Part 3: File and directory management

Content

Introduction

The REST management interface offers end-to-end file and directory management capabilities in IBM DataPower Gateway 7.2.0.0. In Part 3 of this series, you learn about specific file system requests. You learn about directory management, including how to retrieve the contents of an existing directory and how to create and delete directories. You also learn about file management, including how to retrieve file contents, create and update files, and delete files. For information about other request types, such as status monitoring, configuration management, and DataPower operations, see the other parts in this series.

File system navigation

To begin retrieving and modifying existing file system resources, you must become familiar with the filestore resource of the REST management interface that represents the DataPower file system. You can find the filestore resource by accessing the root Uniform Resource Identifier (URI) of the REST management interface, as shown by the following request:

GET https://dphost.com:5554/mgmt/

Listing 1 shows the response that is received from the root URI. The response shows the available resource categories on the DataPower Gateway. The filestore resource is identified by the /mgmt/filestore/ URI.

Root URI response

 {
   "_links": {
     "self": {
       "href": "/mgmt/"
     },
     "config": {
       "href": "/mgmt/config/"
     },
     "domains": {
       "href": "/mgmt/domains/config/"
     },
     "status": {
       "href": "/mgmt/status/"
     },
     "actionqueue": {
       "href": "/mgmt/actionqueue/"
     },
     "filestore": {
       "href": "/mgmt/filestore/"
     },
     "metadata": {
       "href": "/mgmt/metadata/"
     },
     "types": {
       "href": "/mgmt/types/"
     }
   }
 }

When you access the filestore root URI, /mgmt/filestore/, by using the following request, you see the available options for the appliance filestore resource:

GET https://dphost.com:5554/mgmt/filestore/

Listing 2 shows the required URI structure to manipulate individual files and directories on the appliance.

Filestore root URI response

 {
   "_links": {
     "self": {
       "href": "/mgmt/filestore/"
     },
     "top": {
       "href": "/mgmt/filestore/{domain}/{top_directory}"
     },
     "directory": {
       "href": "/mgmt/filestore/{domain}/{top_directory}/{directory_path}"
     },
     "file": {
       "href": "/mgmt/filestore/{domain}/{top_directory}/{file_path}"
     }
   }
 }

Directory management

You can perform all directory manipulation operations. These operations include retrieving the contents of existing directories, creating directories and subdirectories, and deleting existing directories.

Retrieve directory contents

You can retrieve the contents of any appliance directory if you have appropriate access permissions to that directory. To retrieve the contents of any directory, construct a URI according to the directory link in Listing 2. The following request shows an example in which the local:///test-directory directory is accessed within test-domain_1:

GET https://dphost.com:5554/mgmt/filestore/test-domain_1/local/test-directory

Listing 3 shows that the target directory contains one file, test-file, and the relevant information for that file.

Retrieve directory contents response

 {
   "_links": {
     "self": {
       "href": "/mgmt/filestore/test-domain_1/local/test-directory"
     },
     "doc": {
       "href": "/mgmt/docs/filestore"
     }
   },
   "filestore": {
     "location": {
       "name": "local:/test-directory",
       "file": {
         "name": "test-file",
         "size": 1182,
         "modified": "2015-04-07 15:14:17",
         "href":"/mgmt/filestore/test-domain_1/local/test-directory/test-file"
       },
       "href":"/mgmt/filestore/test-domain_1/local/test-directory"
     }
   }
 }

Create directories

You can create a directory with a PUT request or a POST request. Both requests accomplish the same operation, but require a different URI to complete successfully. You can choose which approach is more convenient for you. The following POST request shows the URI that is required to create a subdirectory in the local:/// directory in test-domain_1:

POST https://dphost.com:5554/mgmt/filestore/test-domain_1/local

The following PUT request shows the URI that is required to create a test-directory subdirectory within the local:/// directory in test-domain_1:

PUT https://dphost.com:5554/mgmt/filestore/test-domain_1/local/test-directory

Both URIs in the POST and PUT requests accomplish the same objective if the subdirectory names to be created are the same. Listing 4 shows the required request payload for this request, where the directory name must be specified appropriately in the name parameter. This payload structure is used for both the PUT request and the POST request. The directory name in the payload and the URI for the PUT request must match. Otherwise, an error results.

Create directory request payload

 {
   "directory": {
     "name": "test-directory"
   }
 }

After the directory is created, you see a response similar to the example in Listing 5.

Create directory response

 {
   "_links": {
     "self": {
       "href": "/mgmt/filestore/test-domain_1/local"
     },
     "doc": {
       "href": "/mgmt/docs/filestore"
     }
   },
   "test-directory": "Directory has been created."
 }

The POST request and the PUT request on an existing directory resource do not allow you to overwrite the directory. This feature protects you from accidentally removing the directory contents. If you intend to overwrite a directory with new contents, you must first delete the directory by issuing a DELETE request and then re-create it.

Delete existing directories

To delete an existing directory, send an HTTP DELETE request to the target directory. The following example request shows the local:///test_dir directory in the default domain:

DELETE https://dphost.com:5554/mgmt/filestore/default/local/test_dir

After the directory is deleted, you see a response similar to the example in Listing 6.

Delete directory response

 {
   "_links": {
     "self": {
       "href": "/mgmt/filestore/default/local/test_dir"
     },
     "doc": {
       "href": "/mgmt/docs/filestore"
     }
   },
   "result": "ok",
   "script-log": ""
 }

File management

You can perform all file manipulation operations. These operations include retrieving and updating the contents of existing files, creating files, and deleting existing files.

Retrieve file contents

You can retrieve the contents of any file on the appliance, if you have appropriate access permissions to that file. To retrieve the contents of any file, construct a URI according to the file link in Listing 2. The following request retrieves contents of the test_file.txt file in the local:///test_dir directory in the default domain:

GET https://dphost.com:5554/mgmt/filestore/default/local/test_dir/test_file.txt

Listing 7 shows the file contents that are returned as a base64-encoded payload.

Retrieve file contents response

 {
   "_links": {
     "self": {
       "href": "/mgmt/filestore/default/local/test_dir/test_file.txt"
     },
     "doc": {
       "href": "/mgmt/docs/filestore"
     }
   },
   "file": {
     "name": "local:///test_dir/test_file.txt",
     "value": "SEVMTE8hISE=..."
   }
 }

Create and update files

You can create a file by using a PUT request or a POST request. Both requests accomplish the same operation, but require a different URI to complete successfully. Use the POST request to create files because a POST request results in a failure if a file with the same name exists in the target directory. This feature prevents you from accidentally overwriting an existing file. However, you can also create a file by using a PUT request. Issuing a PUT request on an existing file overwrites the file with the contents in the request payload.

The following POST request shows the URI that is required to create a file in the local:/// directory in test-domain_1:

POST https://dphost.com:5554/mgmt/filestore/test-domain_1/local

The following PUT request shows the URI that is required to create the test-file file in the local:/// directory in test-domain_1:

PUT https://dphost.com:5554/mgmt/filestore/test-domain_1/local/test-file

Both URIs accomplish the same objective if the file names to be created are the same. Listing 8 shows the required request payload for this request. Here, the file name and content must be specified appropriately in the name and content parameters. The file contents must be base64-encoded before they are embedded into the request payload. Use this payload structure for both the PUT request and the POST request. The file name in both the payload and URI for the PUT request must match. Otherwise, an error will result.

Create file request payload

 {
   "file": {     "name":"test-file",
     "content":"dG9wOyBjb25maWd1cmUgdGV..."
   }
 }

After the file is created, a response is returned similar to the one shown in Listing 9.

Create file response

 {
   "_links": {
     "self": {
       "href": "/mgmt/filestore/test-domain_1/local/test-file"
     },
     "doc": {
       "href": "/mgmt/docs/filestore"
     }
   },
   "test-file": "File has been created."
 }

To update an existing file resource, issue the following PUT request to the target file:

PUT https://dphost.com:5554/mgmt/filestore/test-domain_1/local/test-file

The existing file is overwritten with the payload contents as shown in Listing 10.

Update file response

 {
   "_links": {
     "self": {
       "href": "/mgmt/filestore/test-domain_1/local/test-file"
     },
     "doc": {
       "href": "/mgmt/docs/filestore"
     }
   },
   "test-file": "File has been updated."
 }

Delete existing files

To delete an existing file, send an HTTP DELETE request to the target file. The following example shows this request for the test_file.txt file in the local:///test_dir directory in the default domain:

DELETE https://dphost.com:5554/mgmt/filestore/default/local/test_dir/test_file.txt

After the file is deleted, a response is returned that is similar to the example in Listing 11.

Delete file response

 {
   "_links": {
     "self": {
       "href": "/mgmt/filestore/default/local/test_dir/test_file.txt"
     },
     "doc": {
       "href": "/mgmt/docs/filestore"
     }
   },
   "result": "ok"
 }

Conclusion

In this tutorial, you learned about the file and directory management capabilities through the REST management interface for the IBM DataPower Gateway Appliance. You learned how to navigate the appliance file system, how to retrieve the contents of existing files and directories, and how to remove existing resources. You also learned how to compose valid request payloads to create file system resources on the appliance. As you continue in this tutorial series, Part 4 explains the operations that are available through the REST management interface for the DataPower Gateway Appliance.

Resources

See the other parts in this series:

• REST management interface and IBM DataPower Gateway, Part 1: Introduction to the interface and status monitoring
• REST management interface and IBM DataPower Gateway, Part 2: Configuration management
• REST management interface and IBM DataPower Gateway, Part 3: File and directory management
• REST management interface and IBM DataPower Gateway, Part 4: Triggering appliance operations

The following links are helpful when reading this tutorial:

• To get started with the REST management interface, see Enabling the REST management interface.
• For everything related to the REST management interface, see REST management interface.
• For example requests and responses from the REST management interface, see Samples that use the REST management interface.
• For DataPower DataPower documentation, see the IBM Documentation.