github.com/shashidharatd/test-infra@v0.0.0-20171006011030-71304e1ca560/prow/plugins/hold/hold.go (about)

     1  /*
     2  Copyright 2017 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  // Package hold contains a plugin which will allow users to label their
    18  // own pull requests as not ready or ready for merge. The submit queue
    19  // will honor the label to ensure pull requests do not merge when it is
    20  // applied.
    21  package hold
    22  
    23  import (
    24  	"fmt"
    25  	"regexp"
    26  
    27  	"github.com/sirupsen/logrus"
    28  
    29  	"k8s.io/test-infra/prow/github"
    30  	"k8s.io/test-infra/prow/plugins"
    31  )
    32  
    33  const pluginName = "hold"
    34  
    35  var (
    36  	label         = "do-not-merge/hold"
    37  	labelRe       = regexp.MustCompile(`(?mi)^/hold\s*$`)
    38  	labelCancelRe = regexp.MustCompile(`(?mi)^/hold cancel\s*$`)
    39  )
    40  
    41  type hasLabelFunc func(e *github.GenericCommentEvent) (bool, error)
    42  
    43  func init() {
    44  	plugins.RegisterGenericCommentHandler(pluginName, handleGenericComment)
    45  }
    46  
    47  type githubClient interface {
    48  	AddLabel(owner, repo string, number int, label string) error
    49  	RemoveLabel(owner, repo string, number int, label string) error
    50  	GetIssueLabels(org, repo string, number int) ([]github.Label, error)
    51  }
    52  
    53  func handleGenericComment(pc plugins.PluginClient, e github.GenericCommentEvent) error {
    54  	hasLabel := func(e *github.GenericCommentEvent) (bool, error) {
    55  		return hasLabel(pc.GitHubClient, e.Repo.Owner.Login, e.Repo.Name, e.Number, label)
    56  	}
    57  	return handle(pc.GitHubClient, pc.Logger, &e, hasLabel)
    58  }
    59  
    60  // handle drives the pull request to the desired state. If any user adds
    61  // a /hold directive, we want to add a label if one does not already exist.
    62  // If they add /hold cancel, we want to remove the label if it exists.
    63  func handle(gc githubClient, log *logrus.Entry, e *github.GenericCommentEvent, f hasLabelFunc) error {
    64  	if e.Action != github.GenericCommentActionCreated {
    65  		return nil
    66  	}
    67  	needsLabel := false
    68  	if labelRe.MatchString(e.Body) {
    69  		needsLabel = true
    70  	} else if labelCancelRe.MatchString(e.Body) {
    71  		needsLabel = false
    72  	} else {
    73  		return nil
    74  	}
    75  
    76  	hasLabel, err := f(e)
    77  	if err != nil {
    78  		return err
    79  	}
    80  
    81  	org := e.Repo.Owner.Login
    82  	repo := e.Repo.Name
    83  
    84  	if hasLabel && !needsLabel {
    85  		log.Info("Removing %q label for %s/%s#%d", label, org, repo, e.Number)
    86  		return gc.RemoveLabel(org, repo, e.Number, label)
    87  	} else if !hasLabel && needsLabel {
    88  		log.Info("Adding %q label for %s/%s#%d", label, org, repo, e.Number)
    89  		return gc.AddLabel(org, repo, e.Number, label)
    90  	}
    91  	return nil
    92  }
    93  
    94  // hasLabel checks if a label is applied to a pr.
    95  func hasLabel(c githubClient, org, repo string, num int, label string) (bool, error) {
    96  	labels, err := c.GetIssueLabels(org, repo, num)
    97  	if err != nil {
    98  		return false, fmt.Errorf("failed to get the labels on %s/%s#%d: %v", org, repo, num, err)
    99  	}
   100  	for _, candidate := range labels {
   101  		if candidate.Name == label {
   102  			return true, nil
   103  		}
   104  	}
   105  	return false, nil
   106  }