInstanceBuilder, InitContext, PrepareContext, RuntimeFactors,
 };
@@ -81,17 +82,19 @@ impl Factor for KeyValueFactor {
 
     fn prepare<T: RuntimeFactors>(
         &self,
-        ctx: PrepareContext<T, Self>,
+        mut ctx: PrepareContext<T, Self>,
     ) -> anyhow::Result<InstanceBuilder> {
         let app_state = ctx.app_state();
         let allowed_stores = app_state
             .component_allowed_stores
             .get(ctx.app_component().id())
             .expect("component should be in component_stores")
             .clone();
+        let observe_context = ObserveContext::from_prepare_context(&mut ctx)?;
         Ok(InstanceBuilder {
             store_manager: app_state.store_manager.clone(),
             allowed_stores,
+            observe_context,
         })
     }
 }
@@ -140,6 +143,7 @@ pub struct InstanceBuilder {
     store_manager: Arc<AppStoreManager>,
     /// The allowed stores for this component instance.
     allowed_stores: HashSet<String>,
+    observe_context: ObserveContext,
 }
 
 impl FactorInstanceBuilder for InstanceBuilder {
@@ -149,11 +153,13 @@ impl FactorInstanceBuilder for InstanceBuilder {
         let Self {
             store_manager,
             allowed_stores,
+            observe_context,
         } = self;
         Ok(KeyValueDispatch::new_with_capacity(
             allowed_stores,
             store_manager,
             u32::MAX,
+            Some(observe_context),
         ))
     }
 }

crates/factor-key-value/src/lib.rs

@@ -17,6 +17,7 @@ llm-cublas = ["llm", "spin-llm-local/cublas"]
 anyhow = { workspace = true }
 async-trait = { workspace = true }
 serde = { workspace = true }
+spin-factor-observe = { path = "../factor-observe" }
 spin-factors = { path = "../factors" }
 spin-llm-local = { path = "../llm-local", optional = true }
 spin-llm-remote-http = { path = "../llm-remote-http" }

crates/factor-llm/Cargo.toml

@@ -15,6 +15,8 @@ impl v2::Host for InstanceState {
         prompt: String,
         params: Option<v2::InferencingParams>,
     ) -> Result<v2::InferencingResult, v2::Error> {
+        self.observe_context.reparent_tracing_span();
+
         if !self.allowed_models.contains(&model) {
             return Err(access_denied_error(&model));
         }
@@ -42,6 +44,8 @@ impl v2::Host for InstanceState {
         model: v1::EmbeddingModel,
         data: Vec<String>,
     ) -> Result<v2::EmbeddingsResult, v2::Error> {
+        self.observe_context.reparent_tracing_span();
+
         if !self.allowed_models.contains(&model) {
             return Err(access_denied_error(&model));
         }

crates/factor-llm/src/host.rs

@@ -5,6 +5,7 @@ use std::collections::{HashMap, HashSet};
 use std::sync::Arc;
 
 use async_trait::async_trait;
+use spin_factor_observe::ObserveContext;
 use spin_factors::{
     ConfigureAppContext, Factor, PrepareContext, RuntimeFactors, SelfInstanceBuilder,
 };
@@ -76,7 +77,7 @@ impl Factor for LlmFactor {
 
     fn prepare<T: RuntimeFactors>(
         &self,
-        ctx: PrepareContext<T, Self>,
+        mut ctx: PrepareContext<T, Self>,
     ) -> anyhow::Result<Self::InstanceBuilder> {
         let allowed_models = ctx
             .app_state()
@@ -85,10 +86,12 @@ impl Factor for LlmFactor {
             .cloned()
             .unwrap_or_default();
         let engine = ctx.app_state().engine.clone();
+        let observe_context = ObserveContext::from_prepare_context(&mut ctx)?;
 
         Ok(InstanceState {
             engine,
             allowed_models,
+            observe_context,
         })
     }
 }
@@ -103,6 +106,7 @@ pub struct AppState {
 pub struct InstanceState {
     engine: Arc<Mutex<dyn LlmEngine>>,
     pub allowed_models: Arc<HashSet<String>>,
+    observe_context: ObserveContext,
 }
 
 /// The runtime configuration for the LLM factor.