URL File Dialog

    Local Files
    Workspace View
    CloverDX Server
    Hadoop HDFS
    Remote Files
    Filtering Files and Tips

    The URL File Dialog serves to navigate through the file system and select input or output files.

    In many components, you are asked to specify the URL of some files. These files can serve to locate the sources of data that should be read, the sources to which data should be written or the files that must be used to transform data flowing through a component and some other file URL. To specify the URL of such a file, you can use the URL File Dialog.

    The URL File Dialog has several tabs on it.

    Local Files

    The Local files tab serves to locate files on a local file system. The combo contains local file system places and parameters. It can be used to specify both CloverDX projects and any other local files.

    URL File Dialog - Local files

    Figure 23.1. URL File Dialog - Local files


    Best practice is to specify the path to files with Workspace view instead of Local view. Workspace view with help of parameters provides you with better portability of your graphs.

    Workspace View

    Workspace view tab serves to locate files in a workspace of a local CloverDX project.

    URL File Dialog - Workspace view

    Figure 23.2. URL File Dialog - Workspace view

    CloverDX Server

    CloverDX Server dialog serves to locate files of all opened CloverDX Server projects. Available only for CloverDX Server projects.

    URL File Dialog - CloverDX Server

    Figure 23.3. URL File Dialog - CloverDX Server

    Hadoop HDFS

    Hadoop HDFS tab serves to locate files on Hadoop Distributed File System.

    URL File Dialog - Hadoop HDFS

    Figure 23.4. URL File Dialog - Hadoop HDFS

    You need a working Hadoop Connection to choose the particular files.

    Remote Files

    The Remote files tab serves to locate files on a remote computer or on the Internet. You can specify properties of connection, proxy settings, and HTTP properties.

    You can type the URL directly in the format described in Supported File URL Formats for Readers or Supported File URL Formats for Writers, or you can specify it with a help of Edit URL Dialog. The Edit URL Dialog is accessible under the icon .

    Edit URL Dialog

    Edit URL Dialog lets you specify connection to a remote server in an easy way. Choose the protocol, specify a host name, port, credentials, and path.

    The dialog lets you specify the connection using the following protocols:

    • HTTP

    • HTTPS

    • FTP

    • SFTP - FTP over SSH

    • Amazon S3

    • WebDav

    • WebDav over SSL

    • Windows Share - SMB1/CIFS

    • Windows Share - SMB 2.x, SMB 3.x

    Click Save to save the connection settings. Click OK to use it.

    The Load button serves to load a session from the list for subsequent editing.

    The Delete button serves to delete the session from the list.

    HTTP(S), (S)FTP, WebDav, and SMB

    If the protocol is HTTP, HTTPS, FTP, SFTP - FTP over SSH, WebDav, WebDav over SSL, Windows Share - SMB1/CIFS or Windows Share - SMB 2.x or 3.x, the dialog allows you to specify the host name, port, username, password, and path on the server. It allows you to connect anonymously, as well.

    SFTP Certificate in CloverDX

    If you are reading from or writing into remote files and are connected via an SFTP protocol using a certificate-based authorization, you should do one of the following:

    • Create OpenSSH configuration file and specify path to it in the preferenses. The configuration file can hold multiple configurations for different hosts.

    Configuration of OpenSSH file location.

    Figure 23.5. Configuration of OpenSSH file location.

    • Create a directory named ssh-keys in your project;

    • Put the private key files into this directory and choose a suitable filename with the .key suffix.

      Listed in order from the highest to lowest priority when resolving, the private key file can have the following names:

      1. username@hostname.key

      2. hostname.key

      3. *.key (the files are resolved in alphabetical order).


    If you want to explicitly select a certificate for a specific location, the best way is to use the name with the highest priority, i.e. username@hostname.key. In such a case, if the connection succeeds, other keys are ignored.

    Figure below shows the format of the OpenSSH private key generated by ssh-keygen.

    Example of Generated OpenSSH Private Key

    Figure 23.6. Example of Generated OpenSSH Private Key

    URL Syntax for FTP Proxy

    CloverDX is able to connect to FTP proxy using the following URL syntax:



    Your login on the FTP server.
    Your login on the proxy server.
    The hostname of the FTP server.
    Your FTP password.
    Your proxy password.
    The hostname of the proxy server.
    Amazon S3

    In the case of the Amazon S3 protocol, the dialog allows you to fill in access Key, secret key, bucket, and path. For better performance, you should fill in the corresponding region.

    Having the connection specified, you can choose the particular file(s).

    Amazon S3 URL

    It is recommended to connect to S3 via endpoint-specific S3 URL: s3:// The end-point in URL should be the end-point corresponding to the bucket.

    • The URL with a specific endpoint has a much better performance than the generic one (s3://, but you can only access the buckets of the specific region.

    • The endpoint affects the signature version that will be used. If you connect to the generic one, the signature version may not match the endpoint being used. Therefore the signature is sent twice and you can see an error message in the error log:

      DEBUG [main] - Received error response: The authorization mechanism you have provided is not supported. Please use AWS4-HMAC-SHA256. (Service: null; Status Code: 400; Error Code: InvalidRequest; Request ID: 2D7C4933BD5ED2F8), S3 Extended Request ID: 9wmejqgrZ0jRpgqvw43RXUBZOzm9rnd5/wVN19kSe0dHAF/k5rxq34jvRhy8bHd5JnqBcQTBwkM=
      WARN [main] - Attempting to re-send the request to with AWS V4 authentication. To avoid this warning in the future, please use region-specific endpoint to access buckets located in regions that require V4 signing.

    For list of regions and endpoints, see AWS Regions and Endpoints (Amazon S3).

    When the S3 URL does not contain Secret Key + Access Key (e.g. s3://, CloverDX automatically searches for credentials in the following sources (in this order):

    1. Environment Variables


        Recommended since they are recognized by all the AWS SDKs and CLI except for .NET


        only recognized by Java SDK

    2. Java System Properties - aws.accessKeyId and aws.secretKey

    3. Credential profiles file at the default location (~/.aws/credentials)

      shared by all AWS SDKs and the AWS CLI

    4. Credentials delivered through the Amazon EC2 container service

      the AWS_CONTAINER_CREDENTIALS_RELATIVE_URI environment variable must be set and the security manager must have permission to access the variable

    5. Instance profile credentials delivered through the Amazon EC2 metadata service

    For detailed information, see the Walkthrough: Using IAM roles for EC2 instances.


    These sources of credentials may be used for graph development in a local project; for example, set aws.accessKeyId and aws.secretKey Java system properties (for CloverDX Runtime) and add them to CloverDXDesigner.ini (for File URL dialog) so that graphs work in local projects when using S3 URLs without credentials.

    URL File Dialog - Remote files

    Figure 23.7. URL File Dialog - Remote files


    Serves to specify fields and processing type for port reading or writing. Opens only in components that allow such data source or target.

    URL File Dialog - Input Port

    Figure 23.8. URL File Dialog - Input Port

    URL File Dialog - Output Port

    Figure 23.9. URL File Dialog - Output Port

    See also: Input Port Reading or Output Port Writing


    Dictionary tab serves to specify dictionary key value and processing type for dictionary reading or writing. Opens only in components that allow such data source or target.

    URL File Dialog - Dictionary

    Figure 23.10. URL File Dialog - Dictionary

    See also: Using a Dictionary in Graphs

    Filtering Files and Tips

    If you use File URL Dialog configured to display only some files according to the extension, you can see the File Extension below File URL.


    To ensure graph portability, forward slashes are used for defining the path in URLs (even on Microsoft Windows).


    The New Directory action is available at the toolbar of Workspace View and the Local Files tab. F7 key can be used as a shortcut for the action. Newly created directory is selected at the dialog and its name can be edited in-line. Press F2 to rename the directory and DEL to delete it.

    More detailed information of URLs for each of the tabs described above is provided in sections: