Mule CIFS Connector

This is a port of the community based mulesoft 3.9 samba connector to support the Mulesoft 4.x runtime. It allows for authenticated access to CIFS/Samba file shares, which is tragically lacking in Mulesoft 4.x. For some reason the Salesforce company is unable to provide this functionality out of the box on their expensive, buggy, closed source product. But hey, Gartner likes it, so it must be good!

Note that this port was completed using mvn on the CLI and Visual Studio Code because none of Mulesoft's examples work in their Eclipse plugin. It is not the most polished plugin (feedback from a long time Eclipse user that has also developed Eclipse plugins).

Before I ported this connector, our customers were just being told we could not connect to Windows shares because of Java. Some might find that amusing.

The API-Everywhere approach for integration strikes me as a bit naive. While no one would disagree that API abstractions are preferrable to db-to-db synchronization, or other randmom scheduled tasks, a collection of APIs cobbled together and interdependent does not represent a good long term integration strategy, imho. I know of one customer that is managing 400+ APIs between 5 commerical line of business systems. The challenge in mitigating the matrix of complexity that emerges when trying to evolve and change a myriad of interdependent schemas and APIs over time is nontrivial and expensive. Even more difficult when you have no control of the endpoints and their version evolution. Unless you explicitly design for decoupling, Mulesoft will pattern you into a world of largely synchronous web api calls. This is just a new take on DLL hell. Event driven models decouple better, and are more agile over time. I think the industry had that figured out decades ago, if I recall. I'm not certain Mulesoft lends itself well to event driven architecture. At least so far, in my travels, I have not seen a good example of it.

Installation

After fetching this repo type:

mvn install -DskipTests

This will install the mule-cifs-connector in your local maven repository. install -DskipTests is required as the Test Suite depends on the manual setup of a CIFS share.

You may also want to perform the required setup and run the Test Suite to ensure operation:

mvn clean test

Note that you will need to update the test-mule-config.xml Mulesoft test configuration with a valid CIFS configuration, and ensure the necessary sample file is in place. The tests assume that the share specified contains a file called test.xml. Before running the test suite make sure to perform the necessary setup, with the correct credentials and CIFS share information. Review the test-mule-config.xml for specific details before execution.

Setup

If you must use Mulesoft, and you need this functionality:

Add this dependency to your application pom.xml

<groupId>io.idstudios.mule.extension</groupId>
<artifactId>mule-cifs-connector</artifactId>
<version>1.0.0-SNAPSHOT</version>
<classifier>mule-plugin</classifier>

Usage

For a working example see the test-mule-config.xml in src/test/java.

Ensure you add the necessary schema references to your mulesoft project:

<mule xmlns="http://www.mulesoft.org/schema/mule/core"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xmlns:cifs="http://www.mulesoft.org/schema/mule/cifs"
      xsi:schemaLocation="http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
          http://www.mulesoft.org/schema/mule/cifs http://www.mulesoft.org/schema/mule/cifs/current/mule-cifs.xsd">

CIFSConfiguration

The CIFSConfiguration can be re-used among several of the CIFSOperations Actions, and defines common configuration parameters for CIFS/Samba access:

    <cifs:config name="config" 
        username="joeuser" 
        password="Password123"
        host="localhost"
        folder="d$/FileDropTest"
        domain="SOMEDOMAIN">
    </cifs:config>

CIFSOperations

The following CIFS operations are currently supported:

readFile

Reads a specified file from the configured share.

Eg.

    <flow name="readFileFlow">
        <cifs:read-file config-ref="config" fileName="test.xml"/>
    </flow>

readFiles

Returns a Map of file names and their corresponding InputStream for the specified configuration path and matching fileNamePattern:

Map<String, InputStream> files = new HashMap<>();

Eg.

    <flow name="readFilesFlow">
        <cifs:read-files config-ref="config" fileNamePattern="*.xml" />
    </flow>

readFileNames

Returns a List of file names for the specified configuration path and matching fileNamePattern:

List<String> files = new ArrayList<>();

Eg.

    <flow name="readFileNamesFlow">
        <cifs:read-file-names config-ref="config" fileNamePattern="*.xml" />
    </flow>

saveFile

Saves the specified payload to the output fileName:

Eg.

    <flow name="saveFileFlow">
        <cifs:read-file config-ref="config" fileName="test.xml"/>
        <cifs:save-file config-ref="config" fileName="delete-test.xml" payload="#[payload]" />
        <logger level="INFO" message="#[payload]"/>
    </flow>

Note that with the current implementation of saveFile (and deleteFile) the default configuration saves the response as the payload, so after saving the file the payload will be a boolean value indicating if the file was saved (or not). If you do not wish your payload to be overwritten, make sure to set the target as a variable. Investigation into having this be more exception based is ongoing.

deleteFile

Delete the specified fileName at the configured path:

Eg.

    <flow name="deleteFileFlow">
        <cifs:delete-file config-ref="config" fileName="delete-test.xml"/>
    </flow>

Developing with JavaKerberos

The jCIFS library used by this Mulesoft connector uses the JavaKerberos implementation under the hood. This is the same JavaKerberos used by JDBC when connecting to MSSQL using Windows Authentication from Java.

When debugging, it can be helpful to see the JavaKerberos debug messages. This can be enabled by setting the following system property:

-Dsun.security.krb5.debug=true

When developing for Mulesoft on Windows, you may experience long delays when connecting to the file share (or database in the case of JDBC). This can be due to connection failures when the library is auto-discovering domain controllers. To avoid this, it is wise to create a krb5.ini file and place it in the C:\Windows directory:

[libdefaults]
 dns_lookup_realm = false
 ticket_lifetime = 24h
 renew_lifetime = 7d
 forwardable = true
 rdns = false
 default_ccache_name = KEYRING:persistent:%{uid}
 default_realm = EXAMPLE.COM

[realms]
 EXAMPLE.COM = {
  kdc = kdc.example.com
 }

[domain_realm]
.example.com = EXAMPLE.COM
 example.com = EXAMPLE.COM

Replace EXAMPLE.COM with the relevant realm or domain.

Ensure that the server value represented by kdc.example.com points to the correct Kerberos server or domain controller. If you do not know the correct KDC, you can examine the debug log output for successful connect messages when running without a krb5.ini file, and use the specified server mentioned in the output. Configure the krb5.ini accordingly and the specified KDC server will then be the default, and should reduce the timeout/retry delays associated with Kerberos authentication.