node-grpc-temporal-example

Temporal currently only have Go and Java SDK. I wrote my workflows in Java but needed to start, signal, query workflow from Node JS code. Without a Node SDK, I started by use shelljs to drive the official tctl. It works but the problem is the return is hard to parse.

Then I asked in the forum and got some help https://community.temporal.io/t/how-to-do-operations-tctl-can-do-from-any-programming-language/1256/13 . Here is an example of call Temporal from node using grpc.

This tutorial and this blog post also helped me a lot.

The api folder is a git submodule from https://github.com/temporalio/api

Dynamic code using @grpc/proto-loader

https://www.npmjs.com/package/@grpc/proto-loader

dynamic.js is loading proto3 dynamically. Easy to use but easy to make mistake when create the exact request object

Generate static code from the proto3 definations

Code under codegen are generated from the api folder using the following commands. If you have a better way to do this let me know

grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/temporal/api/workflowservice/v1/*.proto
grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/temporal/api/enums/v1/*.proto
grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/temporal/api/common/v1/*.proto
grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/temporal/api/history/v1/*.proto
grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/temporal/api/failure/v1/*.proto
grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/temporal/api/workflow/v1/*.proto
grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/temporal/api/taskqueue/v1/*.proto
grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/temporal/api/command/v1/*.proto
grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/temporal/api/filter/v1/*.proto
grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/temporal/api/namespace/v1/*.proto
grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/temporal/api/query/v1/*.proto
grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/temporal/api/replication/v1/*.proto
grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/temporal/api/version/v1/*.proto
grpc_tools_node_protoc -I=./api --js_out=import_style=commonjs,binary:./codegen --grpc_out=grpc_js:./codegen ./api/dependencies/gogoproto/*.proto

static.js is using the generated code to talk to Temporal