yaml-filter

yaml_filter [-i type,type] [-o type,type]

Takes stdin, selects only objects in the 'in_filter', discards objects in the 'out_filter', and writes the result to stdout.

The use case is with e.g. Kubernetes, you have a YAML file which has CRD, webhook, and objects using these.

Apply the same YAML 3 times:

cat foo.yaml | yaml_filter -i CustomResourceDefinition | kubectl apply -f -
cat foo.yaml | yaml_filter -i ValidatingWebhookConfiguration | kubectl apply -f -
cat foo.yaml | kubectl apply -f -

on the last run you could choose

-o CustomResourceDefinition,ValidatingWebhookConfiguration

to exclude those, but its a bit moot since Kubernetes will properly apply the unchanged CRD and WebHook

Rationale

Tools like kustomize re-order the input YAML. They are designed to be run as kustomize build . |kubectl apply -f -. However, if you are using a CustomResourceDefinition, or ValidatingWebhook, you may have a specific order of input which must be achieved.

This tool allows you to run:

kustomize build . | yaml_filter.py -i CustomResourceDefinition | kubectl apply -f - kustomize build . | yaml_filter.py -i ValidatingWebhookConfiguration | kubectl apply -f - kustomize build . | kubectl apply -f -