Switch operation getting to tower (pantsbuild#7108)

src/rust/engine/process_execution/Cargo.toml

@@ -15,12 +15,13 @@ fs = { path = "../fs" }
 futures = "^0.1.16"
 # TODO: Switch to a release once https://github.com/alexcrichton/futures-timer/pull/11 and https://github.com/alexcrichton/futures-timer/pull/12 merge
 futures-timer = { git = "https://github.com/pantsbuild/futures-timer", rev = "0b747e565309a58537807ab43c674d8951f9e5a0" }
-grpcio = { git = "https://github.com/pantsbuild/grpc-rs.git", rev = "4dfafe9355dc996d7d0702e7386a6fedcd9734c0", default_features = false, features = ["protobuf-codec"] }
 h2 = "0.1.13"
 hashing = { path = "../hashing" }
 http = "0.1"
 log = "0.4"
 parking_lot = "0.6"
+prost = "0.4"
+prost-types = "0.4"
 protobuf = { version = "2.0.4", features = ["with-bytes"] }
 resettable = { path = "../resettable" }
 sha2 = "0.8"

src/rust/engine/process_execution/bazel_protos/Cargo.toml

@@ -10,6 +10,7 @@ bytes = "0.4.5"
 futures = "^0.1.16"
 grpcio = { git = "https://github.com/pantsbuild/grpc-rs.git", rev = "4dfafe9355dc996d7d0702e7386a6fedcd9734c0", default_features = false, features = ["protobuf-codec"] }
 hashing = { path = "../../hashing" }
+log = "0.4"
 prost = "0.4"
 prost-derive = "0.4"
 prost-types = "0.4"

src/rust/engine/process_execution/bazel_protos/build.rs

@@ -176,9 +176,11 @@ fn generate_for_tower(thirdpartyprotobuf: &Path, out_dir: PathBuf) {
     .enable_server(true)
     .enable_client(true)
     .build(
-      &[PathBuf::from(
-        "build/bazel/remote/execution/v2/remote_execution.proto",
-      )],
+      &[
+        PathBuf::from("build/bazel/remote/execution/v2/remote_execution.proto"),
+        PathBuf::from("google/rpc/code.proto"),
+        PathBuf::from("google/rpc/error_details.proto"),
+      ],
       &std::fs::read_dir(&thirdpartyprotobuf)
         .unwrap()
         .into_iter()

src/rust/engine/process_execution/bazel_protos/src/conversions.rs

@@ -1,4 +1,7 @@
+use bytes::BytesMut;
 use hashing;
+use log::error;
+use prost::Message;
 
 impl<'a> From<&'a hashing::Digest> for crate::remote_execution::Digest {
   fn from(d: &hashing::Digest) -> Self {
@@ -97,6 +100,47 @@ impl From<crate::build::bazel::remote::execution::v2::ExecuteRequest>
   }
 }
 
+// This should only be used in test contexts. It should be deleted when the mock systems use tower.
+impl Into<grpcio::RpcStatus> for crate::google::rpc::Status {
+  fn into(self) -> grpcio::RpcStatus {
+    let mut buf = BytesMut::with_capacity(self.encoded_len());
+    self.encode(&mut buf).unwrap();
+    grpcio::RpcStatus {
+      status: self.code.into(),
+      details: None,
+      status_proto_bytes: Some(buf.to_vec()),
+    }
+  }
+}
+
+// TODO: Use num_enum or similar here when TryInto is stable.
+pub fn code_from_i32(i: i32) -> crate::google::rpc::Code {
+  use crate::google::rpc::Code::*;
+  match i {
+    0 => Ok,
+    1 => Cancelled,
+    2 => Unknown,
+    3 => InvalidArgument,
+    4 => DeadlineExceeded,
+    5 => NotFound,
+    6 => AlreadyExists,
+    7 => PermissionDenied,
+    8 => ResourceExhausted,
+    9 => FailedPrecondition,
+    10 => Aborted,
+    11 => OutOfRange,
+    12 => Unimplemented,
+    13 => Internal,
+    14 => Unavailable,
+    15 => DataLoss,
+    16 => Unauthenticated,
+    _ => {
+      error!("Unknown grpc error code: {}, default to Unknown", i);
+      Unknown
+    }
+  }
+}
+
 pub fn prost_any_to_gcprio_any(any: prost_types::Any) -> protobuf::well_known_types::Any {
   let prost_types::Any { type_url, value } = any;
   let mut dst = protobuf::well_known_types::Any::new();

src/rust/engine/process_execution/bazel_protos/src/lib.rs

@@ -16,5 +16,6 @@ mod gen_for_tower;
 pub use crate::gen_for_tower::*;
 
 mod conversions;
+pub use crate::conversions::code_from_i32;
 mod verification;
 pub use crate::verification::verify_directory_canonical;

src/rust/engine/process_execution/src/lib.rs

@@ -34,7 +34,6 @@ use bazel_protos;
 
 use fs;
 
-use grpcio;
 use hashing;
 
 #[cfg(test)]