Display local package contents

Tools can parse and render configuration so it is easier for humans to read.

Topics

kpt cfg count, kpt cfg tree, kpt cfg grep, kpt cfg cat

Steps

1. Fetch a remote package
2. Summarize resource counts
3. Display resources as a tree
4. Filter resources
5. Dump all resources

Fetch a remote package

Packages are fetched from remote git repository subdirectories with kpt pkg get. In this guide we will use the kubernetes examples repository as a public package catalogue.

Fetch Command

kpt pkg get https://github.com/kubernetes/examples/staging/ examples

Fetch the entire examples/staging directory as a kpt package under examples. This will contain many resources.

List Command

tree examples

List Output

examples/
├── Kptfile
├── cloud-controller-manager
│   └── persistent-volume-label-initializer-config.yaml
├── cluster-dns
│   ├── README.md
...

79 directories, 329 files

The package is composed of 79 directories and, 329 files. This is too many to work with using tools such as less.

Summarize resource counts

Count Example Command 1

kpt cfg count examples/

The kpt cfg count command summarizes the resource counts to show the shape of a package.

Count Example Output 1

...
Deployment: 10
Endpoints: 1
InitializerConfiguration: 1
Namespace: 4
Pod: 45
...

Count Example Command 2

kpt cfg count examples/cockroachdb/

Running count on a subdirectory will summarize that directory even if it doesn’t have a Kptfile.

Count Example Output 2

PodDisruptionBudget: 1
Service: 2
StatefulSet: 1

Count Example Command 3

kpt cfg count examples/ --kind=false

The total aggregate resource count can be shown with --kind=false

Count Example Output 3

201

Display resources as a tree

Display Command

kpt cfg tree examples/cockroachdb/ --image --replicas

Because the raw YAML configuration may be difficult for humans to easily view and understand, kpt provides a command for rendering configuration as a tree. Flags may be provided to print specific fields under the resources.

Display Output

examples/cockroachdb
├── [cockroachdb-statefulset.yaml]  Service cockroachdb
├── [cockroachdb-statefulset.yaml]  StatefulSet cockroachdb
│   ├── spec.replicas: 3
│   └── spec.template.spec.containers
│       └── 0
│           └── image: cockroachdb/cockroach:v1.1.0
├── [cockroachdb-statefulset.yaml]  PodDisruptionBudget cockroachdb-budget
└── [cockroachdb-statefulset.yaml]  Service cockroachdb-public

In addition to the built-in printable fields, kpt cfg tree will print arbitrary fields by providing the --field flag.

Filter resources

Filter Command

kpt cfg grep "spec.replicas>3" examples | kpt cfg tree --replicas

Grep can be used to filter resources by field values. The output of kpt cfg grep is the matching full resource configuration, which may be piped to kpt cfg tree for rendering.

Filter Output

.
├── storage/minio
│   └── [minio-distributed-statefulset.yaml]  StatefulSet minio
│       └── spec.replicas: 4
├── sysdig-cloud
│   └── [sysdig-rc.yaml]  ReplicationController sysdig-agent
│       └── spec.replicas: 100
└── volumes/vsphere
    └── [simple-statefulset.yaml]  StatefulSet web
        └── spec.replicas: 14

Dump all resources

Dump Command

kpt cfg cat examples/cockroachdb

The raw YAML configuration may be dumped using kpt cfg cat. This will print only the YAML for Kubernetes resources.

Dump Output

apiVersion: v1
kind: Service
metadata:
  # This service is meant to be used by clients of the database. It exposes a
  # ClusterIP that will automatically load balance connections to the different
  # database pods.
  name: cockroachdb-public
  labels:
    app: cockroachdb
...