Add worker-build-id-based versioning api (#190)

Refer to temporalio/proposals#54 for original proposal

Author: Sushisource

Diff for: temporal/api/taskqueue/v1/message.proto

@@ -83,3 +83,23 @@ message StickyExecutionAttributes {
     //     aip.dev/not-precedent: "to" is used to indicate interval. --)
     google.protobuf.Duration schedule_to_start_timeout = 2 [(gogoproto.stdduration) = true];
 }
+
+// Used by the worker versioning APIs, represents a node in the version graph for a particular
+// task queue
+message VersionIdNode {
+    VersionId version = 1;
+    // A pointer to the previous version this version is considered to be compatible with
+    VersionIdNode previous_compatible = 2;
+    // A pointer to the last incompatible version (previous major version)
+    VersionIdNode previous_incompatible = 3;
+}
+
+// Used by the worker versioning APIs, represents a specific version of something
+// Currently, that's just a whole-worker id. In the future, if we support 
+// WASM workflow bundle based versioning, for example, then the inside of this
+// message may become a oneof of different version types.
+message VersionId {
+    // An opaque whole-worker identifier
+    string worker_build_id = 1;
+}
+

Diff for: temporal/api/workflow/v1/message.proto

@@ -142,3 +142,4 @@ message NewWorkflowExecutionInfo {
     temporal.api.common.v1.SearchAttributes search_attributes = 12;
     temporal.api.common.v1.Header header = 13;
 }
+

Diff for: temporal/api/workflowservice/v1/request_response.proto

@@ -950,3 +950,48 @@ message ListSchedulesResponse {
     repeated temporal.api.schedule.v1.ScheduleListEntry schedules = 1;
     bytes next_page_token = 2;
 }
+
+// (-- api-linter: core::0134::request-mask-required=disabled
+//     aip.dev/not-precedent: UpdateWorkerBuildIdOrderingRequest doesn't follow Google API format --)
+// (-- api-linter: core::0134::request-resource-required=disabled
+//     aip.dev/not-precedent: UpdateWorkerBuildIdOrderingRequest RPC doesn't follow Google API format. --)
+message UpdateWorkerBuildIdOrderingRequest {
+    string namespace = 1;
+    // Must be set, the task queue to apply changes to. Because all workers on
+    // a given task queue must have the same set of workflow & activity
+    // implementations, there is no reason to specify a task queue type here.
+    string task_queue = 2;
+    // The version id we are targeting.
+    temporal.api.taskqueue.v1.VersionId version_id = 3;
+    // When set, indicates that the `version_id` in this message is compatible
+    // with the one specified in this field. Because compatability should form
+    // a DAG, any build id can only be the "next compatible" version for one
+    // other ID of a certain type at a time, and any setting which would create a cycle is invalid.
+    temporal.api.taskqueue.v1.VersionId previous_compatible = 4;
+    // When set, establishes the specified `version_id` as the default of it's type
+    // for the queue. Workers matching it will begin processing new workflow executions.
+    // The existing default will be marked as a previous incompatible version
+    // to this one, assuming it is not also in `is_compatible_with`.
+    bool become_default = 5;
+}
+message UpdateWorkerBuildIdOrderingResponse {}
+
+// (-- api-linter: core::0134::request-resource-required=disabled
+//     aip.dev/not-precedent: GetWorkerBuildIdOrderingRequest RPC doesn't follow Google API format. --)
+message GetWorkerBuildIdOrderingRequest {
+    string namespace = 1;
+    // Must be set, the task queue to interrogate about worker id ordering
+    string task_queue = 2;
+    // Limits how deep the returned DAG will go. 1 will return only the
+    // default build id. A default/0 value will return the entire graph.
+    int32 max_depth = 3;
+}
+message GetWorkerBuildIdOrderingResponse {
+    // The currently established default version
+    temporal.api.taskqueue.v1.VersionIdNode current_default = 1;
+    // Other current latest-compatible versions who are not the overall default. These are the
+    // versions that will be used when generating new tasks by following the graph from the
+    // version of the last task out to a leaf.
+    repeated temporal.api.taskqueue.v1.VersionIdNode compatible_leaves = 2;
+}
+

Diff for: temporal/api/workflowservice/v1/service.proto

@@ -368,4 +368,12 @@ service WorkflowService {
     // List all schedules in a namespace.
     rpc ListSchedules (ListSchedulesRequest) returns (ListSchedulesResponse) {
     }
+
+    // (-- api-linter: core::0134::response-message-name=disabled
+    //     aip.dev/not-precedent: UpdateWorkerBuildIdOrdering RPC doesn't follow Google API format. --)
+    // (-- api-linter: core::0134::method-signature=disabled
+    //     aip.dev/not-precedent: UpdateWorkerBuildIdOrdering RPC doesn't follow Google API format. --)
+    rpc UpdateWorkerBuildIdOrdering (UpdateWorkerBuildIdOrderingRequest) returns (UpdateWorkerBuildIdOrderingResponse) {}
+    // This could / maybe should just be part of `DescribeTaskQueue`, but is broken out here to show easily.
+    rpc GetWorkerBuildIdOrdering (GetWorkerBuildIdOrderingRequest) returns (GetWorkerBuildIdOrderingResponse) {}
 }