A Technical I.T./DevOps Blog
Problem scenario
You want to install Django and have it working for browsing from a desktop workstation. You do not want to leverage Django’s API functionality. How do you install and configure Django from scratch?
Prerequisite
pip3 is probably installed. If you are not sure, you could run this: sudo find / -name pip3
You must have pip or pip3 installed.
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Continue reading “How Do You Install Django on a CentOS/RHEL/Fedora server?”
Problem scenario
You are using RHEL 8.x. You want to install Erlang. What do you do?
Solution
Run these two commands:
curl -Ls https://github.com/rabbitmq/erlang-rpm/releases/download/v22.3.2/erlang-22.3.2-1.el8.x86_64.rpm /tmp/erlang-22.3.2-1.el8.x86_64.rpm
sudo rpm -i /tmp/erlang-22.3.2-1.el8.x86_64.rpm
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Problem scenario
You run this command:
aws eks create-cluster –name contint –role-arn arn:aws:iam::12345678910:role/contintrole –resources-vpc-config subnetIds=subnet-a123456,subnet-b77777777,securityGroupIds=sg-2e324234254
You get this error:
An error occurred (AccessDeniedException) when calling the CreateCluster operation: User: arn:aws:iam::12345678910:user/contintuser is not authorized to perform: iam:PassRole on resource: arn:aws:iam::12345678910:role/contintrole
What should you do?
Solution
1. Log into the AWS Console.
2. Go to IAM -Users
3.
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Problem scenario
You run this command aws eks list-clusters, but you get this message:
“An error occurred (AccessDeniedException) when calling the ListClusters operation: User: arn:aws:iam::12345678910:user/jdoe is not authorized to perform: eks:ListClusters on resource: arn:aws:eks:us-west-1:12345678910:cluster/*”
What should you do?
Solution
1. Go to the AWS Console and log in.
2. Go to IAM -> Users
3. Click on the user’s account.
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Problem scenario
In one region, but not another, you get this error with an “aws eks list-clusters” command:
“An error occurred (AccessDeniedException) when calling the ListClusters operation: Account 12345678910 is not authorized to use this service”
You know that IAM does not require region selection. What is causing this eks error?
Solution
Is your AWS CLI configured to use a region that eks does not support?
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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.
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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.
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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,
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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
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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.
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