jq

Period in Key

{
    "apiVersion": "v1",
    "data": {
        "tls.crt": "Zm9vCg==",
        "tls.key": "YmFyCg=="
    },
    "kind": "Secret",
    "type": "kubernetes.io/tls"
}

echo $KubeSecret | jq -r '.data["tls.crt"]'

Multiline

echo $GithubRelease \
    | jq '.assets[]
          | select(.name == "py-demo-Darwin-x86_64")
          | .name'

Variable as Argument

echo $GithubRelease \
    | jq --arg name "py-demo-Darwin" \
         '.assets[]
          | select(.name | startswith($name))
          | .name'

Select

Name Contains

[
  {"name": "This is item1"},
  {"name": "This is item2"},
  {"name": "item3"}
]

echo $Items \
    | jq -c '.[] | select(.name | contains("item2"))'

Name Starts With

echo $Items \
    | jq -c '.[] | select(.name | startswith("This is"))'

AWS Resources with Tag

Use `aws --filter`

Some AWS commands provide a --filter option that allows filtering by tag.

aws ec2 describe-addresses \
    --filters "Name=tag:Name,Values=cfclrk"

Sorting

aws s3api list-objects-v2 \
    --bucket $BUCKET \
    --prefix "foo/bar" \
    | jq '.Contents | sort_by(.LastModified)'

If you see an error like Cannot index string with string, it's probably because you are not piping a proper list to it. For example:

cat $data | jq '.Stuff[] | sort_by(.Time)'  # Does not work

cat $data | jq '.Stuff | sort_by(.Time)'    # Works!

Stringify JSON

{"message": "foo"}

echo $message | jq '@json'