AmalG Blogs

Tuesday, August 30, 2016

Git push changes in tag to different repository branch

The following method will push changes in the tag to different repository branch along with all the commit history details.
If you don't have a branch in the new repo to commit updates, go to the git web UI and create a branch.

Now in your old repository, let's assume the tag name is v3.6.0. Change the head to tag

git checkout v3.6.0

Now add the external git repo URL as a remote reference. Let's name it as support.

git remote add support https://github.com/user/project.git

Now you can push your tag updates to the branch by using below command.

git push support +v3.6.0~0:dev-3.6.0

Thursday, March 31, 2016

Apache CXF web service implementation with dynamic WSDL

According to the requirements, I need to generate web services from dynamically loaded WSDL files. This is not practical with wsdl2java since it generates classes mapped to WSDL, which result in piling up classes for different WSDL files loaded at runtime.

So after going through Apache CXF API and after experimenting with it for some time, I was able to come up with a POC on how to achieve my requirement.

The sample code is at my Github: https://github.com/amalhub/cxf-test

Happy coding!

Thursday, March 10, 2016

How to reset Ubuntu Software Update source list

Are you getting the "Failed to fetch ... " error when running the update in Ubuntu.

Enter the following commands in a Terminal to clear the source lists and reset them -

sudo rm /var/lib/apt/lists/* -vf

sudo rm /var/lib/apt/lists/partials/* -vf ##Optional

sudo apt-get update

Tuesday, February 16, 2016

How to find and replace text in files recursively from terminal

Search command

find . -name "*.xml" -exec grep -r "4.4.7" {} +

Ex:
Search all xml files containing the string "4.4.7"

find . -name "pom.xml" -exec grep -r "4.4.7" {} +

Replace command

find <mydir> -name <filetype> -exec sed -i 's/<oldString>/<newString>/g' {} +

-to include all files types
use -type f instead -name or exclude the filter.

Ex:

Old string: 4.4.7-SNAPSHOT
New string: 4.4.7

find . -name "pom.xml" -exec sed -i 's/4\.4\.7-SNAPSHOT/4.4.7/g' {} +

Note: When using sed, search string is sensitive to regular expression. Keep in mind to use the escape characters where necessary.

Sunday, January 17, 2016

How to enable debug logs for BPMN in WSO2 BPS Server

Add the below configurations to <BPS_HOME>/repository/conf/log4j.properties

log4j.logger.org.activiti=DEBUG
log4j.logger.org.activiti.engine.impl.db=INFO
log4j.logger.org.activiti.engine.impl.persistence=INFO
log4j.logger.org.activiti.engine.impl.cfg.standalone=INFO
log4j.logger.org.activiti.engine.impl.interceptor.LogInterceptor=INFO
log4j.logger.org.activiti.engine.impl.history.DefaultHistoryManager=INFO
log4j.logger.org.activiti.engine.impl.jobexecutor.AcquireJobsRunnable=INFO

Sunday, November 29, 2015

Creating a custom LDAP structure with Apache Directory Studio

The Lightweight Directory Access Protocol (LDAP) is an application protocol for accessing and maintaining distributed directory information services over an Internet Protocol (IP) network. More info about LDAP.

Download Apache Directory Studio (ADS) Tutorial created with 2.0.0 version.

Run ADS.

Lets assume that we need to create a LDAP structure looks like below example

First you have to create a LDAP server

In ADS window at bottom left corner, go to LDAP servers tab right click inside the panel > New > New server.

Select the server version, enter a name and click finish to create the server.

You will see the new server at the LDAP servers list.

Now if you observe the structure that we are going to create, it starts with the root c=US.

In-order to do this we have to create a partition with the suffix c=US inside the server we created.

Right click on the server we created in LDAP server list (caption 2) and click Open Configuration

In the opened server.xml file, go to the partition section by clicking the partition tab at the bottom of the page.

Click add button and give a name to ID and set the suffixc=US.

Save the settings (ctrl+s).

Now go to LDAP server list (caption 2). Right click on the server and click Run.

Again right click on the server and click Create a connection.

Go to the Connections tab (next to the LDAP servers tab , caption 2)

You will see a new connections has been created with the server name.

Double click on the new created connection. It will open the LDAP structure in the LDAP browser.

Now we can start creating the LDAP structure.

First we'll create the country inside the root.

Right click on the Root in LDAP Browser and click New > New Entry...

In the new window select Create entry from scratch and click Next.

Form the Available object classes select Country and by clicking the Add button add it to the Selected object classes. Click Next.
- Note that it will add the dependent objects automatically. Do not remove them.

Keep the parent empty since this will be the root and fill RDN values c and US.

Click Next and then click Finish.

You will now see the c=US root element in the LDAP browser.

Now let's create the organization unit as BPS.

Right click on the o=WSO2 element in LDAP Browser and click New > New Context Entry...

In the new window select Create entry from scratch and click Next.

Form the Available object classes select OrganizationalUnit and by clicking the Add button add it to the Selected object classes. Click Next.

Note that it will add the dependent objects automatically. Do not remove them.

For the DN pattern enter ou=BPS,o=WSO2,c=US and click Next and Finish.

Now we can add the admin user to BPS.

Right click on the ou=BPS element in LDAP Browser and click New > New Context Entry...

In the new window select Create entry from scratch and click Next.

Form the Available object classes addOrganizationalPerson, uidObject to the Selected object classes. Click Next.

Note that it will add the dependent objects automatically. Do not remove them.

For the DN pattern enteruid=admin,ou=BPS,o=WSO2,c=US and click Next.

Set the same value admin to cn and sn by right clicking on those attributes and select Edit value.

Click Finish after setting all the values as shown in the above caption.

Note that we are unable to create groups without having at least one user. Now since we have at least one user created in the LDAP structure we can start creating groups.

Right click on the ou=BPS element in LDAP Browser and click New > New Context Entry...

In the new window select Create entry from scratch and click Next.

Form the Available object classes add groupOfNames to the Selected object classes. Click Next.

Note that it will add the dependent objects automatically. Do not remove them.

For the DN pattern entercn=allUsers,ou=BPS,o=WSO2,c=US and click Next.

There will be a new popup window asking to enter at-least one member to the group.

Give the admin user DN patter (uid=admin,ou=BPS,o=WSO2,c=US) and click OK.

Click Finish after setting all the values as shown in the above caption.

Lets create another group named as group1.

Right click on the ou=BPS element in LDAP Browser and click New > New Context Entry...

In the new window select use existing entry as template and make sure it has mentioned the correct DN patter for the existing group allUsers. Click Next.

Note that the objects has been already loaded to theSelected object classes since we are using the settings from allUser group. Click Next.

For the DN pattern entercn=group1,ou=BPS,o=WSO2,c=US and click Next.

Keep the rest of the settings as it is and click Finish.

Now lets create some users in allUsers group.

Right click on the uid=admin element in LDAP Browser and click New > New Context Entry...

In the new window select use existing entry as template and make sure it has mentioned the correct DN patter for the existing user admin. Click Next.

Note that the objects has been already loaded to theSelected object classes since we are using the settings from admin user. Click Next.

For the DN pattern enteruid=user1,cn=allUsers,ou=BPS,o=WSO2,c=US and click Next.

Set the same value user1 to cn and sn by right clicking on those attributes and select Edit value.

Click Finish after setting all the values.

Repeat the same steps to create more users. Create user2 and user3.

Now lets add user2, user3 to group1.

Click on the group1 from the LDAP browser. The settings will open in the right side window.

Right click on the empty space and select New Attribute.

In the new window set member for the attribute type and click Finish.

In the new popup window enter the DN pattern for user1 as uid=user2,cn=allUsers,ou=BPS,o=WSO2,c=US.

Repeat the above 4 steps to add user3 to group1 as well.

Congratulations !! You have created the LDAP structure.

After creating an LDAP structure, if you want to backup the data, you can always right click on the Root element in LDAP browser and select Export as a ldif file. Then next time you can Import them in the same way after creating the partition (c=US in this example) in the server with the suffix.

Wednesday, September 9, 2015

WSO2 ESB IP address whitelisting with Throttle mediator

The following configurations will show you how to whitelist set of IP addresses (range) using ESB Throttle mediator with an embedded WS-Policy.

For an instance let say you need to secure a specific ESB API resource by whitelisting a set of IPs.

Call the ESB Throttle mediator as soon as the API resource get's in to inSequence as shown below.

<?xml version="1.0" encoding="UTF-8"?>
<api xmlns="http://ws.apache.org/ns/synapse"
     name="ipWhitelistingSample"
     context="/whitelisting-ip"
     hostname="localhost">
   <resource methods="GET" uri-template="/access">
      <inSequence>
         <throttle id="A">
            <policy key="conf:/policy/policy.xml"/>
            <onReject>
               <log level="custom">
                  <property name="text" value="**Access Denied**"/>
               </log>
               <property name="HTTP_SC"
                         value="401"
                         scope="axis2"
                         type="STRING"
                         description="HTTP_SC_401"/>
               <property name="RESPONSE"
                         value="true"
                         scope="default"
                         type="STRING"
                         description="RESPONSE"/>
               <respond/>
            </onReject>
            <onAccept>
               <log level="custom">
                  <property name="text" value="**Access Granted**"/>
               </log>
               <payloadFactory media-type="xml">
                  <format>
                     <status>OK</status>
                  </format>
                  <args/>
               </payloadFactory>
               <respond/>
            </onAccept>
         </throttle>
      </inSequence>
      <outSequence/>
      <faultSequence/>
   </resource>
</api>

In the above example I have referenced the WS-Policy from a resource file from the registry.
On accept you can call another sequence or write the work inline itself.
On reject we send a response back to the client stating "Unauthorized".
The sample WS-Policy looks like below.

<wsp:Policy xmlns:wsp="http://schemas.xmlsoap.org/ws/2004/09/policy"
            xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd"
            xmlns:throttle="http://www.wso2.org/products/wso2commons/throttle"
            wsu:Id="WSO2MediatorThrottlingPolicy">
    <throttle:MediatorThrottleAssertion>
        <wsp:Policy>
            <throttle:ID throttle:type="IP">192.168.10.10 - 192.168.10.20</throttle:ID>
            <wsp:Policy>
                     <throttle:Allow/>
            </wsp:Policy>
        </wsp:Policy>
        <wsp:Policy>
          <throttle:ID throttle:type="IP">other</throttle:ID>
          <wsp:Policy>
            <throttle:Deny/>
          </wsp:Policy>
        </wsp:Policy>
    </throttle:MediatorThrottleAssertion>
</wsp:Policy>

According to above configurations, Throttle mediator will only allow access to IP addresses within the range of 192.168.10.10 to 192.168.10.20. Every other request that comes from different IPs will get denied to pass through.

Note: Let's say you have multiple IP addresses (2) that need to pass through but do not want to allow all the IP addresses within the range to pass through. In that case you can define 2 "<wsp:Policy>" tags and define "Allow" access to them.

Ex:

<wsp:Policy>
    <throttle:ID throttle:type="IP">192.168.10.12</throttle:ID>
    <wsp:Policy>
             <throttle:Allow/>
    </wsp:Policy>
</wsp:Policy>
<wsp:Policy>
    <throttle:ID throttle:type="IP">192.168.10.18</throttle:ID>
    <wsp:Policy>
             <throttle:Allow/>
    </wsp:Policy>
</wsp:Policy>
<wsp:Policy>
    <throttle:ID throttle:type="IP">other</throttle:ID>
    <wsp:Policy>
             <throttle:Deny/>
    </wsp:Policy>
</wsp:Policy>

Further reading:

Happy Coding!!