How Do You Connect to a VM in Oracle VirtualBox from a Desktop?

Problem scenario
You are connecting to a VM in Oracle VirtualBox from a desktop. The pings to the VM are not responding. What should you do?

Solution
Go to Devices -Network -Network Settings
The “Attached to:” setting hould be “Bridged Adapter”
The “Name” setting should what you think is appropriate. Not uncommonly this will be en0 Wi-Fi.

How Do You Install CentOS when the Installation Source Option is a URL Exclusively (without an Option for a Local ISO)?

Problem scenario
You are trying to install CentOS in an offline manner. You get to the “Installation Summary” screen. The Software section says “Installation Source…Setting up installation source.” There is a yellow triangle with an exclamation point near the “Installation Source” button. The “Begin installation” button is grayed out. You want to choose a local ISO, and you thought it was installing via a local ISO. You do not have access to the internet.

How Do You Use the Bisect Module in Python?

Problem scenario
You want to use bisect in Python. How do you do this?

Solution

# This program was adapted from code found
# https://docs.python.org/3/library/bisect.html

import bisect
def grade(score, breakpoints=[60, 70, 80, 90], grades=’FDCBA’):
i = bisect.bisect(breakpoints, score)
return grades[i]

x = [grade(score) for score in [71, 88, 94]]
print(x)

import bisect
def whether(temperature, breakpoints=[38, 70, 80, 100], descriptors=[”cold”, “cool”, “warm”, …

How Do You Configure Email Alerts for AWS Spending Thresholds of Specific Dollar Amounts?

Problem scenario
Sometimes you forget what is running in AWS. You want to be notified when you have spent a certain amount of money. How do you set up a notification in your AWS account that will apprise you when you have have spent over a certain amount of money for a given month?

Solution

  1. Log into the AWS Management Console (aka the web UI).

What Do You Do when ImportExportTools is Not an Option in Thunderbird?

Problem scenario
You installed ImportExportTolls NG, the add-on in Mozilla Thunderbird. In Thunderbird you go to Tools, but “ImportExportTools” or “ImportExportTools NG” is not visible. What do you do?

Solution
You need to have a mailbox — even an empty mailbox — configured. This will import all the messages you are trying to import into that mailbox. The hamburger icon’s Tools -Import,

Why Cannot a User Approve a Release Pipeline to an Environment?

Problem scenario
A user in Azure DevOps cannot approve releases to a given environment. The permissions are correct; the user is a member of the relevant custom security group in the project. Why can’t the user approve the deployment to an environment?

Solution
Can the user go to the Azure DevOps organization? Can the user also see the project? The organization subsumes a project,

How Do You Troubleshoot a Kubernetes Cluster That is Not Working at the Node Level?

Problem scenario
The nodes in a Kubernetes cluster are not working. What should you do?

Possible Solution #1
Run this command: kubectl get nodes
For the node that is not healthy, assuming its hostname is called “foobar”, run this command: kubectl describe node foobar

Possible Solution #2
If you have pods and no nodes (which could be the case),

How Do You Troubleshoot “java.io.IOException: Stream closed at java.base/java.lang.ProcessBuilder$NullOutputStream.write(ProcessBuilder.java:442)”?

Problem scenario
You are trying to run a Hadoop job. You get this error:
“java.io.IOException: Stream closed at java.base/java.lang.ProcessBuilder$NullOutputStream.write(ProcessBuilder.java:442)”

What should you do?

Solution
Is the “python” command recognized as such? You may need to install Python or link the python3 binary to be in a typical location where env variables would look for it (e.g., /usr/bin/python).

Here are commands that could help you:

whereis python3
sudo ln -s python3 /bin/python

If you need help installing Python,