A Technical I.T./DevOps Blog
Problem scenario
You have a server in Azure you want to turn off. What should you do to stop it?
Solution
Prerequisite
You need to know the server’s name and resource group. You can do this by finding the server in the Azure Portal.
Procedures
Run this command:
Stop-AzureRmVM -ResourceGroupName $nameOfResourceGroup -Name $nameOfVM
# Replace $nameOfResourceGroup with the name of the Resource Group. …
Continue reading “How Do You Use a PowerShell Command to Stop an Azure VM?”
Problem scenario
You want to write a Python that will test if a string is a palindrome with two other requirements. One requirement is to not use a “::” (a colon pair) in the code. The second requirement is to search for a substring that is a palindrome if the full string is not a palindrome. This substring is not any substring however: it must include the leftmost character.
…
Continue reading “Using Python How Do You Write a Palindrome Tester with Special Requirements?”
Problem scenario
You have a server in Azure you no longer need. You want to save money by deleting it. What should you do to eliminate it?
Solution
Prerequisite
You need to know the server’s name and resource group. You can do this by finding the server in the Azure Portal.
Procedures
Run this command:
Remove-AzureRmVM -ResourceGroupName $nameOfResourceGroup -Name $nameOfVM
# Replace $nameOfResourceGroup with the name of the Resource Group. …
Continue reading “How Do You Use a PowerShell Command to Destroy an Azure VM?”
Problem scenario
You are trying to run Apache Zookeeper or some other application. You enounter the problem Error: Config file not found: /usr/lib/jvm/java-9-openjdk-amd64/conf/management/management.properties. What should you do?
Possible solution
This is a workaround. Run these commands:
sudo mkdir -p /usr/lib/jvm/java-9-openjdk-amd64/conf/management/
sudo touch /usr/lib/jvm/java-9-openjdk-amd64/conf/management/management.properties
…
Problem scenario
Your Python function prints out the value of the variable immediately before it returns the variable. When it is assigned via the “return” statement, the value is “None”. You were expecting an integer or some other value. What is wrong?
Solution
Does your function use recursion? If it is using recursion rather than merely calling the function and it returns “None”,
…
Continue reading “Why Does Your Python Function Return None?”
Problem scenario
In Linux you are trying to run a Java program that connects to a MySQL database. The program compiles, but it does not run. You get this error: “java.lang.ClassNotFoundException: com.mysql.jdbc.Driver” What should you do?
Solution
1. Set the CLASSPATH variable in two steps. First set it to where the .class file is for the Java file you are running.
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Problem scenario
You try to run sudo python setup.py build but you encounter a problem. You get a message that says “ImportError: No module named setuptools”. What should you do?
Solution
If you are running Debian/Ubuntu Linux, run this: sudo apt-get -y install python-setuptools
If you are running CentOS/RedHat/Fedora Linux, run this: sudo yum -y install python-setuptools
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Problem scenario
You want to know if a particular KB was installed on your Windows machine. You know the KB number. How do you use PowerShell to find out if this update has been installed or not?
Solution
Run this: get-hotfix | sls “kb123456789” # Replace kb123456789 with the KB of your choice.
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Question
When programming in Python what does ‘if name == “main“:’ mean?
Answer
To grasp this, realize that “main” is merely a quoted string. Now you must know how the built-in variable “name” is assigned. The name variable is set to main at run time by default.
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Continue reading “What Does ‘if name == “main”:’ in Python Mean?”
Problem scenario
You are familiar with Groovy scripts. Now you want to use a class and a method in the class. How do you do this?
Solution
Prerequisites
Install Groovy. See these directions for Ubuntu/Debian if you need assistance; see these directions for CentOS.
Procedures
class Example {
def static Display(nifty) {
nifty.call(“Red”); …
Continue reading “How Write a Custom Method inside of a Class in Groovy?”