totem
Totem
Crystal configuration with spirit. Inspired from Go's viper. Totem Icon by lastspark from Noun Project.
Configuration file formats is always the problem, you want to focus on building awesome things. Totem is here to help with that.
Totem has following features:
- Reading from JSON, YAML, dotenv formats config files or raw string.
- Reading from environment variables.
- Reading from remote key-value store systems(redis/etcd).
- Provide a mechanism to set default values for your different configuration options.
- Provide an alias system to easily rename parameters without breaking existing code.
- Write configuration to file with JSON, YAML formats.
And we keep it minimize and require what you want with adapter and remote provider! No more dependenices what you do not need. Only JSON and YAML adapters were auto requires.
Uses the following precedence order. Each item takes precedence over the item below it:
- alias
- override, explicit call to
set
- env
- config
- kvstores
- default
Totem configuration keys are case insensitive.
- Installation
- Quick Start
- Usage
- Advanced Usage
- Q & A
- Help and Discussion
- Donate
- How to Contribute
- You may also like
- License
Installation
Add this to your application's shard.yml
:
dependencies:
totem:
github: icyleaf/totem
Quick Start
require "totem"
Operating configuration
totem = Totem.new
totem.set_default("name", "foo")
totem.set_defaults({
"age" => 18,
"gender" => "male",
"hobbies" => [
"skateboarding",
"snowboarding",
"go"
]
})
totem.get("name").as_s # => "foo"
totem.get("age").as_i # => 18
totem.set("name", "bar")
totem.alias(alias_key: "key", key: "name")
totem.get("name").as_s # => "bar"
totem.get("key").as_s # => "bar"
Loading configuration
Support JSON
, YAML
and dotenv data from raw string and file.
From raw string
Load yaml string
raw = <<-EOF
Hacker: true
name: steve
hobbies:
- skateboarding
- snowboarding
- go
clothing:
jacket: leather
trousers: denim
pants:
size: large
age: 35
eyes : brown
EOF
totem = Totem.from_yaml raw
totem.get("Hacker").as_bool # => true
totem.get("age").as_i # => 35
totem.get("clothing").as_h["pants"].as_h["size"].as_s # => "large"
Load json string
raw = <<-EOF
{
"id": "0001",
"type": "donut",
"name": "Cake",
"ppu": 0.55,
"batters": {
"batter": [
{
"type": "Regular"
},
{
"type": "Chocolate"
},
{
"type": "Blueberry"
},
{
"type": "Devil's Food"
}
]
}
}
EOF
totem = Totem.from_json raw
totem.get("name") # => "Cake"
totem.get("ppu") # => 0.55
totem.get("batters").as_h["batter"].as_a[0].as_h["type"] # => "Regular"
Load dotenv string
Add poncho to
shards.yml
and require the adapter.
require "totem"
require "totem/config_types/env" # Make sure you require
raw = <<-EOF
# COMMENTS=work
STR='foo'
STR_WITH_COMMENTS=bar # str with comment
STR_WITH_HASH_SYMBOL="abc#123"#stick comment
INT=33
EOF
totem = Totem.from_env raw
totem.get("str") # => "foo"
totem.get("str_with_comments") # => bar
totem.get("str_with_hash_symbol") # => "abc#123"
totem.get("int") # => "33"
From file
Add poncho to
shards.yml
and require the adapter if you need load dotenv file.
# Load yaml file from file with path
totem = Totem.from_file "./spec/fixtures/config.yaml"
# Load json file from file with multi-paths
totem = Totem.from_file "config.yaml", ["/etc", ".", "./spec/fixtures"]
# Load dotenv file
totem = Totem.from_file "config.env"
Usage
Load configuration with multiple paths
Totem can search multiple paths, but currently a single Totem instance only supports a single configuration file.
totem = Totem.new("config", "/etc/totem/") # => New a instance with name and path of config file
totem.config_paths << "~/.totem" # => path to look for the config file in
totem.config_paths << "./config" # => optionally look for config in the working directory
begin
totem.load! # => Find and read the config file (order by yaml/yml/json/env)
rescue e
puts "Fatal error config file: #{e.message}"
end
Set Alias and using alias
Aliases permit a single value to be referenced by multiple keys
totem.alias("nickname", "Name")
totem.set("name", "foo")
totem.set("nickname", "bar")
totem.get("name") # => "foo"
totem.get("nickname") # => "foo"
Working with nested key
All accessor methods accept nested key:
totem.set_default("profile.user.name", "foo")
totem.set("profile.user.age", 13)
totem.alias("username", "profile.user.name")
totem.bind_env("profile.user.nickname", "PROFILE_USER_NICKNAME")
totem.get("profile.user.age")
Working with envoriment variables
Totem has full support for environment variables, example:
ENV["ID"] = "123"
ENV["FOOD"] = "Pinapple"
ENV["NAME"] = "Polly"
totem = Totem.new
totem.bind_env("ID")
totem.get("id").as_i # => 123
totem.bind_env("f", "FOOD")
totem.get("f").as_s # => "Pinapple"
totem.automative_env
totem.get("name").as_s # => "Polly"
Working with envoriment prefix:
totem.automative_env(prefix: "totem")
# Same as
# totem.env_prefix = "totem"
# totem.automative_env = true
totem.get("id").as_i # => 123
totem.get("food").as_s # => "Pinapple"
totem.get("name").as_s # => "Polly"
Working with remote providers
Totem retrieve configuration from Key-Value store, which means that you can get your configuration values on the air.
Avaliable providers is redis
and etcd
.
Use redis
It dependency redis shard. Install is before use.
require "totem"
require "totem/remote_providers/redis"
totem = Totem.new
totem.add_remote(provider: "redis", endpoint: "redis://localhost:6379/0")
totem.get("user:name") # => "foo"
totem.get("user:id").as_i # => 123
You can also get raw data from one key with path
:
totem.config_type = "json" # There is no file extension in a stream data, supported extensions are all registed config types in Totem.
totem.add_remote(provider: "redis", endpoint: "redis://localhost:6379/0", path: "config:development")
totem.get("user:name") # => "foo"
totem.get("user:id").as_i # => 123
Use etcd
It dependency etcd-crystal shard. Install is before use.
require "totem"
require "totem/remote_providers/etcd"
totem = Totem.new
totem.add_remote(provider: "etcd", endpoint: "http://localhost:2379")
totem.get("user:name") # => "foo"
totem.get("user:id").as_i # => 123
You can also get raw data from one key with path
:
totem.config_type = "yaml" # There is no file extension in a stream data, supported extensions are all registed config types in Totem.
totem.add_remote(provider: "etcd", endpoint: "http://localhost:2379", path: "/config/development.yaml")
totem.get("user:name") # => "foo"
totem.get("user:id").as_i # => 123
Iterating configuration
Iterate in Totem is very easy, you can get #keys
, #flat_keys
, #settings
(a.k.a #to_h
) even iterating it directly with #each
:
totem.settings # => {"id" => 123, "user" => {"name" => "foobar", "age" => 20}}
totem.keys # => ["id", "user"]
totem.flat_keys # => ["id", "user.name", "user.age"]
totem.each do |key, value|
# do something
end
Serialization
Serialize configuration to Struct
, at current stage you can pass a JSON::Serializable
/YAML::Serializable
struct to mapping.
struct Profile
include JSON::Serializable
property name : String
property hobbies : Array(String)
property age : Int32
property eyes : String
end
totem = Totem.from_file "spec/fixtures/config.yaml"
profile = totem.mapping(Profile)
profile.name # => "steve"
profile.age # => 35
profile.eyes # => "brown"
profile.hobbies # => ["skateboarding", "snowboarding", "go"]
Serialize configuration with part of key:
struct Clothes
include JSON::Serializable
property jacket : String
property trousers : String
property pants : Hash(String, String)
end
totem = Totem.from_file "spec/fixtures/config.yaml"
clothes = profile.mapping(Clothes, "clothing")
# => Clothes(@jacket="leather", @pants={"size" => "large"}, @trousers="denim")
Storing configuration to file
Simple to use #store!
method.
raw = <<-EOF
Hacker: true
name: steve
hobbies:
- skateboarding
- snowboarding
- go
clothing:
jacket: leather
trousers: denim
pants:
size: large
age: 35
eyes : brown
EOF
totem = Totem.from_yaml raw
totem.set("nickname", "Freda")
totem.set("eyes", "blue")
totem.store!("profile.json")
Advanced Usage
Write a config adapter
Creating the custom adapter by integration Totem::ConfigTypes::Adapter
abstract class. Here has two methods must be implement:
read
and write
. For example, let us write a INI adapter:
require "ini"
class INIAdapter < Totem::ConfigTypes::Adapter
def read(raw)
INI.parse(raw)
end
def write(io, config)
config.settings.each do |key, items|
next unless data = items.as_h?
io << "[" << key << "]\n"
data.each do |name, value|
io << name << " = " << value << "\n"
end
end
end
end
# Do not forget register it
Totem::ConfigTypes.register_adapter("ini", INIAdapter.new)
# Also you can set aliases
Totem::ConfigTypes.register_alias("cnf", "ini")
More examples to review built-in adapters.
Write a remote provider
Creating the custom remote provider by integration Totem::RemoteProviders::Adapter
abstract class. Here has two methods must be implement:
read
and get
, please reivew the built-in remote providers.
Q & A
How to debug?
You can use Crystal built-in #pp
or #pp!
method to prints a series of instance variables:
#<Totem::Config
@config_paths=["/etc/totem", "~/.totem"],
@config_name="config",
@config_type="json",
@key_delimiter=".",
@automatic_env=false,
@env_prefix=nil,
@aliases={"user" => "profile.user.name"},
@overrides={"profile" => {"user" => {"gender" => "male"}}, "name" => "foo"},
@config={"profile" => {"user" => {"gender" => "unkown"}}, "name" => "bar"}},
@env={"name" => "TOTEM_NAME"},
@defaults={"name" => "alana"}>
Help and Discussion
You can browse the API documents:
https://icyleaf.github.io/totem/
You can browse the Changelog:
https://github.com/icyleaf/totem/blob/master/CHANGELOG.md
If you have found a bug, please create a issue here:
https://github.com/icyleaf/totem/issues/new
Donate
Totem is a open source, collaboratively funded project. If you run a business and are using Totem in a revenue-generating product, it would make business sense to sponsor Totem development. Individual users are also welcome to make a one time donation if Totem has helped you in your work or personal projects.
You can donate via Paypal.
How to Contribute
Your contributions are always welcome! Please submit a pull request or create an issue to add a new question, bug or feature to the list.
All Contributors are on the wall.
You may also like
- halite - HTTP Requests Client with a chainable REST API, built-in sessions and loggers.
- markd - Yet another markdown parser built for speed, Compliant to CommonMark specification.
- poncho - A .env parser/loader improved for performance.
- popcorn - Easy and Safe casting from one type to another.
- fast-crystal - 💨 Writing Fast Crystal 😍 -- Collect Common Crystal idioms.
License
MIT License © icyleaf