adding doc

Signed-off-by: Thomas Poignant <[email protected]>

README.md

@@ -280,6 +280,7 @@ The available retrievers are:
 - **Local file**
 - **Google Cloud Storage**
 - **Kubernetes ConfigMaps**
+- **MongoDB**
 
 _[See the full list and more information.](https://gofeatureflag.org/docs/configure_flag/store_your_flags)_
 

website/docs/configure_flag/store_your_flags.mdx

@@ -12,6 +12,7 @@ import gitlablogo from '@site/static/docs/retrievers/gitlab.png';
 import googlelogo from '@site/static/docs/retrievers/google.png';
 import s3logo from '@site/static/docs/retrievers/s3.png';
 import k8slogo from '@site/static/docs/retrievers/k8s.png';
+import mongodblogo from '@site/static/docs/retrievers/mongodb.png';
 
 
 # Where to store your flags' configuration?
@@ -96,6 +97,14 @@ configuration and will evaluate your feature flags based on this configuration.
       goModuleLink={'../go_module/store_file/file'}
     />
   },
+  {
+    logoImg: mongodblogo,
+    title:"MongoDB",
+    content: <ConfigCardContent
+      relayproxyLink={'../relay_proxy/configure_relay_proxy#mongodb'}
+      goModuleLink={'../go_module/store_file/mongodb'}
+    />
+  },
   {
     logoImg: customlogo,
     title:"Custom ...",

website/docs/go_module/store_file/file.md

@@ -1,5 +1,5 @@
 ---
-sidebar_position: 7
+sidebar_position: 25
 ---
 
 # File

website/docs/go_module/store_file/mongodb.md

@@ -0,0 +1,55 @@
+---
+sidebar_position: 7
+---
+
+# MongoDB
+The `mongodbRetriever` will use the mongoDB database to get your flags.
+
+## Example
+```go linenums="1"
+awsConfig, _ := config.LoadDefaultConfig(context.Background())
+err := ffclient.Init(ffclient.Config{
+    PollingInterval: 3 * time.Second,
+	  Retriever: &mongodbretriever.Retriever{
+        Collection: "featureFlags",
+        Database: "appConfig",
+        URI: "mongodb://root:[email protected]:27017/",
+    },
+})
+defer ffclient.Close()
+```
+
+## Expected format
+If you use mongodb to store your flags, you need a specific format to store your flags.
+
+We expect the flag to be store in JSON format as defined in the [flag format](../configure_flag/flag_format#format-details),
+but you should also add a new field called ` "flag` containing the name of the flag.
+
+The retriever will read all the flags from the collection.
+
+### Example:
+```json
+{
+    "flag": "new-admin-access",
+    "variations": {
+        "default_var": false,
+        "false_var": false,
+        "true_var": true
+    },
+    "defaultRule": {
+        "percentage": {
+            "false_var": 70,
+            "true_var": 30
+        }
+    }
+}
+```
+
+## Configuration fields
+To configure your mongodb retriever:
+
+| Field            | Description                                                 |
+|------------------|-------------------------------------------------------------|
+| **`Collection`** | Name of the collection where your flags are stored          |
+| **`Database`**   | Name of the mongo database where the collection is located. |
+| **`URI`**        | Connection URI of your mongoDB instance.                    |