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Minor revisions to README.md 

* Change the order to "JSON, TOML and YAML" because that is
   the order that Viper attempts to find the config file,
   as listed in SupportedExts string array

 * Rename "Indexes" to "Taxonomies" (re: Hugo)

 * GitHub now forces https, so update GitHub URLs accordingly

 * Add links to Wikipedia pages about Viper and Cobra Commander
   in case the users do not know the G.I. Joe reference

 * Other minor copyediting
This commit is contained in:
Anthony Fok 2015-03-07 03:52:13 -07:00
parent 1258332127
commit 0c5f3e2462
1 changed files with 36 additions and 36 deletions
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@ -10,7 +10,7 @@ been designed to work within an application to handle all types of
configuration. It supports configuration. It supports
* setting defaults * setting defaults
* reading from yaml, toml and json config files * reading from json, toml and yaml config files
* reading from environment variables * reading from environment variables
* reading from remote config systems (Etcd or Consul) * reading from remote config systems (Etcd or Consul)
* reading from command line flags * reading from command line flags
@ -21,15 +21,15 @@ configuration needs.
## Why Viper? ## Why Viper?
When building a modern application you don’t want to have to worry about When building a modern application, you don’t want to have to worry about
configuration file formats, you want to focus on building awesome software. configuration file formats; you want to focus on building awesome software.
Viper is here to help with that. Viper is here to help with that.
Viper does the following for you: Viper does the following for you:
1. Find, load and marshal a configuration file in YAML, TOML or JSON. 1. Find, load and marshal a configuration file in JSON, TOML or YAML.
2. Provide a mechanism to set default values for your different 2. Provide a mechanism to set default values for your different
configuration options configuration options.
3. Provide a mechanism to set override values for options specified 3. Provide a mechanism to set override values for options specified
through command line flags. through command line flags.
4. Provide an alias system to easily rename parameters without breaking 4. Provide an alias system to easily rename parameters without breaking
@ -62,13 +62,13 @@ Examples:
viper.SetDefault("ContentDir", "content") viper.SetDefault("ContentDir", "content")
viper.SetDefault("LayoutDir", "layouts") viper.SetDefault("LayoutDir", "layouts")
viper.SetDefault("Indexes", map[string]string{"tag": "tags", "category": "categories"}) viper.SetDefault("Taxonomies", map[string]string{"tag": "tags", "category": "categories"})
### Reading Config Files ### Reading Config Files
If you want to support a config file, Viper requires a minimal If you want to support a config file, Viper requires a minimal
configuration so it knows where to look for the config file. Viper configuration so it knows where to look for the config file. Viper
supports yaml, toml and json files. Viper can search multiple paths, but supports json, toml and yaml files. Viper can search multiple paths, but
currently a single viper only supports a single config file. currently a single viper only supports a single config file.
viper.SetConfigName("config") // name of config file (without extension) viper.SetConfigName("config") // name of config file (without extension)
@ -106,20 +106,20 @@ with working with ENV:
* SetEnvPrefix(string) * SetEnvPrefix(string)
* SetEnvReplacer(string...) *strings.Replacer * SetEnvReplacer(string...) *strings.Replacer
_When working with ENV variables it’s important to recognize that Viper _When working with ENV variables, it’s important to recognize that Viper
treats ENV variables as case sensitive._ treats ENV variables as case sensitive._
Viper provides a mechanism to try to ensure that ENV variables are Viper provides a mechanism to try to ensure that ENV variables are
unique. By using SetEnvPrefix you can tell Viper to use add a prefix unique. By using SetEnvPrefix, you can tell Viper to use add a prefix
while reading from the environment variables. Both BindEnv and while reading from the environment variables. Both BindEnv and
AutomaticEnv will use this prefix. AutomaticEnv will use this prefix.
BindEnv takes one or two parameters. The first parameter is the key BindEnv takes one or two parameters. The first parameter is the key
name, the second is the name of the environment variable. The name of name, the second is the name of the environment variable. The name of
the environment variable is case sensitive. If the ENV variable name is the environment variable is case sensitive. If the ENV variable name is
not provided then Viper will automatically assume that the key name not provided, then Viper will automatically assume that the key name
matches the ENV variable name but the ENV variable is IN ALL CAPS. When matches the ENV variable name but the ENV variable is IN ALL CAPS. When
you explicitly provide the env variable name it **Does not** you explicitly provide the ENV variable name, it **does not**
automatically add the prefix. automatically add the prefix.
One important thing to recognize when working with ENV variables is that One important thing to recognize when working with ENV variables is that
@ -135,7 +135,7 @@ uppercased and prefixed with the EnvPrefix if set.
SetEnvReplacer allows you to use a `strings.Replacer` object to rewrite Env keys SetEnvReplacer allows you to use a `strings.Replacer` object to rewrite Env keys
to an extent. This is useful if you want to use `-` or something in your Get() to an extent. This is useful if you want to use `-` or something in your Get()
calls, but want your environmental variables to use `_` delimiters. An example calls, but want your environmental variables to use `_` delimiters. An example
of using it can be found in `viper_test.go` of using it can be found in `viper_test.go`.
#### Env example #### Env example
@ -149,10 +149,10 @@ of using it can be found in `viper_test.go`
### Working with Flags ### Working with Flags
Viper has the ability to bind to flags. Specifically Viper supports Viper has the ability to bind to flags. Specifically, Viper supports
Pflags as used in the [Cobra](http://github.com/spf13/cobra) library. Pflags as used in the [Cobra](https://github.com/spf13/cobra) library.
Like BindEnv the value is not set when the binding method is called, but Like BindEnv, the value is not set when the binding method is called, but
when it is accessed. This means you can bind as early as you want, even when it is accessed. This means you can bind as early as you want, even
in an init() function. in an init() function.
@ -160,8 +160,8 @@ The BindPFlag() method provides this functionality.
Example: Example:
serverCmd.Flags().Int("port", 1138, "Port to run Application server on") serverCmd.Flags().Int("port", 1138, "Port to run Application server on")
viper.BindPFlag("port", serverCmd.Flags().Lookup("port")) viper.BindPFlag("port", serverCmd.Flags().Lookup("port"))
### Remote Key/Value Store Support ### Remote Key/Value Store Support
@ -171,7 +171,7 @@ over default values, but are overriden by configuration values retrieved from di
flags, or environment variables. flags, or environment variables.
Viper uses [crypt](https://github.com/xordataexchange/crypt) to retrieve configuration Viper uses [crypt](https://github.com/xordataexchange/crypt) to retrieve configuration
from the k/v store, which means that you can store your configuration values from the K/V store, which means that you can store your configuration values
encrypted and have them automatically decrypted if you have the correct encrypted and have them automatically decrypted if you have the correct
gpg keyring. Encryption is optional. gpg keyring. Encryption is optional.
@ -179,7 +179,7 @@ You can use remote configuration in conjunction with local configuration, or
independently of it. independently of it.
`crypt` has a command-line helper that you can use to put configurations `crypt` has a command-line helper that you can use to put configurations
in your k/v store. `crypt` defaults to etcd on http://127.0.0.1:4001. in your K/V store. `crypt` defaults to etcd on http://127.0.0.1:4001.
go get github.com/xordataexchange/crypt/bin/crypt go get github.com/xordataexchange/crypt/bin/crypt
crypt set -plaintext /config/hugo.json /Users/hugo/settings/config.json crypt set -plaintext /config/hugo.json /Users/hugo/settings/config.json
@ -206,7 +206,7 @@ to use Consul.
## Getting Values From Viper ## Getting Values From Viper
In Viper there are a few ways to get a value depending on what type of value you want to retrieved. In Viper, there are a few ways to get a value depending on what type of value you want to retrieved.
The following functions and methods exist: The following functions and methods exist:
* Get(key string) : interface{} * Get(key string) : interface{}
@ -222,15 +222,15 @@ The following functions and methods exist:
* IsSet(key string) : bool * IsSet(key string) : bool
One important thing to recognize is that each Get function will return One important thing to recognize is that each Get function will return
it’s zero value if it’s not found. To check if a given key exists, the IsSet() its zero value if it’s not found. To check if a given key exists, the IsSet()
method has been provided. method has been provided.
Example: Example:
viper.GetString("logfile") // case insensitive Setting & Getting viper.GetString("logfile") // case-insensitive Setting & Getting
if viper.GetBool("verbose") { if viper.GetBool("verbose") {
fmt.Println("verbose enabled") fmt.Println("verbose enabled")
} }
### Marshaling ### Marshaling
@ -260,10 +260,10 @@ Example:
Viper comes ready to use out of the box. There is no configuration or Viper comes ready to use out of the box. There is no configuration or
initialization needed to begin using Viper. Since most applications will initialization needed to begin using Viper. Since most applications will
want to use a single central repository for their configuration the want to use a single central repository for their configuration, the
viper package provides this. It is similar to a singleton. viper package provides this. It is similar to a singleton.
In all of the examples above they demonstrate using viper in it’s In all of the examples above, they demonstrate using viper in its
singleton style approach. singleton style approach.
### Working with multiple vipers ### Working with multiple vipers
@ -275,33 +275,33 @@ functions that viper package supports are mirrored as methods on a viper.
Example: Example:
x := viper.New() x := viper.New()
y := viper.New() y := viper.New()
x.SetDefault("ContentDir", "content") x.SetDefault("ContentDir", "content")
y.SetDefault("ContentDir", "foobar") y.SetDefault("ContentDir", "foobar")
... ...
When working with multiple vipers it is up to the user to keep track of When working with multiple vipers, it is up to the user to keep track of
the different vipers. the different vipers.
## Q & A ## Q & A
Q: Why not INI files? Q: Why not INI files?
A: Ini files are pretty awful. There’s no standard format and they are hard to A: Ini files are pretty awful. There’s no standard format, and they are hard to
validate. Viper is designed to work with YAML, TOML or JSON files. If someone validate. Viper is designed to work with JSON, TOML or YAML files. If someone
really wants to add this feature, I’d be happy to merge it. It’s easy to really wants to add this feature, I’d be happy to merge it. It’s easy to
specify which formats your application will permit. specify which formats your application will permit.
Q: Why is it called "viper"? Q: Why is it called “Viper”?
A: Viper is designed to be a companion to A: Viper is designed to be a [companion](http://en.wikipedia.org/wiki/Viper_(G.I._Joe)) to
[Cobra](http://github.com/spf13/cobra). While both can operate completely [Cobra](https://github.com/spf13/cobra). While both can operate completely
independently, together they make a powerful pair to handle much of your independently, together they make a powerful pair to handle much of your
application foundation needs. application foundation needs.
Q: Why is it called "Cobra"? Q: Why is it called “Cobra”?
A: Is there a better name for a commander? A: Is there a better name for a [commander](http://en.wikipedia.org/wiki/Cobra_Commander)?