=== Git Configuration Store

The Git Configuration Store is an extension to the Vert.x Configuration Retriever to
retrieve configuration from a Git repository.

==== Using the Git Configuration Store

To use the Git Configuration, add the following dependency to the
_dependencies_ section of your build descriptor:

* Maven (in your `pom.xml`):

[source,xml,subs="+attributes"]
----
<dependency>
  <groupId>io.vertx</groupId>
  <artifactId>vertx-config-git</artifactId>
  <version>3.4.0</version>
</dependency>
<dependency>
  <groupId>io.vertx</groupId>
  <artifactId>vertx-config</artifactId>
  <version>3.4.0</version>
</dependency>
----

* Gradle (in your `build.gradle` file):

[source,groovy,subs="+attributes"]
----
compile 'io.vertx:vertx-config:3.4.0'
compile 'io.vertx:vertx-config-git:3.4.0'
----

==== Configuring the store

Once added to your classpath or dependencies, you need to configure the
`link:../../jsdoc/module-vertx-config-js_config_retriever-ConfigRetriever.html[ConfigRetriever]` to use this store:

[source, js]
----
var ConfigRetriever = require("vertx-config-js/config_retriever");

var git = {
  "type" : "git",
  "config" : {
    "url" : "https://github.com/cescoffier/vertx-config-test.git",
    "path" : "local",
    "filesets" : [
      {
        "pattern" : "*.json"
      }
    ]
  }
};

var retriever = ConfigRetriever.create(vertx, {
  "stores" : [
    git
  ]
});

----

The configuration requires:

* the `url` of the repository
* the `path` where the repository is cloned (local directory)
* at least `fileset` indicating the set of files to read (same behavior as the
directory configuration store).

You can also configure the `branch` (`master` by default) to use and the name of the
`remote` repository (`origin` by default).

==== How does it works

If the local `path` does not exist, the configuration store clones the repository into
this directory. Then it reads the file matching the different file sets.

It the local `path` exist, it tried to update it (it switches branch if needed)). If the
update failed the configuration retrieval fails.

Periodically, the repositories is updated to check if the configuration has been updated.