A Technical I.T./DevOps Blog
Problem scenario
You are running a Python program that uses “import json”. You get this error: “json.decoder.JSONDecode..”Expecting property name enclosed in double quotes…” You are not allowed to use bson, but you can use other Python packages. What should you do?
Solution
This solution only works if you can eliminate single quotes in the content to be serialized (or translated into JSON). This will get rid of single quotes indiscriminately.
…
Problem scenario
How do you copy a file from a Linux server with AWS CLI to an S3 bucket?
Solution
Draft a command like this but replace /tmp/good.txt with the path and name of the source file you are copying, and replace “foobar” with the name of the s3 bucket you are copying to (as the destination):
aws s3 cp /tmp/good.txt s3://foobar/
Run the command.
…
Continue reading “How Do You Copy a File into an S3 Bucket using the AWS CLI?”
Question
You have been asked to explain how an external request for a website is routed and ultimately fulfilled by a pod in Kubernetes via an ingress controller. When a web browser downloads a website via HTTP and the website is running from a Kubernetes cluster, how does an individual container provide the HTML and/or data? How is external traffic routed to an underlying pod in a Kubernetes Cluster?
Answer
Assuming that external traffic can reach an ingress controller in Kubernetes,
…
Problem scenario
You want the dot utility to transform “terraform graph” command output to usable files. What should you do?
Solution
Run this command: sudo yum -y install graphviz
…
Continue reading “How Do You Install the dot Utility on a CentOS/RHEL/Fedora Server?”
Question
You have read about the DOM. What is the Document Object Model and what do the three words mean in this phrase?
Answer
“The Document Object Model (DOM) is an abstract representation of an HTML document that can be queried and manipulated through its API.” This quote was taken from page 62 of The Web Application Hacker’s Handbook 2nd Edition.
…
Problem scenario
You are using Oracle VirtualBox. You get “ssh connect to host x.x.x.x port 22: No route to host”. What do you do?
Solution
In Oracle VirtualBox, go to Devices -Network -Network Settings. Is it attached to “Internal Network”? Try attaching it to “Bridged Adapter” instead.
…
Problem scenario
Your Python program is trying to invoke a Bash command. But you get an error like this: “FileNotFoundError: [Errno 2] No such file or directory”. What should you do?
Possible Solution #1 Use the shell=True command if your environment is secure. This is not a recommended practice from a security perspective. We have found that this with shell=True syntax can make the error go away:
subprocess.Popen(variableofcommand,
…
Problem scenario
You only want your Android phone to ring if certain phone numbers call you. You have “blocked unknown callers” on your Android phone with certain settings. You went to the Phone app -three vertical dots -Settings -Block numbers -Block unknown callers
But you still get calls, or your phone still rings, when unknown callers call you. You tried rebooted or using Hiya’s caller ID and spam protection.
…
Question
You have seen the initialism RDS. What does this term mean?
Answer
Normally it is a reference to AWS’ PaaS offering for relational databases called Amazon Relational Database Service.
The term RDS can refer to Reference Data Services in the Microsoft realm (e.g., Azure or SQL Server). Here is more information.
…
Continue reading “What Does RDS Mean in the Context of Databases?”
Problem scenario
You are using the AWS CLI. You want to know what region is being used by default. You do not what to use the aws configure command. What should you do?
Solution
Run this:
cat ~/.aws/config …
Continue reading “How Do You Determine the AWS CLI Default Region?”