[SOLVED] Filtering EC2 instances using JMESPath query

Filtering EC2 instances using JMESPath query

This works:

aws ec2 describe-instances \
  --region eu-west-1 \
  --query Reservations[].Instances[].ImageId

[
    "ami-0123456789abcdefg",
    "ami-023456789bcdefghi",
    "ami-03456789cdefghijk"
]

But, when I try to add a filter it doesn't work anymore and returns empty arrays, plus I would only expect one result not many.

aws ec2 describe-instances \
  --region eu-west-1 \
  --query Reservations[].Instances[?ImageId=='"ami-0123456789abcdefg"'].ImageId

[
    [],
    [],
    []
]

What am I doing wrong?

Solution

Use backticks (`) instead of double quotes when using strings in the filter expression.

e.g.:

aws ec2 describe-instances \
  --query 'Reservations[].Instances[?ImageId==`ami-0123456789abcdefg`].ImageId'

Single quotes can be used, but I would recommend wrapping the entire query in those to keep the shell from interpreting any part of it.
Backticks are a alternative and allow for more human-readable queries.