config-go

= config
Matt Nicholls <[email protected]>
:keywords: golang,config,configuration
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== Overview

Compact, no frills, configuration library for Go.

== Installation

.Prerequisites
* The link:https://golang.org/dl/[Golang Runtime], version 1.24.x or later

[source%nowrap,bash]
----
❯ go get -u github.com/transientvariable/config-go
----

== Usage
Configuration property values are specified using a configuration file (e.g. YAML) whose default values can be overridden using environment variables.

Using an environment variable override:

.Example application.yaml
[source,yaml]
----
config:
  api:
    url: ${APP_API_URL | https://example.com}
----

=== Property Value Syntax

Property values that use the placeholder syntax `${ ... }` are resolved via environment variables. For example, on a POSIX system, the following variable could be defined in `.bashrc`, `.profile`, `.bash_profile`, or via the command-line:

  export FOO="bar"

which could then be referenced by value:

  someApplicationProperty: ${FOO}

At runtime, the value for `someApplicationProperty` would be `bar`.

The pipe `|` symbol can be used within a placeholder to specify a default value if an environment variable cannot be resolved. For example:

  requiredApplicationProperty: ${DOES_NOT_EXIST | baz}

At runtime, the value for `requiredApplicationProperty` would be `baz` if the environment variable `DOES_NOT_EXIST` was not set.

== License
This project is licensed under the link:LICENSE[MIT License].