github.com/coreos/mantle@v0.13.0/platform/api/gcloud/pending.go (about)

     1  // Copyright 2017 CoreOS, Inc.
     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 gcloud
    16  
    17  import (
    18  	"fmt"
    19  	"time"
    20  
    21  	"google.golang.org/api/compute/v1"
    22  	"google.golang.org/api/googleapi"
    23  )
    24  
    25  type doable interface {
    26  	Do(opts ...googleapi.CallOption) (*compute.Operation, error)
    27  }
    28  
    29  type Pending struct {
    30  	Interval time.Duration
    31  	Timeout  time.Duration // for default progress function
    32  	Progress func(desc string, elapsed time.Duration, op *compute.Operation) error
    33  
    34  	desc string
    35  	do   doable
    36  }
    37  
    38  func (a *API) NewPending(desc string, do doable) *Pending {
    39  	pending := &Pending{
    40  		Interval: 10 * time.Second,
    41  		Timeout:  10 * time.Minute,
    42  		desc:     desc,
    43  		do:       do,
    44  	}
    45  	pending.Progress = pending.defaultProgress
    46  	return pending
    47  }
    48  
    49  func (p *Pending) Wait() error {
    50  	var op *compute.Operation
    51  	var err error
    52  	failures := 0
    53  	start := time.Now()
    54  	for {
    55  		op, err = p.do.Do()
    56  		if err == nil {
    57  			err := p.Progress(p.desc, time.Now().Sub(start), op)
    58  			if err != nil {
    59  				return err
    60  			}
    61  		} else {
    62  			failures++
    63  			if failures > 5 {
    64  				return fmt.Errorf("Fetching %q status failed: %v", p.desc, err)
    65  			}
    66  		}
    67  		if op != nil && op.Status == "DONE" {
    68  			break
    69  		}
    70  		time.Sleep(p.Interval)
    71  	}
    72  	if op.Error != nil {
    73  		if len(op.Error.Errors) > 0 {
    74  			return fmt.Errorf("Operation %q failed: %+v", p.desc, op.Error.Errors)
    75  		}
    76  		return fmt.Errorf("Operation %q failed to start", p.desc)
    77  	}
    78  	return nil
    79  }
    80  
    81  func (p *Pending) defaultProgress(desc string, elapsed time.Duration, op *compute.Operation) error {
    82  	var err error
    83  	switch op.Status {
    84  	case "PENDING", "RUNNING":
    85  		err = fmt.Errorf("Operation %q is %q", desc, op.Status)
    86  	case "DONE":
    87  		return nil
    88  	default:
    89  		err = fmt.Errorf("Unknown operation status %q for %q: %+v", op.Status, desc, op)
    90  	}
    91  
    92  	if p.Timeout > 0 && elapsed > p.Timeout {
    93  		return fmt.Errorf("Failed to wait for operation %q: %v", desc, err)
    94  	}
    95  
    96  	return nil
    97  }