1 | # Copacetic
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2 | [![JavaScript Style Guide](https://img.shields.io/badge/code_style-standard-brightgreen.svg)](https://standardjs.com)
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3 | [![Coverage Status](https://coveralls.io/repos/github/fresh8/copacetic/badge.svg?branch=master)](https://coveralls.io/github/fresh8/copacetic?branch=master)
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4 | [![CircleCI](https://circleci.com/gh/fresh8/copacetic.svg?style=svg)](https://circleci.com/gh/fresh8/copacetic)
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5 |
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6 | A package to help your service check the health of its dependencies.
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7 |
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8 |
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9 | ## Requirements
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10 | Node v6.4.0 and above
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11 |
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12 | ## Installation
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13 | ```
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14 | npm install @fresh8/copacetic --save
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15 | ```
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16 |
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17 | #### Quick Start - Javascript
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18 | ```javascript
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19 | const Copacetic = require('@fresh8/copacetic')
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20 | const level = require('@fresh8/copacetic').dependencyLevel
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21 |
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22 | const copacetic = Copacetic()
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23 |
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24 | // Register a dependency
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25 | copacetic.registerDependency({
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26 | name: 'My-Dependency',
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27 | url: 'https://my-Dependency.io',
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28 | // Defaults to SOFT
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29 | level: level.HARD
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30 | })
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31 |
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32 |
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33 | // Check its health
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34 | copacetic
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35 | .check({
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36 | name: 'My-Dependency',
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37 | retries: 2
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38 | })
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39 | .on('healthy', (Dependency) => {
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40 | /**
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41 | * { name: 'My-Dependency',
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42 | * healthy: true/false,
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43 | * lastChecked: Date,
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44 | * level: 'SOFT'
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45 | * }
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46 | */
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47 | })
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48 | .on('unhealthy', (Dependency) => {
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49 | // Handle degraded state...
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50 | })
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51 | ```
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52 |
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53 | #### Quick Start - Typescript
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54 | ```typescript
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55 | import * as Copacetic from '@fresh8/copacetic'
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56 |
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57 | const copacetic = Copacetic('my-service')
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58 |
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59 | const myDependencyOverHttp : Copacetic.DependencyOptions = {
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60 | name: 'my-web-service',
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61 | url: 'http://example.com'
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62 | }
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63 |
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64 | copacetic.registerDependency(myDependencyOverHttp)
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65 |
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66 | instance
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67 | .check({ name: 'my-web-service' })
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68 | .on('healthy', (res: Copacetic.Health) => {
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69 | // do something with your healthy dependency :)
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70 | })
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71 | .on('unhealthy', (res: Copacetic.Health) => {
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72 | // handle degraded state
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73 | })
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74 | ```
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75 |
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76 | <a name="Copacetic"></a>
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77 |
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78 | <a name="Copacetic"></a>
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79 |
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80 | ## Copacetic ⇐ <code>EventEmitter</code>
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81 | **Kind**: global class
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82 | **Extends**: <code>EventEmitter</code>
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83 |
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84 | * [Copacetic](#Copacetic) ⇐ <code>EventEmitter</code>
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85 | * [new Copacetic([name])](#new_Copacetic_new)
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86 | * [.isHealthy](#Copacetic+isHealthy) ⇒ <code>Boolean</code>
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87 | * [.healthInfo](#Copacetic+healthInfo) ⇒ <code>Array.<DependencyHealth></code>
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88 | * [.getDependency(dependency)](#Copacetic+getDependency) ⇒ <code>Dependency</code>
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89 | * [.isDependencyRegistered(dependency)](#Copacetic+isDependencyRegistered) ⇒ <code>Boolean</code>
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90 | * [.registerDependency(opts)](#Copacetic+registerDependency) ⇒ [<code>Copacetic</code>](#Copacetic)
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91 | * [.deregisterDependency(name)](#Copacetic+deregisterDependency) ⇒ [<code>Copacetic</code>](#Copacetic)
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92 | * [.pollAll([interval], [parallel], [schedule])](#Copacetic+pollAll) ⇒ [<code>Copacetic</code>](#Copacetic)
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93 | * [.poll([dependencies], [interval], [parallel], [schedule])](#Copacetic+poll) ⇒ [<code>Copacetic</code>](#Copacetic)
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94 | * [.stop()](#Copacetic+stop)
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95 | * [.checkAll([parallel])](#Copacetic+checkAll) ⇒ [<code>Copacetic</code>](#Copacetic)
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96 | * [.check([name], [dependencies], [retries], [parallel])](#Copacetic+check) ⇒ [<code>Copacetic</code>](#Copacetic)
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97 | * ["healthy"](#Copacetic+event_healthy)
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98 | * ["unhealthy"](#Copacetic+event_unhealthy)
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99 | * ["health"](#Copacetic+event_health)
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100 |
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101 | <a name="new_Copacetic_new"></a>
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102 |
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103 | ### new Copacetic([name])
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104 |
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105 | | Param | Type | Default | Description |
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106 | | --- | --- | --- | --- |
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107 | | [name] | <code>String</code> | <code>''</code> | The name of your service |
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108 |
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109 | <a name="Copacetic+isHealthy"></a>
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110 |
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111 | ### copacetic.isHealthy ⇒ <code>Boolean</code>
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112 | **Kind**: instance property of [<code>Copacetic</code>](#Copacetic)
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113 | **Returns**: <code>Boolean</code> - Copacetic is healthy when all hard dependencies are healthy
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114 | <a name="Copacetic+healthInfo"></a>
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115 |
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116 | ### copacetic.healthInfo ⇒ <code>Array.<DependencyHealth></code>
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117 | **Kind**: instance property of [<code>Copacetic</code>](#Copacetic)
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118 | **Returns**: <code>Array.<DependencyHealth></code> - Health information on all dependencies
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119 | <a name="Copacetic+getDependency"></a>
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120 |
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121 | ### copacetic.getDependency(dependency) ⇒ <code>Dependency</code>
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122 | **Kind**: instance method of [<code>Copacetic</code>](#Copacetic)
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123 |
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124 | | Param | Type |
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125 | | --- | --- |
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126 | | dependency | <code>Dependency</code> \| <code>String</code> |
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127 |
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128 | <a name="Copacetic+isDependencyRegistered"></a>
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129 |
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130 | ### copacetic.isDependencyRegistered(dependency) ⇒ <code>Boolean</code>
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131 | **Kind**: instance method of [<code>Copacetic</code>](#Copacetic)
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132 | **Returns**: <code>Boolean</code> - Whether the dependency has been registered
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133 |
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134 | | Param | Type |
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135 | | --- | --- |
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136 | | dependency | <code>Dependency</code> \| <code>String</code> |
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137 |
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138 | <a name="Copacetic+registerDependency"></a>
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139 |
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140 | ### copacetic.registerDependency(opts) ⇒ [<code>Copacetic</code>](#Copacetic)
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141 | Adds a dependency to a Copacetic instance
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142 |
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143 | **Kind**: instance method of [<code>Copacetic</code>](#Copacetic)
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144 |
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145 | | Param | Type | Description |
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146 | | --- | --- | --- |
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147 | | opts | <code>Object</code> | The configuration for a dependency |
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148 |
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149 | <a name="Copacetic+deregisterDependency"></a>
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150 |
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151 | ### copacetic.deregisterDependency(name) ⇒ [<code>Copacetic</code>](#Copacetic)
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152 | Removes a dependency from a Copacetic instance
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153 |
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154 | **Kind**: instance method of [<code>Copacetic</code>](#Copacetic)
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155 |
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156 | | Param | Type | Description |
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157 | | --- | --- | --- |
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158 | | name | <code>String</code> | The name used to identify a dependency |
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159 |
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160 | <a name="Copacetic+pollAll"></a>
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161 |
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162 | ### copacetic.pollAll([interval], [parallel], [schedule]) ⇒ [<code>Copacetic</code>](#Copacetic)
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163 | Polls the health of all registered dependencies
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164 |
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165 | **Kind**: instance method of [<code>Copacetic</code>](#Copacetic)
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166 |
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167 | | Param | Type | Default |
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168 | | --- | --- | --- |
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169 | | [interval] | <code>String</code> | <code>'5 seconds'</code> |
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170 | | [parallel] | <code>Boolean</code> | <code>true</code> |
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171 | | [schedule] | <code>String</code> | <code>'start'</code> |
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172 |
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173 | <a name="Copacetic+poll"></a>
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174 |
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175 | ### copacetic.poll([dependencies], [interval], [parallel], [schedule]) ⇒ [<code>Copacetic</code>](#Copacetic)
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176 | Polls the health of a set of dependencies
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177 |
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178 | **Kind**: instance method of [<code>Copacetic</code>](#Copacetic)
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179 | **Emits**: [<code>health</code>](#Copacetic+event_health)
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180 |
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181 | | Param | Type | Default | Description |
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182 | | --- | --- | --- | --- |
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183 | | [dependencies] | <code>Array.<Object></code> | | An explicit set of dependencies to be polled |
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184 | | [interval] | <code>String</code> | <code>'5 seconds'</code> | |
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185 | | [parallel] | <code>Boolean</code> | <code>true</code> | Kick of health checks in parallel or series |
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186 | | [schedule] | <code>String</code> | <code>'start'</code> | Schedule the next check to start (interval - ms) | ms |
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187 |
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188 | **Example**
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189 | ```js
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190 | copacetic.poll({
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191 | dependencies: [
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192 | { name: 'my-dep' },
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193 | { name: 'my-other-dep', retries: 2 }
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194 | ],
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195 | schedule: 'end',
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196 | interval: '1 minute 30 seconds'
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197 | })
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198 | .on('health', (serviceHealth) => {
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199 | // Do something with the result
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200 | // [{ name: String, health: Boolean, level: HARD/SOFT, lastCheck: Date }]
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201 | })
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202 | ```
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203 | <a name="Copacetic+stop"></a>
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204 |
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205 | ### copacetic.stop()
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206 | stops polling registered dependencies
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207 |
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208 | **Kind**: instance method of [<code>Copacetic</code>](#Copacetic)
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209 | <a name="Copacetic+checkAll"></a>
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210 |
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211 | ### copacetic.checkAll([parallel]) ⇒ [<code>Copacetic</code>](#Copacetic)
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212 | Checks the health of all registered dependencies
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213 |
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214 | **Kind**: instance method of [<code>Copacetic</code>](#Copacetic)
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215 |
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216 | | Param | Type | Default | Description |
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217 | | --- | --- | --- | --- |
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218 | | [parallel] | <code>Boolean</code> | <code>true</code> | Kick of health checks in parallel or series |
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219 |
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220 | <a name="Copacetic+check"></a>
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221 |
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222 | ### copacetic.check([name], [dependencies], [retries], [parallel]) ⇒ [<code>Copacetic</code>](#Copacetic)
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223 | Checks the health of a set, or single dependency
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224 |
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225 | **Kind**: instance method of [<code>Copacetic</code>](#Copacetic)
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226 | **Emits**: [<code>health</code>](#Copacetic+event_health), [<code>healthy</code>](#Copacetic+event_healthy), [<code>unhealthy</code>](#Copacetic+event_unhealthy)
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227 |
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228 | | Param | Type | Default | Description |
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229 | | --- | --- | --- | --- |
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230 | | [name] | <code>String</code> | | The identifier of a single dependency to be checked |
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231 | | [dependencies] | <code>Array.<Object></code> | | An explicit set of dependencies to be checked |
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232 | | [retries] | <code>Integer</code> | <code>1</code> | How many times should a dependency be checked, until it is deemed unhealthy |
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233 | | [parallel] | <code>Boolean</code> | <code>true</code> | Kick of health checks in parallel or series |
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234 |
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235 | **Example**
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236 | ```js
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237 | copacetic.check({ name: 'my-dependency' })
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238 | ```
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239 | **Example**
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240 | ```js
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241 | copacetic.check({ name: 'my-dependency', retries: 5 })
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242 | .on('healthy', serviceHealth => { // Do stuff })
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243 | .on('unhealthy', serviceHealth => { // Handle degraded state })
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244 | ```
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245 | **Example**
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246 | ```js
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247 | copacetic.check({ dependencies: [
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248 | { name: 'my-dep' },
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249 | { name: 'my-other-dep', retries: 2 }
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250 | ] })
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251 | .on('health', (servicesHealth) => {
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252 | // Do something with the result
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253 | // [{ name: String, health: Boolean, level: HARD/SOFT, lastCheck: Date }]
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254 | })
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255 | ```
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256 | <a name="Copacetic+event_healthy"></a>
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257 |
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258 | ### "healthy"
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259 | Health information on a single dependency
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260 |
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261 | **Kind**: event emitted by [<code>Copacetic</code>](#Copacetic)
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262 | <a name="Copacetic+event_unhealthy"></a>
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263 |
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264 | ### "unhealthy"
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265 | Health information on a single dependency
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266 |
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267 | **Kind**: event emitted by [<code>Copacetic</code>](#Copacetic)
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268 | <a name="Copacetic+event_health"></a>
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269 |
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270 | ### "health"
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271 | Health information on a set of dependencies
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272 |
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273 | **Kind**: event emitted by [<code>Copacetic</code>](#Copacetic)
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