Quick Post: Parsing AWS Instance Data with JQ
Published on 23 May 2018 · Filed in Explanation · 210 words (estimated 1 minutes to read)I recently had a need to get a specific subset of information about some AWS instances. Naturally, I turned to the CLI and some CLI tools to help. In this post, I’ll share the command I used to parse the AWS instance data down using the ever-so-handy jq tool.
What I needed, specifically, was the public IP address and the private IP address for each instance. That information is readily accessible using the aws ec2 describe-instances command, but that command provides a ton more information than I needed. So, I decided to try to use jq to parse the JSON output from the AWS CLI. If you’re not familiar with jq, I recommend you take a look at this brief introductory post I wrote back in 2015.
After some trial and error, here’s the final command I used:
aws ec2 describe-instances | jq '.Reservations[] | .Instances[] | \
{Id: .InstanceId, PublicAddress: .PublicIpAddress, \
PrivateAddress: .PrivateIpAddress}'
I’ll refer you to the jq manual for details on breaking down how this filter works. I’ll also point out that there’s nothing terribly groundbreaking or revolutionary about this command; I wanted to share it here just in case it may save someone a bit of time if they find themselves in a similar situation.