# PutFileSystemPolicy
<a name="API_PutFileSystemPolicy"></a>

Applies an Amazon EFS `FileSystemPolicy` to an Amazon EFS file system. A file system policy is an IAM resource-based policy and can contain multiple policy statements. A file system always has exactly one file system policy, which can be the default policy or an explicit policy set or updated using this API operation. EFS file system policies have a 20,000 character limit. When an explicit policy is set, it overrides the default policy. For more information about the default file system policy, see [ Default EFS file system policy](https://docs.amazonaws.cn/efs/latest/ug/iam-access-control-nfs-efs.html#default-filesystempolicy). 

**Note**  
EFS file system policies have a 20,000 character limit.

This operation requires permissions for the `elasticfilesystem:PutFileSystemPolicy` action.

## Request Syntax
<a name="API_PutFileSystemPolicy_RequestSyntax"></a>

```
PUT /2015-02-01/file-systems/FileSystemId/policy HTTP/1.1
Content-type: application/json

{
   "BypassPolicyLockoutSafetyCheck": boolean,
   "Policy": "string"
}
```

## URI Request Parameters
<a name="API_PutFileSystemPolicy_RequestParameters"></a>

The request uses the following URI parameters.

 ** [FileSystemId](#API_PutFileSystemPolicy_RequestSyntax) **   <a name="efs-PutFileSystemPolicy-request-uri-FileSystemId"></a>
The ID of the EFS file system that you want to create or update the `FileSystemPolicy` for.  
Length Constraints: Maximum length of 128.  
Pattern: `^(arn:aws[-a-z]*:elasticfilesystem:[0-9a-z-:]+:file-system/fs-[0-9a-f]{8,40}|fs-[0-9a-f]{8,40})$`   
Required: Yes

## Request Body
<a name="API_PutFileSystemPolicy_RequestBody"></a>

The request accepts the following data in JSON format.

 ** [BypassPolicyLockoutSafetyCheck](#API_PutFileSystemPolicy_RequestSyntax) **   <a name="efs-PutFileSystemPolicy-request-BypassPolicyLockoutSafetyCheck"></a>
(Optional) A boolean that specifies whether or not to bypass the `FileSystemPolicy` lockout safety check. The lockout safety check determines whether the policy in the request will lock out, or prevent, the IAM principal that is making the request from making future `PutFileSystemPolicy` requests on this file system. Set `BypassPolicyLockoutSafetyCheck` to `True` only when you intend to prevent the IAM principal that is making the request from making subsequent `PutFileSystemPolicy` requests on this file system. The default value is `False`.   
Type: Boolean  
Required: No

 ** [Policy](#API_PutFileSystemPolicy_RequestSyntax) **   <a name="efs-PutFileSystemPolicy-request-Policy"></a>
The `FileSystemPolicy` that you're creating. Accepts a JSON formatted policy definition. EFS file system policies have a 20,000 character limit. To find out more about the elements that make up a file system policy, see [Resource-based policies within Amazon EFS](https://docs.amazonaws.cn/efs/latest/ug/security_iam_service-with-iam.html#security_iam_service-with-iam-resource-based-policies).   
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 20000.  
Pattern: `[\s\S]+`   
Required: Yes

## Response Syntax
<a name="API_PutFileSystemPolicy_ResponseSyntax"></a>

```
HTTP/1.1 200
Content-type: application/json

{
   "FileSystemId": "string",
   "Policy": "string"
}
```

## Response Elements
<a name="API_PutFileSystemPolicy_ResponseElements"></a>

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.

 ** [FileSystemId](#API_PutFileSystemPolicy_ResponseSyntax) **   <a name="efs-PutFileSystemPolicy-response-FileSystemId"></a>
Specifies the EFS file system to which the `FileSystemPolicy` applies.  
Type: String  
Length Constraints: Maximum length of 128.  
Pattern: `^(arn:aws[-a-z]*:elasticfilesystem:[0-9a-z-:]+:file-system/fs-[0-9a-f]{8,40}|fs-[0-9a-f]{8,40})$` 

 ** [Policy](#API_PutFileSystemPolicy_ResponseSyntax) **   <a name="efs-PutFileSystemPolicy-response-Policy"></a>
The JSON formatted `FileSystemPolicy` for the EFS file system.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 20000.  
Pattern: `[\s\S]+` 

## Errors
<a name="API_PutFileSystemPolicy_Errors"></a>

 ** BadRequest **   
Returned if the request is malformed or contains an error such as an invalid parameter value or a missing required parameter.    
 ** ErrorCode **   
The error code is a string that uniquely identifies an error condition. It is meant to be read and understood by programs that detect and handle errors by type.   
 ** Message **   
The error message contains a generic description of the error condition in English. It is intended for a human audience. Simple programs display the message directly to the end user if they encounter an error condition they don't know how or don't care to handle. Sophisticated programs with more exhaustive error handling and proper internationalization are more likely to ignore the error message.
HTTP Status Code: 400

 ** FileSystemNotFound **   
Returned if the specified `FileSystemId` value doesn't exist in the requester's Amazon Web Services account.    
 ** ErrorCode **   
The error code is a string that uniquely identifies an error condition. It is meant to be read and understood by programs that detect and handle errors by type.   
 ** Message **   
The error message contains a generic description of the error condition in English. It is intended for a human audience. Simple programs display the message directly to the end user if they encounter an error condition they don't know how or don't care to handle. Sophisticated programs with more exhaustive error handling and proper internationalization are more likely to ignore the error message.
HTTP Status Code: 404

 ** IncorrectFileSystemLifeCycleState **   
Returned if the file system's lifecycle state is not "available".    
 ** ErrorCode **   
The error code is a string that uniquely identifies an error condition. It is meant to be read and understood by programs that detect and handle errors by type.   
 ** Message **   
The error message contains a generic description of the error condition in English. It is intended for a human audience. Simple programs display the message directly to the end user if they encounter an error condition they don't know how or don't care to handle. Sophisticated programs with more exhaustive error handling and proper internationalization are more likely to ignore the error message.
HTTP Status Code: 409

 ** InternalServerError **   
Returned if an error occurred on the server side.    
 ** ErrorCode **   
The error code is a string that uniquely identifies an error condition. It is meant to be read and understood by programs that detect and handle errors by type.   
 ** Message **   
The error message contains a generic description of the error condition in English. It is intended for a human audience. Simple programs display the message directly to the end user if they encounter an error condition they don't know how or don't care to handle. Sophisticated programs with more exhaustive error handling and proper internationalization are more likely to ignore the error message.
HTTP Status Code: 500

 ** InvalidPolicyException **   
Returned if the `FileSystemPolicy` is malformed or contains an error such as a parameter value that is not valid or a missing required parameter. Returned in the case of a policy lockout safety check error.    
 ** ErrorCode **   
The error code is a string that uniquely identifies an error condition. It is meant to be read and understood by programs that detect and handle errors by type.   
 ** Message **   
The error message contains a generic description of the error condition in English. It is intended for a human audience. Simple programs display the message directly to the end user if they encounter an error condition they don't know how or don't care to handle. Sophisticated programs with more exhaustive error handling and proper internationalization are more likely to ignore the error message.
HTTP Status Code: 400

## Examples
<a name="API_PutFileSystemPolicy_Examples"></a>

### Create an EFS FileSystemPolicy
<a name="API_PutFileSystemPolicy_Example_1"></a>

The following request creates a `FileSystemPolicy` that allows all Amazon principals to mount the specified EFS file system with read and write permissions.

#### Sample Request
<a name="API_PutFileSystemPolicy_Example_1_Request"></a>

```
PUT /2015-02-01/file-systems/fs-01234567/file-system-policy HTTP/1.1
{
    "Version": "2012-10-17",		 	 	 
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "elasticfilesystem:ClientMount",
                "elasticfilesystem:ClientWrite"
            ],
            "Principal": {
                "AWS": ["*"]
            },
        }
    ]
}
```

#### Sample Response
<a name="API_PutFileSystemPolicy_Example_1_Response"></a>

```
{
    "Version": "2012-10-17",		 	 	 
    "Id": "1",
    "Statement": [
        {
            "Sid": "efs-statement-abcdef01-1111-bbbb-2222-111122224444",
            "Effect": "Allow",
            "Action": [
                "elasticfilesystem:ClientMount",
                "elasticfilesystem:ClientWrite"
            ],
            "Principal": {
                "AWS": ["*"]
            },
            "Resource":"arn:aws:elasticfilesystem:us-east-1:1111222233334444:file-system/fs-01234567"
        }
    ]
}
```

## See Also
<a name="API_PutFileSystemPolicy_SeeAlso"></a>

For more information about using this API in one of the language-specific Amazon SDKs, see the following:
+  [Amazon Command Line Interface V2](https://docs.amazonaws.cn/goto/cli2/elasticfilesystem-2015-02-01/PutFileSystemPolicy) 
+  [Amazon SDK for .NET V4](https://docs.amazonaws.cn/goto/DotNetSDKV4/elasticfilesystem-2015-02-01/PutFileSystemPolicy) 
+  [Amazon SDK for C\$1\$1](https://docs.amazonaws.cn/goto/SdkForCpp/elasticfilesystem-2015-02-01/PutFileSystemPolicy) 
+  [Amazon SDK for Go v2](https://docs.amazonaws.cn/goto/SdkForGoV2/elasticfilesystem-2015-02-01/PutFileSystemPolicy) 
+  [Amazon SDK for Java V2](https://docs.amazonaws.cn/goto/SdkForJavaV2/elasticfilesystem-2015-02-01/PutFileSystemPolicy) 
+  [Amazon SDK for JavaScript V3](https://docs.amazonaws.cn/goto/SdkForJavaScriptV3/elasticfilesystem-2015-02-01/PutFileSystemPolicy) 
+  [Amazon SDK for Kotlin](https://docs.amazonaws.cn/goto/SdkForKotlin/elasticfilesystem-2015-02-01/PutFileSystemPolicy) 
+  [Amazon SDK for PHP V3](https://docs.amazonaws.cn/goto/SdkForPHPV3/elasticfilesystem-2015-02-01/PutFileSystemPolicy) 
+  [Amazon SDK for Python](https://docs.amazonaws.cn/goto/boto3/elasticfilesystem-2015-02-01/PutFileSystemPolicy) 
+  [Amazon SDK for Ruby V3](https://docs.amazonaws.cn/goto/SdkForRubyV3/elasticfilesystem-2015-02-01/PutFileSystemPolicy)