Wednesday, January 18, 2017

OpenVPN how to route all IPV4 traffic through the OpenVPN tunnel


Originally I was connected from a Windows 10 machine via OpenVPN to a network (segment?) for "our" project. I could access all servers and websites related to it.  But when switching to another project (using the same OpenVPN settings) I could only access the new project's servers when at the premise of that project. At home or from any other place, I could not get to the servers, e.g Jenkins. The error shown was "This site can't be reached" in Chrome. See screenshot below for the exact error:

But I could get to the microservices pods directly by IP address, e.g (xyz are not the same in below example IP addresses, just obfuscators). So quite strange.

The administrator of the OpenVPN server didn't know how to fix the problem either. Suggested was to make sure "to route all IPV4 traffic through VPN". That made me search on the interwebs and I found below solution to work, without having to change any server settings. (I did not even have access to those server settings.)

Analyzing the problem

A) Trying the website with the hostname:
Tracing route to [] over a maximum of 30 hops:
  1     1 ms     1 ms     1 ms  MODEM [192.169.178.x]
  2    20 ms    19 ms    20 ms []
  3    22 ms    22 ms    22 ms []

B) Trying the well-known google gateway:
Tracing route to [] over a maximum of 30 hops:
  1     1 ms     1 ms     1 ms  MODEM [192.169.178.x]
  2    21 ms    20 ms    21 ms []

Hmm so its route goes via the same initial gateway for both external IPs and the hostname, so not via the VPN.

C) Trying with the IP that works (note not the IP for the hostname from above!):
Tracing route to over a maximum of 30 hops
  1    97 ms    21 ms    20 ms
  2    45 ms    98 ms    29 ms
  3   130 ms    65 ms    68 ms

As you can see, the first entrypoint gateway is a different one, and most likely the wrong one.

The solution

The solution was to add this to the .ovpn OpenVPN configuration file:

route-method exe
route-delay 2
redirect-gateway def1

For me even only the last line (redirect-gateway def1) was sufficient, but for others the other two lines had to be added too.

D) After adding the setting, you can see the IP of the gateway changed to, the what turns out to, be the correct one:
Tracing route to [183.45.163.yyy] over a maximum of 30 hops:
  1   143 ms    31 ms    21 ms
  2    21 ms    20 ms    21 ms []
  3    21 ms    21 ms    25 ms
  4    25 ms    21 ms    91 ms

References used:

Wednesday, December 14, 2016

Nodejs Express enabling HSTS and cookie secure attribute

To enable HSTS (adds Strict-Transport-Security header to the response) for Node + Express using Helmet, this should be sufficient to add to your app.js:

var hsts = require('hsts')

  maxAge: 15552000  // 180 days in seconds

But a few things didn't work for me. First of all I had to add the force: true attribute. Also I was using an older version of HSTS ([0.14.0 instead of current latest release 2.0.0), so the maxAge was not in seconds but in milliseconds. It says in the README at github but I hadn't checked the version we were using...

To enable the 'secure' attribute for cookies (so they are only sent over HTTPs), I added the cookie-session module. But there is an issue with the secure flag. See the code below for more details.

Below is a full viewcounter.js application that shows the result for enabling hsts and secure cookes. Note also the comments in the code.

Start it with: node viewcounterhelmet.js


var cookieSession = require('cookie-session')
var helmet = require('helmet');
var express = require('express')

var app = express()

// Works, makes in response show Cache-Control, Pragma, Expires: app.use(helmet.noCache());
var oneYearInSeconds = 31536000;
  maxAge: oneYearInSeconds,
  includeSubDomains: true,
  force: true

var expiryDate = + 60 * 60 * 1000; // 1 hour in milliseconds
  name: 'session',
  secret: '10dfaf09-cf6f-43a9-b40b-4eaacbcceb8a',
  maxAge: expiryDate,
  // Not setting secure attr does not show it Secure
  // secure : true, // Set to true and no cookies at all in response. Created ticket for this for v1.2.0
  // secure : false, // Set to false it indeed doesn't show the Secure value with the cookie; it does show the cookies
  secureProxy: true, // Since this is running behind a proxy. But deprecated when using 2.0.0-alpha! Says to use secure option but that stops passing on cookies. When set to true, the cookie is set to Secure. If commented out, cookie not set to Secure
  httpOnly: true  // Don't allow javascript to access the cookie

app.get('/', function (req, res, next) {
  // Update something in the session, needed for a cookie to appear
  req.session.views = (req.session.views || 0) + 1

  // Write response
  res.end(req.session.views + ' views')


So when issuing the following curl command, this is the result:

vagrant$ curl -c - -v http://localhost:3000/
* Hostname was NOT found in DNS cache
*   Trying
* Connected to localhost ( port 3000 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.37.1
> Host: localhost:3000
> Accept: */*
< HTTP/1.1 200 OK
< X-Content-Type-Options: nosniff
< X-Frame-Options: SAMEORIGIN
< X-Download-Options: noopen
< X-XSS-Protection: 1; mode=block
< Surrogate-Control: no-store
< Cache-Control: no-store, no-cache, must-revalidate, proxy-revalidate
< Pragma: no-cache
< Expires: 0
< Strict-Transport-Security: max-age=31536; includeSubDomains
* Added cookie session="eyJ2aWV3cyI6MX0=" for domain localhost, path /, expire 2961374488
< Set-Cookie: session=eyJ2aWV3cyI6MX0=; path=/; expires=Sun, 04 Nov 2063 04:01:28 GMT; secure; httponly
* Added cookie session.sig="DJaPtrG-tmTnVr33fOWXqWGnVlw" for domain localhost, path /, expire 2961374488
< Set-Cookie: session.sig=DJaPtrG-tmTnVr33fOWXqWGnVlw; path=/; expires=Sun, 04 Nov 2063 04:01:28 GMT; secure; httponly
< Date: Fri, 02 Dec 2016 13:30:45 GMT
< Connection: keep-alive
< Content-Length: 7
* Connection #0 to host localhost left intact
1 views# Netscape HTTP Cookie File
# This file was generated by libcurl! Edit at your own risk.

#HttpOnly_localhost     FALSE   /       TRUE    2961374488      session eyJ2aWV3cyI6MX0=
#HttpOnly_localhost     FALSE   /       TRUE    2961374488      session.sig     DJaPtrG-tmTnVr33fOWXqWGnVlw

Notice the Strict-Transport-Security header and the set cookies with the 'secure' attribute set.

But when setting secure:true (also for the currently latest version 1.2.0), this is the result:

vagrant$ curl -c - -v http://localhost:3000/
* Hostname was NOT found in DNS cache
*   Trying
* Connected to localhost ( port 3000 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.37.1
> Host: localhost:3000
> Accept: */*
< HTTP/1.1 200 OK
< X-Content-Type-Options: nosniff
< X-Frame-Options: SAMEORIGIN
< X-Download-Options: noopen
< X-XSS-Protection: 1; mode=block
< Surrogate-Control: no-store
< Cache-Control: no-store, no-cache, must-revalidate, proxy-revalidate
< Pragma: no-cache
< Expires: 0
< Strict-Transport-Security: max-age=31536; includeSubDomains
< Date: Tue, 13 Dec 2016 11:27:37 GMT
< Connection: keep-alive
< Content-Length: 7
* Connection #0 to host localhost left intact

So no cookies anymore, while they should be there!  Reported issue here.

Versions used:
  • node js: 6.7.0
  • express: 4.13.30
  • cookie-session: 1.2.0
  • helmet: 0.14.0

Saturday, December 3, 2016

Kubernetes Software Components Architecture Diagram

For a recent innovative project we were able to work with Kubernetes 1.3 as tool for automating deployment, scaling, and management of containerized applications. In our case (micro)services.

A lot of documentation is available, but I was missing an as-complete-as-possible architecture picture of all components within k8s. Or sometimes the link between certain components was not shown, or a related but very relevant component for the system was missing (e.g. Flannel). Below is the result of this: a full components architecture diagram of all components in Kubernetes. It was hard to fit everything in, but I think I have everything for the level of detail I wanted to capture.

The following components can be found in the diagram: kubectl, etcd, master node, worker node, controller manager, scheduler, etcd-watch, API server, Docker, kubeproxy, deployments, container, pod, service, kubelet, label selectors, config maps, secrets, daemon sets, jobs, flannel (for subnet), client app accessing the services.

Let me know in the comments if I'm missing anything! 😊

Inspiration for this diagram came from (amongst other things):

Wednesday, February 10, 2016

Tomcat 7 request processing threading architecture and performance tuning

Tomcat has many parameters for performance tuning (see, but for some attribute descriptions it is not a 100% clear how some properties affect each other.

A pretty good explanation regarding acceptCount and maxThreads can be found here: 
But that article is missing a ... picture! That's what I tried to create here, with the numbers 1-5 indicating the steps described in the above article:

Just in case should the Netflix URL ever get lost and for easy reference, here's the 5 steps:

The Tomcat attribute maxThreads worked best in my case with value 50, as it won't saturate the machine/CPU. (due to too many workerthreads, many context-switches)

To set maxThreads when using Spring Boot + embedded Tomcat:

Other remarks

Referenced material

Wednesday, December 9, 2015

com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: / (Timeout during read)

In a recent project, seemingly randomly, this exception occurred when doing a CQL 'select' statement from a Spring Boot project to Cassandra:

com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: / (Timeout during read), / (Timeout during read))

After a lot of research, some people seemed to have reported the same issue. But no clear answer anywhere. Except that some Cassandra driver versions might be the cause of it: they mark (all) the node(s) as down and don't recognize it when it becomes available again.

But, the strange this is we have over 10 (micro) services running, all running at with least 2 instances. But only one of these services had this timeout problem. So it almost couldn't be the driver.... Though it did seem to be related with not using the connection for a while, because often our end-to-end tests just ran fine, time after time. But after a few hours, the tests would just fail. Then we didn't see the pattern yet...

But, as a test, we decided to let nobody use the environment against which the end-to-end tests run for a few hours; especially also because some of the below articles do mention as a solution to set the heartbeat (keep-alive) of the driver.

And indeed, the end-to-end tests started failing again after the grace period. Then we realized it: all our services have a Spring Boot health-check implemented, which is called every X seconds. EXCEPT the service that has the timeouts; it only recently got connected with Cassandra!

After fixing that, the error disappeared! Of course depending on the healthcheck for a connection staying alive is not the ideal solution. A better solution is probably setting the heartbeat interval on the driver on Cluster creation:

var poolingOptions = new PoolingOptions()
var cluster = Cluster

In the end it was the firewall which resets all TCP connections every two hours!


Tips to analyse the problem:

Similar error reports

Wednesday, December 2, 2015

iOS9 / iOS 9 / iOS 9.1 / ATS 9: An SSL error has occurred and a secure connection to the server cannot be made due to old sha1 signed certificate

In iOS 9 and higher apps, a higher level of ciphers is required for a certificate for Forward Secrecy.

Before iOS 9, it was possible to let a site within a webview forward/redirect to another SSL protected site.
For example it was possible to let another site redirect to this one in iOS 8:

But since iOS 9 it is not allowed anymore and you'll get an error like:

An SSL error has occurred and a secure connection to the server cannot be made." UserInfo={NSUnderlyingError=0x7f9855dcb520 {Error Domain=kCFErrorDomainCFNetwork Code=-1200 "An SSL error has occurred and a secure connection to the server cannot be made." UserInfo={_kCFStreamErrorDomainKey=3, NSLocalizedRecoverySuggestion=Would you like to connect to the server anyway?, _kCFNetworkCFStreamSSLErrorOriginalValue=-9802, _kCFStreamPropertySSLClientCertificateState=0, NSLocalizedDescription=An SSL error has occurred and a secure connection to the server cannot be made., NSErrorFailingURLKey=

You'll just see a blank/white screen in the webview; no errors or whatsoever on the screen.

The by-default supported list in iOS 9 and higher can be found here:

You can test easily whether a webpage/site is accepted at this site:

So when run for the above mentioned securesuite site, it tells us even in red the signature is still using the old SHA-1:

The site also even checks different clients like browsers and mobile operating systems like Android and iOS. And see the error in the Handshake Simulation section for ATS 9/ iOS 9: Client requires SHA2 certificate signatures

Running it against, which has SHA-2 as signature algorithm, the forwarding does work in iOS 8 and ios 9+: 
And the iOS 9 client also likes it:

To still be able to have iOS 9 and higher apps work with those less-secure sites which still use SHA-1, you can specify which domains are "ok-ish", i.e whitelist per domain. 
In the sections in you can read how to whitelist: "Allowing Insecure Connection to a Single Server" and "Allowing Lowered Security to a Single Server" and "Using ATS For Your Servers and Allowing Insecure Connections Elsewhere".

Sunday, September 27, 2015

JBoss EAP 6.2.0 + Camel + CXF + JSF 2.2.8 Project Summary


This blogpost is a short summary of a project I did a short while ago in 2014.

Tools used

  1. Oracle's jdk1.8.0_05 with target 7
  2. JBoss EAP 6.2.0
  3. Testng 6.8 (instead of JUnit)
  4. Camel 2.13
  5. CXF (for calls to external webservices)
  6. Less (CSS similar a bit to SASS)
  7. Spring 4.0
  8. Lombok
  9. Mockito 1.0
  10. Hamcrest 1.3
  11. DBUnit 2.5
  12. Embedded tomcat 7 for integration tests with maven 3
  13. Sonar, Confluence, Sourcetree (for Git over SVN)
  14. Spring-rabbit 1.2 for accessing RabbitMQ
  15. JSF 2.2.8
  16. Hibernate 5.1.1
  17. Hsqldb 2.3

Lessons learned

  1. My first time use of the Maven plugin dependency which gives warnings of undeclared and used or unused declared dependencies:

    mvn dependency:analyze-only

    Very handy. You *can't* trust on analyze-only though! In the end you still need to perform a full build to make sure all still works. The plugin can only determine dependencies.

    It is possible that some "hidden" non-explicit dependency on an @Entity class creates a FK, which causes the project (with the missing explicit ) not be able to drop a table because it doesn't know about that FK (and thus can't drop that and thus not the table).

    Luckily in log (perhaps you need to set the hibernate level to log all queries/statements) you can see what exactly is being dropped and thus can you spot the missing 'drop contraint xyz' line, where xyz is the constraint the current project doesn't know about. Add it as to the project's pom.xml and the statement should appear. Note that mvn dependency:analyze-only will complain about it as 'unused declared dependency'. Probably this FK dependency is an incorrect project setup anyway.

  2. Sonar's //NOSONAR does not seem to ignore code-coverage violations... Only issues (e.g the Blocker, Critical etc rules).

  3. Camel 2.13: example expression to only have file moved if same file prefix file but with extension .ready already exists:

    // Reference:
    private static final String FILE_READY_TO_BE_PICKED_UP_EXPRESSION = "doneFileName=$simple{file:name.noext}.ready";

  4. Parsing in jodatime:

    private final DateTimeParser[] parsers = {

    DateTimeFormatter formatter = new DateTimeFormatterBuilder().append(null, parsers).toFormatter().withZone(DateTimeZone.UTC);

    And the other direction:

    String nowText =;

  5. Suppose you have two maven profiles A and B. When running mvn clean install -PA,B it appeared only the <exclude> of the last profile was being used (as seen when adding the -X parameter when running the mvn command).

    Problem was that both profiles had the same <id> in the <execution> part!

    Solution: prefix the execution ids to make them unique. E.g:


  6. TestNG (and JUnit vx.y in a bit different way but same mechanism) supports groups to divide tests in for example unit vs integration tests.
    But what if you have a combination of previous unittests which don't have that annotation yet, and you don't want to have to update all tests classes?
    Because if you have specified in your root pom.xml, then the tests w/o the groups attribute in the @Test annotation  won't get picked up by the maven-sure-fire plugin.

    For that you need this specified with your maven-surefire-plugin configuration:

        <!-- Need to specify an empty variable. Leaving the tags empty does not make it overrule the defined in the inmotiv-root/pom.xml -->

    Note the ${emptyProperty} property. It has *no* value set!

    Would you remove the ${emptyProperty}, so you have <groups><groups/>, or replace the line with <groups/> you'll see the test class won't get run! My guess is that maven just removes the empty tag, but won't if you put in a variable...

  7. When renaming files by change the casing (uppercase or lowercase) that are already git controlled, use

    git mv -f FILE file
    otherwise GIT won't see it.

Saturday, January 31, 2015

Recreate Vagrant box when original .box is gone from vagrantcloud


Suppose you've setup a cool Vagrant image based upon a box from the Vagrant Hashicorp cloud. But suddenly one day the URL is gone! So the original box is gone. E.g this one, which gives a 404 page:
Your 'vagrant up' still works, vagrant will just complain it can't find the box anymore, but the VirtualBox image will start up fine.

But you are still getting new team-members on board, and you want them to use the Vagrant setup you created; but the URL is gone so the base box can't be downloaded anymore. What to do?
Well, it turns out you can recreate the .box file which the above URL is pointing to.
This post describes how.


  1. Locate where the Vagrant box from the URL is stored on your local machine. On Windows 7 it is C:/Users/ttlnews/.vagrant.d/boxes 
    At this location are all the base Vagrant boxes downloaded. So without any changes/provisioning made to them. The exact directory of the above ubuntu1404-desktop URL is: C:/Users/ttlnews/.vagrant.d/boxes/box-cutter-VAGRANTSLASH-ubuntu1404-desktop

  2. Create a zip of the deepest directory in there. In my case it I 7zipped all the files in C:/Users/ttlnews/.vagrant.d/boxes/box-cutter-VAGRANTSLASH-ubuntu1404-desktop/1.0.11/virtualbox So not the directory, just the files, like the box.ovf, metadata.json, *.vmdk, Vagrantfile. The resulting file was:

    This is what it should look like in the .7z file:

  3. Rename the file to

  4. Put it in c:/tmp or wherever you want; make sure to change accordingly in the below steps.

  5. In the directory where you have your (already existing because you have created it successfully before from the now-defunct box URL) Vagrantfile add the following line below

    config.vm.box_url = "file:///c:/tmp/"

    Tip 1: when testing this out, it's safer to copy your Vagrantfile + whatever else you had to a new directory, so you won't mess up your working Vagrant setup.

    Tip 2: in that new setup from tip 1, also change the value of in the Vagrantfile, so you can clearly identify this new image.

  6. Run 'vagrant up' and you should see it copy (extract) the files, start a VirtualBox and start provisioning the box!
Main source for this solution:

Thursday, November 20, 2014

JasperReports/iReports dynamically show and hide fields conditionally


With JasperReports and its visual designer iReports you can have (blocks of) fields collapse based on certain conditions.
You can use a subreport, but that's not necessary. This post describes how to show/hide fields without subreports.


Basically you have to do two things:

  1. Put the elements (static text, textfields etc) you want to hide on a frame. Make sure the fields are not behind the frame.
  2. Set the correct properties on the frame, including the expression to show/hide it dynamically. By hiding the frame you hide all the fields on it. 
The most important thing is to make sure no other element besides those that need to be on it is overlapping with the frame! Below is a screenshot to make it clearer.
There are three static and three textfields on the frame. Plus two (separate!) vertical lines.

Note the green, red and black vertical lines in the screenshot: the red and black vertical lines are not on the frame at all. The frame has its own green vertical line. That way JasperReports can shrink it based on the condition. Otherwise it doesn't know what to do with the overlap, and doesn't (can't?) collapse it. Notice also the frame is selected (little square blue boxes on its lines) to make clear from where to where the frame runs.
So basically you have to make sure the frame is all by itself, all its elements only on the frame, and no other elements overlapping the frame.

PS: it might be possible to do it per field, but since I needed at least a label + field to be shown/hidden, I didn't even try that.

To put in the other necessary settings, you have two ways of doing that:

  1. Via the XML:

    Put in the condition of the frame. So if theObject is not null, the frame will be shown. Also make sure you add 'isRemoveLineWhenBlank="true"'. E.g:

  2. Or via the Eclipse properties tab: see below screenshot:

    Notice setting the flag and the expression, see the arrow pointing at $F, that's the start of the same above expression in the XML.

Thursday, July 3, 2014

Vaadin 7 + Spring 3 + JPA project summary and lessons learned

This blogpost is a short summary of the Vaadin 7.0 project I did last year, including tools used, lessons learned and a bunch of screenshots to show the results.

Tools used

  • Spring 3.2 including annotation based configuration, Spring Task*Executor framework
  • JPA2 with Hibernate 4.2 + JPA modelgen, including Envers for auditing
  • JMS 2
  • Vaadin 7.0.1
  • JAXB 2.1
  • Spring WS 2.1
  • Shiro 1.2
  • JUnit 4.8
  • Mockito
  • Eclipse 3.7
  • SOAP + SoapUI
  • MySql 5.5 + H2
  • Tomcat 7
  • Jenkins
  • Fisheye/Crucible
  • Sonar
  • Subversion
  • Maven 3
  • Java 6

Lessons learned

  • Don't only trust SoapUI of being able to validate your WSDL. Also try to generate stubs with Axis2 and JAXWS generators. *AND* actually make sure you can make a call to the webservice, because on our project it did work perfectly fine in SoapUI, but not in Axis nor JAXWS. Example: soap fault in operation but not in porttype defined. It required the project to defining one or more xyz.jaxb files for JAX-WS  (using .episodes dit not work for us). Then use these in the wsimport etc. Related links: Compiling multiple WSDLs that share a common schema and Customizing Java Packages.
  • If sources not found of e.g junit-4.11 ( is also giving a lot of 404s), then run mvn clean dependency:sources, that will download the sources too into the .m2 repo.
  • Try to keep the WSDL and XSD as semantic as possible, so use Strings instead of IDs for for example lookup /reference values like: started, finished. Makes the interface much more readable and understandable by just looking at it.
  • count(case ...) is NOT supported by Hibernate criteria API, when using it it gives: java.lang.IllegalArgumentException: org.hibernate.hql.internal.ast.QuerySyntaxException: unexpected token: case near line 1, column 92 [...  Use sum(case) since that is supported.

    So instead of:

    cb.count(cb.selectCase().when(cb.equal(workOrder.get(WorkOrder_.priority), 1), workOrder.get(WorkOrder_.priority)).otherwise(0)),

    cb.sum(cb.selectCase().when(cb.equal(workOrder.get(WorkOrder_.priority), 1), 1).otherwise(0)) 

    SQL equivalent:

    Instead of:

    COUNT(CASE WHEN priority = 1 THEN priority ELSE NULL END) AS prio1,


    SUM(CASE WHEN priority = 1 THEN 1 ELSE 0 END) AS prio1,

    Links about this:
    Sums replacement for count
    JPA 2.0 spec including 'case expressions' and this one and this one.
  • When trying to upgrade from Vaadin from version 7.0.1 to 7.0.4 by updating the version number in the pom.xml, a serial UID problem occurred when generating the widgetset for this new version:

    [INFO]  at
    [INFO] Caused by:; local class incompatible: stream classdesc serialVersionUID = 5017484276333252513, local class serialVersionUID = 9103713597467037978

    Tried it then with 7.0.2, that one worked fine! 7.0.3 gave the same error. This post talks about maybe the GWT cache being the problem. So I deleted the directory (even though the timestamp on that directory was recent!) and that worked. In my case the directory to delete was:


The application

Below you can find a bunch of screenshots of the resulting application Planning Optimizer or ePOp.

The login screen, authentication via Shiro with a custom Realm that does a SOAP call to the backend:

The dashboard so the planner can immediately see the status + what needs attention first:

The Vaadin Charts 90 days look ahead graph shows the status for the coming 90 days. Clicking on a bar shows the orders at the bottom table for that day. A similar 12 weeks graph is available on another tab:

Different ways of looking at the status exist, for example these week-based graphs, the first one based on craft, the second one on priority:
Notice in the above graph the multiple y-axis: the bars are for the left y-axis, the lines for the right y-axis.

And other filters:

When clicking on a row in the bottom table, details for that order can be filled in:

Links (from a whitelist) and documents can be attached too (including drag 'n drop), and in the end a PDF can be generated with all the info (including the attachments + where the links are pointing to!) included: