Add necessary data types to api and database to support pipeline version.

backend/api/pipeline.proto

@@ -20,8 +20,10 @@ package api;
 import "google/api/annotations.proto";
 import "google/protobuf/timestamp.proto";
 import "google/protobuf/empty.proto";
-import "backend/api/parameter.proto";
 import "backend/api/error.proto";
+import "backend/api/parameter.proto";
+import "backend/api/pipeline_spec.proto";
+import "backend/api/resource_reference.proto";
 import "protoc-gen-swagger/options/annotations.proto";
 
 option (grpc.gateway.protoc_gen_swagger.options.openapiv2_swagger) = {
@@ -136,6 +138,32 @@ message GetTemplateResponse {
   string template = 1;
 }
 
+message GetPipelineVersionTemplateRequest{
+  string version_id = 1;
+}
+
+message CreatePipelineVersionRequest {
+  // ResourceReference inside PipelineVersion specifies the pipeline that this
+  // version belongs to.
+  PipelineVersion version = 1;
+}
+
+message GetPipelineVersionRequest {
+  string version_id = 1;
+}
+
+message ListPipelineVersionsRequest {
+  // ResourceKey specifies the pipeline whose versions are to be listed.
+  ResourceKey resource_key = 1;
+  int32 page_size = 2;
+  string page_token = 3;
+}
+
+message ListPipelineVersionsResponse {
+  repeated PipelineVersion versions = 1;
+  string next_page_token = 2;
+}
+
 message Pipeline {
   // Output. Unique pipeline ID. Generated by API server.
   string id = 1;
@@ -151,14 +179,53 @@ message Pipeline {
   string description = 4;
 
   // Output. The input parameters for this pipeline.
+  // TODO(jingzhang36): replace this parameters field with the parameters field
+  // inside PipelineVersion when all usage of the former has been changed to use
+  // the latter.
   repeated Parameter parameters = 5;
 
   // The URL to the source of the pipeline. This is required when creating the
   // pipeine through CreatePipeline API.
+  // TODO(jingzhang36): replace this url field with the code_source_urls field
+  // inside PipelineVersion when all usage of the former has been changed to use
+  // the latter.
   Url url = 7;
 
   // In case any error happens retrieving a pipeline field, only pipeline ID
   // and the error message is returned. Client has the flexibility of choosing
   // how to handle error. This is especially useful during listing call.
   string error = 6;
+
+  // Output only. The default version of the pipeline. As of now, the latest
+  // version is used as default. (In the future, if desired by customers, we
+  // can allow them to set default version.)
+  // TODO(jingzhang36): expose this in API pipeline definition with FE changes.
+  // PipelineVersion default_version = 8;
 }
+
+message PipelineVersion {
+  // Output. Unique version ID. Generated by API server.
+  string id = 1;
+
+  // Optional input field. Version name provided by user.
+  string name = 2;
+
+  // Output. The time this pipeline version is created.
+  google.protobuf.Timestamp created_at = 3;
+
+  // Output. The input parameters for this pipeline.
+  repeated Parameter parameters = 4;
+
+  // Input. Optional. Pipeline version code source.
+  string code_source_url = 5;
+
+  // Input. Required. Pipeline version package url.
+  // Whe calling CreatePipelineVersion API method, need to provide one package
+  // file location.
+  Url package_url = 6;
+
+  // Input. Required. E.g., specify which pipeline this pipeline version belongs
+  // to.
+  repeated ResourceReference resource_references = 7;
+}
+

backend/api/resource_reference.proto

@@ -21,6 +21,7 @@ enum ResourceType {
   UNKNOWN_RESOURCE_TYPE = 0;
   EXPERIMENT = 1;
   JOB = 2;
+  PIPELINE = 3;
 }
 
 enum Relationship {

backend/src/apiserver/BUILD.bazel

@@ -26,6 +26,7 @@ go_library(
         "@com_github_grpc_ecosystem_grpc_gateway//runtime:go_default_library",
         "@com_github_jinzhu_gorm//:go_default_library",
         "@com_github_jinzhu_gorm//dialects/sqlite:go_default_library",
+        "@com_github_masterminds_squirrel//:go_default_library",
         "@com_github_minio_minio_go//:go_default_library",
         "@com_github_spf13_viper//:go_default_library",
         "@io_k8s_client_go//kubernetes/typed/core/v1:go_default_library",

backend/src/apiserver/client_manager.go

@@ -176,11 +176,24 @@ func initDBClient(initConnectionTimeout time.Duration) *storage.DB {
 	db, err := gorm.Open(driverName, arg)
 	util.TerminateIfError(err)
 
+	// If pipeline_versions table is introduced into DB for the first time,
+	// it needs initialization or data backfill.
+	var tableNames []string
+	var initializePipelineVersions = true
+	db.Raw(`show tables`).Pluck("Tables_in_mlpipeline", &tableNames)
+	for _, tableName := range tableNames {
+		if tableName == "pipeline_versions" {
+			initializePipelineVersions = false
+			break
+		}
+	}
+
 	// Create table
 	response := db.AutoMigrate(
 		&model.Experiment{},
 		&model.Job{},
 		&model.Pipeline{},
+		&model.PipelineVersion{},
 		&model.ResourceReference{},
 		&model.RunDetail{},
 		&model.RunMetric{},
@@ -201,6 +214,18 @@ func initDBClient(initConnectionTimeout time.Duration) *storage.DB {
 	if response.Error != nil {
 		glog.Fatalf("Failed to create a foreign key for RunID in run_metrics table. Error: %s", response.Error)
 	}
+	response = db.Model(&model.PipelineVersion{}).
+		AddForeignKey("PipelineId", "pipelines(UUID)", "CASCADE" /* onDelete */, "CASCADE" /* update */)
+	if response.Error != nil {
+		glog.Fatalf("Failed to create a foreign key for PipelineId in pipeline_versions table. Error: %s", response.Error)
+	}
+
+	// Data backfill for pipeline_versions if this is the first time for
+	// pipeline_versions to enter mlpipeline DB.
+	if initializePipelineVersions {
+		initPipelineVersionsFromPipelines(db)
+	}
+
 	return storage.NewDB(db.DB(), storage.NewMySQLDialect())
 }
 
@@ -288,3 +313,34 @@ func newClientManager() ClientManager {
 
 	return clientManager
 }
+
+// Data migration in 2 steps to introduce pipeline_versions table. This
+// migration shall be called only once when pipeline_versions table is created
+// for the first time in DB.
+func initPipelineVersionsFromPipelines(db *gorm.DB) {
+	tx := db.Begin()
+
+	// Step 1: duplicate pipelines to pipeline versions.
+	// The pipeline versions created here are not through KFP pipeine version
+	// API, and are only for the legacy pipelines that are created
+	// before pipeline version API is introduced.
+	// For those legacy pipelines, who don't have versions before, we create one
+	// implicit version for each of them. Given a legacy pipeline, the implicit
+	// version created here is assigned an ID the same as the pipeline ID. This
+	// way we don't need to move the minio file of pipeline package around,
+	// since the minio file's path is based on the pipeline ID (and now on the
+	// implicit version ID too). Meanwhile, IDs are required to be unique inside
+	// the same resource type, so pipeline and pipeline version as two different
+	// resources useing the same ID is OK.
+	// On the other hand, pipeline and its pipeline versions created after
+	// pipeline version API is introduced will have different Ids; and the minio
+	// file will be put directly into the directories for pipeline versions.
+	tx.Exec(`INSERT INTO
+	pipeline_versions (UUID, Name, CreatedAtInSec, Parameters, Status, PipelineId)
+	SELECT UUID, Name, CreatedAtInSec, Parameters, Status, UUID FROM pipelines;`)
+
+	// Step 2: modifiy pipelines table after pipeline_versions are populated.
+	tx.Exec("update pipelines set DefaultVersionId=UUID;")
+
+	tx.Commit()
+}

backend/src/apiserver/list/list.go

@@ -51,6 +51,8 @@ type token struct {
 	KeyFieldValue interface{}
 	// IsDesc is true if the sorting order should be descending.
 	IsDesc bool
+	// ModelName is the table where ***FieldName belongs to.
+	ModelName string
 	// Filter represents the filtering that should be applied in the query.
 	Filter *filter.Filter
 }
@@ -125,7 +127,9 @@ func NewOptions(listable Listable, pageSize int, sortBy string, filterProto *api
 		return nil, err
 	}
 
-	token := &token{KeyFieldName: listable.PrimaryKeyColumnName()}
+	token := &token{
+		KeyFieldName: listable.PrimaryKeyColumnName(),
+		ModelName:    listable.GetModelName()}
 
 	// Ignore the case of the letter. Split query string by space.
 	queryList := strings.Fields(strings.ToLower(sortBy))
@@ -177,15 +181,23 @@ func (o *Options) AddPaginationToSelect(sqlBuilder sq.SelectBuilder) sq.SelectBu
 // containing these.
 func (o *Options) AddSortingToSelect(sqlBuilder sq.SelectBuilder) sq.SelectBuilder {
 	// If next row's value is specified, set those values in the clause.
+	var modelNamePrefix string
+	if len(o.ModelName) == 0 {
+		modelNamePrefix = ""
+	} else {
+		modelNamePrefix = o.ModelName + "."
+	}
 	if o.SortByFieldValue != nil && o.KeyFieldValue != nil {
 		if o.IsDesc {
 			sqlBuilder = sqlBuilder.
-				Where(sq.Or{sq.Lt{o.SortByFieldName: o.SortByFieldValue},
-					sq.And{sq.Eq{o.SortByFieldName: o.SortByFieldValue}, sq.LtOrEq{o.KeyFieldName: o.KeyFieldValue}}})
+				Where(sq.Or{sq.Lt{modelNamePrefix + o.SortByFieldName: o.SortByFieldValue},
+					sq.And{sq.Eq{modelNamePrefix + o.SortByFieldName: o.SortByFieldValue},
+						sq.LtOrEq{modelNamePrefix + o.KeyFieldName: o.KeyFieldValue}}})
 		} else {
 			sqlBuilder = sqlBuilder.
-				Where(sq.Or{sq.Gt{o.SortByFieldName: o.SortByFieldValue},
-					sq.And{sq.Eq{o.SortByFieldName: o.SortByFieldValue}, sq.GtOrEq{o.KeyFieldName: o.KeyFieldValue}}})
+				Where(sq.Or{sq.Gt{modelNamePrefix + o.SortByFieldName: o.SortByFieldValue},
+					sq.And{sq.Eq{modelNamePrefix + o.SortByFieldName: o.SortByFieldValue},
+						sq.GtOrEq{modelNamePrefix + o.KeyFieldName: o.KeyFieldValue}}})
 		}
 	}
 
@@ -194,8 +206,8 @@ func (o *Options) AddSortingToSelect(sqlBuilder sq.SelectBuilder) sq.SelectBuild
 		order = "DESC"
 	}
 	sqlBuilder = sqlBuilder.
-		OrderBy(fmt.Sprintf("%v %v", o.SortByFieldName, order)).
-		OrderBy(fmt.Sprintf("%v %v", o.KeyFieldName, order))
+		OrderBy(fmt.Sprintf("%v %v", modelNamePrefix+o.SortByFieldName, order)).
+		OrderBy(fmt.Sprintf("%v %v", modelNamePrefix+o.KeyFieldName, order))
 
 	return sqlBuilder
 }
@@ -258,6 +270,8 @@ type Listable interface {
 	// APIToModelFieldMap returns a map from field names in the API representation
 	// of the model to its corresponding field name in the model itself.
 	APIToModelFieldMap() map[string]string
+	// GetModelName returns table name used as sort field prefix.
+	GetModelName() string
 }
 
 // NextPageToken returns a string that can be used to fetch the subsequent set
@@ -292,6 +306,7 @@ func (o *Options) nextPageToken(listable Listable) (*token, error) {
 		KeyFieldValue:    keyField.Interface(),
 		IsDesc:           o.IsDesc,
 		Filter:           o.Filter,
+		ModelName:        o.ModelName,
 	}, nil
 }
 

backend/src/apiserver/list/list_test.go

@@ -39,6 +39,10 @@ func (f *fakeListable) APIToModelFieldMap() map[string]string {
 	return fakeAPIToModelMap
 }
 
+func (f *fakeListable) GetModelName() string {
+	return ""
+}
+
 func TestNextPageToken_ValidTokens(t *testing.T) {
 	l := &fakeListable{PrimaryKey: "uuid123", FakeName: "Fake", CreatedTimestamp: 1234}
 

backend/src/apiserver/model/BUILD.bazel

@@ -1,4 +1,4 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
@@ -10,10 +10,30 @@ go_library(
         "listable_model.go",
         "pipeline.go",
         "pipeline_spec.go",
+        "pipeline_version.go",
         "resource_reference.go",
         "run.go",
     ],
     importpath = "github.com/kubeflow/pipelines/backend/src/apiserver/model",
     visibility = ["//visibility:public"],
     deps = ["//backend/src/apiserver/common:go_default_library"],
 )
+
+go_test(
+    name = "go_default_test",
+    srcs = [
+        "pipeline_version_test.go",
+    ],
+    importpath = "github.com/kubeflow/pipelines/backend/src/apiserver/model",
+    visibility = ["//visibility:public"],
+    embed = [":go_default_library"],
+    deps = [
+        "//backend/api:go_default_library",
+        "//backend/src/apiserver/filter:go_default_library",
+        "//backend/src/apiserver/list:go_default_library",
+        "@com_github_google_go_cmp//cmp:go_default_library",
+        "@com_github_google_go_cmp//cmp/cmpopts:go_default_library",
+        "@com_github_masterminds_squirrel//:go_default_library",
+        "@com_github_stretchr_testify//assert:go_default_library",
+    ],
+)

backend/src/apiserver/model/experiment.go

@@ -37,3 +37,8 @@ var experimentAPIToModelFieldMap = map[string]string{
 func (e *Experiment) APIToModelFieldMap() map[string]string {
 	return experimentAPIToModelFieldMap
 }
+
+// GetModelName returns table name used as sort field prefix
+func (e *Experiment) GetModelName() string {
+	return "experiments"
+}

backend/src/apiserver/model/job.go

@@ -97,3 +97,8 @@ var jobAPIToModelFieldMap = map[string]string{
 func (k *Job) APIToModelFieldMap() map[string]string {
 	return jobAPIToModelFieldMap
 }
+
+// GetModelName returns table name used as sort field prefix
+func (j *Job) GetModelName() string {
+	return "jobs"
+}

backend/src/apiserver/model/pipeline.go

@@ -31,9 +31,14 @@ type Pipeline struct {
 	CreatedAtInSec int64  `gorm:"column:CreatedAtInSec; not null"`
 	Name           string `gorm:"column:Name; not null; unique"`
 	Description    string `gorm:"column:Description; not null"`
+	// TODO(jingzhang36): remove Parameters when no code is accessing this
+	// field. Should use PipelineVersion.Parameters instead.
 	/* Set size to 65535 so it will be stored as longtext. https://dev.mysql.com/doc/refman/8.0/en/column-count-limit.html */
 	Parameters string         `gorm:"column:Parameters; not null; size:65535"`
 	Status     PipelineStatus `gorm:"column:Status; not null"`
+	// Default version of this pipeline. It could be null.
+	DefaultVersionId string           `gorm:"column:DefaultVersionId;"`
+	DefaultVersion   *PipelineVersion `gorm:"-"`
 }
 
 func (p Pipeline) GetValueOfPrimaryKey() string {
@@ -59,10 +64,17 @@ var pipelineAPIToModelFieldMap = map[string]string{
 	"name":        "Name",
 	"created_at":  "CreatedAtInSec",
 	"description": "Description",
+	// TODO(jingzhang36): uncomment this field when we expose it to API
+	// "default_version_id": "DefaultVersionId",
 }
 
 // APIToModelFieldMap returns a map from API names to field names for model
 // Pipeline.
 func (p *Pipeline) APIToModelFieldMap() map[string]string {
 	return pipelineAPIToModelFieldMap
 }
+
+// GetModelName returns table name used as sort field prefix
+func (p *Pipeline) GetModelName() string {
+	return "pipelines"
+}