Month: June 2015

Generate a Random String of a Specified Size with a Shell Script

Posted on by rchapin

The following is a one-liner for generating a random string of a fixed size in bash, where the possible characters to use in the string are any digit, letter, and a newline.

By adding the newline, you are fairly sure to prevent getting one long line of text.

< /dev/urandom tr -dc "[:digit:][:alpha:][\n]" | head -c1000 > file.out

Connecting To a Test Kitchen Instance Via SFTP, SSH, or SCP

Posted on by rchapin

If you are using Chef and Test Kitchen to test your cookbooks you may have need to connect to the Test Kitchen VM in some other fashion other than $ kitchen login instance-name.

To do so:

Do a $ kitchen list to see the running vms

kitchen list
Instance                      Driver   Provisioner  Verifier  Transport  Last Action
default-centos-66             Vagrant  ChefSolo     Busser    Ssh        Converged

Then look in the .kitchen directory from where you ran your $ kitchen command and look for the corresponding .yml config file for the vm

ls .kitchen
default-centos-66.yml  kitchen-vagrant  logs

Inside the .yml file for the vm is the path to the ssh key

more .kitchen/default-centos-66.yml
---
hostname: 127.0.0.1
port: '2222'
username: vagrant
ssh_key: "/home/rchapin/.vagrant.d/insecure_private_key"
last_action: converge

With that, just use the -i argument to point to the identity file and sftp to the box

sftp -P 2222 -i /home/rchapin/.vagrant.d/insecure_private_key vagrant@127.0.0.1

If the VM prompts you for a user name when logging in, you can always login via kitchen, change the password for that user and then retry

To login via kitchen issue the following command:

kitchen login default-centos-66

Setting the Compiler Version for Maven from the Command Line

Posted on by rchapin

By default maven sets the compiler version for you.  Of course, you can always set it in the pom, but there are cases where you cannot modify the pom, and/or you might want to test compilation and tests with different versions of java.

Following are the specific arguments to pass the compiler version to maven from the command line:

mvn clean install -Dmaven.compiler.source=1.7 -Dmaven.compiler.target=1.7
© 2005 Ryan Chapin