├── .travis.yml
├── README.md
├── LICENSE
├── healthchecks_test.go
└── healthchecks.go


/.travis.yml:
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 1 | language: go
 2 | go:
 3 |   - 1.3
 4 |   - tip
 5 | notifications:
 6 |   # See http://about.travis-ci.org/docs/user/build-configuration/ to learn more
 7 |   # about configuring notification recipients and more.
 8 |   email:
 9 |     recipients:
10 |       - coda.hale@gmail.com
11 | 


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/README.md:
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1 | healthchecks
2 | ============
3 | 
4 | [![Build Status](https://travis-ci.org/codahale/healthchecks.png?branch=master)](https://travis-ci.org/codahale/healthchecks)
5 | 
6 | A Go package which exposes health check results as expvars.
7 | 
8 | For documentation, check [godoc](http://godoc.org/github.com/codahale/healthchecks).
9 | 


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/LICENSE:
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 1 | The MIT License (MIT)
 2 | 
 3 | Copyright (c) 2014 Coda Hale
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining a copy
 6 | of this software and associated documentation files (the "Software"), to deal
 7 | in the Software without restriction, including without limitation the rights
 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 | 
12 | The above copyright notice and this permission notice shall be included in
13 | all copies or substantial portions of the Software.
14 | 
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
21 | THE SOFTWARE.
22 | 


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/healthchecks_test.go:
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 1 | package healthchecks
 2 | 
 3 | import (
 4 | 	"encoding/json"
 5 | 	"expvar"
 6 | 	"fmt"
 7 | 	"reflect"
 8 | 	"testing"
 9 | 	"time"
10 | )
11 | 
12 | func TestHealthchecks(t *testing.T) {
13 | 	start := time.Now()
14 | 	v := expvar.Get("healthchecks").String()
15 | 	elapsed := time.Now().Sub(start)
16 | 
17 | 	if elapsed.Seconds() > 1.2 {
18 | 		t.Errorf("Took %v, not running in parallel", elapsed)
19 | 	}
20 | 
21 | 	var actual map[string]string
22 | 	if err := json.Unmarshal([]byte(v), &actual); err != nil {
23 | 		t.Fatal(err)
24 | 	}
25 | 
26 | 	expected := map[string]string{
27 | 		"good":  "OK",
28 | 		"bad":   "bad thing happen",
29 | 		"ugly":  "well dang",
30 | 		"slow1": "OK",
31 | 		"slow2": "OK",
32 | 	}
33 | 
34 | 	if !reflect.DeepEqual(actual, expected) {
35 | 		t.Errorf("Was %#v, but expected %#v", actual, expected)
36 | 	}
37 | }
38 | 
39 | func init() {
40 | 	Add("good", func() error {
41 | 		return nil
42 | 	})
43 | 
44 | 	Add("bad", func() error {
45 | 		return fmt.Errorf("bad thing happen")
46 | 	})
47 | 
48 | 	Add("ugly", func() error {
49 | 		panic("well dang")
50 | 	})
51 | 
52 | 	Add("slow1", func() error {
53 | 		time.Sleep(1 * time.Second)
54 | 		return nil
55 | 	})
56 | 
57 | 	Add("slow2", func() error {
58 | 		time.Sleep(1 * time.Second)
59 | 		return nil
60 | 	})
61 | }
62 | 


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/healthchecks.go:
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 1 | // Package healthchecks provides functionality to add application-level
 2 | // healthchecks which evaluate the health of components at runtime and expose
 3 | // the results as expvars.
 4 | package healthchecks
 5 | 
 6 | import (
 7 | 	"expvar"
 8 | 	"fmt"
 9 | 	"sync"
10 | )
11 | 
12 | // A Healthcheck checks the functionality of a component of your application and
13 | // returns and error if anything is wrong.
14 | type Healthcheck func() error
15 | 
16 | // Add adds the given healthcheck to the set of known healthchecks.
17 | func Add(name string, healthcheck Healthcheck) {
18 | 	healthchecksMutex.Lock()
19 | 	defer healthchecksMutex.Unlock()
20 | 
21 | 	healthchecks[name] = healthcheck
22 | }
23 | 
24 | func execAll() map[string]string {
25 | 	healthchecksMutex.Lock()
26 | 	defer healthchecksMutex.Unlock()
27 | 
28 | 	var m sync.Mutex
29 | 	var wg sync.WaitGroup
30 | 	wg.Add(len(healthchecks))
31 | 
32 | 	results := make(map[string]string, len(healthchecks))
33 | 	for name, healthcheck := range healthchecks {
34 | 		go func(name string, healthcheck Healthcheck) {
35 | 			defer wg.Done()
36 | 
37 | 			res := exec(healthcheck)
38 | 
39 | 			m.Lock()
40 | 			defer m.Unlock()
41 | 
42 | 			results[name] = res
43 | 		}(name, healthcheck)
44 | 	}
45 | 	wg.Wait()
46 | 	return results
47 | }
48 | 
49 | func exec(hc Healthcheck) (s string) {
50 | 	defer func() {
51 | 		err := recover()
52 | 		if err != nil {
53 | 			s = fmt.Sprintf("%v", err)
54 | 		}
55 | 	}()
56 | 
57 | 	err := hc()
58 | 	if err != nil {
59 | 		return err.Error()
60 | 	}
61 | 	return "OK"
62 | }
63 | 
64 | var (
65 | 	healthchecks      = make(map[string]Healthcheck)
66 | 	healthchecksMutex sync.Mutex
67 | )
68 | 
69 | func init() {
70 | 	expvar.Publish("healthchecks", expvar.Func(func() interface{} {
71 | 		return execAll()
72 | 	}))
73 | }
74 | 


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