remote_execution: implement OSS write_action_result for `local_only…

…` cache uploads

Forward port of part of <#477>,
which implements code in the OSS path for putting results of actions marked
`local_only = True` into the RBE `ActionCache`.

For people actually using the "remote execution" part of RBE and not just a
cache, this rather large omission in the system will often be transparently
mitigated because RBE services will not only record `ActionCache` entries
on your behalf, they will also implement "EX-to-AC" forwarding where any
execution calls will immediately get looked up in the `ActionCache` anyway as an
optimization. Which means you'll never see this for things that properly hit CAS
inputs/outputs.

However, a `CommandExecutorConfig` configured with `remote_enabled = False` can
still enable `remote_cache_enabled = allow_cache_uploads = True` which will both
enable the ActionCache/CAS support, and also allow uploads to those interfaces
too.

The most useful example of this type of setup is in a CI system like GitHub
Actions: where you run the build inside a container or image that provides
something quasi-hermetic (e.g. including your toolchains), while the RBE system
is purely a cache storing inputs/outputs/ActionCache entries and never uses
remote execution.

The hope is that this functionality will soon be plug-and-play on GitHub using
an RBE-to-GHA caching proxy, so Buck2 projects will be able to get a quick and
easy cache, but without RE. Therefore this functionality will become highly
useful.

Co-authored-by: Austin Seipp <aseipp@pobox.com>

remote_execution/oss/re_grpc/src/client.rs

@@ -46,13 +46,17 @@ use re_grpc_proto::build::bazel::remote::execution::v2::Digest;
 use re_grpc_proto::build::bazel::remote::execution::v2::ExecuteOperationMetadata;
 use re_grpc_proto::build::bazel::remote::execution::v2::ExecuteRequest as GExecuteRequest;
 use re_grpc_proto::build::bazel::remote::execution::v2::ExecuteResponse as GExecuteResponse;
+use re_grpc_proto::build::bazel::remote::execution::v2::ExecutedActionMetadata;
 use re_grpc_proto::build::bazel::remote::execution::v2::FindMissingBlobsRequest;
 use re_grpc_proto::build::bazel::remote::execution::v2::FindMissingBlobsResponse;
 use re_grpc_proto::build::bazel::remote::execution::v2::GetActionResultRequest;
 use re_grpc_proto::build::bazel::remote::execution::v2::GetCapabilitiesRequest;
+use re_grpc_proto::build::bazel::remote::execution::v2::OutputDirectory;
+use re_grpc_proto::build::bazel::remote::execution::v2::OutputFile;
 use re_grpc_proto::build::bazel::remote::execution::v2::RequestMetadata;
 use re_grpc_proto::build::bazel::remote::execution::v2::ResultsCachePolicy;
 use re_grpc_proto::build::bazel::remote::execution::v2::ToolDetails;
+use re_grpc_proto::build::bazel::remote::execution::v2::UpdateActionResultRequest;
 use re_grpc_proto::google::bytestream::byte_stream_client::ByteStreamClient;
 use re_grpc_proto::google::bytestream::ReadRequest;
 use re_grpc_proto::google::bytestream::ReadResponse;
@@ -117,6 +121,13 @@ fn check_status(status: Status) -> Result<(), REClientError> {
     })
 }
 
+fn ttimestamp_to(ts: TTimestamp) -> Option<prost_types::Timestamp> {
+    Some(prost_types::Timestamp {
+        seconds: ts.seconds,
+        nanos: ts.nanos,
+    })
+}
+
 fn ttimestamp_from(ts: Option<::prost_types::Timestamp>) -> TTimestamp {
     match ts {
         Some(timestamp) => TTimestamp {
@@ -589,10 +600,37 @@ impl REClient {
 
     pub async fn write_action_result(
         &self,
-        _metadata: RemoteExecutionMetadata,
-        _request: WriteActionResultRequest,
+        metadata: RemoteExecutionMetadata,
+        write_request: WriteActionResultRequest,
     ) -> anyhow::Result<WriteActionResultResponse> {
-        Err(anyhow::anyhow!("Not supported"))
+        let mut client = self.grpc_clients.action_cache_client.clone();
+        let action_digest = tdigest_to(write_request.action_digest.clone());
+        let action_result = convert_taction_result_to_rbe(write_request.action_result);
+        let request = UpdateActionResultRequest {
+            action_digest: Some(action_digest),
+            action_result: Some(action_result),
+            results_cache_policy: None,
+            instance_name: self.instance_name.as_str().to_owned(),
+        };
+
+        let t: ActionResult = client
+            .update_action_result(with_re_metadata(
+                request,
+                metadata,
+                self.runtime_opts.use_fbcode_metadata,
+            ))
+            .await?
+            .into_inner();
+
+        let result = convert_action_result(t)?;
+        let result = WriteActionResultResponse {
+            actual_action_result: result,
+            // NOTE: This is an arbitrary number because RBE does not return information
+            // on the TTL of the ActionResult.
+            // Also buck2 does not appear to read this value anywhere.
+            ttl_seconds: 0,
+        };
+        Ok(result)
     }
 
     pub async fn execute_with_progress(
@@ -912,7 +950,89 @@ impl REClient {
     }
 }
 
+fn convert_taction_result_to_rbe(result: TActionResult2) -> ActionResult {
+    let TActionResult2 {
+        output_files,
+        output_directories,
+        output_symlinks: _,
+        exit_code,
+        stdout_raw,
+        stdout_digest,
+        stderr_raw,
+        stderr_digest,
+        execution_metadata: metadata,
+        auxiliary_metadata: _,
+        _dot_dot_default,
+    } = result;
+
+    let output_files = output_files.into_map(|output_file| {
+        OutputFile {
+            digest: Some(tdigest_to(output_file.digest.digest)),
+            path: output_file.name,
+            is_executable: output_file.executable,
+            // Clients SHOULD NOT populate this field when uploading to the cache.
+            contents: Vec::new(),
+            node_properties: None,
+        }
+    });
+
+    let output_directories = output_directories.into_map(|output_directory| {
+        OutputDirectory {
+            path: output_directory.path,
+            tree_digest: Some(tdigest_to(output_directory.tree_digest)),
+            // TODO(cormacrelf): check whether buck2_execute::directory::directory_to_re_tree
+            // conforms with the requirements of passing `true` here (see .proto file)
+            is_topologically_sorted: false,
+        }
+    });
+
+    let execution_metadata = Some(ExecutedActionMetadata {
+        worker: metadata.worker,
+        worker_start_timestamp: ttimestamp_to(metadata.worker_start_timestamp),
+        worker_completed_timestamp: ttimestamp_to(metadata.worker_completed_timestamp),
+        input_fetch_start_timestamp: ttimestamp_to(metadata.input_fetch_start_timestamp),
+        input_fetch_completed_timestamp: ttimestamp_to(metadata.input_fetch_completed_timestamp),
+        execution_start_timestamp: ttimestamp_to(metadata.execution_start_timestamp),
+        execution_completed_timestamp: ttimestamp_to(metadata.execution_completed_timestamp),
+        output_upload_start_timestamp: ttimestamp_to(metadata.output_upload_start_timestamp),
+        output_upload_completed_timestamp: ttimestamp_to(
+            metadata.output_upload_completed_timestamp,
+        ),
+        queued_timestamp: ttimestamp_to(metadata.queued_timestamp),
+        // TODO(cormacrelf): calculate this in a reasonable way for buck.
+        // see protobuf docs on virtual_execution_duration.
+        // May be able to use last_queued_timestamp
+        virtual_execution_duration: None,
+        // Ugh, need a routine to convert TAny to prost_type::Any...
+        auxiliary_metadata: vec![],
+    });
+
+    ActionResult {
+        exit_code,
+        execution_metadata,
+        output_directories,
+        output_files,
+        // TODO: support symlinks
+        output_symlinks: vec![],
+        output_file_symlinks: vec![],
+        output_directory_symlinks: vec![],
+        // If missing, it's because we uploaded it already
+        // if present, it's inline
+        stdout_raw: stdout_raw.unwrap_or(Vec::new()),
+        stdout_digest: stdout_digest.map(tdigest_to),
+        stderr_raw: stderr_raw.unwrap_or(Vec::new()),
+        stderr_digest: stderr_digest.map(tdigest_to),
+    }
+}
+
 fn convert_action_result(action_result: ActionResult) -> anyhow::Result<TActionResult2> {
+    if !action_result.output_symlinks.is_empty()
+        || !action_result.output_file_symlinks.is_empty()
+        || !action_result.output_directory_symlinks.is_empty()
+    {
+        return Err(anyhow::anyhow!("Symlinks are not supported"));
+    }
+
     let execution_metadata = action_result
         .execution_metadata
         .with_context(|| "The execution metadata are not defined.")?;