From efcb8cf8f3e77c48ceec8639edd77456fe08d077 Mon Sep 17 00:00:00 2001
From: Mike Yoder <mike.yoder@paradigm.com>
Date: Fri, 11 Feb 2022 16:21:10 -0800
Subject: [PATCH] A Helm chart for a cloudflare tunnel.

This is in reference to github issue #569. I saw the example yaml in
https://github.com/cloudflare/argo-tunnel-examples/tree/master/named-tunnel-k8s
and thought it would be much more useful as a helm chart. And I had to
make a helm chart anyway so I could deploy it with Terraform.  Here's
the result, and figured I'd contribute it back.
---
 helm/cloudflare-tunnel/.helmignore            |  23 ++++
 helm/cloudflare-tunnel/Chart.yaml             |  22 ++++
 helm/cloudflare-tunnel/templates/_helpers.tpl |  51 +++++++++
 .../templates/configmap.yaml                  |  29 +++++
 .../templates/deployment.yaml                 | 102 ++++++++++++++++++
 helm/cloudflare-tunnel/templates/secret.yaml  |  16 +++
 .../templates/serviceaccount.yaml             |  12 +++
 helm/cloudflare-tunnel/values.yaml            |  79 ++++++++++++++
 8 files changed, 334 insertions(+)
 create mode 100644 helm/cloudflare-tunnel/.helmignore
 create mode 100644 helm/cloudflare-tunnel/Chart.yaml
 create mode 100644 helm/cloudflare-tunnel/templates/_helpers.tpl
 create mode 100644 helm/cloudflare-tunnel/templates/configmap.yaml
 create mode 100644 helm/cloudflare-tunnel/templates/deployment.yaml
 create mode 100644 helm/cloudflare-tunnel/templates/secret.yaml
 create mode 100644 helm/cloudflare-tunnel/templates/serviceaccount.yaml
 create mode 100644 helm/cloudflare-tunnel/values.yaml

diff --git a/helm/cloudflare-tunnel/.helmignore b/helm/cloudflare-tunnel/.helmignore
new file mode 100644
index 00000000..0e8a0eb3
--- /dev/null
+++ b/helm/cloudflare-tunnel/.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/
diff --git a/helm/cloudflare-tunnel/Chart.yaml b/helm/cloudflare-tunnel/Chart.yaml
new file mode 100644
index 00000000..c15ca5c6
--- /dev/null
+++ b/helm/cloudflare-tunnel/Chart.yaml
@@ -0,0 +1,22 @@
+apiVersion: v2
+name: cloudflare-tunnel
+description: Creation of a cloudflared deployment - a reverse tunnel for an environment
+
+# A chart can be either an 'application' or a 'library' chart.
+# Application charts are a collection of templates that can be packaged into versioned archives
+# to be deployed.
+type: application
+
+# This is the chart version. This version number should be incremented each time you make changes
+# to the chart and its templates, including the app version.
+# Versions are expected to follow Semantic Versioning (https://semver.org/)
+version: 0.1.0
+
+# This is the version number of the application being deployed. This version number should be
+# incremented each time you make changes to the application. Versions are not expected to
+# follow Semantic Versioning. They should reflect the version the application is using.
+# It is recommended to use it with quotes.
+appVersion: "2022.1.3"
+
+# Let's look professional with a Cloudflare icon.
+icon: https://developers.cloudflare.com/cloudflare-one/favicon-32x32.png
diff --git a/helm/cloudflare-tunnel/templates/_helpers.tpl b/helm/cloudflare-tunnel/templates/_helpers.tpl
new file mode 100644
index 00000000..9d856240
--- /dev/null
+++ b/helm/cloudflare-tunnel/templates/_helpers.tpl
@@ -0,0 +1,51 @@
+{{/*
+Expand the name of the chart.
+*/}}
+{{- define "cloudflare-tunnel.name" -}}
+{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" }}
+{{- end }}
+
+{{/*
+Create a default fully qualified app name.
+We truncate at 63 chars because some Kubernetes name fields are limited to this (by the DNS naming spec).
+If release name contains chart name it will be used as a full name.
+*/}}
+{{- define "cloudflare-tunnel.fullname" -}}
+{{- if .Values.fullnameOverride }}
+{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" }}
+{{- else }}
+{{- $name := default .Chart.Name .Values.nameOverride }}
+{{- if contains $name .Release.Name }}
+{{- .Release.Name | trunc 63 | trimSuffix "-" }}
+{{- else }}
+{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" }}
+{{- end }}
+{{- end }}
+{{- end }}
+
+{{/*
+Create chart name and version as used by the chart label.
+*/}}
+{{- define "cloudflare-tunnel.chart" -}}
+{{- printf "%s-%s" .Chart.Name .Chart.Version | replace "+" "_" | trunc 63 | trimSuffix "-" }}
+{{- end }}
+
+{{/*
+Common labels
+*/}}
+{{- define "cloudflare-tunnel.labels" -}}
+helm.sh/chart: {{ include "cloudflare-tunnel.chart" . }}
+{{ include "cloudflare-tunnel.selectorLabels" . }}
+{{- if .Chart.AppVersion }}
+app.kubernetes.io/version: {{ .Chart.AppVersion | quote }}
+{{- end }}
+app.kubernetes.io/managed-by: {{ .Release.Service }}
+{{- end }}
+
+{{/*
+Selector labels
+*/}}
+{{- define "cloudflare-tunnel.selectorLabels" -}}
+app.kubernetes.io/name: {{ include "cloudflare-tunnel.name" . }}
+app.kubernetes.io/instance: {{ .Release.Name }}
+{{- end }}
diff --git a/helm/cloudflare-tunnel/templates/configmap.yaml b/helm/cloudflare-tunnel/templates/configmap.yaml
new file mode 100644
index 00000000..07d52192
--- /dev/null
+++ b/helm/cloudflare-tunnel/templates/configmap.yaml
@@ -0,0 +1,29 @@
+# This configmap stores the configuration used by cloudflared.
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ include "cloudflare-tunnel.fullname" . }}
+data:
+  config.yaml: |
+    # Name of the tunnel you want to run
+    tunnel: {{ .Values.cloudflare.tunnelName }}
+    # The location of the secret containing the tunnel credentials
+    credentials-file: /etc/cloudflared/creds/credentials.json
+    # General purpose TCP routing for the network
+    warp-routing:
+      enabled: {{ .Values.cloudflare.enableWarp }}
+    # Serves the metrics server under /metrics and the readiness server under /ready
+    metrics: 0.0.0.0:2000
+    # Autoupdates applied in a k8s pod will be lost when the pod is removed or restarted, so
+    # autoupdate doesn't make sense in Kubernetes. However, outside of Kubernetes, we strongly
+    # recommend using autoupdate.
+    no-autoupdate: true
+    # The `ingress` block tells cloudflared which local service to route incoming
+    # requests to. For more about ingress rules, see
+    # https://developers.cloudflare.com/cloudflare-one/connections/connect-apps/configuration/ingress
+    ingress:
+      {{- with .Values.cloudflare.ingress }}
+      {{- toYaml . | nindent 6 }}
+      {{- end }}
+      # This rule matches any traffic which didn't match a previous rule, and responds with HTTP 404.
+      - service: http_status:404
diff --git a/helm/cloudflare-tunnel/templates/deployment.yaml b/helm/cloudflare-tunnel/templates/deployment.yaml
new file mode 100644
index 00000000..12f5bcfd
--- /dev/null
+++ b/helm/cloudflare-tunnel/templates/deployment.yaml
@@ -0,0 +1,102 @@
+# Here we deploy cloudflared images. The tunnel credentials are stored in
+# a k8s secret, and the configuration is stored in a k8s configmap.
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: {{ include "cloudflare-tunnel.fullname" . }}
+  labels:
+    {{- include "cloudflare-tunnel.labels" . | nindent 4 }}
+spec:
+  replicas: {{ .Values.replicaCount }}
+  selector:
+    matchLabels:
+      {{- include "cloudflare-tunnel.selectorLabels" . | nindent 6 }}
+  template:
+    metadata:
+      annotations:
+        # These are here so the deployment rolls when the config or secret change.
+        checksum/configmap: {{ include (print $.Template.BasePath "/configmap.yaml") . | sha256sum }}
+        checksum/secret: {{ include (print $.Template.BasePath "/secret.yaml") . | sha256sum }}
+        {{- with .Values.podAnnotations }}
+        {{- toYaml . | nindent 8 }}
+        {{- end }}
+      labels:
+        {{- include "cloudflare-tunnel.selectorLabels" . | nindent 8 }}
+    spec:
+      {{- with .Values.imagePullSecrets }}
+      imagePullSecrets:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
+      serviceAccountName: {{ include "cloudflare-tunnel.fullname" . }}
+      securityContext:
+        {{- toYaml .Values.podSecurityContext | nindent 8 }}
+      containers:
+        - name: {{ .Chart.Name }}
+          securityContext:
+            {{- toYaml .Values.securityContext | nindent 12 }}
+          image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
+          imagePullPolicy: {{ .Values.image.pullPolicy }}
+          args:
+            - tunnel
+            # Points cloudflared to the config file, which configures what
+            # cloudflared will actually do. This file is created by a ConfigMap.
+            - --config
+            - /etc/cloudflared/config/config.yaml
+            - run
+          livenessProbe:
+            httpGet:
+              # Cloudflared has a /ready endpoint which returns 200 if and only if
+              # it has an active connection to the edge.
+              path: /ready
+              port: 2000
+            failureThreshold: 1
+            initialDelaySeconds: 10
+            periodSeconds: 10
+          volumeMounts:
+            - name: config
+              mountPath: /etc/cloudflared/config
+              readOnly: true
+            # Each tunnel has an associated "credentials file" which authorizes machines
+            # to run the tunnel. cloudflared will read this file from its local filesystem,
+            # and it'll be stored in a k8s secret.
+            - name: creds
+              mountPath: /etc/cloudflared/creds
+              readOnly: true
+          resources:
+            {{- toYaml .Values.resources | nindent 12 }}
+      volumes:
+        - name: creds
+          secret:
+            secretName: {{ include "cloudflare-tunnel.fullname" . }}
+        - name: config
+          configMap:
+            name: {{ include "cloudflare-tunnel.fullname" . }}
+            items:
+              - key: config.yaml
+                path: config.yaml
+      {{- with .Values.nodeSelector }}
+      nodeSelector:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
+      affinity:
+        {{- with .Values.affinity }}
+        {{- toYaml . | nindent 8 }}
+        {{- else }}
+        podAntiAffinity:
+          preferredDuringSchedulingIgnoredDuringExecution:
+            - weight: 10
+              podAffinityTerm:
+                topologyKey: kubernetes.io/hostname
+                labelSelector:
+                  matchExpressions:
+                  {{- range $k, $v := include "cloudflare-tunnel.selectorLabels" . | fromYaml }}
+                    - key: {{ $k }}
+                      operator: In
+                      values:
+                        - {{ $v }}
+                  {{- end }}
+      {{- end }}
+      {{- with .Values.tolerations }}
+      tolerations:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
diff --git a/helm/cloudflare-tunnel/templates/secret.yaml b/helm/cloudflare-tunnel/templates/secret.yaml
new file mode 100644
index 00000000..139b8a43
--- /dev/null
+++ b/helm/cloudflare-tunnel/templates/secret.yaml
@@ -0,0 +1,16 @@
+# This credentials secret allows cloudflared to authenticate itself
+# to the Cloudflare infrastructure.
+apiVersion: v1
+kind: Secret
+metadata:
+  name: {{ include "cloudflare-tunnel.fullname" . }}
+  labels:
+    {{- include "cloudflare-tunnel.labels" . | nindent 4 }}
+stringData:
+  credentials.json: |-
+    {
+      "AccountTag": {{ .Values.cloudflare.account | quote }},
+      "TunnelID": {{ .Values.cloudflare.tunnelId | quote }},
+      "TunnelName": {{ .Values.cloudflare.tunnelName | quote }},
+      "TunnelSecret": {{ .Values.cloudflare.secret | quote }}
+    }
diff --git a/helm/cloudflare-tunnel/templates/serviceaccount.yaml b/helm/cloudflare-tunnel/templates/serviceaccount.yaml
new file mode 100644
index 00000000..ecb321e7
--- /dev/null
+++ b/helm/cloudflare-tunnel/templates/serviceaccount.yaml
@@ -0,0 +1,12 @@
+# Here we create a service account with no privileges to run the
+# deployment - just in case the default service account is different.
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: {{ include "cloudflare-tunnel.fullname" . }}
+  labels:
+    {{- include "cloudflare-tunnel.labels" . | nindent 4 }}
+  {{- with .Values.serviceAccount.annotations }}
+  annotations:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
diff --git a/helm/cloudflare-tunnel/values.yaml b/helm/cloudflare-tunnel/values.yaml
new file mode 100644
index 00000000..0bb75695
--- /dev/null
+++ b/helm/cloudflare-tunnel/values.yaml
@@ -0,0 +1,79 @@
+# Default values for cloudflare-tunnel.
+
+# Cloudflare parameters.
+cloudflare:
+  # Your Cloudflare account number.
+  account: ""
+  # The name of the tunnel this instance will serve
+  tunnelName: ""
+  # The ID of the above tunnel.
+  tunnelId: ""
+  # The secret for the tunnel.
+  secret: ""
+  # If true, turn on WARP routing for TCP
+  enableWarp: false
+  # Define ingress rules for the tunnel. See
+  # https://developers.cloudflare.com/cloudflare-one/connections/connect-apps/configuration/configuration-file/ingress
+  ingress: []
+    # The first rule proxies traffic to the httpbin sample service named web-server at port 80
+    # - hostname: tunnel.example.com
+    #  service: http://web-service:80
+    # This rule sends traffic to the built-in hello-world HTTP server. This can help debug connectivity
+    # issues. If hello.example.com resolves and tunnel.example.com does not, then the problem is
+    # in the connection from cloudflared to your local service, not from the internet to cloudflared.
+    # - hostname: hello.example.com
+    #   service: hello_world
+
+image:
+  repository: cloudflare/cloudflared
+  pullPolicy: IfNotPresent
+  # If supplied, this overrides "appVersion"
+  tag: ""
+
+replicaCount: 2
+
+imagePullSecrets: []
+nameOverride: ""
+fullnameOverride: ""
+
+serviceAccount:
+  # Annotations to add to the service account
+  annotations: {}
+  # The name of the service account to use.
+  # If not set and create is true, a name is generated using the fullname template
+  name: ""
+
+podAnnotations: {}
+
+# Security items common to everything in the pod.  Here we require that it
+# does not run as the user defined in the image, literally named "nonroot".
+podSecurityContext:
+  runAsNonRoot: true
+  runAsUser: 65532
+
+# Security items for one container. We lock it down.
+securityContext:
+  allowPrivilegeEscalation: false
+  capabilities:
+    drop:
+    - ALL
+  readOnlyRootFilesystem: true
+
+resources: {}
+  # We usually recommend not to specify default resources and to leave this as a conscious
+  # choice for the user. This also increases chances charts run on environments with little
+  # resources, such as Minikube. If you do want to specify resources, uncomment the following
+  # lines, adjust them as necessary, and remove the curly braces after 'resources:'.
+  # limits:
+  #   cpu: 100m
+  #   memory: 128Mi
+  # requests:
+  #   cpu: 100m
+  #   memory: 128Mi
+
+nodeSelector: {}
+
+tolerations: []
+
+# Default affinity is to spread out over nodes; use this to override.
+affinity: {}