The Virtual File System (VFS) transport is used by WSO2 Enterprise Integrator(WSO2 EI) to process files in the specified source directory. After processing the files, it moves them to a specified location or deletes them. Note that files cannot remain in the source directory after processing or they will be processed again. If you need to maintain these files or keep track of which files have been processed, specify the option to move them instead of deleting them after processing. If you want to move files into a database, use the VFS transport and the DBReport mediator (for an example, see Sample 271: File Processing).
Note that when you transfer a file to a remote FTP location via VFS, WSO2 EI tries to detect the FTP location by navigating from the root folder first. If the EI does not have at least list permission to the root (/), the file transfer fails.
Enabling the transport
This transport is based on the Apache Commons VFS implementation, which is provided in the <EI_HOME>/wso2/components/plugins/commons-vfs<version>.jar
file. The transport is a module of the Apache Synapse project, and the synapse-vfs-transport.jar
file contains the necessary classes, including those that implement the listener and sender APIs:
org.apache.synapse.transport.vfs.VFSTransportListener
org.apache.synapse.transport.vfs.VFSTransportSender
To enable the VFS transport
- Edit the
<EI_HOME>/conf/axis2/axis2.xml
file and uncomment the VFS listener and the VFS sender as follows:
<transportReceiver name="vfs" class="org.apache.synapse.transport.vfs.VFSTransportListener"/> ... <transportSender name="vfs" class="org.apache.synapse.transport.vfs.VFSTransportSender"/>
Configuring the endpoint
To configure a VFS endpoint, use the vfs:file
prefix in the URI. For example:
<endpoint> <address uri="vfs:file:///home/user/test/out"/> </endpoint>
Security
The VFS transport supports the FTPS protocol with Secure Sockets Layer (SSL). The configuration is identical to other protocols with the only difference being the URL prefixes and parameters. For more information, see VFS URL parameters below.
Securing VFS password in a proxy service
The following instructions describe how to secure the VFS password in a proxy service configuration.
Provide configuration for the password decryption by adding the following lines in
<EI_HOME>/conf/axis2/axis2.xml
file:<transportReceiver class="org.apache.synapse.transport.vfs.VFSTransportListener" name="vfs"> <parameter locked="false" name="keystore.identity.location">repository/resources/security/wso2carbon.jks</parameter> <parameter locked="false" name="keystore.identity.type">JKS</parameter> <parameter locked="false" name="keystore.identity.store.password">wso2carbon</parameter> <parameter locked="false" name="keystore.identity.key.password">wso2carbon</parameter> <parameter locked="false" name="keystore.identity.alias">wso2carbon</parameter> </transportReceiver>
If you need to secure the passwords provided in the above configuration, you can do so using secure vault. The secured configuration would look like this:
<transportReceiver class="org.apache.synapse.transport.vfs.VFSTransportListener" name="vfs"> <parameter locked="false" name="keystore.identity.location">repository/resources/security/wso2carbon.jks</parameter> <parameter locked="false" name="keystore.identity.type">JKS</parameter> <parameter locked="false" name="keystore.identity.store.password" svns:secretAlias="vfs.transport.keystore.password">password</parameter> <parameter locked="false" name="keystore.identity.key.password" svns:secretAlias="vfs.transport.key.password">password</parameter> <parameter locked="false" name="keystore.identity.alias">wso2carbon</parameter> </transportReceiver>
- Manually encrypt the password using Cipher Tool. See, Encrypting Passwords in Cipher Tool in the administration guide.
Provide the encrypted password value in your proxy configuration by adding the following parameter:
<parameter name="transport.vfs.FileURI">smb://{wso2:vault-decrypt('encryptedValue')}
Failure tracking
To track failures in file processing, which can occur when a resource becomes unavailable, the VFS transport creates and maintains a failed records file. This text file contains a list of files that failed to be processed. When a failure occurs, an entry with the failed file name and the timestamp is logged in the text file. When the next polling iteration occurs, the VFS transport checks each file against the failed records file, and if a file is listed as a failed record, it will skip processing and schedule a move task to move that file.
Transferring large files
If you need to transfer large files using the VFS transport, you can avoid out-of-memory failures by taking the following steps:
In
<EI_HOME>/conf/axis2/axis2.xml
, in themessageBuilders
section, add the binary message builder as follows:<messageBuilder contentType="application/binary" class="org.apache.axis2.format.BinaryBuilder"/>
and in the
messageFormatters
section, add the binary message formatter as follows:<messageFormatter contentType="application/binary" class="org.apache.axis2.format.BinaryFormatter"/>
In the proxy service where you use the VFS transport, add the following parameter to enable streaming (see VFS service-level parameters below for more information):
<parameter name="transport.vfs.Streaming">true</parameter>
In the same proxy service, before the Send mediator, add the following property:
Note
You also need to add the following property if you want to use the VFS transport to transfer files from VFS to VFS.
<property name="ClientApiNonBlocking" value="true" scope="axis2" action="remove"/>
For more information, see Example 3 of the Send Mediator.
VFS service-level parameters
The VFS transport does not have any global parameters to be configured. Rather, it has a set of service-level parameters that must be specified for each proxy service that uses the VFS transport.
Parameter Name | Description | Required | Possible Values | Default Value |
---|---|---|---|---|
transport.vfs. | The URI where the files you want to process are located. You can specify connection-level parameters on the URL (see VFS URL parameters below). When you need to access the absolute path of the URL, you can define the URL with
| Yes | A valid file URI in the following form: |
|
transport.vfs. | Content type of the files processed by the transport. To specify the encoding, follow the content type with a semi-colon and the character set. For example: <parameter name="transport.vfs.ContentType“>text/plain;charset=UTF-32</parameter> When writing a file, you can set a different encoding with the CHARACTER_SET_ENCODING property:<property name="CHARACTER_SET_ENCODING" value="UTF-8" scope="axis2" type="STRING"/> | Yes | A valid content type for the files (e.g., |
|
transport.vfs. | If the VFS listener should process only a subset of the files available at the specified file URI location, use this parameter to select those files by name using a regular expression. | No | A regular expression to select files by name (e.g., |
|
transport. | The polling interval for the transport receiver to poll the file URI location. The value is expressed in seconds unless you add "ms" for milliseconds, e.g., "2" or "2000ms" to specify 2 seconds. | No | A positive integer. |
|
transport.vfs. | Whether to move, delete or take no action on the files after the transport has processed them. | No |
|
|
transport.vfs. | Whether to move, delete or take no action on the files if a failure occurs. | No |
|
|
transport.vfs. | Where to move the files after processing if ActionAfterProcess is MOVE. | Yes, if | A valid file URI |
|
transport.vfs. | Where to move the files after processing if ActionAfterFailure is MOVE. | Yes, if | A valid file URI |
|
transport.vfs. | The location where reply files should be written by the transport. | No | A valid file URI |
|
transport.vfs. | The name for reply files written by the transport. | No | A valid file name |
|
transport.vfs. | The pattern/format of the timestamps added to file names as prefixes when moving files. | No | A valid timestamp pattern |
|
transport.vfs. | Whether files should be transferred in streaming mode, which is useful when transferring large files | No |
|
|
transport.vfs. | Reconnect timeout value in seconds to be used in case of an error when transferring files | No | A positive integer | 30 sec |
transport.vfs. | Maximum number of retry attempts to carry out in case of errors. | No | A positive integer | 3 |
transport.vfs.Append | When writing the response to a file, whether the response should be appended to the response file instead of overwriting the file. This value should be defined as a query parameter in the out/reply or:
| No |
|
|
transport.vfs. | Where to move the failed file. | No | A valid file URI |
|
transport.vfs. | The name of the file that maintains | No | A valid file name |
|
transport.vfs. | Where to store the failed records file. | No | A folder URI | |
transport.vfs. | Entries in the failed records file include the name of the file that failed and the timestamp of its failure. This property configures the time stamp format. | No | A valid timestamp pattern |
|
transport.vfs. | The time in milliseconds to wait before retrying the move task. | No | A positive integer | 3000 milliseconds |
transport.vfs.Locking | By default, file locking is enabled in the VFS transport. This parameter lets you configure the locking behavior on a per service basis. You can also disable locking globally by specifying the parameter at the receiver level and selectively enable locking only for a set of services. | No |
|
|
transport.vfs. FileProcessCount | This setting allows you to throttle the VFS listener by processing files in batches. Specify the number of files you want to process in each batch. | No | A positive integer, such as 10 | N/A |
transport.vfs. FileProcessInterval | The interval in milliseconds between two file processes. | No | A positive integer, such as 1000 | N/A |
transport.vfs.ClusterAware | Whether VFS coordination support is enabled in a clustered deployment or not. | No | true or false | false |
transport.vfs.FileSizeLimit | Only file sizes that are less than the defined limit will be processed. | No | File size in bytes | -1(unlimited file size) |
transport.vfs.AutoLockReleaseInterval | The timeout value for stale locks where the VFS transport will ignore those file locks once the defined time period is reached. (The time period is calculated from the time the lock is created to the time you attempt to access it.) If you need stale locks to never timeout provide -1 as the timeout value. | No | Time in milliseconds | 20000 |
transport.vfs.SFTPIdentities | Location of the private key | No | A valid file path | N/A |
transport.vfs.SFTPIdentityPassPhrase | Passphrase of the private key | No | A valid passphrase | N/A |
transport.vfs.SFTPUserDirIsRoot | If the SFTP user directory should be treated as root | No | true or false | true |
VFS URL parameters
VSF connection-specific parameters can be set as URL query parameters. For example, to use FTPS with SSL, you could specify the URL as follows:
<parameter name="transport.vfs.FileURI">vfs:ftps://test:test123@10.200.2.63/vfs/in?vfs.ssl.keystore=/home/user/openssl/keystore.jks&vfs.ssl.truststore=/home/user/openssl/vfs-truststore.jks&vfs.ssl.kspassword=importkey&vfs.ssl.tspassword=wso2vfs&vfs.ssl.keypassword=importkey</parameter>
Following are details on the URL parameters you can set. To configure the proxy over ftp/sftp click here.
Parameter Name | Description | Possible Values | Default Value |
---|---|---|---|
vfs.passive | Enable FTP passive mode. This is required when the FTP client and server are not in the same network. | true | false | false |
transport. vfs . Append | If file with same name exists, this parameter tells whether to create a new file and write content or append content to existing file | true | false | false |
vfs.protection | Set data channel protection level using FTP PROT command |
| C |
vfs.ssl.keystore | Private key store to use for mutual SSL. Your keystore must be signed by a certificate authority. For more information, see http://docs.oracle.com/cd/E19509-01/820-3503/ggfen/index.html. | String - Path of keystore | |
vfs.ssl.kspassword | Private key store password | String | |
vfs.ssl.keypassword | Private key password | String | |
vfs.ssl.truststore | Trust store to use for FTPS | String - Path of keystore | |
vfs.ssl.tspassword | Trust store password | String | |
transport.vfs.CreateFolder | If the directory does not exists create and write the file | true | false | false |
transport. vfs.SendFileSynchronously | Whether to send files synchronously to the file host. When this parameter is set to true , files will be sent one after another to the file host. This synchronous write can be configured on a per host basis. | true | false | false |