How to use wildcard domain with OpenShift hosting?

If you have a domain name and want to use OpenShift for hosting then using wildcard domain name is bit tricky with some domain registrars like GoDaddy. The reason is IP address of app on OpenShift doesn’t remain same and to use wildcard domain a DNS A record is setup with the IP address of hosting server. So, how do we make sure following to be true:

  • user enters mysitename.com > user sees www.mysitename.com
  • user enters mysitename.com/about.html > user sees www.mysitename.com/about.html

That is, the www prefix is always displayed anywhere on the site.

But due to the non-static IP of OpenShift app it is not possible to adjust the A record. But you can set up a cname with the following:

www > appname-username.rhcloud.com

where the format for the OpenShift app is

http://appname-username.rhcloud.com.

This means the site is accessible at www.mysitename.com but not at mysitename.com. To make it work you need to do the following.

On domain registrar like GoDaddy
– Create new Record with
Record Type CNAME
HOST: www
POINT TO: appname-username.rhcloud.com

  • Setup Forwarding
    Forward to: www.mysitename.com
    Redirect: 301 (Permanent)
    Type: Forward only

On Openshift
1. Select Application tab > select application appname-username.rhcloud.com > click change
2. Enter Domain name www.mysitename.com

That’s it! Wait for 10-15 min and see the magic.

Deploy your first ASP.Net MVC App to AppHarbor

If you’ve been developing ASP.Net MVC apps lately you might be thinking some online or cloud based app hosting platform available as PaaS for Microsoft technologies specially for hosting ASP.Net MVC apps just like OpenShift, Heroku and other platforms are available for technologies like Ruby, Python, PHP, Node.js and even supporting CMS like WordPress. The good news for ASP.Net developers is that there is a PaaS platform available which you might already know. The platform is AppHarbor. AppHarbor runs over Amazon AWS and has some nice features that I won’t go into the details of. If you are interested in knowing how AppHarbor works you can see their page here.

Regardless of AppHarbor provides a decent service, new developers might still face some difficulty in deploying their applications to AppHarbor. Specially, if you are developing apps based on new Visual Studio 2015 templates like MVC. Their are different ways to deploy but I would follow below approach which in my opinion is good and provide auto deployment or in other words Continuous Integration (CI).

What you need?

We will be using following tools and accounts.

  • Visual Studio 2015 (any edition, I used Professional version)
  • ASP.Net MVC app created from VS2015 MVC template
  • GitHub repo for the app/project
  • Local git repo for app with remote repo set as your GitHub app repo
  • AppHarbor app

What’s not covered?

Our focus today is deployment of our ASP.Net MVC app to AppHarbor. Therefore, we won’t be going into the details of how application is created or its architecture, what’s new in Visual Studio 2015, what is MVC, what is Git and GitHub, and how to connect your GitHub repo to AppHarbor etc. We will assume that you already have all the pre-requisites and we will just focus what problems can we come across during deployment and how to fix them.

Deployment Steps

  1. Initialize a Git repo and connect it with your GitHub repo.
  2. Create AppHarbor app from your GitHub repo. Whenever we commit/push our changes to our GitHub repo AppHarbor will automatically fetches the latest push and build it. Upon successful build it will deploy the app on its server otherwise it will keep last successful build. This makes things very easy.
  3. Create an ASP.Net MVC application using Visual Studio 2015 MVC template.
  4. Add the packages folder to .gitignore
  5. Enable NuGet Package Restore. In VS2015 click Tools>Options and then select NuGet Package Manager and make sure both checkboxes are checked in this section.
  6. In VS2015 right click on project and click properties, then goto Build Events tab. In the Post-build event command line text area paste the following command.
    1. if not exist “$(WebProjectOutputDir)\bin\Roslyn” md “$(WebProjectOutputDir)\bin\Roslyn”
      start /MIN xcopy /s /y /R “$(OutDir)roslyn\*.*” “$(WebProjectOutputDir)\bin\Roslyn”
  7. Now commit and push your changes to GitHub.
  8. That’s it! AppHarbor will automatically fetch the latest version changes and build it and you can check your AppHarbor application on its URL.

What’s Next?

There are few things that you need to take care of specially related to security. This MVC app uses SQL Server Compact which isn’t a good option for production level apps. Secondly, your connection string or password to database must not be committed to public GitHub repo.

This post will just give you smooth start without any difficulties which I faced among other people that you can see in the resources section below.

If you think this was helpful or if I have missed anything please do let me know in the comments below.

Happy coding!

Resources

  1. https://blog.appharbor.com/2012/02/06/use-nuget-package-restore-to-avoid-pushing-packages-to-appharbor
  2. https://support.appharbor.com/discussions/problems/79727-error-msb3202-when-building
  3. https://support.appharbor.com/discussions/problems/78633-cant-build-aspnet-mvc-project-generated-from-vstudio-2015-enterprise#comment_37577678

What J talked about in 2013

The WordPress.com stats helper monkeys prepared a 2013 annual report for this blog.

Here’s an excerpt:

The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 37,000 times in 2013. If it were a concert at Sydney Opera House, it would take about 14 sold-out performances for that many people to see it.

Click here to see the complete report.

 

2012 in review

The WordPress.com stats helper monkeys prepared a 2012 annual report for this blog.

Here’s an excerpt:

4,329 films were submitted to the 2012 Cannes Film Festival. This blog had 24,000 views in 2012. If each view were a film, this blog would power 6 Film Festivals

Click here to see the complete report.

 

Connecting to Amazon Linux/UNIX EC2 Instances from Windows Using PuTTY

To connect to your Linux/UNIX instance from a Windows machine, use an SSH client. The following instructions explain how to use PuTTY, a free SSH client for Windows machines.

Converting Your Private Key

PuTTY does not natively support the private key format generated by Amazon EC2. Fortunately, PuTTY has a tool called PuTTYgen, which can convert keys to the required PuTTY format.

To convert your private key

  1. Start PuTTYgen (e.g., from the Start menu, click All Programs > PuTTY > PuTTYgen).
  2. Click Load and browse to the location of the private key file that you want to convert (e.g., GSG_Keypair.pem). By default, PuTTYgen displays only files with extension .ppk; you’ll need to change that to display files of all types in order to see your.pem key file. The private key file must end with a newline character or PuTTYgen cannot load it correctly.

     

     

  3. Select your .pem key file and click Open.

    PuTTYgen displays the following message.

     

     

    When you click OK, PuTTYgen displays a dialog box with information about the key you loaded, such as the public key and the fingerprint. The keys that Amazon EC2 generates are 1024-bit SSH-2 RSA keys.

  4. Click Save private key to save the key in PuTTY’s format.

    PuTTYgen asks if you want to save the key without a passphrase.

     

     

  5. Click Yes.
    [Note] Note
    A passphrase on a private key is an extra layer of protection, so even if your private key is discovered, it will not be usable without the passphrase. The downside to using a passphrase is that it makes automation harder because human intervention is needed to log on to an instance, or copy files to an instance. For this exercise, we’re not using a passphrase.
  6. Name the key with the same name you used for the key pair (e.g., GSG_Keypair). PuTTY automatically adds the .ppk file extension.

Your private key is now in the correct format for use with PuTTY. You can now connect to your instance using PuTTY’s SSH client.

Connecting Using PuTTY SSH

You’ll connect by starting a PuTTY SSH session.

To use SSH to connect

  1. If you’ve launched a public AMI that you have not rebundled, run the ec2-get-console-output command on your local system (not on the instance), and locate the SSH HOST KEY FINGERPRINTS section. For more information, go to ec2-get-console-output in the Amazon Elastic Compute Cloud Command Line Reference.
    PROMPT>  ec2-get-console-output instance_id
     ... ec2: -----BEGIN SSH HOST KEY FINGERPRINTS----- ec2: 2048 bc:89:29:c6:45:4b:b3:e2:c1:41:81:22:cb:3c:77:54 /etc/ssh/ssh_host_key.pub ec2: 2048 fc:8d:0c:eb:0e:a6:4a:6a:61:50:00:c4:d2:51:78:66 /etc/ssh/ssh_host_rsa_key.pub ec2: 1024 b5:cd:88:6a:18:7f:83:9d:1f:3b:80:03:10:17:7b:f5 /etc/ssh/ssh_host_dsa_key.pub ec2: -----END SSH HOST KEY FINGERPRINTS-----
    ...

    Note the fingerprints so that you can compare them to the fingerprints of the instance.

  2. Start PuTTY (e.g., from the Start menu, click All Programs > PuTTY > PuTTY).

    A dialog box opens with a Category menu on the left side. On the right side, the basic options for your PuTTY session are displayed.

  3. In the Host Name field, enter the public DNS name of your instance (available through the AWS Management Console or theec2-describe-instances command). You can optionally prefix the DNS name with [email protected] to automatically log in with superuser privileges when the session opens.

     

     

  4. In the Category menu, under Connection, click SSH, and then Auth.

    The options controlling SSH authentication are displayed.

  5. Click Browse and navigate to the PuTTY private key file you generated in the preceding section.

     

     

  6. Click Open.

    An SSH session window opens and PuTTY displays a security alert asking if you trust the host you’re connecting to.

    [Important] Important
    If you’ve launched a public AMI, verify that the fingerprint in the security alert matches the fingerprint from the output of the ec2-get-console-output command. If it doesn’t, someone might be attempting a “man-in-the-middle” attack.
  7. Click Yes.
  8. In the SSH session window, log in as root (or ec2-user) if you didn’t as part of starting the SSH session.
    [Note] Note
    Some AMIs let you log in as root, but some require you to log in with the username ec2-user. For log in information for your chosen AMI, contact your AMI provider directly or go to Amazon Machine Images(AMIs) page, then locate and click your AMI on the list.
    [Note]
    Note
    If you specified a passphrase when you converted your private key to PuTTY's format, you must provide that passphrase when you log in to the instance.

    [Reference: http://docs.amazonwebservices.com/AWSEC2/latest/UserGuide/index.html?LaunchingAndUsingInstances.html]