Error waiting for instance (i-…) to become ready: unexpected state ‘terminated’, wanted target ‘running’

When you launch a server instance with Terraform, sometimes the error message does not contain the underlying cause. When the cloud provider cannot complete the request, many times Terraform displays a generic error message: Error waiting for instance (i-…) to become ready: unexpected state ‘terminated’, wanted target ‘running’ To find the root cause of the …

Upgrade a server on an AWS EC2 instance with minimum risk and downtime

When you need to upgrade an application on an AWS EC2 instance with minimum downtime, there are many options. Upgrade an EC2 instance Stop the application, so users don’t make more changes, Create a backup of the database (snapshot of the RDS instance), Create a backup of the server (backup image of the EC2 instance), …

Test your RightScale script without creating unnecessary revisions

There are certain functions in RightScale scripts (RightScripts) that you cannot test without launching a new instance. To test your script: Edit the Head revision of the RightScale script and save it, Attach the Head revision of the RightScale script to the Head revision of the RightScale Server Template, Select the Head revision of the …

Custom Git Status and Git Pull commands to work with all of your repositories

If you work with many Git repositories it is easy to miss a repository when you commit your changes, and very time consuming to pull from all repositories. It is easy to automate both processes. In this example, we will place all files in the ~/Git/devops-scripts folder. If you want to place your files at another …

Useful Bash commands

Most of these commands work in all Linux, MacOSX, and Unix shells, but some of them only work in selected shells. Find files recursively by file name pattern find . -name ‘*.MY_EXTENSION’ Find files, but exclude a directory from the search. (The -print is needed at the end of the line) find . -path ./tmp/windows …

Windows 10 can’t connect to this network

If your Windows 10 computer can successfully connect to some wireless networks, but cannot connect to certain wireless networks, it is possible, that the stored credentials are out of date. To force Windows 10 to ask you for the updated username and password In the Start Menu select Settings,   On the Windows Settings page …

Find the AWS AMI that a RightScale server template is using

When you use RightScale to launch servers in the cloud, you want to use the same base image to test your Chef cookbooks in Test Kitchen. Packer by Hashicorp is a utility to create custom server images based on cloud images. You supply the image ID and other configuration parameters to create a new custom image. …

Mailbox unavailable. The server response was: No such user here

When you send email from an application, most SMTP servers require authentication. Your application needs to supply a valid username and password to be able to connect to the server. This prevents strangers to use your SMTP server and send millions of spam emails. When your application does not supply the correct credentials to connect to …

Unable to read data from the transport connection: net_io_connectionclosed.

When your application tries to send an email using a Gmail account you may get the error message: Unable to read data from the transport connection: net_io_connectionclosed. One of the causes can be, when “Less secure apps” are not allowed to use the Gmail account. To enable “Less secure apps” to use the Gmail account Log …