updating Kubernetes tutorial to use local registry with KIND, and pro…

…vide steps to create containers with spring boot

Signed-off-by: salaboy <Salaboy@gmail.com>

spring-boot-examples/kubernetes/README.md

@@ -5,10 +5,12 @@ We install Dapr on a Kubernetes cluster and then we will deploy both the `produc
 
 ## Creating a cluster and installing Dapr
 
-If you don't have any Kubernetes cluster you can use Kubernetes KIND to create a local cluster. 
+If you don't have any Kubernetes cluster you can use Kubernetes KIND to create a local cluster. We will create a cluster 
+with a local container registry, so we can push our container images to it. This is covered in the 
+[KIND documentation here](https://kind.sigs.k8s.io/docs/user/local-registry/).
 
 ```bash
-kind create cluster
+./kind-with-registry.sh
 ```
 
 Once you have the cluster up and running you can install Dapr: 
@@ -23,6 +25,39 @@ helm upgrade --install dapr dapr/dapr \
 --wait
 ```
 
+## Creating containers using Spring Boot and pushing to local registry
+
+Now that we have our cluster set up with a local container registry, we need to build our `producer-app` and `consumer-app` containers.
+For this we will use Spring Boot build it functions to create container images using [Buildpacks](https://buildpacks.io): 
+
+From inside the `spring-boot-examples/producer-app` directory you can run the following command to create a container: 
+```bash
+mvn spring-boot:build-image
+```
+
+Once we have the container image created, we need to tag and push to the local registry, so the image can be used from our local cluster.
+Alternatively, you can push the images to a public registry and update the Kubernetes manifests accordingly. 
+
+```bash
+docker tag producer-app:0.14.0-SNAPSHOT localhost:5001/sb-producer-app
+docker push localhost:5001/sb-producer-app
+```
+
+From inside the `spring-boot-examples/consumer-app` directory you can run the following command to create a container:
+```bash
+mvn spring-boot:build-image
+```
+
+Once we have the container image created, we need to tag and push to the local registry, so the image can be used from our local cluster.
+Alternatively, you can push the images to a public registry and update the Kubernetes manifests accordingly.
+
+```bash
+docker tag consumer-app:0.14.0-SNAPSHOT localhost:5001/sb-consumer-app
+docker push localhost:5001/sb-consumer-app
+```
+
+Now we are ready to install our application into the cluster.
+
 ## Installing and interacting with the application
 
 Now that we have a running Kubernetes cluster, we need to first install the components needed by the application. 
@@ -38,7 +73,8 @@ Then PostgreSQL:
 helm install postgresql oci://registry-1.docker.io/bitnamicharts/postgresql --set global.postgresql.auth.database=dapr --set global.postgresql.auth.postgresPassword=password
 ```
 
-Once we have these components up and running we can install the application by running: 
+Once we have these components up and running we can install the application by running from inside 
+the `spring-boot-examples/kubernetes/` directory: 
 
 ```bash
 kubectl apply -f .

spring-boot-examples/kubernetes/consumer-app.yaml

@@ -37,7 +37,7 @@ spec:
         app: consumer-app
     spec:
       containers:
-        - image: salaboy/sb-consumer-app
+        - image: localhost:5001/sb-consumer-app
           name: consumer-app
           imagePullPolicy: Always
           ports:

spring-boot-examples/kubernetes/kind-with-registry.sh

@@ -0,0 +1,64 @@
+#!/bin/sh
+set -o errexit
+
+# 1. Create registry container unless it already exists
+reg_name='kind-registry'
+reg_port='5001'
+if [ "$(docker inspect -f '{{.State.Running}}' "${reg_name}" 2>/dev/null || true)" != 'true' ]; then
+  docker run \
+    -d --restart=always -p "127.0.0.1:${reg_port}:5000" --network bridge --name "${reg_name}" \
+    registry:2
+fi
+
+# 2. Create kind cluster with containerd registry config dir enabled
+# TODO: kind will eventually enable this by default and this patch will
+# be unnecessary.
+#
+# See:
+# https://github.com/kubernetes-sigs/kind/issues/2875
+# https://github.com/containerd/containerd/blob/main/docs/cri/config.md#registry-configuration
+# See: https://github.com/containerd/containerd/blob/main/docs/hosts.md
+cat <<EOF | kind create cluster --config=-
+kind: Cluster
+apiVersion: kind.x-k8s.io/v1alpha4
+containerdConfigPatches:
+- |-
+  [plugins."io.containerd.grpc.v1.cri".registry]
+    config_path = "/etc/containerd/certs.d"
+EOF
+
+# 3. Add the registry config to the nodes
+#
+# This is necessary because localhost resolves to loopback addresses that are
+# network-namespace local.
+# In other words: localhost in the container is not localhost on the host.
+#
+# We want a consistent name that works from both ends, so we tell containerd to
+# alias localhost:${reg_port} to the registry container when pulling images
+REGISTRY_DIR="/etc/containerd/certs.d/localhost:${reg_port}"
+for node in $(kind get nodes); do
+  docker exec "${node}" mkdir -p "${REGISTRY_DIR}"
+  cat <<EOF | docker exec -i "${node}" cp /dev/stdin "${REGISTRY_DIR}/hosts.toml"
+[host."http://${reg_name}:5000"]
+EOF
+done
+
+# 4. Connect the registry to the cluster network if not already connected
+# This allows kind to bootstrap the network but ensures they're on the same network
+if [ "$(docker inspect -f='{{json .NetworkSettings.Networks.kind}}' "${reg_name}")" = 'null' ]; then
+  docker network connect "kind" "${reg_name}"
+fi
+
+# 5. Document the local registry
+# https://github.com/kubernetes/enhancements/tree/master/keps/sig-cluster-lifecycle/generic/1755-communicating-a-local-registry
+cat <<EOF | kubectl apply -f -
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: local-registry-hosting
+  namespace: kube-public
+data:
+  localRegistryHosting.v1: |
+    host: "localhost:${reg_port}"
+    help: "https://kind.sigs.k8s.io/docs/user/local-registry/"
+EOF

spring-boot-examples/kubernetes/producer-app.yaml

@@ -37,7 +37,7 @@ spec:
         app: producer-app
     spec:
       containers:
-        - image: salaboy/sb-producer-app
+        - image: localhost:5001/sb-producer-app
           name: producer-app
           imagePullPolicy: Always
           ports: