68 lines
1.9 KiB
Markdown
68 lines
1.9 KiB
Markdown
## Introduction
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**config** is a simple golang library and designed to read configurations from JSON, Yaml files, environment variables and command line. **config** depends on [go-yaml](https://github.com/go-yaml/yaml) to anlayze Yaml file and uses built-in golang library to handle JSON file.
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## Installation
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1. Install [Yaml](https://github.com/go-yaml/yaml) library first:
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```
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go get gopkg.in/yaml.v2
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```
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2. Install **config** library:
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```
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go get github.com/eschao/config
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```
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## Usage
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#### I. Data types
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Like JSON, Yaml, **config** uses tags to define configurations. It supports the following golang data types:
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* bool
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* string
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* int8, int16, int, int32, int64
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* uint8, uint16, uint, uint32, uint64
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* float32, float64
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* slice type. e.g: []string, []int ...
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#### II. Defines **default** values
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Using **default** keyword in structure tags to define default value. Example codes:
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```golang
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type Log struct {
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Path string `default:"/var/logs"`
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Level string `default:"debug"`
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}
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```
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After that, calls ```config.ParseDefault(interface{})``` to set structure instance with default values. Example codes:
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```golang
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logConfig := Log{}
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config.ParseDefault(&logConfig)
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```
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#### III. Reads configurations from JSON and Yaml files
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##### 1. Using ```json``` to define configuration name
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```golang
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type Database struct {
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Host string `json:"host"`
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Port int `json:"port"`
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Username string `json:"username" default:"admin"`
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Password string `json:"password" default:"admin"`
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Log Log `json:"log"`
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}
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```
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##### 2. Using ```yaml``` to define configuration name
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```golang
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type Database struct {
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Host string `yaml:"host"`
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Port int `yaml:"port"`
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Username string `yaml:"username" default:"admin"`
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Password string `yaml:"password" default:"admin"`
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Log Log `yaml:"log"`
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}
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```
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Parsing configurations from JSON:
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```golang
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dbConfig := Database{}
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config.ParseConfigFile(&dbConfig, "config.json")
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```
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