cli-utils/examples/alphaTestExamples/init.md

Demo: Init Command

This demo shows how the kapply init command works.

First define a place to work:

DEMO_HOME=$(mktemp -d)

Alternatively, use

DEMO_HOME=~/demo

Establish the base

BASE=$DEMO_HOME/base
mkdir -p $BASE
OUTPUT=$DEMO_HOME/output
mkdir -p $OUTPUT
GREEN='\033[0;32m'
RED='\033[0;31m'
NC='\033[0m' # No Color

function expectedOutputLine() {
  if ! grep -q "$@" "$OUTPUT/status"; then
    echo -e "${RED}Error: output line not found${NC}"
    echo -e "${RED}Expected: $@${NC}"
    exit 1
  else
    echo -e "${GREEN}Success: output line found${NC}"
  fi
}

Create the first "app"

Create the config yaml for three config maps: (cm-a, cm-b, cm-c).

cat <<EOF >$BASE/namespace.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: test-namespace
EOF

cat <<EOF >$BASE/config-map-a.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: cm-a
  namespace: test-namespace
  labels:
    name: test-config-map-label
EOF

cat <<EOF >$BASE/config-map-b.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: cm-b
  namespace: test-namespace
  labels:
    name: test-config-map-label
EOF

cat <<EOF >$BASE/config-map-c.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: cm-c
  namespace: test-namespace
  labels:
    name: test-config-map-label
EOF

Run end-to-end tests

The following requires installation of kind.

Delete any existing kind cluster and create a new one. By default the name of the cluster is "kind".

kind delete cluster
kind create cluster

Use the kapply init command to generate the inventory template. This contains the namespace and inventory id used by apply to create inventory objects.

kapply init $BASE | tee $OUTPUT/status
expectedOutputLine "namespace: test-namespace is used for inventory object"

Add another ConfigMap (cm-d) which is in the default namespace. The init command should calculate the namespace to be default, since not all objects are in the test-namespace.

cat <<EOF >$BASE/config-map-d.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: cm-d
  labels:
    name: test-config-map-label
EOF

# Remove the initial inventory template.
rm -f $BASE/inventory-template.yaml

kapply init $BASE | tee $OUTPUT/status
expectedOutputLine "namespace: default is used for inventory object"

Remove the ConfigMap (cm-d) which is in the default namespace, and add a cluster-scoped object. This cluster-scoped object should not be used in the init namespace calculations, so we should calculate the namespace as test-namespace.

# Remove the initial inventory template.
rm -f $BASE/inventory-template.yaml

# Remove the ConfigMap in the default namespace.
rm -f $BASE/config-map-d.yaml

# Add cluster-scoped resource--cluster-role
cat <<EOF >$BASE/cluster-role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  # "namespace" omitted since ClusterRoles are not namespaced
  name: secret-reader
rules:
- apiGroups: [""]
  #
  # at the HTTP level, the name of the resource for accessing Secret
  # objects is "secrets"
  resources: ["secrets"]
  verbs: ["get", "watch", "list"]
EOF

kapply init $BASE | tee $OUTPUT/status
expectedOutputLine "namespace: test-namespace is used for inventory object"