Feature-gate the http_post and query_service oracles. (#2396)

.github/workflows/rust.yml

@@ -69,11 +69,11 @@ jobs:
       run: |
         cargo build --release -p linera-storage-service
         target/release/linera-storage-server memory --endpoint $LINERA_STORAGE_SERVICE &
-        cargo test --features storage-service -- storage_service --nocapture
+        cargo test --features storage-service,unstable-oracles -- storage_service --nocapture
     - name: Run Ethereum tests
       run: |
         cargo test -p linera-ethereum --features ethereum
-        cargo test test_wasm_end_to_end_ethereum_tracker --features ethereum,storage-service
+        cargo test test_wasm_end_to_end_ethereum_tracker --features ethereum,storage-service,unstable-oracles
     - name: Compile Wasm test modules for Witty integration tests
       run: |
         cargo build -p linera-witty-test-modules --target wasm32-unknown-unknown
@@ -82,7 +82,7 @@ jobs:
         cargo run --bin wit-generator -- -c
     - name: Run all tests using the default features
       run: |
-        cargo test --locked
+        cargo test --features unstable-oracles --locked
     - name: Run some extra execution tests with wasmtime
       run: |
         cargo test --locked -p linera-execution --features wasmtime

linera-execution/Cargo.toml

@@ -15,6 +15,7 @@ version.workspace = true
 test = ["tokio/macros", "linera-views/test"]
 fs = ["tokio/fs"]
 metrics = ["prometheus", "linera-views/metrics"]
+unstable-oracles = []
 wasmer = [
     "bytes",
     "dep:wasmer",

linera-execution/src/lib.rs

@@ -180,6 +180,10 @@ pub enum ExecutionError {
     EventKeyTooLong,
     #[error("Stream names can be at most {MAX_STREAM_NAME_LEN} bytes.")]
     StreamNameTooLong,
+    // TODO(#2127): Remove this error and the unstable-oracles feature once there are fees
+    // and enforced limits for all oracles.
+    #[error("Unstable oracles are disabled on this network.")]
+    UnstableOracle,
 }
 
 /// The public entry points provided by the contract part of an application.

linera-execution/src/runtime.rs

@@ -919,6 +919,10 @@ impl<UserInstance> BaseRuntime for SyncRuntimeInternal<UserInstance> {
         application_id: ApplicationId,
         query: Vec<u8>,
     ) -> Result<Vec<u8>, ExecutionError> {
+        ensure!(
+            cfg!(feature = "unstable-oracles"),
+            ExecutionError::UnstableOracle
+        );
         let response =
             if let Some(response) = self.transaction_tracker.next_replayed_oracle_response()? {
                 match response {
@@ -945,6 +949,10 @@ impl<UserInstance> BaseRuntime for SyncRuntimeInternal<UserInstance> {
         content_type: String,
         payload: Vec<u8>,
     ) -> Result<Vec<u8>, ExecutionError> {
+        ensure!(
+            cfg!(feature = "unstable-oracles"),
+            ExecutionError::UnstableOracle
+        );
         let bytes =
             if let Some(response) = self.transaction_tracker.next_replayed_oracle_response()? {
                 match response {