From 2cbe336ad37c94de890300c27a17586614a9bc60 Mon Sep 17 00:00:00 2001
From: Kyle Hodgetts <kyle@kubeshop.io>
Date: Tue, 28 Sep 2021 17:20:32 +0300
Subject: [PATCH] Docs for Ambassador 2 + fixes for preview breakages (#174)

* Add docs for ambassador 2.0 generator usage

* make host option mandatory. Introduce template func for splitting a comma separated string into its components for the mapping template cors section as Ambassador 2.0 doesn't support comma separated strings as paramters for cors anymore.

* host option is now mandatory for Ambassador 2.0 as AmbassadorMappings must match an AmbassadorHost resource in order to work

* host option is now mandatory for Ambassador 2.0 as AmbassadorMappings must match an AmbassadorHost resource in order to work

* split CORS comma separated strings into array using template func and iterate over them creating a yaml array in the resulting AmbassadorMapping resource

* Add warnings to Ambassador 2.0 docs regarding unstability of the Developer Preview
---
 README.md                                    |   4 +-
 docs/ambassador2.md                          | 550 +++++++++++++++++++
 examples/booksapp/booksapp_extension.yaml    |   1 +
 generators/ambassador/v2/ambassador.go       |  18 +-
 generators/ambassador/v2/ambassador_test.go  | 107 +++-
 generators/ambassador/v2/mapping_template.go |  38 +-
 6 files changed, 698 insertions(+), 20 deletions(-)
 create mode 100644 docs/ambassador2.md

diff --git a/README.md b/README.md
index b337ccf..b00c311 100644
--- a/README.md
+++ b/README.md
@@ -50,11 +50,13 @@ allowing you to
 
 Kusk currently supports (click for configuration options)
 - [Ambassador 1.x](https://kubeshop.github.io/kusk/ambassador/)
+- [Ambassador 2.0](https://kubeshop.github.io/kusk/ambassador/)
+  - **Warning** This is a developer preview and should be treated as unstable
 - [Linkerd](https://kubeshop.github.io/kusk/linkerd/)
 - [Nginx-Ingress](https://kubeshop.github.io/kusk/nginx-ingress/)
 - [Traefik V2 (v2.x)](https://kubeshop.github.io/kusk/traefik/)
 
-Some of the upcoming tools we'd like to support are Kong, Ambassador 2.x, etc. Please don't hesitate to 
+Some of the upcoming tools we'd like to support are Kong and Contour. Please don't hesitate to 
 suggest others or contribute your own generator!
 
 ## Documentation & Support
diff --git a/docs/ambassador2.md b/docs/ambassador2.md
new file mode 100644
index 0000000..743ea0e
--- /dev/null
+++ b/docs/ambassador2.md
@@ -0,0 +1,550 @@
+# Ambassador 2.0
+**Warning**: Ambassador 2.0 is currently in Developer Preview and could change at any point, breaking the implementation here.
+
+
+```shell
+kusk ambassador2 --help
+Generates Ambassador 2.0 Mappings for your service
+
+Usage:
+  kusk ambassador2 [flags]
+
+Flags:
+  -i, --in string                         file path to api spec file to generate mappings from. e.g. --in apispec.yaml
+      --namespace string                  namespace for generated resources (default "default")
+      --service.name string               target Service name
+      --service.namespace string          namespace containing the target Service (default "default")
+      --service.port int32                target Service port (default 80)
+      --host string                       the Host header value to listen on
+      --path.base string                  a base path for Service endpoints (default "/")
+      --path.split                        force Kusk to generate a separate Mapping for each operation
+      --path.trim_prefix string           a prefix to trim from the URL before forwarding to the upstream Service
+      --rate_limits.burst uint32          request per second burst
+      --rate_limits.rps uint32            request per second rate limit
+      --timeouts.idle_timeout uint32      idle connection timeout (seconds)
+      --timeouts.request_timeout uint32   total request timeout (seconds)
+  -h, --help
+```
+
+The Ambassador generator generates [AmbassadorMapping]s (https://www.getambassador.io/docs/edge-stack/2.0/topics/using/intro-mappings/) resources for mapping resource to services. All options that can be set via 
+flags can also be set using our `x-kusk` OpenAPI extension in your specification.
+
+CLI flags apply only at the global level i.e. applies to all paths and methods.
+
+To override settings on the path or HTTP method level, you are required to use the x-kusk extension at that path in your API specification.
+
+## Full Options Reference
+| Name                    | CLI Option                 | OpenAPI Spec x-kusk label | Descriptions                                                                                                       | Overwritable at path / method |
+|-------------------------|----------------------------|---------------------------|--------------------------------------------------------------------------------------------------------------------|-------------------------------|
+| OpenAPI or Swagger File | --in                       | N/A                       | Location of the OpenAPI or Swagger specification                                                                   | ❌                             |
+| Namespace               | --namespace                | namespace                 | the namespace in which to create the generated resources (Required)                                                | ❌                             |
+| Service Name            | --service.name             | service.name              | the name of the service running in Kubernetes (Required)                                                           | ❌                             |
+| Service Namespace       | --service.namespace        | service.namespace         | The namespace where the service named above resides (default value: default)                                       | ❌                             |
+| Service Port            | --service.port             | service.port              | Port the service is listening on (default value: 80)                                                               | ❌                             |
+| Path Base               | --path.base                | path.base                 | Prefix for your resource routes                                                                                    | ❌                             |
+| Path Trim Prefix        | --path.trim_prefix         | path.trim_prefix          | Trim the specified prefix from URl before passing request onto service                                             | ❌                             |
+| Path split              | --path.split               | path.split                | Boolean; whether or not to force generator to generate a mapping for each path                                     | ❌                             |
+| Host                    | --host                     | host                      | The value to set the host field to in the AmbassadorMapping resource                                                         | ✅                             |
+| Rate limit (RPS)        | --rate_limits.rps          | rate_limits.rps           | Request per second rate limit                                                                                      | ✅                             |
+| Rate limit (burst)      | --rate_limits.burst        | rate_limits.burst         | Rate limit burst                                                                                                   | ✅                             |
+| Rate limit group        | N/A                        | rate_limits.group         | Rate limit endpoint group                                                                                          |                               |
+| Request Timeout         | --timeouts.request_timeout | timeouts.request_timeout  | Total request timeout (seconds)                                                                                    | ✅                             |
+| Idle Timeout            | --timeouts.idle_timeout    | timeouts.idle_timeout     | Idle connection timeout (seconds)                                                                                  | ✅                             |
+| CORS Origins            | N/A                        | cors.origins              | Array of origins                                                                                                   | ✅                             |
+| CORS Methods            | N/A                        | cors.methods              | Array of methods                                                                                                   | ✅                             |
+| CORS Headers            | N/A                        | cors.headers              | Array of headers                                                                                                   | ✅                             |
+| CORS ExposeHeaders      | N/A                        | cors.expose_headers       | Array of headers to expose                                                                                         | ✅                             |
+| CORS Credentials        | N/A                        | cors.credentials          | Boolean: enable credentials (default value: false)                                                                 | ✅                             |
+| CORS Max Age            | N/A                        | cors.max_age              | Integer:how long the response to the preflight request can be cached for without sending another preflight request | ✅                             |
+
+## Ambassador 2.0 Setup
+[source](https://www.getambassador.io/docs/edge-stack/latest/tutorials/getting-started/)
+
+### Create cluster
+`k3d cluster create -p "8080:80@loadbalancer" -p "8443:443@loadbalancer" --k3s-server-arg '--disable=traefik' cl1`
+
+### Install the edge-stack
+```
+# Add the Repo:
+helm repo add datawire https://www.getambassador.io
+helm repo update
+
+# Create Namespace and Install:
+helm install -n ambassador --create-namespace \
+        edge-stack --devel \
+        datawire/edge-stack && \
+    kubectl rollout status  -n ambassador deployment/edge-stack -w
+```
+
+### Create the AmbassadorListeners
+```
+kubectl apply -f - <<EOF
+---
+apiVersion: x.getambassador.io/v3alpha1
+kind: AmbassadorListener
+metadata:
+  name: edge-stack-listener-8080
+  namespace: ambassador
+spec:
+  port: 8080
+  protocol: HTTP
+  securityModel: XFP
+  hostBinding:
+    namespace:
+      from: ALL
+---
+apiVersion: x.getambassador.io/v3alpha1
+kind: AmbassadorListener
+metadata:
+  name: edge-stack-listener-8443
+  namespace: ambassador
+spec:
+  port: 8443
+  protocol: HTTPS
+  securityModel: XFP
+  hostBinding:
+    namespace:
+      from: ALL
+EOF
+```
+
+### Create the AmbassadorHost
+```
+cat <<EOF | kubectl apply -f -
+---
+apiVersion: x.getambassador.io/v3alpha1
+kind: AmbassadorHost
+metadata:
+  name: my-host
+  namespace: ambassador
+spec:
+  hostname: "*"
+  requestPolicy:
+    insecure:
+      action: Redirect
+EOF
+```
+
+### Deploy the example booksapp
+```
+kubectl create ns booksapp && \
+kubectl apply -n booksapp -f /Users/kylehodgetts/kubeshop/kusk/examples/booksapp/manifest.yaml && \
+kubectl rollout status  -n booksapp deployment/webapp -w
+```
+
+## Basic Usage
+
+### CLI Flags
+
+```shell
+kusk ambassador2 -i examples/booksapp/booksapp.yaml \
+--namespace booksapp \
+--host "*" \
+--service.name webapp \
+--service.port 7000 \
+--service.namespace booksapp
+```
+
+### OpenAPI Specification
+
+```yaml
+openapi: 3.0.1
+x-kusk:
+  namespace: booksapp
+  host: "*"
+  service:
+    name: webapp
+    namespace: booksapp
+    port: 7000
+paths:
+  /:
+    get: {}
+...
+```
+
+### Sample Output
+
+```yaml
+---
+apiVersion: x.getambassador.io/v3alpha1
+kind: AmbassadorMapping
+metadata:
+  name: booksapp
+  namespace: booksapp
+spec:
+  prefix: "/"
+  hostname: '*'
+  service: booksapp.booksapp:7000
+  rewrite: ""
+```
+
+### Test
+`curl -Lki https://localhost:8443`
+
+Or go to your web browser
+
+---
+## Split Path
+
+By setting split path to true, kusk will generate a mapping per route specified in the 
+provided OpenAPI specification
+
+### CLI Flags
+
+```shell
+kusk ambassador2 -i examples/booksapp/booksapp.yaml \
+--namespace booksapp \
+--host "*" \
+--service.name webapp \
+--service.port 7000 \
+--service.namespace booksapp \
+--path.split true
+```
+
+### OpenAPI Specification
+
+```yaml
+openapi: 3.0.1
+x-kusk:
+  namespace: booksapp
+  host: "*"
+  service:
+    name: webapp
+    namespace: booksapp
+    port: 7000
+  path:
+    split: true
+paths:
+  /:
+    get: {}
+
+  /books:
+    post: {}
+...
+```
+
+### Sample Output
+
+```yaml
+---
+apiVersion: x.getambassador.io/v3alpha1
+kind: AmbassadorMapping
+metadata:
+  name: booksapp-get
+  namespace: booksapp
+spec:
+  prefix: "/"
+  hostname: '*'
+  method: GET
+  service: booksapp.booksapp:7000
+  rewrite: ""
+---
+apiVersion: x.getambassador.io/v3alpha1
+kind: AmbassadorMapping
+metadata:
+  name: booksapp-postbooks
+  namespace: booksapp
+spec:
+  prefix: "/books"
+  hostname: '*'
+  method: POST
+  service: booksapp.booksapp:7000
+  rewrite: ""
+```
+
+### Test
+`curl -Lki https://localhost:8443`
+
+Or go to your web browser
+
+---
+
+## Base Path and Trim Prefix
+
+Setting the Base path option allows your service to be identified with the base path acting as a prefix.
+
+Setting the trim prefix options will instruct ambassador to trim the prefix before sending the 
+request onto the service.
+
+### CLI Flags
+
+```shell
+kusk ambassador2 -i examples/booksapp/booksapp.yaml \
+--namespace booksapp \
+--host "*" \
+--service.name webapp \
+--service.port 7000 \
+--service.namespace booksapp \
+--path.base /my-app \
+--path.trim_prefix /my-app
+```
+
+### OpenAPI Specification
+
+```yaml
+openapi: 3.0.1
+x-kusk:
+  namespace: booksapp
+  host: "*"
+  service:
+    name: webapp
+    namespace: booksapp
+    port: 7000
+  path:
+    base: /my-app
+    trim_prefix: /my-app
+paths:
+  /:
+    get: {}
+...
+```
+
+### Sample Output
+
+```yaml
+---
+apiVersion: x.getambassador.io/v3alpha1
+kind: AmbassadorMapping
+metadata:
+  name: booksapp
+  namespace: booksapp
+spec:
+  prefix: "/my-app"
+  hostname: '*'
+  service: booksapp.booksapp:7000
+  regex_rewrite:
+    pattern: '/my-app(.*)'
+    substitution: '\1'
+```
+
+### Test
+`curl -Lki https://localhost:8443/my-app/`
+
+Or go to your web browser
+
+**Note** the trailing `/` is mandatory.
+
+---
+
+## Setting timeouts
+
+kusk allows for setting both idle and request timeouts via flags or the x-kusk OpenAPI extension
+
+### CLI Flags
+
+```shell
+kusk ambassador2 -i examples/booksapp/booksapp.yaml \
+--namespace booksapp \
+--host "*" \
+--service.name booksapp \
+--service.port 7000 \
+--service.namespace booksapp \
+--timeouts.idle_timeout 120 \
+--timeouts.request_timeout 120
+```
+
+### OpenAPI Specification
+
+```yaml
+openapi: 3.0.1
+x-kusk:
+  namespace: booksapp
+  host: "*"
+  service:
+    name: webapp
+    namespace: booksapp
+    port: 7000
+  timeouts:
+    request_timeout: 120
+    idle_timeout: 120
+paths:
+  /:
+    get: {}
+...
+```
+
+### Sample Output
+
+```yaml
+---
+apiVersion: x.getambassador.io/v3alpha1
+kind: AmbassadorMapping
+metadata:
+  name: booksapp
+  namespace: booksapp
+spec:
+  prefix: "/"
+  hostname: '*'
+  service: booksapp.booksapp:7000
+  rewrite: ""
+  timeout_ms: 120000
+  idle_timeout_ms: 120000
+```
+
+## CORS
+
+Via the x-kusk extension, you can set cors policies on your resources
+
+kusk ambassador2 -i examples/booksapp/booksapp_extension.yaml
+
+Here we only set the `-i` input flag as the other mandatory options have been set using
+the `x-kusk` extension in the OpenAPI spec file.
+
+### OpenAPI Specification
+
+```yaml
+openapi: 3.0.1
+x-kusk:
+  namespace: booksapp
+  host: "*"
+  service:
+    name: webapp
+    namespace: booksapp
+    port: 7000
+  cors:
+    origins:
+      - http://foo.example
+      - http://bar.example
+    methods:
+      - POST
+      - GET
+      - OPTIONS
+    headers:
+      - Content-Type
+    credentials: true
+    expose_headers:
+      - X-Custom-Header
+    max_age: 86400
+paths:
+  /:
+    get: {}
+...
+```
+
+### Sample Output
+
+```yaml
+---
+apiVersion: x.getambassador.io/v3alpha1
+kind: AmbassadorMapping
+metadata:
+  name: webapp
+  namespace: booksapp
+spec:
+  prefix: "/"
+  hostname: '*'
+  service: webapp.booksapp:7000
+  rewrite: ""
+  cors:
+    origins:
+      - "http://foo.example"
+      - "http://bar.example"
+    methods:
+      - "POST"
+      - "GET"
+      - "OPTIONS"
+    headers:
+      - "Content-Type"
+    exposed_headers:
+      - "X-Custom-Header"
+    credentials: true
+    max_age: "86400"
+```
+
+### Test
+```
+curl -kI -X GET -H "Origin: http://foo.example" --verbose https://localhost:8443/
+```
+
+## Basic Path settings override
+
+For this example, let's assume that one of the paths in the API specification should have different CORS headers than the rest.
+
+### OpenAPI Specification
+
+```yaml
+openapi: 3.0.1
+x-kusk:
+  namespace: booksapp
+  host: "*"
+  service:
+    name: webapp
+    namespace: booksapp
+    port: 7000
+  cors:
+    methods:
+      - POST
+      - GET
+      - OPTIONS
+    headers:
+      - Content-Type
+    credentials: true
+    expose_headers:
+      - X-Custom-Header
+    max_age: 86400
+paths:
+  /:
+    get: {}
+  /books:
+    x-kusk:
+      cors:
+        methods:
+          - POST
+        headers:
+          - Other-Content-Type
+        credentials: true
+        expose_headers:
+          - X-Other-Custom-Header
+        max_age: 120
+    post: {}
+...
+```
+
+### Sample Output
+
+```yaml
+----
+apiVersion: x.getambassador.io/v3alpha1
+kind: AmbassadorMapping
+metadata:
+  name: webapp-get
+  namespace: booksapp
+spec:
+  prefix: "/"
+  hostname: '*'
+  method: GET
+  service: webapp.booksapp:7000
+  rewrite: ""
+  cors:
+    methods:
+      - "POST"
+      - "GET"
+      - "OPTIONS"
+    headers:
+      - "Content-Type"
+    exposed_headers:
+      - "X-Custom-Header"
+    credentials: true
+    max_age: "86400"
+---
+apiVersion: x.getambassador.io/v3alpha1
+kind: AmbassadorMapping
+metadata:
+  name: webapp-postbooks
+  namespace: booksapp
+spec:
+  prefix: "/books"
+  hostname: '*'
+  method: POST
+  service: webapp.booksapp:7000
+  rewrite: ""
+  cors:
+    methods:
+      - "POST"
+    headers:
+      - "Other-Content-Type"
+    exposed_headers:
+      - "X-Other-Custom-Header"
+    credentials: true
+    max_age: "120"
+```
diff --git a/examples/booksapp/booksapp_extension.yaml b/examples/booksapp/booksapp_extension.yaml
index 12a74f9..d320a6a 100644
--- a/examples/booksapp/booksapp_extension.yaml
+++ b/examples/booksapp/booksapp_extension.yaml
@@ -1,6 +1,7 @@
 openapi: 3.0.1
 x-kusk:
   namespace: booksapp
+  host: "*"
   path:
     base: /bookstore
     trim_prefix: /bookstore
diff --git a/generators/ambassador/v2/ambassador.go b/generators/ambassador/v2/ambassador.go
index dda0b60..1005b53 100644
--- a/generators/ambassador/v2/ambassador.go
+++ b/generators/ambassador/v2/ambassador.go
@@ -1,6 +1,8 @@
 package v2
 
 import (
+	"errors"
+	"strings"
 	"text/template"
 
 	"github.com/getkin/kin-openapi/openapi3"
@@ -18,7 +20,9 @@ var (
 
 func init() {
 	mappingTemplate = template.New("mapping")
-	mappingTemplate = template.Must(mappingTemplate.Parse(mappingTemplateRaw))
+	mappingTemplate = template.Must(mappingTemplate.Funcs(template.FuncMap{
+		"split": split,
+	}).Parse(mappingTemplateRaw))
 
 	rateLimitTemplate = template.New("rateLimit")
 	rateLimitTemplate = template.Must(rateLimitTemplate.Parse(ambassador.RateLimitTemplateRaw))
@@ -58,5 +62,17 @@ func (g *Generator) Flags() *pflag.FlagSet {
 }
 
 func (g *Generator) Generate(opts *options.Options, spec *openapi3.T) (string, error) {
+	if opts.Host == "" {
+		return "", errors.New("host option is required for ambassador 2.0")
+	}
 	return g.abstractGenerator.Generate(opts, spec)
 }
+
+// template func for splitting comma separated strings into an array for iteration
+func split(s string, d string) []string {
+	if s == "" {
+		return []string{}
+	}
+
+	return strings.Split(s, d)
+}
diff --git a/generators/ambassador/v2/ambassador_test.go b/generators/ambassador/v2/ambassador_test.go
index 57ca3cd..8124cf0 100644
--- a/generators/ambassador/v2/ambassador_test.go
+++ b/generators/ambassador/v2/ambassador_test.go
@@ -27,6 +27,7 @@ func TestAmbassador(t *testing.T) {
 		{
 			name: "basic",
 			options: options.Options{
+				Host:      "*",
 				Namespace: "default",
 				Service: options.ServiceOptions{
 					Namespace: "default",
@@ -45,6 +46,7 @@ info:
   version: 1.0.5
 x-kusk:
   namespace: notdefault
+  host: "*"
   service:
     name: petstore
 paths:
@@ -64,6 +66,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/pet"
+  hostname: '*'
   method: PUT
   service: petstore.default:80
   rewrite: ""
@@ -73,6 +76,7 @@ spec:
 			name: "basic-json",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -113,6 +117,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/pet"
+  hostname: '*'
   method: PUT
   service: petstore.default:80
   rewrite: ""
@@ -122,6 +127,7 @@ spec:
 			name: "basic-namespace",
 			options: options.Options{
 				Namespace: "amb",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -154,6 +160,7 @@ metadata:
   namespace: amb
 spec:
   prefix: "/pet"
+  hostname: '*'
   method: PUT
   service: petstore.default:80
   rewrite: ""
@@ -163,6 +170,7 @@ spec:
 			name: "parameter",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -204,6 +212,7 @@ metadata:
 spec:
   prefix: "/pet/([a-zA-Z0-9]*)/uploadImage"
   prefix_regex: true
+  hostname: '*'
   method: POST
   service: petstore.default:80
   rewrite: ""
@@ -213,6 +222,7 @@ spec:
 			name: "empty-operationId",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -253,6 +263,7 @@ metadata:
 spec:
   prefix: "/pet/([a-zA-Z0-9]*)/uploadImage"
   prefix_regex: true
+  hostname: '*'
   method: POST
   service: petstore.default:80
   rewrite: ""
@@ -262,6 +273,7 @@ spec:
 			name: "basepath",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -302,6 +314,7 @@ metadata:
 spec:
   prefix: "/api/v3/pet/([a-zA-Z0-9]*)/uploadImage"
   prefix_regex: true
+  hostname: '*'
   method: POST
   service: petstore.default:80
   rewrite: ""
@@ -311,6 +324,7 @@ spec:
 			name: "basepath-rootonly",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -356,6 +370,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/api/v3"
+  hostname: '*'
   service: petstore.default:80
   rewrite: ""
 `,
@@ -364,6 +379,7 @@ spec:
 			name: "basepath-trimprefix",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -404,6 +420,7 @@ metadata:
 spec:
   prefix: "/petstore/api/v3/pet/([a-zA-Z0-9]*)/uploadImage"
   prefix_regex: true
+  hostname: '*'
   method: POST
   service: petstore.default:80
   regex_rewrite:
@@ -415,6 +432,7 @@ spec:
 			name: "swagger-yaml",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -517,6 +535,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/pets"
+  hostname: '*'
   method: POST
   service: petstore.default:80
   rewrite: ""
@@ -528,6 +547,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/pets"
+  hostname: '*'
   method: GET
   service: petstore.default:80
   rewrite: ""
@@ -540,6 +560,7 @@ metadata:
 spec:
   prefix: "/pets/([a-zA-Z0-9]*)"
   prefix_regex: true
+  hostname: '*'
   method: GET
   service: petstore.default:80
   rewrite: ""
@@ -549,6 +570,7 @@ spec:
 			name: "swagger-json",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -694,6 +716,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/pets"
+  hostname: '*'
   method: POST
   service: petstore.default:80
   rewrite: ""
@@ -705,6 +728,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/pets"
+  hostname: '*'
   method: GET
   service: petstore.default:80
   rewrite: ""
@@ -717,6 +741,7 @@ metadata:
 spec:
   prefix: "/pets/([a-zA-Z0-9]*)"
   prefix_regex: true
+  hostname: '*'
   method: GET
   service: petstore.default:80
   rewrite: ""
@@ -726,6 +751,7 @@ spec:
 			name: "port specified",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -759,6 +785,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/pet"
+  hostname: '*'
   method: PUT
   service: petstore.default:443
   rewrite: ""
@@ -768,6 +795,7 @@ spec:
 			name: "port 0 specified",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -801,6 +829,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/pet"
+  hostname: '*'
   method: PUT
   service: petstore.default:80
   rewrite: ""
@@ -810,6 +839,7 @@ spec:
 			name: "path-disabled",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -858,6 +888,7 @@ metadata:
 spec:
   prefix: "/pet/([a-zA-Z0-9]*)/uploadImage"
   prefix_regex: true
+  hostname: '*'
   method: POST
   service: petstore.default:80
   rewrite: ""
@@ -867,6 +898,7 @@ spec:
 			name: "operation-disabled",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -915,6 +947,7 @@ metadata:
 spec:
   prefix: "/pet/([a-zA-Z0-9]*)/uploadImage"
   prefix_regex: true
+  hostname: '*'
   method: POST
   service: petstore.default:80
   rewrite: ""
@@ -924,6 +957,7 @@ spec:
 			name: "cors-global",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -972,13 +1006,22 @@ metadata:
   namespace: default
 spec:
   prefix: "/"
+  hostname: '*'
   service: petstore.default:80
   rewrite: ""
   cors:
-    origins: http://foo.example,http://bar.example
-    methods: POST,GET,OPTIONS
-    headers: Content-Type
-    exposed_headers: X-Custom-Header,X-Other-Custom-Header
+    origins:
+      - "http://foo.example"
+      - "http://bar.example"
+    methods:
+      - "POST"
+      - "GET"
+      - "OPTIONS"
+    headers:
+      - "Content-Type"
+    exposed_headers:
+      - "X-Custom-Header"
+      - "X-Other-Custom-Header"
     credentials: false
     max_age: "120"
 `,
@@ -987,6 +1030,7 @@ spec:
 			name: "cors-path-override",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -1050,14 +1094,20 @@ metadata:
   namespace: default
 spec:
   prefix: "/pet"
+  hostname: '*'
   method: PUT
   service: petstore.default:80
   rewrite: ""
   cors:
-    origins: http://bar.example
-    methods: POST
-    headers: Content-Type
-    exposed_headers: X-Custom-Header,X-Other-Custom-Header
+    origins:
+      - "http://bar.example"
+    methods:
+      - "POST"
+    headers:
+      - "Content-Type"
+    exposed_headers:
+      - "X-Custom-Header"
+      - "X-Other-Custom-Header"
     credentials: false
     max_age: "240"
   timeout_ms: 5000
@@ -1070,14 +1120,23 @@ metadata:
 spec:
   prefix: "/pet/([a-zA-Z0-9]*)/uploadImage"
   prefix_regex: true
+  hostname: '*'
   method: POST
   service: petstore.default:80
   rewrite: ""
   cors:
-    origins: http://foo.example,http://bar.example
-    methods: POST,GET,OPTIONS
-    headers: Content-Type
-    exposed_headers: X-Custom-Header,X-Other-Custom-Header
+    origins:
+      - "http://foo.example"
+      - "http://bar.example"
+    methods:
+      - "POST"
+      - "GET"
+      - "OPTIONS"
+    headers:
+      - "Content-Type"
+    exposed_headers:
+      - "X-Custom-Header"
+      - "X-Other-Custom-Header"
     credentials: false
     max_age: "120"
   timeout_ms: 5000
@@ -1087,6 +1146,7 @@ spec:
 			name: "timeouts-global",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -1131,6 +1191,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/"
+  hostname: '*'
   service: petstore.default:80
   rewrite: ""
   timeout_ms: 42000
@@ -1141,6 +1202,7 @@ spec:
 			name: "timeouts-path-override",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -1193,6 +1255,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/pet"
+  hostname: '*'
   method: PUT
   service: petstore.default:80
   rewrite: ""
@@ -1207,6 +1270,7 @@ metadata:
 spec:
   prefix: "/pet/([a-zA-Z0-9]*)/uploadImage"
   prefix_regex: true
+  hostname: '*'
   method: POST
   service: petstore.default:80
   rewrite: ""
@@ -1251,7 +1315,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/"
-  host: somehost.io
+  hostname: 'somehost.io'
   service: petstore.default:80
   rewrite: ""
 `,
@@ -1260,6 +1324,7 @@ spec:
 			name: "rate-limit-global",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -1304,6 +1369,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/"
+  hostname: '*'
   service: petstore.default:80
   rewrite: ""
   labels:
@@ -1332,6 +1398,7 @@ spec:
 			name: "rate-limit-path-override",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -1384,6 +1451,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/pet"
+  hostname: '*'
   method: PUT
   service: petstore.default:80
   rewrite: ""
@@ -1402,6 +1470,7 @@ metadata:
 spec:
   prefix: "/pet/([a-zA-Z0-9]*)/uploadImage"
   prefix_regex: true
+  hostname: '*'
   method: POST
   service: petstore.default:80
   rewrite: ""
@@ -1445,6 +1514,7 @@ spec:
 			name: "rate-limit-group",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -1499,6 +1569,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/pet"
+  hostname: '*'
   method: PUT
   service: petstore.default:80
   rewrite: ""
@@ -1517,6 +1588,7 @@ metadata:
 spec:
   prefix: "/pet/([a-zA-Z0-9]*)/uploadImage"
   prefix_regex: true
+  hostname: '*'
   method: POST
   service: petstore.default:80
   rewrite: ""
@@ -1547,6 +1619,7 @@ spec:
 			options: options.Options{
 				Disabled:  true,
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -1571,6 +1644,7 @@ paths:
 			name: "path disabled, operation enabled",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -1609,6 +1683,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/"
+  hostname: '*'
   method: GET
   service: petstore.default:80
   rewrite: ""
@@ -1618,6 +1693,7 @@ spec:
 			name: "path disabled not specified operation disabled specified",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -1660,6 +1736,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/"
+  hostname: '*'
   method: PATCH
   service: petstore.default:80
   rewrite: ""
@@ -1671,6 +1748,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/"
+  hostname: '*'
   method: POST
   service: petstore.default:80
   rewrite: ""
@@ -1680,6 +1758,7 @@ spec:
 			name: "path disabled not specified operation disabled specified operation enabled not specified",
 			options: options.Options{
 				Namespace: "default",
+				Host:      "*",
 				Service: options.ServiceOptions{
 					Namespace: "default",
 					Name:      "petstore",
@@ -1712,6 +1791,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/"
+  hostname: '*'
   method: PATCH
   service: petstore.default:80
   rewrite: ""
@@ -1723,6 +1803,7 @@ metadata:
   namespace: default
 spec:
   prefix: "/"
+  hostname: '*'
   method: POST
   service: petstore.default:80
   rewrite: ""
diff --git a/generators/ambassador/v2/mapping_template.go b/generators/ambassador/v2/mapping_template.go
index faf067a..459bc69 100644
--- a/generators/ambassador/v2/mapping_template.go
+++ b/generators/ambassador/v2/mapping_template.go
@@ -15,7 +15,7 @@ spec:
   {{end}}
 
   {{ if .Host}}
-  host: {{.Host}}
+  hostname: '{{.Host}}'
   {{end}}
 
   {{if .Method}}
@@ -34,10 +34,38 @@ spec:
 
   {{if .CORSEnabled}}
   cors:
-    origins: {{.CORS.Origins}}
-    methods: {{.CORS.Methods}}
-    headers: {{.CORS.Headers}}
-    exposed_headers: {{.CORS.ExposedHeaders}}
+    {{ $origins := split .CORS.Origins "," }}
+    {{ if gt (len $origins) 0 }}
+    origins:
+    {{ range $val := $origins }}
+      - "{{ $val }}"
+    {{ end }}
+    {{ end }}
+
+    {{ $methods := split .CORS.Methods "," }}
+    {{ if gt (len $methods) 0 }}
+    methods:
+    {{ range $val := $methods }}
+      - "{{ $val }}"
+    {{ end }}
+    {{ end }}
+
+    {{ $headers := split .CORS.Headers "," }}
+    {{ if gt (len $methods) 0 }}
+    headers:
+    {{ range $val := $headers }}
+      - "{{ $val }}"
+    {{ end }}
+    {{ end }}
+
+    {{ $exposedHeaders := split .CORS.ExposedHeaders "," }}
+    {{ if gt (len $exposedHeaders) 0 }}
+    exposed_headers:
+    {{ range $val := $exposedHeaders }}
+      - "{{ $val }}"
+    {{ end }}
+    {{ end }}
+
     credentials: {{.CORS.Credentials}}
     max_age: "{{.CORS.MaxAge}}"
   {{end}}