kubectl-grep

Kubectl Grep Plugin

A plugin to filter resources Kubernetes resources in YAML. kubectl grep will preserve the original YAML structure, including comments, when transformations are not applied.

In addition to filtering out objects, a variety of transformations can be applied:

• List types will automatically be unrolled.
• Secret types can be decoded (base64) with --decode/-d.
• Noisy fields can be removed with --clean/-n, and status can additional be exluded with --clean-status/-N.
• The list of object names and types can be summarized with --summary/-s.

Install

go install github.com/howardjohn/kubectl-grep@latest

Usage

A plugin to grep Kubernetes resources.

Usage:
  kubectl-grep [flags]

Flags:
  -n, --clean               Cleanup generate fields
  -N, --clean-status        Cleanup generate fields, including status
  -d, --decode              Decode base64 fields in Secrets
  -w, --diff                Show diff of changes. Use with 'kubectl -ojson -w | kubectl grep -w'
      --diff-mode string    Format for diffs. Can be [line, inline]. (default "line")
  -h, --help                help for kubectl-grep
  -i, --insensitive-regex   Invert regex match
  -v, --invert-regex        Invert regex match
  -r, --regex string        Raw regex to match against
  -s, --summary             Summarize output

Matching

kubectl grep takes matching clauses as arguments. These follow the form <KIND>/<NAME>.<NAMESPACE>. For example, Service/kubernetes.default.

Partial forms are also accepted:

• <KIND>/<NAME>
• <KIND>/
• <NAME>

Wildcards are allowed as well. For example:

• */name.namespace - match any kinds
• Service/*.default - match all services in default
• Service/echo-*.default - match all services in default with a naming starting with echo-

Grepping

Regex matches can be applied on a per-object basis.

For example, kubectl grep -r security will search all objects that have the phrase 'security' within them.

-i can make this case insensitive, and -v can invert the match.

Diffing

A stream of events, as output by kubectl get -w -ojson, can be processed and show the diffs of what is changing. This can be helpful to debug controllers.

For example:

kubectl get pods -w -ojson | kubectl grep -w

Examples

Apply just the Services in some configuration

cat some-config.yaml | kubectl grep Service/ | kubectl apply -f -

Find a specific resource

cat some-config.yaml | kubectl grep Service/helloworld.default

Display all Pods in the dev namespace, hiding fields that add clutter like managedFields

cat some-config.yaml | kubectl grep 'Pod/*/dev' -N

Display all resources that contain the string pertrytimeout (case-insensitive), but do not contain timeout.

cat some-config.yaml | kubectl grep -r pertrytimeout -i | kubectl grep -v -r timeout