filter docker images with json output - docker

Question

Several requests.
I'd like to get json output from docker images, I can do by this way
$ docker images --format "{{json . }}" |jq .
{
"Containers": "N/A",
"CreatedAt": "2022-07-27 11:12:07 +1000 AEST",
"CreatedSince": "8 days ago",
"Digest": "<none>",
"ID": "b673851840e8",
"Repository": "python",
"SharedSize": "N/A",
"Size": "915MB",
"Tag": "3.9",
"UniqueSize": "N/A",
"VirtualSize": "914.7MB"
}
{
"Containers": "N/A",
"CreatedAt": "2022-07-19 07:00:15 +1000 AEST",
"CreatedSince": "2 weeks ago",
"Digest": "<none>",
"ID": "d7d3d98c851f",
"Repository": "alpine",
"SharedSize": "N/A",
"Size": "5.53MB",
"Tag": "latest",
"UniqueSize": "N/A",
"VirtualSize": "5.529MB"
}
then I want to get the iamge name with tag and ID
$ docker images --format "{{json . }}" |jq -r "[.Repository,.Tag,.ID]|#csv"
"python","3.9","b673851840e8"
"alpine","latest","d7d3d98c851f"
So my question is, how can I get the output as
python:3.9 b673851840e8
alpine:latest d7d3d98c851f
(optional) second request, how can I filter the output that only output the images with *python*

Answer 1

You don't have to use jq to filter images based out of name, use the native --format flag itself
docker images --format "{{.Repository}}:{{.Tag}} {{.ID}}"
(or) to filter names starting with python
docker images --filter=reference='python*' --format "{{.Repository}}:{{.Tag}} {{.ID}}"
Using jq, collect the required fields into an array and use any of the string concatenation operators. You could also use join("\t") in place of #tsv to retain consistent usage of join method.
jq -r '[([.Repository, .Tag] | join(":")), .ID] | #tsv'