wricardo/protoc-gen-go-temporal

a protoc plugin for generating Temporal clients and workers in Go from protobuf schemas

protoc-gen-go-temporal

https://buf.build/cludden/protoc-gen-go-temporal A protoc plugin for generating typed Temporal clients and workers in Go from protobuf schemas. This plugin allows Workflow authors to configure sensible defaults and guardrails, simplifies the implementation and testing of Temporal workers, and streamlines integration by providing typed client SDKs and a generated CLI application.

Inspired by Chad Retz's awesome github.com/cretz/temporal-sdk-go-advanced and Jacob LeGrone's excellent Replay talk on Temporal @ Datadog

Table of Contents

• protoc-gen-go-temporal
  • How it works
  • Features
  • Examples
  • Getting Started
  • Options
    • Bloblang Expressions
  • Workflow Update
  • CLI
  • Test Client
  • Cross-Namespace (XNS)
  • Codec
  • Documentation
  • Reference
  • License

How it works

1. Annotate your protobuf services and methods with Temporal options provided by this plugin
2. Generate Go code that includes types, methods, and functions for implementing Temporal clients, workers, and cli applications
3. Define implementations for the required Workflow and Activity interfaces
4. Run your Temporal worker using the generated helpers and interact with it using the generated client and/or cli

Features

Generated Client with:

• methods for executing workflows, queries, signals, and updates
• methods for cancelling or terminating workflows
• default client.StartWorkflowOptions and client.UpdateWorkflowWithOptionsRequest
• dynamic workflow ids, update ids, and search attributes via Bloblang expressions
• default timeouts, id reuse policies, retry policies, wait policies

Generated Worker resources with:

• functions for calling activities and local activities from workflows
• functions for executing child workflows and signalling external workflows
• default workflow.ActivityOptions, workflow.ChildWorkflowOptions
• default timeouts, parent cose policies, retry policies

Optional CLI with:

• commands for executing workflows, synchronously or asynchronously
• commands for starting workflows with signals, synchronously or asynchronously
• commands for querying existing workflows
• commands for sending signals to existing workflows
• typed flags for conventiently specifying workflow, query, and signal inputs

Generated Cross-Namespace (XNS) helpers: [Experimental]

• with support for invoking a service's workflows, queries, signals, and updates from workflows in a different temporal namespace

Generated Remote Codec Server helpers

Generated Markdown Documentation

Examples

See examples for more usage:

• codecserver
• example
• helloworld
• mutex
• searchattributes
• updatabletimer
• xns

Getting Started

1. Install buf

2. Install this plugin

   1. via homebrew

   brew install cludden/formula/protoc-gen-go_temporal

   2. manually by grabbing a binary for your OS from the releases page and placing it in your $PATH
   3. via go:

   go install github.com/cludden/protoc-gen-go-temporal/cmd/protoc-gen-go_temporal@<version>

3. Install Go protoc plugin

go install google.golang.org/protobuf/cmd/protoc-gen-go@latest

4. Initialize buf repository

mkdir proto && cd proto && buf mod init

5. Add dependency to buf.yaml

version: v1
deps:
  - buf.build/cludden/protoc-gen-go-temporal:<version>

6. Add plugin to buf.gen.yaml and exclude it from managed mode go prefix

version: v1
managed:
  enabled: true
  go_package_prefix:
    default: github.com/foo/bar/gen
    except:
      - buf.build/cludden/protoc-gen-go-temporal
plugins:
  - plugin: go
    out: gen
    opt: paths=source_relative
  - plugin: go_temporal
    out: gen
    opt: paths=source_relative,cli-enabled=true,cli-categories=true,workflow-update-enabled=true,docs-out=./proto/README.md
    strategy: all

7. Define your service
   note: see examples and test for more details on generated code and usage

syntax="proto3";

package example.v1;

import "google/protobuf/empty.proto";
import "temporal/v1/temporal.proto";

service Example {
  option (temporal.v1.service) = {
    task_queue: "example-v1"
  };

  // CreateFoo creates a new foo operation
  rpc CreateFoo(CreateFooRequest) returns (CreateFooResponse) {
    option (temporal.v1.workflow) = {
      execution_timeout: { seconds: 3600 } // foos can take awhile to create
      id_reuse_policy: WORKFLOW_ID_REUSE_POLICY_ALLOW_DUPLICATE
      id: 'create-foo/${! name.slug() }'
      query: { ref: "GetFooProgress" }
      signal: { ref: "SetFooProgress", start: true }
      update: { ref: "UpdateFooProgress" }
    };
  }

  // GetFooProgress returns the status of a CreateFoo operation
  rpc GetFooProgress(google.protobuf.Empty) returns (GetFooProgressResponse) {
    option (temporal.v1.query) = {};
  }

  // Notify sends a notification
  rpc Notify(NotifyRequest) returns (google.protobuf.Empty) {
    option (temporal.v1.activity) = {
      start_to_close_timeout: { seconds: 30 }
      retry_policy: {
        max_attempts: 3
      }
    };
  }

  // SetFooProgress sets the current status of a CreateFoo operation
  rpc SetFooProgress(SetFooProgressRequest) returns (google.protobuf.Empty) {
    option (temporal.v1.signal) = {};
  }

  // UpdateFooProgress sets the current status of a CreateFoo operation
  rpc UpdateFooProgress(SetFooProgressRequest) returns (GetFooProgressResponse) {
    option (temporal.v1.update) = {
      id: 'update-progress/${! progress.string() }',
    };
  }
}

// CreateFooRequest describes the input to a CreateFoo workflow
message CreateFooRequest {
  // unique foo name
  string name = 1;
}

// SampleWorkflowWithMutexResponse describes the output from a CreateFoo workflow
message CreateFooResponse {
  Foo foo = 1; 
}

// Foo describes an illustrative foo resource
message Foo {
  string name = 1;
  Status status = 2;

  enum Status {
    FOO_STATUS_UNSPECIFIED = 0;
    FOO_STATUS_READY = 1;
    FOO_STATUS_CREATING = 2;
  }
}

// GetFooProgressResponse describes the output from a GetFooProgress query
message GetFooProgressResponse {
  float progress = 1;
  Foo.Status status = 2;
}

// NotifyRequest describes the input to a Notify activity
message NotifyRequest {
  string message = 1;
}

// SetFooProgressRequest describes the input to a SetFooProgress signal
message SetFooProgressRequest {
  // value of current workflow progress
  float progress = 1;
}

8. Generate temporal worker, client, and cli types, methods, interfaces, and functions

buf mod update && buf generate

9. Implement the required Workflow and Activity interfaces

package main

import (
  "context"
  "fmt"

  examplev1 "github.com/cludden/protoc-gen-go-temporal/gen/example/v1"
  "go.temporal.io/sdk/activity"
  "go.temporal.io/sdk/log"
  "go.temporal.io/sdk/workflow"
)

type (
  // Workflows manages shared state for workflow constructors and is used to
  // register workflows with a worker
  Workflows struct{}

  // Activities manages shared state for activities and is used to register
  // activities with a worker
  Activities struct{}
)

// CreateFooWorkflow manages workflow state for a CreateFoo workflow
type CreateFooWorkflow struct {
  // it embeds the generated workflow Input type that contains the workflow
  // input and signal helpers
  *examplev1.CreateFooWorkflowInput

  log      log.Logger
  progress float32
  status   examplev1.Foo_Status
}

// CreateFoo initializes a new CreateFooWorkflow value
func (w *Workflows) CreateFoo(ctx workflow.Context, input *examplev1.CreateFooWorkflowInput) (examplev1.CreateFooWorkflow, error) {
  return &CreateFooWorkflow{
    CreateFooWorkflowInput: input,
    log:                    workflow.GetLogger(ctx),
    status:                 examplev1.Foo_FOO_STATUS_CREATING,
  }, nil
}

// Execute defines the entrypoint to a CreateFooWorkflow value
func (wf *CreateFooWorkflow) Execute(ctx workflow.Context) (*examplev1.CreateFooResponse, error) {
  // listen for signals
  workflow.Go(ctx, func(ctx workflow.Context) {
    for {
      signal, _ := wf.SetFooProgress.Receive(ctx)
      wf.UpdateFooProgress(ctx, signal)
    }
  })

  // execute Notify activity using generated helper
  if err := examplev1.Notify(ctx, &examplev1.NotifyRequest{
    Message: fmt.Sprintf("creating foo resource (%s)", wf.Req.GetName()),
  }); err != nil {
    return nil, fmt.Errorf("error sending notification: %w", err)
  }

  // block until progress has reached 100 via signals and/or updates
  if err := workflow.Await(ctx, func() bool {
    return wf.status == examplev1.Foo_FOO_STATUS_READY
  }); err != nil {
    return nil, fmt.Errorf("error awaiting ready status: %w", err)
  }

  return &examplev1.CreateFooResponse{
    Foo: &examplev1.Foo{
      Name:   wf.Req.GetName(),
      Status: wf.status,
    },
  }, nil
}

// GetFooProgress defines the handler for a GetFooProgress query
func (wf *CreateFooWorkflow) GetFooProgress() (*examplev1.GetFooProgressResponse, error) {
  return &examplev1.GetFooProgressResponse{Progress: wf.progress, Status: wf.status}, nil
}

// UpdateFooProgress defines the handler for an UpdateFooProgress update
func (wf *CreateFooWorkflow) UpdateFooProgress(ctx workflow.Context, req *examplev1.SetFooProgressRequest) (*examplev1.GetFooProgressResponse, error) {
  wf.progress = req.GetProgress()
  switch {
  case wf.progress < 0:
    wf.progress, wf.status = 0, examplev1.Foo_FOO_STATUS_CREATING
  case wf.progress < 100:
    wf.status = examplev1.Foo_FOO_STATUS_CREATING
  case wf.progress >= 100:
    wf.progress, wf.status = 100, examplev1.Foo_FOO_STATUS_READY
  }
  return &examplev1.GetFooProgressResponse{Progress: wf.progress, Status: wf.status}, nil
}

// Notify defines the implementation for a Notify activity
func (a *Activities) Notify(ctx context.Context, req *examplev1.NotifyRequest) error {
  activity.GetLogger(ctx).Info("notification", "message", req.GetMessage())
  return nil
}

func main() {
  // initialize the generated cli application
  app, err := examplev1.NewExampleCli(
    examplev1.NewExampleCliOptions().WithWorker(func(cmd *cli.Context, c client.Client) (worker.Worker, error) {
      // register activities and workflows using generated helpers
      w := worker.New(c, examplev1.ExampleTaskQueue, worker.Options{})
      examplev1.RegisterExampleActivities(w, &example.Activities{})
      examplev1.RegisterExampleWorkflows(w, &example.Workflows{})
      return w, nil
    }),
  )
  if err != nil {
    log.Fatalf("error initializing example cli: %v", err)
  }

  // run cli
  if err := app.Run(os.Args); err != nil {
    log.Fatal(err)
  }
}

10. Run your worker

start temporal

temporal server start-dev \
  --dynamic-config-value "frontend.enableUpdateWorkflowExecution=true" \
  --dynamic-config-value "frontend.enableUpdateWorkflowExecutionAsyncAccepted=true"

start worker

go get -u github.com/cludden/protoc-gen-go-temporal@<release> && go mod tidy
go run main.go worker

11. Execute workflows, queries, signals, and updates

with generated client

package main

import (
  "context"
  "log"

  examplev1 "github.com/cludden/protoc-gen-go-temporal/gen/example/v1"
  "go.temporal.io/sdk/client"
)

func main() {
  c, _ := client.Dial(client.Options{})
  client, ctx := examplev1.NewClient(c), context.Background()

  run, _ := client.CreateFooAsync(ctx, &examplev1.CreateFooRequest{Name: "test"})
  log.Printf("started workflow: workflow_id=%s, run_id=%s\n", run.ID(), run.RunID())

  log.Println("signalling progress")
  _ = run.SetFooProgress(ctx, &examplev1.SetFooProgressRequest{Progress: 5.7})

  progress, _ := run.GetFooProgress(ctx)
  log.Printf("queried progress: %s\n", progress.String())

  update, _ := run.UpdateFooProgress(ctx, &examplev1.SetFooProgressRequest{Progress: 100})
  log.Printf("updated progress: %s\n", update.String())

  resp, _ := run.Get(ctx)
  log.Printf("workflow completed: %s\n", resp.String())
}

with generated cli

$ go run main.go -h
NAME:
Example - an example temporal cli

USAGE:
Example [global options] command [command options] [arguments...]

COMMANDS:
worker   run service worker
help, h  Shows a list of commands or help for one command
QUERIES:
  get-foo-progress  GetFooProgress returns the status of a CreateFoo operation
SIGNALS:
  set-foo-progress  SetFooProgress sets the current status of a CreateFoo operation
UPDATES:
  update-foo-progress  UpdateFooProgress sets the current status of a CreateFoo operation
WORKFLOWS:
  create-foo                        CreateFoo creates a new foo operation
  create-foo-with-set-foo-progress  sends a SetFooProgress signal to a CreateFoo workflow, starting it if necessary

GLOBAL OPTIONS:
--help, -h  show help (default: false)

$ go run main.go create-foo -d --name test
success
workflow id: create-foo/test
run id: 44cacae1-6a13-4b4a-8db7-d29eaafd1499

$ go run main.go set-foo-progress -w create-foo/test --progress 5.7
success

$ go run main.go get-foo-progress -w create-foo/test
{
  "progress": 5.7,
  "status": "FOO_STATUS_CREATING"
}

$ go run main.go update-foo-progress -w create-foo/test --progress 100
{
  "progress": 100,
  "status": "FOO_STATUS_READY"
}

$ go run main.go get-foo-progress -w create-foo/test
{
  "progress": 100,
  "status": "FOO_STATUS_READY"
}

Options

See docs for all Service and Method options supported by this plugin.

Bloblang Expressions

Default workflow IDs, update IDs, and search attributes can be defined using Bloblang expressions via the ${!<expression>} interpolation syntax. The expression is evaluated against the protojson serialized input, allowing it to leverage fields from the input parameter, as well as Bloblang's native functions and methods.

Example

The following schema definition:

syntax="proto3"

package example.v1;

import "google/protobuf/empty.proto";
import "temporal/v1/temporal.proto";

service Example {
  rpc SayGreeting(SayGreetingRequest) returns (google.protobuf.Empty) {
    option (temporal.v1.workflow) = {
      id: 'say-greeting/${! greeting.or("hello").capitalize() }/${! subject.or("world").capitalize() }/${! uuid_v4() }'
    };
  }
}

message SayGreetingRequest {
  string greeting = 1;
  string subject = 2;
}

Can be used like so:

c, _ := client.Dial(client.Options{})
example := examplev1.NewClient(c)

run, _ := example.ExecuteSayGreeting(context.Background(), &examplev1.SayGreetingRequest{})
require.Regexp(`^say-greeting/Hello/World/[a-f0-9-]{32}$`, run.ID())

run, _ := example.ExecuteSayGreeting(context.Background(), &examplev1.SayGreetingRequest{
  Greeting: "howdy",
  Subject: "stranger",
})
require.Regexp(`^say-greeting/Howdy/Stranger/[a-f0-9-]{32}$`, run.ID())

Workflow Update

Experimental

This plugin has experimental support for Temporal's experimental Workflow Update capability. Note that this requires cluster support enabled with both of the following dynamic config values set to true

• frontend.enableUpdateWorkflowExecution
• frontend.enableUpdateWorkflowExecutionAsyncAccepted

CLI

This plugin can optionally generate a configurable CLI using github.com/urfave/cli/v2. To enable this functionality, use the corresponding plugin option. When enabled, this plugin will generate a CLI command for each workflow, start-workflow-with-signal, query, and signal. Each command provides typed flags for configuring the corresponding inputs and options.

package main

import (
  "log"
  "os"

  example "github.com/cludden/protoc-gen-go-temporal/example"
  examplev1 "github.com/cludden/protoc-gen-go-temporal/gen/example/v1"
  "github.com/urfave/cli/v2"
  "go.temporal.io/sdk/client"
  "go.temporal.io/sdk/worker"
)

func main() {
  app, err := examplev1.NewExampleCli(
    examplev1.NewExampleCliOptions().
      WithClient(func(cmd *cli.Context) (client.Client, error) {
        return client.Dial(client.Options{})
      }).
      WithWorker(func(cmd *cli.Context, c client.Client) (worker.Worker, error) {
        w := worker.New(c, examplev1.ExampleTaskQueue, worker.Options{})
        examplev1.RegisterExampleWorkflows(w, &example.Workflows{})
        examplev1.RegisterExampleActivities(w, &example.Activities{})
        return w, nil
      }),
  )
  if err != nil {
    log.Fatalf("error initializing cli: %v", err)
  }
  if err := app.Run(os.Args); err != nil {
    log.Fatal(err)
  }
}

Test Client

The generated code includes resources that are compatible with the Temporal Go SDK's testsuite module. See examples for example usage.

Note: that all queries, signals, and udpates must be called via the test environment's RegisterDelayedCallback method prior to invoking the test client's synchronous <Workflow> method or an asynchronous workflow run's Get method.

Example:

See the example_test.go example for more details.

Cross-Namespace (XNS)

Experimental

This plugin provides experimental support for cross-namespace and/or cross-cluster integration by enabling the enable-xns plugin option. When enabled, the plugin will generate an additional path/to/generated/code/<package>xns go package containing types, methods, and helpers for calling workflows, queries, signals, and updates from other Temporal workflows via activities. The activities use heartbeating to maintain liveness for long-running workflows or updates, and their associated timeouts can be configured using the generated options helpers.

Example:

See the xns example for more details.

Codec

Temporal's default data converter will serialize protobuf types using the json/protobuf encoding provided by the ProtoJSONPayloadConverter, which allows the Temporal UI to automatically decode the underlying payload and render it as JSON. If you'd prefer to take advantage of protobuf's binary format for smaller payloads, you can provide an alternative data converter to the Temporal client at initialization that prioritizes the ProtoPayloadConverter ahead of the ProtoJSONPayloadConverter. See below for an example.

If you choose to use binary/protobuf encoding, you'll lose the ability to view decoded payloads in the Temporal UI unless you configure the Remote Codec Server integration. This plugin can generate helpers that simplify the process of implementing a remote codec server for use with the Temporal UI to support conversion between binary/protobuf and json/protobuf or json/plain payload encodings. See below for a simple example. For a more advanced example that supports different codecs per namespace, cors, and authentication, see the codec-server go sample.

Example:

See the codecserver example for more details.

Documentation

This plugin has experimental support for generating documentation via Go templates. You can enable it by setting the docs-out plugin option. By default, it uses the embedded basic template (see example). A custom template can be specified using the docs-template plugin option. Templates receive a Data struct value as input, and have access to various Template functions, including the functions included via text/template, as well as the third-party sprig template functions.

Reference

• Generated code reference

License

Licensed under the MIT License
Copyright for portions of project cludden/protoc-gen-go-temporal are held by Chad Retz, 2021 as part of project cretz/temporal-sdk-go-advanced. All other copyright for project cludden/protoc-gen-go-temporal are held by Chris Ludden, 2024.