Added info on workflows

Updates on github-actions

Author: AlexRogalskiy

.prettierignore

@@ -12,4 +12,5 @@ node_modules
 flow-typed
 coverage
 dist
+helm
 tilt_modules

Dockerfile

@@ -14,13 +14,13 @@ ARG UID
 ARG GID
 
 ARG NAME="java-patterns"
-ARG VERSION="0.0.0-dev"
+ARG VERSION="$(git describe --abbrev=0 --tag)"
 ARG PACKAGE="AlexRogalskiy/java-patterns"
 ARG DESCRIPTION="Java Design Patterns"
 
 ARG LC_ALL="en_US.UTF-8"
-ARG BUILD_DATE="$(git rev-parse --short HEAD)"
-ARG VCS_REF="$(date -u +\"%Y-%m-%dT%H:%M:%SZ\")"
+ARG BUILD_DATE="$(date -u +\"%Y-%m-%dT%H:%M:%SZ\")"
+ARG VCS_REF="$(git rev-parse --short HEAD)"
 
 ## Working directories
 ARG APP_DIR="/usr/src/app"
@@ -119,6 +119,7 @@ RUN pip3.8 install mkdocs-material --no-cache-dir --quiet
 RUN pip3.8 install pygments --no-cache-dir --quiet
 RUN pip3.8 install markdown --no-cache-dir --quiet
 RUN pip3.8 install markdown-include --no-cache-dir --quiet
+RUN pip3.8 install markdown-checklist --no-cache-dir --quiet
 RUN pip3.8 install fontawesome_markdown --no-cache-dir --quiet
 RUN pip3.8 install mkdocs-redirects --no-cache-dir --quiet
 RUN pip3.8 install mkdocs-material-extensions --no-cache-dir --quiet

build.txt

@@ -1,2 +1,2 @@
-startTimeSecs = 1628508136;
-startTimeNanos = 406841278;
+startTimeSecs = 1628533547;
+startTimeNanos = 510196924;

helm/.helmignore

@@ -0,0 +1,23 @@
+# Patterns to ignore when building packages.
+# This supports shell glob matching, relative path matching, and
+# negation (prefixed with !). Only one pattern per line.
+.DS_Store
+# Common VCS dirs
+.git/
+.gitignore
+.bzr/
+.bzrignore
+.hg/
+.hgignore
+.svn/
+# Common backup files
+*.swp
+*.bak
+*.tmp
+*.orig
+*~
+# Various IDEs
+.project
+.idea/
+*.tmproj
+.vscode/

helm/Chart.yaml

@@ -0,0 +1,13 @@
+apiVersion: v2
+version: 1.0.0
+appVersion: 1.0.0
+name: java-patterns
+description: A demo application for a Kubernetes cluster.
+home: https://alexander-rogalsky.gitbook.io/java-patterns
+type: application
+maintainers:
+  - email: alexrogalskiy@users.noreply.github.com
+    name: AlexRogalskiy
+sources:
+  - https://github.com/AlexRogalskiy/java-patterns
+kubeVersion: '>=1.19.0-0'

helm/README.md

@@ -0,0 +1,94 @@
+# Hello Kubernetes!
+
+This container image can be deployed on a Kubernetes cluster. It runs a web app, that displays the following:
+
+- a default **Hello world!** message
+- namespace, pod, and node details
+- container image details
+
+## Quick start
+
+You can deploy `java-patterns` to your Kubernetes cluster using [Helm 3](https://helm.sh/docs/intro/install/). The Helm chart installation and configuration
+options can be found in the [Deploy using Helm](docs/deploy-using-helm.md) guide.
+
+When running through the following examples, ensure that you are in the chart directory in the repo, since you are referencing a local helm chart.
+
+```bash
+$ cd helm
+```
+
+### Example 1: Default
+
+Deploy the `java-patterns` app into the `webapp` namespace. The app is exposed via a public Load Balancer on port 80 by default - note that a LoadBalancer
+service typically only works in cloud provider based Kubernetes offerings.
+
+```bash
+$ helm install --create-namespace --namespace webapp java-patterns .
+
+# get the LoadBalancer ip address.
+$ kubectl get svc webapp-java-patterns -n webapp -o 'jsonpath={ .status.loadBalancer.ingress[0].ip }'
+```
+
+### Example 2: Custom message
+
+Deploy the `java-patterns` app into the `webapp` namespace with an "I just deployed this on Kubernetes!" message. The app is exposed via a public Load Balancer
+on port 80 by default - note that a LoadBalancer service typically only works in cloud provider based Kubernetes offerings.
+
+```bash
+$ helm install --create-namespace --namespace webapp custom-java-patterns . --set message="I just deployed this on Kubernetes!"
+
+# get the LoadBalancer ip address.
+$ kubectl get svc webapp-custom-java-patterns -n webapp -o 'jsonpath={ .status.loadBalancer.ingress[0].ip }'
+```
+
+### Example 3: Ingress
+
+Deploy the `java-patterns` app into the `webapp` namespace. This example assumes that an ingress has been deployed and configured in the cluster, and that the
+ingress has a path of `/app/java-patterns/` mapped to the `java-patterns` service.
+
+The `java-patterns` app can be reached on the ip address of the ingress via the `/app/java-patterns/` path.
+
+```bash
+$ helm install --create-namespace --namespace webapp ingress . \
+  --set ingress.configured=true \
+  --set ingress.pathPrefix="/app/java-patterns/" \
+  --set service.type="ClusterIP"
+```
+
+Alternatively, a YAML file that specifies the values for the above parameters can be provided while installing the chart. For example,
+
+```bash
+$ helm install --create-namespace --namespace webapp java-patterns . -f values.yaml
+```
+
+> **Tip**: You can use the default [values.yaml](values.yaml)
+
+## Documentation
+
+### Deploying
+
+If you'd like to explore the various Helm chart configuration options, then read the [Deploy with Helm](docs/deploy-using-helm.md) documentation. You can also
+discover more about the ingress configuration options in the [Deploy with ingress](docs/deploy-with-ingress.md) documentation
+
+### Building your own images
+
+If you'd like to build the `java-patterns` container image yourself and reference from your own registry or DockerHub repository, then you can get more details
+on how to do this in the [Build and push container images](docs/build-and-push-container-images.md) documentation.
+
+### Development environment
+
+If you have [VS Code](https://code.visualstudio.com/) and
+the [VS Code Remote Containers](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers) extension installed, the `.devcontainer`
+folder will be used to provide a container based development environment. You can read more about how to use this in
+the [Development environments](docs/development-environment.md) documentation.
+
+## Upgrading the chart
+
+### To =< 5.0.0
+
+Version 5.0.0 is a major update.
+
+* The chart now follows the new Kubernetes label recommendations:
+  <https://kubernetes.io/docs/concepts/overview/working-with-objects/common-labels/>
+
+The simplest way to update is to do a force upgrade, which recreates the resources by doing a delete and an install.

helm/deploy-using-helm.md

@@ -0,0 +1,75 @@
+# Deploy using Helm
+
+The `java-patterns` Helm chart can be used to deploy the `java-patterns` application. The chart will deploy the following resources:
+
+- ServiceAccount
+- Service
+- Deployment
+
+## Prerequisites
+
+- [Helm 3](https://v3.helm.sh/)
+
+If you are using the [VS Code Remote Containers](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers) based development
+environment, all of the prerequisites will be available in the terminal.
+
+## Configuration and installation
+
+The following table lists the configuration parameters of the java-patterns chart, and their default values.
+
+| Parameter | Type | Default | Description |
+| --------- | ---- | ------- | ----------- |
+| `message` | `string` | `""` | A custom message to display instead of the default. |
+| `ingress.configured` | `bool` | `false` | Indicates whether an ingress has been configured in the cluster. <br/>Note: this chart will not install or configure an ingress. You will need to install an ingress controller and add ingress record to the app namespace. |
+| `ingress.rewritePath` | `bool` | `true` | Indicates whether pathPrefix is rewritten by the ingress. <br/> If this is set to `true` then the java-patterns dynamic content and static assets will be served from `/`, otherwise, they will be served from `/$pathPrefix`. |
+| `ingress.pathPrefix` | `string` | `""` | The path prefix configured in the ingress for the java-patterns service.<br/> Must be provided when ingress is used. |
+| `service.type` | `string` | `"LoadBalancer"` | The service type. |
+| `service.port` | `int` | `80` | The port exposed by the service. |
+| `deployment.replicaCount` | `int` | `2` | The number of replicas for the java-patterns deployment. |
+| `deployment.container.image.repository` | `string` | `java-patterns` | The container image to run in the java-patterns pods. |
+| `deployment.container.image.tag` | `string` | `""` | The container image tag. If not specified, the chart's appVersion is used. |
+| `deployment.container.image.pullPolicy` | `string` | `"IfNotPresent"` | The pull policy for the container image. |
+| `deployment.container.port` | `int` | `"8080"` | The port that java-patterns app listens on. |
+| `deployment.nodeSelector` | `object` | `{"kubernetes.io/os":"linux", "kubernetes.io/arch":"amd64"}` | The node selector for the deployment. |
+| `deployment.resources` | `object` | `{}` | The resource limits for the deployment. |
+| `deployment.tolerations` | `object` | `[]` | The tolerations for the deployment. |
+| `deployment.affinity` | `object` | `{}` | The affinity for the deployment. |
+
+### Installing the chart
+
+Ensure that you are in the chart directory in the repo, since the instructions reference a local helm chart.
+
+To install `java-patterns` via the Helm chart, use the following to:
+
+- create the webapp namespace if it doesn't exist
+- deploy the chart located in the current folder into the webapp namespace
+- create a Helm release named java-patterns
+
+```bash
+$ helm install --create-namespace --namespace webapp java-patterns .
+```
+
+You can override the values for the configuration parameter defined in the table above, either directly in the `values.yaml` file, or via the `--set` switches.
+
+```bash
+$ helm install --create-namespace --namespace webapp custom-message . --set message="I just deployed this on Kubernetes!"
+```
+
+### Upgrading the chart
+
+Ensure that you are in the chart directory in the repo, since the instructions reference a local helm chart.
+
+You can modify the `java-patterns` app by providing new values for the configuration parameter defined in the table above, either directly in the `values.yaml`
+file, or via the `--set` switches.
+
+```bash
+$ helm upgrade --namespace webapp custom-java-patterns . --set message="This is a different message"
+```
+
+### Uninstalling the chart
+
+You can uninstall the `java-patterns` app as follows:
+
+```bash
+$ helm uninstall --namespace webapp custom-java-patterns
+```

helm/deploy-with-ingress.md

@@ -0,0 +1,104 @@
+# Deploy with ingress
+
+The `java-patterns` Helm chart can be used to deploy and configure the `java-patterns` application for use with an ingress controller.
+
+> **Note:**
+>
+> The `java-patterns` Helm chart does **not** deploy an [Ingress Controller](https://kubernetes.io/docs/concepts/services-networking/ingress-controllers/) and does **not** deploy the [Ingress](https://kubernetes.io/docs/concepts/services-networking/ingress/) definition.
+>
+> The chart aims to support deployment to as many platforms and providers as possible, so the choice of Ingress Controller and configuration of Ingress resource is left to the person deploying.
+
+## Prerequisites
+
+- [Helm 3](https://v3.helm.sh/)
+
+If you are using the [VS Code Remote Containers](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers) based development
+environment, all of the prerequisites will be available in the terminal.
+
+## Install ingress controller
+
+Install an [Ingress Controller](https://kubernetes.io/docs/concepts/services-networking/ingress-controllers/) that is available for your platform or provider.
+Here is an example that uses the [Nginx Ingress Controller](https://kubernetes.github.io/ingress-nginx/deploy/) on a cloud provider:
+
+```bash
+$ helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
+
+$ helm install nginx-ingress ingress-nginx/ingress-nginx \
+    --create-namespace --namespace ingress \
+    --set controller.replicaCount=2
+```
+
+## Use webapp with ingress
+
+### Deploy webapp instances
+
+Install two `java-patterns` instances that will be available via 2 different paths on the ingress.
+
+The `java-patterns` instance will display the default "Hello world!" message, and the `custom-java-patterns` instance will display a "This is my custom
+message!" message.
+
+```bash
+$ helm install --create-namespace --namespace webapp java-patterns . \
+  --set ingress.configured=true --set ingress.pathPrefix=hello-world \
+  --set service.type=ClusterIP
+
+$ helm install --create-namespace --namespace webapp custom-java-patterns . \
+  --set ingress.configured=true --set ingress.pathPrefix=custom-message \
+  --set service.type=ClusterIP \
+  --set message="This is my custom message!"
+```
+
+### Deploy ingress definition
+
+The `java-patterns` Helm chart has a `ingress.rewritePath` configuration parameter that is `true` by default. When used together with
+the `ingress.configured=true` configuration parameter, there is an assumption that the ingress being used supports path rewrites. See
+the [Deploy using Helm](deploy-using-helm.md) guidance for more details.
+
+So from our example, a request to `/java-patterns` should be rewritten to `/` before being passed to the `java-patterns` app instance.
+
+Create a file named `webapp-ingress.yaml` with the content below. This ingress definition will be serviced by the nginx ingress controller due to
+the `kubernetes.io/ingress.class: nginx` annotation. It will also leverage the path rewrite capabilities of nginx via
+the `nginx.ingress.kubernetes.io/rewrite-target: /$2` annotation.
+
+```yaml
+# webapp-ingress.yaml
+apiVersion: networking.k8s.io/v1beta1
+kind: Ingress
+metadata:
+  name: webapp-ingress
+  annotations:
+    kubernetes.io/ingress.class: nginx
+    nginx.ingress.kubernetes.io/rewrite-target: /$2
+spec:
+  rules:
+    - http:
+        paths:
+          - backend:
+              serviceName: webapp-java-patterns
+              servicePort: 8000
+            path: /hello-world(/|$)(.*)
+          - backend:
+              serviceName: webapp-custom-java-patterns
+              servicePort: 8000
+            path: /custom-message(/|$)(.*)
+```
+
+Deploy the contents of the `webapp-ingress.yaml` into the same namespace as the two `java-patterns` apps.
+
+```bash
+$ kubectl apply -n webapp -f webapp-ingress.yaml
+```
+
+### Browse
+
+You can browse to each of the `java-patterns` apps via the $INGRESS_CONTROLLER_IPADDRESS and each of the configured paths. So for our example at:
+
+- `$INGRESS_CONTROLLER_IPADDRESS/hello-world` - the `java-patterns` instance with the default "Hello world!" message
+- `$INGRESS_CONTROLLER_IPADDRESS/custom-java-patterns` - the `custom-java-patterns` instance with the "This is my custom message!" message
+
+## Alternatives
+
+You can deploy the `java-patterns` app via the Helm chart with the `ingress.rewritePath=false` configuration parameter if you are deploying with an ingress
+controller that does not support path rewrites.
+
+In this case, the `java-patterns` apps will serve dynamic content and static assets from the path defined by the `ingress.pathPrefix` configuration parameter.