Core SDK that can be used as a base for other Temporal SDKs. It is currently used as the base of:
For the reasoning behind the Core SDK, see:
See the Architecture doc for some high-level information about how Core works and how language layers interact with it.
Development
You will need the protoc protobuf compiler installed to build Core.
This repo is composed of multiple crates:
- temporal-sdk-core-protos
./sdk-core-protos- Holds the generated proto code and extensions - temporal-client
./client- Defines client(s) for interacting with the Temporal gRPC service - temporal-sdk-core-api
./core-api- Defines the API surface exposed by Core - temporal-sdk-core
./core- The Core implementation - temporal-sdk
./sdk- A (currently prototype) Rust SDK built on top of Core. Used for testing. - rustfsm
./fsm- Implements a procedural macro used by core for defining state machines (contains subcrates). It is temporal agnostic.
Visualized (dev dependencies are in blue):
All the following commands are enforced for each pull request:
Building and testing
You can buld and test the project using cargo:
cargo build
cargo test
Run integ tests with cargo integ-test. You will need to already be running the server:
docker-compose -f .buildkite/docker/docker-compose.yaml up
Run load tests with cargo test --features=save_wf_inputs --test heavy_tests.
Formatting
To format all code run:
cargo fmt --all
Linting
We are using clippy for linting.
You can run it using:
cargo clippy --all -- -D warnings
Debugging
The crate uses tracing to help with debugging. To enable it for a test, insert the below snippet at the start of the test. By default, tracing data is output to stdout in a (reasonably) pretty manner.
crate::telemetry::test_telem_console();The passed in options to initialization can be customized to export to an OTel collector, etc.
To run integ tests with OTel collection on, you can use integ-with-otel.sh. You will want to make
sure you are running the collector via docker, which can be done like so:
docker-compose -f .buildkite/docker/docker-compose.yaml -f .buildkite/docker/docker-compose-telem.yaml up
If you are working on a language SDK, you are expected to initialize tracing early in your main
equivalent.
Proto files
This repo uses a subtree for upstream protobuf files. The path protos/api_upstream is a
subtree. To update it, use:
git pull --squash -s subtree ssh://[email protected]/temporalio/api.git master --allow-unrelated-histories
Do not question why this git command is the way it is. It is not our place to interpret git's ways.
The java testserver protos are also pulled from the sdk-java repo, but since we only need a subdirectory of that repo, we just copy the files with read-tree:
# add sdk-java as a remote if you have not already
git remote add -f -t master --no-tags testsrv-protos [email protected]:temporalio/sdk-java.git
# delete existing protos
git rm -rf protos/testsrv_upstream
# pull from upstream & commit
git read-tree --prefix protos/testsrv_upstream -u testsrv-protos/master:temporal-test-server/src/main/proto
git commitFetching Histories
Tests which would like to replay stored histories rely on that history being made available in binary format. You can fetch histories in that format like so (from a local docker server):
cargo run --bin histfetch {workflow_id} [{run_id}]
You can change the TEMPORAL_SERVICE_ADDRESS env var to fetch from a different address.
Style Guidelines
Error handling
Any error which is returned from a public interface should be well-typed, and we use thiserror for that purpose.
Errors returned from things only used in testing are free to use anyhow for less verbosity.
The Rust "SDK"
This repo contains a prototype Rust sdk in the sdk/ directory. This SDK should be considered
pre-alpha in terms of its API surface. Since it's still using Core underneath, it is generally
functional. We do not currently have any firm plans to productionize this SDK. If you want to write
workflows and activities in Rust, feel free to use it - but be aware that the API may change at any
time without warning and we do not provide any support guarantees.