• In the command line, you can ssh to a remote host using -i and specify a identity file, which is the SSH private key file.  SSH command line works fine.
• If you use Ruby Net::SSH Library using the following code, it will not work.  SSH connection fails.

keys = "/home/user/ssh/ssh_key"
Net::SSH.start(ssh_host, ssh_option["ssh_username"], :port => ssh_option["ssh_port"], \
 :password => ssh_option["ssh_password"], :keys => keys) do |ssh|
  #your ssh code
end

After working with it, it turns out that for whatever reason, Net::SSH library SSH Private Key authentication requires a pair of keys, both the private key and the public key.  For the above example, the /home/user/ssh directory needs to contain ssh_key AND ssh_key.pub, which is the public key.  You need both to exist, in the same path.  Once that is the case, Net::SSH can then authenticate using SSH key that you specify vs. looking through /home/user/.ssh directory, which is the default.

You can now do exactly this using ESC, Emergence Software Configurator at http://www.emergsoft.com.  Let me go through the high level use case:

1. Launch any Amazon EC2 instance using AMI ID.
2. Wait for instances to launch, with the status ALIVE.
3. Once instances are launched, apply your specific deployment recipe (yum / apt-get packages, configure configuration files, deploy code from SVN / GIT)
4. Do all this with one click

Here are the steps on how you use ESC to accomplish this:

1. Create an account at http://www.emergsoft.com if you don’t have an account
2. Go to Deploy
3. Create TWO Deploy targets – one is Amazon EC2 Deploy Target (Target 1), which allows you to enter your AWS Credentials to launch an instance; Next, create a CentOS, Ubuntu, or Linux OS Type of your choice Deploy Target (Target 2), enter SSH information, leave Host: BLANK, port: is usually 22, your will need to enter your AWS SSH Private key.
4. Select whatever recipes that you want to apply to Target 2, answer all the questions via the question wizard.  Notice that a Deploy Target Published Recipe UUID is generated.
5. Select Run EC2 Instances and Deploy Recipe and add that to Target 1, answer questions from the question wizard.  The UUID for this recipe is the one you created in step 4.
6. Click Deploy and you are done.

You can now one click deploy your app to Amazon EC2 anytime you want, without bundling or storing your custom AMI.

1. Everyday Open Source user can quickly install Open Source applications.
2. Users can use ESC to solve an Open Source software problem, not necessarily using it to install applications.  For example, there are best practices on configuring secure PHP by modifying the PHP.ini file.  A recipe can do this for a user.  Essentially, ESC and automate solving any problem in Linux that can be solved by using a combination of command line, configuration file, scripts … etc.  We can generialize the solution to a specific Linux distribution and allow many users to benefit from the solution in an automated fashion.
3. Popular Open Source software (Apache, Joomla, SugarCRM … etc) can provide a more complete installation recipe for one click install.  These packages are already easy to install, but they still require you to use yum install or apt-get, then unarchiving, run some commands, get dependencies … etc.  This can be easier, simpler for an everyday user.  A user can click on a link, answers some questions, and install the recipe.
4. Support and Professional Services can use ESC to manage and maintain their solutions for their customers.  For example, upgrade and performance tweaking scripts, to name a few.
5. IT can manage and maintain their custom installation and administrative scripts for their Open Source applications via private recipes in a private organization.  For example, IT can create a Linux Desktop based recipe, then whowever needs that recipe / solution, can go to a single place to run the recipe.
6. ESC is perfect for automating install of applications for cloud computing, like Amazon EC2.  Combine recipes with virtual appliances, you now have a quick and easy way to install and update your cloud Open Source applications.

For example, to quickly install Joomla on Ubuntu, you can go to Install Joomla on Ubuntu.

Open Source application deployment has come a long way. Currently, there is excellent way for Linux distributions to install and update its software. For example, both Fedora and Debian based distribution has RPM / DEB package management systems with its associated tools YUM / APT. This simplifies Open Source application deployment and update with easy to use tools.

However, we would like to raise two issues for discussion:

1. In order to create a RPM / DEB package, you will need to learn and understand how to build and maintain these package systems. You need to understand spec / control files; how scripts interact with packages. They are not hard to learn, but there is a learning curve.
2. The current ways of asking users to specify parameters are not re-usable. A package maintainer can use script and command line to query user input, but that requires hard coding the questions inside the package. Debian has the debconf templating system, which provides a centralized location to store question templates, default values, and variables. This again require learning the debconf system – not difficult to do – but there is a learning curve.

Emergence Software Configurator (ESC) essentially automates the generation of RPM / DEB packages without having the package maintainer having to know the details of RPM / DEB. It leverages the existing robust, simple interface of updating user’s Linux machines and provide an easier way to build, maintain, and reuse these packages. There are several key benefits:

1. Anyone who has sufficient knowledge of Linux commands, scripts, and installation process can now create a installation recipe for deploying applications without knowing the details of RPM / DEB package system.
2. It is easier to maintain RPM / DEB package details using ESC. Recipes contain ingredients. Each ingredient is like a lego block, which is reusable. Many installation recipes share similar ingredients. Therefore, you can quickly reuse and build new recipes. You can also customize installation process for different needs easily and quickly.
3. Once you create a recipe, you can provide alternative installation method. A user can leverage RPM / DEB package manager, but a user can also download the script directly, or use Install URL to copy and paste commands to download, unzip, install the script via a SSH shell.
4. ESC’s question wizard provides both user and creator of the recipe an easy way to address the issue of asking for user input. Using web forms, a user can enter answers to questions. Non-password answers are saved for future use. From a recipe creator perspective, each question and variable forms a lego block for future recipes, they are re-usable. In addition, a creator can provide detailed help and information to guide the user in entering their answers. Recipe Creator can also update question texts easily and quckily via the web.

We believe that these benefits can help increase the adoption of Open Source software in two major ways. First, by providing an simplified way to generate RPM / DEB packages. We can increase the productivity and overall quantity of installation script creators. This in turn, will increase the amount of Open Source deployment recipes available and frequency of it. Second, with more deployment recipes, it can promote more Open Source application usage by users because it is easier to install and configure Open Source applications. Instead of users having to type yum install / apt-get and other Linux commands. Users can quickly install an Open Source application. For the novice users, ease of install increases adoption. For the experts, automated install reduces time and errors of manual installs. Therefore, ESC can contribute to the adoption of Open Source software for the everyday user.

We welcome your comments, thoughts, and feedback.