fix an api-gateway bug (#177)

* fix a api-gateway bug related to cors #174

- enable query params to http body tranform for OPTIONS method, previous only for GET
- automatically add OPTIONS method for cors-enabled api
- will not add OPTIONS method while register the corresponding kong cors plugin, this is a hard requirement from kong, as listed in the issue too.

Also: for convenience of local dev: print Kong https and http port in dispatch install output
which looks like this:
```
$ dispatch install --file config.yaml --charts-dir charts
...
Installing charts/kong helm chart
Installing charts/openfaas helm chart
Installing charts/dispatch helm chart
dispatch api-gateway is running at http port 32519 and https port 31841
Config file written to: /Users/xueyangh/.dispatch/config.json
...

note: the line for api-gateway port is only printed only when kong is deployed at nodePort mode

```

* import api-gateway ports into ~/.dispatch/config.json

* re-trigger e2e

* revert changes in e2e

Author: seanhuxy

charts/kong/dispatch-transformer/handler.lua

@@ -60,7 +60,9 @@ local function transform_method(conf)
 
     -- for GET to POST transform:
     -- tranform query strings into the req body
-    if org_http_method == "GET" and rpl_http_method == "POST" then
+    -- hack: cors sends OPTIONS as a preflight query
+    -- hence, we also need to support OPTIONS
+    if (org_http_method == "GET" or org_http_method == "OPTIONS") and rpl_http_method == "POST" then
       local body = {}
       local args = ngx.req.get_uri_args()
       for key, val in pairs(args) do

e2e/tests/variables.bash

@@ -1,7 +1,6 @@
 #!/bin/bash
 
 ### COMMON VARIABLES ###
-
 : ${DOCKER_REGISTRY:="vmware"}
 : ${BASE_IMAGE_PYTHON3:="dispatch-openfaas-python-base:0.0.5-dev1"}
 : ${BASE_IMAGE_NODEJS6:="dispatch-openfaas-nodejs6-base:0.0.3-dev1"}

pkg/api-manager/gateway/kong/kong.go

@@ -116,6 +116,12 @@ func (k *Client) apiEntityToKong(entity *gateway.API) *API {
 	} else {
 		a.HTTPSOnly = false
 	}
+	if entity.CORS == true {
+		// note: OPTIONS is a CORS preflight request
+		// it is added by dispatch automatically
+		// users should not add them mannually
+		a.Methods = append(a.Methods, "OPTIONS")
+	}
 	return &a
 }
 
@@ -237,7 +243,9 @@ func (k *Client) AddAPI(entity *gateway.API) (*gateway.API, error) {
 			Config: map[string]interface{}{
 				// TODO: '*' for now, should be able to configure the origin later
 				"config.origins": "*",
-				"config.methods": strings.Join(a.Methods, ","),
+				// Workaround: fix https://github.com/vmware/dispatch/issues/174
+				// OPTIIONS is not an allowed method in kong cors plugin
+				"config.methods": strings.Join(entity.Methods, ","),
 			},
 		}
 		err := k.updatePluginByName(a.Name, corsPlugin.Name, &corsPlugin)
@@ -290,7 +298,9 @@ func (k *Client) UpdateAPI(name string, entity *gateway.API) (*gateway.API, erro
 			Config: map[string]interface{}{
 				// TODO: '*' for now, should be able to configure the origin later
 				"config.origins": "*",
-				"config.methods": strings.Join(a.Methods, ","),
+				// Workaround: fix https://github.com/vmware/dispatch/issues/174
+				// OPTIIONS is not an allowed method in kong cors plugin
+				"config.methods": strings.Join(entity.Methods, ","),
 			},
 		}
 		err := k.updatePluginByName(name, "cors", &corsPlugin)

pkg/dispatchcli/cmd/cmd.go

@@ -26,6 +26,8 @@ var dispatchConfig struct {
 	SkipAuth     bool   `json:"skipauth"`
 	Insecure     bool   `json:"insecure"`
 	Json         bool   `json:"-"`
+	APIHTTPSPort int    `json:"api-https-port"`
+	APIHTTPPort  int    `json:"api-http-port"`
 }
 
 var validResources = i18n.T(`Valid resource types include:

pkg/dispatchcli/cmd/install.go

@@ -160,7 +160,7 @@ func installCert(out, errOut io.Writer, configDir, namespace, domain string, tls
 	var key, cert string
 	if tls.CertFile != "" {
 		if tls.PrivateKey == "" {
-			return errors.New("Error installing certificate: missing private key for the tls cert.")
+			return errors.New("error installing certificate: missing private key for the tls cert")
 		}
 		key = tls.PrivateKey
 		cert = tls.CertFile
@@ -306,6 +306,10 @@ func writeConfig(out, errOut io.Writer, configDir string, config *installConfig)
 	if err != nil {
 		return err
 	}
+	if config.APIGateway.ServiceType == "NodePort" {
+		fmt.Fprintf(out, "dispatch api-gateway is running at http port: %d and https port: %d\n",
+			dispatchConfig.APIHTTPPort, dispatchConfig.APIHTTPSPort)
+	}
 	if installDryRun {
 		fmt.Fprintf(out, "Copy the following to your %s/config.json\n", configDir)
 		fmt.Fprintln(out, string(b))
@@ -486,17 +490,15 @@ func runInstall(out, errOut io.Writer, cmd *cobra.Command, args []string) error
 		if config.APIGateway.ServiceType == "NodePort" {
 
 			service := fmt.Sprintf("%s-kongproxy", config.APIGateway.Chart.Release)
-			httpsPort, err := getK8sServiceNodePort(service, config.APIGateway.Chart.Namespace, true)
+			dispatchConfig.APIHTTPSPort, err = getK8sServiceNodePort(service, config.APIGateway.Chart.Namespace, true)
 			if err != nil {
 				return err
 			}
-			httpPort, err := getK8sServiceNodePort(service, config.APIGateway.Chart.Namespace, false)
+			dispatchConfig.APIHTTPPort, err = getK8sServiceNodePort(service, config.APIGateway.Chart.Namespace, false)
 			if err != nil {
 				return err
 			}
 
-			os.Setenv("API_GATEWAY_HTTPS_PORT", strconv.Itoa(httpsPort))
-			os.Setenv("API_GATEWAY_HTTP_PORT", strconv.Itoa(httpPort))
 		}
 	}