How to show all deployments/daemonsets which mount specific configmap/secret? - kubernetes

Question

Sometimes, I want to explore all deployments/daemonsets which mount specific configmap/secret.
Is there any way can achieve this by kubectl?

Answer 1

You need to have jq to do such a complex queries.
Here you go:
kubectl get -o json deploy,daemonset | jq '[.items[] | . as $parent | .spec.template.spec.volumes[]? | select(.configMap != null) | {kind:$parent.kind, name:$parent.metadata.name, configMap:.configMap.name}]'
The jq command de-constructed:
[ // output as array
.items[] // iterate over root key 'items'
|
. as $parent // store the current entry as $parent to refer to it later
|
.spec.template.spec.volumes[]? // iterate over its volumes (the ? to prevent error if there is no volume
|
select(.configMap != null) // select only those volumes with configMap key
|
{kind:$parent.kind, name:$parent.metadata.name, configMap:.configMap.name} // now construct the output using $parent's kind and name and the configMap's name
]
Example output:
[
{
"kind": "Deployment",
"name": "telemetry-agent",
"configMap": "telemetry-config-map"
},
{
"kind": "DaemonSet",
"name": "fluent-bit",
"configMap": "fluent-bit"
},
{
"kind": "DaemonSet",
"name": "telegraf",
"configMap": "telegraf"
}
]
N.B. If you want to find specific configMap, just replace the select() clause .configMap != null to .configMap.name == "specific-configmap". Also, feel free to add --all-namespaces to the kubectl get command if you want to query from all namespaces