AppInterface enhancements for subscription

Added new translateSubscribe() and processSubscribe() functions to
appInterface as per HLD sonic-net/SONiC#1287

Also added stub implementation of these functions to all existing app
modules. It blindly treats all paths as non-db. Basic subscription
features, without on_change, are enabled with this mapping.

Signed-off-by: Sachin Holla <[email protected]>

Author: sachinholla

translib/acl_app.go

@@ -26,6 +26,7 @@ import (
 	"reflect"
 	"strconv"
 	"strings"
+
 	"github.com/Azure/sonic-mgmt-common/translib/db"
 	"github.com/Azure/sonic-mgmt-common/translib/ocbinds"
 	"github.com/Azure/sonic-mgmt-common/translib/tlerr"
@@ -168,68 +169,8 @@ func (app *AclApp) translateGet(dbs [db.MaxDB]*db.DB) error {
 }
 
 func (app *AclApp) translateAction(dbs [db.MaxDB]*db.DB) error {
-    err := errors.New("Not supported")
-    return err
-}
-
-func (app *AclApp) translateSubscribe(dbs [db.MaxDB]*db.DB, path string) (*notificationOpts, *notificationInfo, error) {
-	pathInfo := NewPathInfo(path)
-	notifInfo := notificationInfo{dbno: db.ConfigDB}
-	notSupported := tlerr.NotSupportedError{
-		Format: "Subscribe not supported", Path: path}
-
-	if isSubtreeRequest(pathInfo.Template, "/openconfig-acl:acl/acl-sets") {
-		// Subscribing to top level ACL record is not supported. It requires listening
-		// to 2 tables (ACL and ACL_RULE); TransLib does not support it yet
-		if pathInfo.HasSuffix("/acl-sets") ||
-			pathInfo.HasSuffix("/acl-set") ||
-			pathInfo.HasSuffix("/acl-set{}{}") {
-			log.Errorf("Subscribe not supported for top level ACL %s", pathInfo.Template)
-			return nil, nil, notSupported
-		}
-
-		t, err := getAclTypeOCEnumFromName(pathInfo.Var("type"))
-		if err != nil {
-			return nil, nil, err
-		}
-
-		aclkey := getAclKeyStrFromOCKey(pathInfo.Var("name"), t)
-
-		if strings.Contains(pathInfo.Template, "/acl-entry{}") {
-			// Subscribe for one rule
-			rulekey := "RULE_" + pathInfo.Var("sequence-id")
-			notifInfo.table = db.TableSpec{Name: RULE_TABLE}
-			notifInfo.key = asKey(aclkey, rulekey)
-			notifInfo.needCache = !pathInfo.HasSuffix("/acl-entry{}")
-
-		} else if pathInfo.HasSuffix("/acl-entries") || pathInfo.HasSuffix("/acl-entry") {
-			// Subscribe for all rules of an ACL
-			notifInfo.table = db.TableSpec{Name: RULE_TABLE}
-			notifInfo.key = asKey(aclkey, "*")
-
-		} else {
-			// Subscibe for ACL fields only
-			notifInfo.table = db.TableSpec{Name: ACL_TABLE}
-			notifInfo.key = asKey(aclkey)
-			notifInfo.needCache = true
-		}
-
-	} else if isSubtreeRequest(pathInfo.Template, "/openconfig-acl:acl/interfaces") {
-		// Right now interface binding config is maintained within ACL
-		// table itself. Multiple ACLs can be bound to one intf; one
-		// inname can occur in multiple ACL entries. So we cannot map
-		// interface binding xpaths to specific ACL table entry keys.
-		// For now subscribe for full ACL table!!
-		notifInfo.table = db.TableSpec{Name: ACL_TABLE}
-		notifInfo.key = asKey("*")
-		notifInfo.needCache = true
-
-	} else {
-		log.Errorf("Unknown path %s", pathInfo.Template)
-		return nil, nil, notSupported
-	}
-
-	return nil, &notifInfo, nil
+	err := errors.New("Not supported")
+	return err
 }
 
 func (app *AclApp) processCreate(d *db.DB) (SetResponse, error) {
@@ -295,10 +236,10 @@ func (app *AclApp) processGet(dbs [db.MaxDB]*db.DB) (GetResponse, error) {
 }
 
 func (app *AclApp) processAction(dbs [db.MaxDB]*db.DB) (ActionResponse, error) {
-    var resp ActionResponse
-    err := errors.New("Not implemented")
+	var resp ActionResponse
+	err := errors.New("Not implemented")
 
-    return resp, err
+	return resp, err
 }
 
 func (app *AclApp) translateCRUCommon(d *db.DB, opcode int) ([]db.WatchKeys, error) {
@@ -1716,10 +1657,19 @@ func getAclKeyStrFromOCKey(aclname string, acltype ocbinds.E_OpenconfigAcl_ACL_T
 	return aclN + "_" + aclT
 }
 
-/* Check if targetUriPath is child (subtree) of nodePath
+/*
+Check if targetUriPath is child (subtree) of nodePath
 The return value can be used to decide if subtrees needs
 to visited to fill the data or not.
 */
 func isSubtreeRequest(targetUriPath string, nodePath string) bool {
 	return strings.HasPrefix(targetUriPath, nodePath)
 }
+
+func (app *AclApp) translateSubscribe(req *translateSubRequest) (*translateSubResponse, error) {
+	return emptySubscribeResponse(req.path)
+}
+
+func (app *AclApp) processSubscribe(req *processSubRequest) (processSubResponse, error) {
+	return processSubResponse{}, errors.New("not implemented")
+}

translib/api_tests_app.go

@@ -17,6 +17,7 @@
 //                                                                            //
 ////////////////////////////////////////////////////////////////////////////////
 
+//go:build test
 // +build test
 
 package translib
@@ -101,8 +102,12 @@ func (app *apiTests) translateAction(dbs [db.MaxDB]*db.DB) error {
 	return nil
 }
 
-func (app *apiTests) translateSubscribe(dbs [db.MaxDB]*db.DB, path string) (*notificationOpts, *notificationInfo, error) {
-	return nil, nil, nil
+func (app *apiTests) translateSubscribe(req *translateSubRequest) (*translateSubResponse, error) {
+	return emptySubscribeResponse(req.path)
+}
+
+func (app *apiTests) processSubscribe(req *processSubRequest) (processSubResponse, error) {
+	return processSubResponse{}, tlerr.New("not implemented")
 }
 
 func (app *apiTests) processCreate(d *db.DB) (SetResponse, error) {

translib/app_interface.go

@@ -11,7 +11,7 @@
 //                                                                            //
 //  Unless required by applicable law or agreed to in writing, software       //
 //  distributed under the License is distributed on an "AS IS" BASIS,         //
-//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  //  
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  //
 //  See the License for the specific language governing permissions and       //
 //  limitations under the License.                                            //
 //                                                                            //
@@ -31,22 +31,23 @@ package translib
 
 import (
 	"errors"
-	log "github.com/golang/glog"
-	"github.com/openconfig/ygot/ygot"
 	"reflect"
 	"strings"
+
 	"github.com/Azure/sonic-mgmt-common/translib/db"
+	log "github.com/golang/glog"
+	"github.com/openconfig/ygot/ygot"
 )
 
-//Structure containing app module information
+// Structure containing app module information
 type appInfo struct {
 	appType       reflect.Type
 	ygotRootType  reflect.Type
 	isNative      bool
 	tablesToWatch []*db.TableSpec
 }
 
-//Structure containing the app data coming from translib infra
+// Structure containing the app data coming from translib infra
 type appData struct {
 	path       string
 	payload    []byte
@@ -59,23 +60,23 @@ type appData struct {
 // These include RESTCONF query parameters like - depth, fields etc.
 type appOptions struct {
 
-    // depth limits subtree levels in the response data.
-    // 0 indicates unlimited depth.
-    // Valid for GET API only.
-    depth uint
+	// depth limits subtree levels in the response data.
+	// 0 indicates unlimited depth.
+	// Valid for GET API only.
+	depth uint
 
-    // deleteEmptyEntry indicates if the db entry should be deleted upon
-    // deletion of last field. This is a non standard option.
-    deleteEmptyEntry bool
+	// deleteEmptyEntry indicates if the db entry should be deleted upon
+	// deletion of last field. This is a non standard option.
+	deleteEmptyEntry bool
 }
 
-//map containing the base path to app module info
+// map containing the base path to app module info
 var appMap map[string]*appInfo
 
-//array containing all the supported models
+// array containing all the supported models
 var models []ModelData
 
-//Interface for all App Modules
+// Interface for all App Modules
 type appInterface interface {
 	initialize(data appData)
 	translateCreate(d *db.DB) ([]db.WatchKeys, error)
@@ -84,16 +85,17 @@ type appInterface interface {
 	translateDelete(d *db.DB) ([]db.WatchKeys, error)
 	translateGet(dbs [db.MaxDB]*db.DB) error
 	translateAction(dbs [db.MaxDB]*db.DB) error
-	translateSubscribe(dbs [db.MaxDB]*db.DB, path string) (*notificationOpts, *notificationInfo, error)
+	translateSubscribe(req *translateSubRequest) (*translateSubResponse, error)
 	processCreate(d *db.DB) (SetResponse, error)
 	processUpdate(d *db.DB) (SetResponse, error)
 	processReplace(d *db.DB) (SetResponse, error)
 	processDelete(d *db.DB) (SetResponse, error)
 	processGet(dbs [db.MaxDB]*db.DB) (GetResponse, error)
 	processAction(dbs [db.MaxDB]*db.DB) (ActionResponse, error)
+	processSubscribe(req *processSubRequest) (processSubResponse, error)
 }
 
-//App modules will use this function to register with App interface during boot up
+// App modules will use this function to register with App interface during boot up
 func register(path string, info *appInfo) error {
 	var err error
 	log.Info("Registering for path =", path)
@@ -114,7 +116,7 @@ func register(path string, info *appInfo) error {
 	return err
 }
 
-//Adds the model information to the supported models array
+// Adds the model information to the supported models array
 func addModel(model *ModelData) error {
 	var err error
 
@@ -124,7 +126,7 @@ func addModel(model *ModelData) error {
 	return err
 }
 
-//Translib infra will use this function get the app info for a given path
+// Translib infra will use this function get the app info for a given path
 func getAppModuleInfo(path string) (*appInfo, error) {
 	log.Info("getAppModule called for path =", path)
 
@@ -135,23 +137,23 @@ func getAppModuleInfo(path string) (*appInfo, error) {
 
 		log.Info("found the entry in the map for path =", pattern)
 
-		return app, nil 
+		return app, nil
 	}
 
 	/* If no specific app registered fallback to default/common app */
 	log.Infof("No app module registered for path %s hence fallback to default/common app", path)
 	app := appMap["*"]
 
-	return app, nil 
+	return app, nil
 }
 
-//Get all the supported models
+// Get all the supported models
 func getModels() []ModelData {
 
 	return models
 }
 
-//Creates a new app from the appType and returns it as an appInterface
+// Creates a new app from the appType and returns it as an appInterface
 func getAppInterface(appType reflect.Type) (appInterface, error) {
 	var err error
 	appInstance := reflect.New(appType)

translib/common_app.go

@@ -129,59 +129,12 @@ func (app *CommonApp) translateGet(dbs [db.MaxDB]*db.DB) error {
 	return err
 }
 
-func (app *CommonApp) translateSubscribe(dbs [db.MaxDB]*db.DB, path string) (*notificationOpts, *notificationInfo, error) {
-    var err error
-    var subscDt transformer.XfmrTranslateSubscribeInfo
-    var notifInfo notificationInfo
-    var notifOpts notificationOpts
-    txCache := new(sync.Map)
-    err = tlerr.NotSupportedError{Format: "Subscribe not supported", Path: path}
-
-    log.Info("tranlateSubscribe:path", path)
-    subscDt, err = transformer.XlateTranslateSubscribe(path, dbs, txCache)
-    if subscDt.PType == transformer.OnChange {
-        notifOpts.pType = OnChange
-    } else {
-        notifOpts.pType = Sample
-    }
-    notifOpts.mInterval = subscDt.MinInterval
-    notifOpts.isOnChangeSupported = subscDt.OnChange
-    if err != nil {
-        log.Infof("returning: notificationOpts - %v, nil, error - %v", notifOpts, err)
-        return &notifOpts, nil, err
-    }
-    if subscDt.DbDataMap == nil {
-        log.Infof("DB data is nil so returning: notificationOpts - %v, nil, error - %v", notifOpts, err)
-        return &notifOpts, nil, err
-    } else {
-        for dbNo, dbDt := range(subscDt.DbDataMap) {
-            if (len(dbDt) == 0) { //ideally all tables for a given uri should be from same DB
-                continue
-            }
-            log.Infof("Adding to notifInfo, Db Data - %v for DB No - %v", dbDt, dbNo)
-            notifInfo.dbno = dbNo
-            // in future there will be, multi-table in a DB, support from translib, for now its just single table
-            for tblNm, tblDt := range(dbDt) {
-                notifInfo.table = db.TableSpec{Name:tblNm}
-                if (len(tblDt) == 1) {
-                    for tblKy := range(tblDt) {
-                        notifInfo.key = asKey(tblKy)
-                        notifInfo.needCache = subscDt.NeedCache
-                    }
-                } else {
-                    if (len(tblDt) >  1) {
-                        log.Warningf("More than one DB key found for subscription path - %v", path)
-                    } else {
-                        log.Warningf("No DB key found for subscription path - %v", path)
-                    }
-                    return &notifOpts, nil, err
-                }
+func (app *CommonApp) translateSubscribe(req *translateSubRequest) (*translateSubResponse, error) {
+	return emptySubscribeResponse(req.path)
+}
 
-            }
-        }
-    }
-    log.Infof("For path - %v, returning: notifOpts - %v, notifInfo - %v, error - nil", path, notifOpts, notifInfo)
-    return &notifOpts, &notifInfo, nil
+func (app *CommonApp) processSubscribe(req *processSubRequest) (processSubResponse, error) {
+	return processSubResponse{}, errors.New("not implemented")
 }
 
 func (app *CommonApp) translateAction(dbs [db.MaxDB]*db.DB) error {