docs(examples): add nginx example chart

This adds an nginx chart that shows off more of the template system's
capabilities.

docs/examples/README.md

@@ -2,3 +2,18 @@
 
 This directory contains example charts to help you get started with
 chart development.
+
+## Alpine
+
+The `alpine` chart is very simple, and is a good starting point.
+
+It simply deploys a single pod running Alpine Linux.
+
+## Nginx
+
+The `nginx` chart shows how to compose several resources into one chart,
+and it illustrates more complex template usage.
+
+It deploys a `deployment` (which creates a `replica set`), a `config
+map`, and a `service`. The replica set starts an nginx pod. The config
+map stores the files that the nginx server can serve.

docs/examples/nginx/.helmignore

+# 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
+.git

docs/examples/nginx/Chart.yaml

+name: nginx
+description: A basic NGINX HTTP server
+version: 0.1.0
+keywords:
+  - http
+  - nginx
+  - www
+  - web
+home: "https://github.com/kubernetes/helm"
+sources:
+  - "https://hub.docker.com/_/nginx/"
+maintainers:
+  - name: technosophos
+    email: mbutcher@deis.com

docs/examples/nginx/README.md

+# nginx: An advanced example chart
+
+This Helm chart provides examples of some of Helm's more powerful
+features.
+
+**This is not a production-grade chart. It is an example.**
+
+The chart installs a simple nginx server according to the following
+pattern:
+
+- A `ConfigMap` is used to store the files the server will serve.
+  (`templates/configmap.yaml`)
+- A `Deployment` is used to create a Replica Set of nginx pods.
+  (`templates/deployment.yaml`)
+- A `Service` is used to create a gateway to the pods running in the
+  replica set (`templates/svc.yaml`)
+
+The `values.yaml` exposes a few of the configuration options in the
+charts, though there are some that are not exposed there (like
+`.image`).
+
+The `templates/_helpers.tpl` file contains helper templates. The leading
+underscore (`_`) on the filename is semantic. It tells the template renderer
+that this file does not contain a manifest. That file declares some
+templates that are used elsewhere in the chart.
+
+You can deploy this chart with `helm install docs/examples/nginx`. Or
+you can see how this chart would render with `helm install --dry-run
+--debug docs/examples/nginx`.

docs/examples/nginx/templates/_helpers.tpl

+{{/* vim: set filetype=mustache: */}}
+{{/*
+Expand the name of the chart.
+*/}}
+{{define "name"}}{{default "nginx" .nameOverride | trunc 24 }}{{end}}
+
+{{/*
+Create a default fully qualified app name.
+
+We truncate at 24 chars because some Kubernetes name fields are limited to this
+(by the DNS naming spec).
+*/}}
+{{define "fullname"}}{{.Release.Name}}-{{default "nginx" .nameOverride | trunc 24 }}{{end}}

docs/examples/nginx/templates/configmap.yaml

+# This is a simple example of using a config map to create a single page
+# static site.
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{template "fullname" .}}
+  labels:
+    release: {{.Release.Name}}
+    app: {{template "fullname" .}}
+data:
+  # When the config map is mounted as a volume, these will be created as
+  # files.
+  index.html: {{default "Hello" .index | squote}}
+  test.txt: test

docs/examples/nginx/templates/deployment.yaml

+apiVersion: extensions/v1beta1
+kind: Deployment
+metadata:
+  # This uses a "fullname" template (see _helpers)
+  # Basing names on .Release.Name means that the same chart can be installed
+  # multiple times into the same namespace.
+  name: {{template "fullname" .}}
+  labels:
+    heritage: helm
+    # This makes it easy to search using kubectl
+    release: {{.Release.Name}}
+    # This makes it easy to audit chart usage.
+    chart: {{.Chart.Name}}-{{.Chart.Version}}
+spec:
+  replicas: {{default 1 .replicaCount}}
+  template:
+    metadata:
+      labels:
+        app: {{template "fullname" .}}
+        release: {{.Release.Name}}
+    spec:
+      containers:
+      - name: {{template "fullname" .}}
+        # Making image configurable is not necessary. Making imageTag configurable
+        # is a nice option for the user. Especially in the strange cases like
+        # nginx where the base distro is determined by the tag. Using :latest
+        # is frowned upon, using :stable isn't that great either.
+        image: "{{default "nginx" .image}}:{{default "stable-alpine" .imageTag}}"
+        imagePullPolicy: {{default "IfNotPresent" .pullPolicy}}
+        ports:
+        - containerPort: 80
+        # This (and the volumes section below) mount the config map as a volume.
+        volumeMounts:
+        - mountPath: /usr/share/nginx/html
+          name: wwwdata-volume
+      volumes:
+        - name: wwwdata-volume
+          configMap:
+            name: {{template "fullname" .}}

docs/examples/nginx/templates/svc.yaml

+# This is a service gateway to the replica set created by the deployment.
+apiVersion: v1
+kind: Service
+metadata:
+  name: {{template "fullname" .}}
+  labels:
+    heritage: helm
+    release: {{.Release.Name}}
+    chart: {{.Chart.Name}}-{{.Chart.Version}}
+spec:
+  ports:
+  - port: {{default 80 .httpPort}}
+    targetPort: 80
+    protocol: TCP
+    name: http
+  selector:
+    app: {{template "fullname" .}}

docs/examples/nginx/values.yaml

+# Default values for nginx.
+# This is a YAML-formatted file.
+# Declare name/value pairs to be passed into your templates.
+
+# See the list at https://hub.docker.com/r/library/nginx/tags/
+imageTag: "1.11.0"
+
+# The port (defined on the service) to access the HTTP server.
+httpPort: 8888
+
+# Number of nginx instances to run
+replicaCount: 1
+
+index: >-
+  <h1>Hello</h1>
+  <p>This is a test</p>