ADD / REMOVE a backend block within k8s ingress manifest with JQ (YQ) - json

Question

I have a kubernetes ingress manifest YAML, looking like next:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
certmanager.k8s.io/acme-http01-edit-in-place: "true"
certmanager.k8s.io/cluster-issuer: letsencrypt
name: staging
namespace: dev
spec:
rules:
- host: staging.domain.com
http:
paths:
- backend:
serviceName: task-11111
servicePort: 80
path: /task-11111/*
- backend:
serviceName: task-22222
servicePort: 80
path: /task-22222/*
- backend:
serviceName: task-33333
servicePort: 80
path: /task-33333/*
tls:
- hosts:
- staging.domain.com
secretName: staging-domain-com
What I'm trying to achieve is to add (if not present) or remove (if present) a backend block. What I have now:
yq -y '.spec.rules[].http.paths += [{ "backend": { "serviceName": "'${CI_COMMIT_REF_NAME}'", "servicePort": 80}, "path": "/'${CI_COMMIT_REF_NAME}'/*"}]'
(adds a new block with variable value, but doesn't bother if it already exists)
yq -y 'del(.. | .paths? // empty | .[] | select(.path |contains("'${CI_COMMIT_REF_NAME}'")) )'
(fails with jq: error (at <stdin>:0): Invalid path expression with result {"backend":{"serviceName":...)
So rules may look like this after deletion (assume that CI_COMMIT_REF_NAME = task-33333):
spec:
rules:
- host: staging.domain.com
http:
paths:
- backend:
serviceName: task-11111
servicePort: 80
path: /task-11111/*
- backend:
serviceName: task-22222
servicePort: 80
path: /task-22222/*
or like this after adding (assume that CI_COMMIT_REF_NAME = task-44444):
spec:
rules:
- host: staging.domain.com
http:
paths:
- backend:
serviceName: task-11111
servicePort: 80
path: /task-11111/*
- backend:
serviceName: task-22222
servicePort: 80
path: /task-22222/*
- backend:
serviceName: task-33333
servicePort: 80
path: /task-33333/*
- backend:
serviceName: task-44444
servicePort: 80
path: /task-44444/*
Any help is greatly appreciated.

Answer 1

[The following has been revised to reflect the update to the question.]
Assuming CI_COMMIT_REF_NAME is available to jq as $CI_COMMIT_REF_NAME, which can be done using jq with the command-line argument:
--arg CI_COMMIT_REF_NAME "$CI_COMMIT_REF_NAME"
an appropriate jq filter would be along the following lines:
.spec.rules[0].http.paths |=
(map(select(.path | index($CI_COMMIT_REF_NAME) | not)) as $new
| if ($new | length) == length
then . + [{ "backend": { "serviceName": $CI_COMMIT_REF_NAME, "servicePort": 80}, "path": ($CI_COMMIT_REF_NAME + "/*") }]
else $new
end )
You can test this with the following jq invocation:
jq --arg CI_COMMIT_REF_NAME task-4444 -f program.jq input.json
where of course input.json is the JSON version of your YAML.
(I'd use index in preference to contains if at all possible.)