Working in security/operations in the tech industry, I use SSH a lot. To various different machines (some with hostnames, some without), using various different users and keys, and often (as was the case in my previous post) via a bastion host. Over the years, I’ve collected a number of SSH tricks that make my life easier.
JP's Blog
Clock drift in Docker containers
I was working on a docker container which uses the aws cli to mess around with some autoscaling groups when I got a somewhat strange error:
A client error (SignatureDoesNotMatch) occurred when calling the DescribeAutoScalingGroups operation: Signature not yet current: 20171115T012426Z is still later than 20171115T012420Z (20171115T011920Z + 5 min.)
Hmm.
Are the clocks off?
Finding EC2 instances by tag
Another script similar to my previous post about Finding AWS IAM users by access key. This time, we want to do much the same thing for EC2 instances by tag.
Performance problems with Flask and Docker
I had an interesting problem recently on a project I was working on. It’s a simple Flask-based webapp, designed to be deployed to AWS using Docker. The application worked just fine when I was running it locally, but as soon as I pushed the docker container…
Latency spikes. Bad enough that the application was failing AWS’s healthy host checks, cycling in and out of existence1:
Parsing AWS instance data with jq
Semi-random amusing code snippet of the day:
aws ec2 describe-instances | jq << EOF
.[][].Instances[]
| select(.Tags[]?.Value == "production")
| .PrivateIpAddress
EOF