go.ligato.io/vpp-agent/v3@v3.5.0/examples/kvscheduler/mock_plugins/scenario/failure_fixed_by_retry.go (about)

     1  //  Copyright (c) 2019 Cisco and/or its affiliates.
     2  //
     3  //  Licensed under the Apache License, Version 2.0 (the "License");
     4  //  you may not use this file except in compliance with the License.
     5  //  You may obtain a copy of the License at:
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  //  Unless required by applicable law or agreed to in writing, software
    10  //  distributed under the License is distributed on an "AS IS" BASIS,
    11  //  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  //  See the License for the specific language governing permissions and
    13  //  limitations under the License.
    14  
    15  package scenario
    16  
    17  import (
    18  	"log"
    19  
    20  	"go.ligato.io/vpp-agent/v3/client"
    21  	mocksb "go.ligato.io/vpp-agent/v3/examples/kvscheduler/mock_plugins/ifplugin/mockcalls"
    22  )
    23  
    24  // FailureFixedWithRetry presents a scenario, in which interface fails to get
    25  // created at a first attempt, but an automatic retry, triggered in the background
    26  // after a delay, will succeed to create the interface and all the objects that
    27  // were waiting for it.
    28  func FailureFixedWithRetry() {
    29  	c := client.LocalClient
    30  	listKnownModels(c)
    31  
    32  	mocksb.SimulateFailedTapCreation = true
    33  	printMessage(
    34  		"Resync config",
    35  		"  - TAP interfaces tap1 to be configured inside a bridge-domain",
    36  		"  - FIB entry defined to forward traffic for a certain",
    37  		"    MAC address via tap1",
    38  		"  - the TAP interface fails to get created (simulated in the mock SB)",
    39  		"     -> the binding between the interface and the BD will remain pending",
    40  		"     -> FIB will remain pending",
    41  	)
    42  	err := c.ResyncConfig(
    43  		tap1, bd2, fib3,
    44  	)
    45  	if err != nil {
    46  		log.Println(err)
    47  	}
    48  	informAboutGraphURL(0, true, false)
    49  
    50  	printMessage(
    51  		"Automatic Retry (triggered in the background)",
    52  		"  - the repeated attempt to add tap1 will succeed",
    53  		"     -> once configured, the interface is also added into the BD",
    54  		"        and the pending FIB entry is created, both within the same",
    55  		"        transaction",
    56  	)
    57  	// retry is scheduler to run 1 second after the failed transaction and
    58  	// since printMessage() waits 2 seconds, the interface should be fixed by now
    59  	informAboutGraphURL(1, false, true)
    60  }