A Technical I.T./DevOps Blog
Problem scenario
A user has no access to a VPC from her workstation. What are three ways a user can be given access to resources in a VPC?
Four Possible, Independent Solutions
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Problem scenario
Using Windows Server and Active Directory, you try to add a PTR record to a Reverse Lookup Zone. You get “DNS: A new record cannot be created. Refused.” What do you do?
Possible Solution #1
Click “Ok” to the pop up. Continue where you were interrupted. The error message should be ignorable (other than the fact that you have to click “Ok” to the pop-up itself and the window to create a New Resource Record).
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Problem scenario
You want to create multiple A records in DNS. But to do it manually using the MMC would take too long. What should you do?
Solution
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Continue reading “How Do You Add Multiple DNS A Records in Active Directory Using a File?”
Problem scenario
You have a VPC with route tables. You want to search the targets to find a given value. What should you do?
Solution
As of early 2020, the output of aws describe-route-tables –filters –route-table-id abcd1234 –region us-west-2 will not include the word “target”. The value of the target in the JSON output will be the ID of the given target.
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Problem scenario
You want to list the Route Tables in your AWS account (under VPC). You are using Python and Boto3. What should you do?
Solution
Run this program with Python 3:
import boto3
ec2 = boto3.client(‘ec2’)
rts = ec2.describe_route_tables()
print(rts) …
Continue reading “How Do You Use Python and Boto3 to List VPC Route Tables?”
Problem scenario
You have found an AWS CLI command that shows you output consistent with the console. You run this:
aws ec2 describe-vpc-peering-connection –region us-west-2 | grep pcx-abcd1234
The results show you a peering connection called pcx-abcd1234
You run this from a Python3 interpreter prompt:
import boto3
foo = boto3.resource(‘ec2’)
foo.describe_vpc_peering.connections()
print(foo)
You then search the output for pcx-abcd1234. You do not see it.
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Continue reading “Why Would Boto3 Not Show a Peering Connection That the AWS CLI Shows?”
Problem scenario
You are now administering an AWS account. You have the AWS CLI installed and configured. How do you find out what the VPC IDs are?
Solution
Run this command:
aws ec2 describe-vpcs | grep VpcId
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Continue reading “What is the AWS CLI Command to Determine the VPC ID?”
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?
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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.
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Problem scenario
You are using CentOS/RHEL/Fedora and want to troubleshoot DNS functionality. You are getting “command not found” errors when you try to use the dig or nslookup utilities. What should you do?
Solution
Run this command:
sudo yum -y install bind-utils …
Continue reading “How Do You Install dig and nslookup on a CentOS/RHEL/Fedora Server?”