datasource/vmware: introduce guestinfo.coreos.config.url

allow use of a URL instead of an inline document.
Inline document takes precedence.

Documentation/vmware-backdoor.md

@@ -19,6 +19,7 @@ are supported by coreos-cloudinit:
 | `dns.server.<x>`                      | `IP address`                    |
 | `coreos.config.data`                  | `string`                        |
 | `coreos.config.data.encoding`         | `{"", "base64", "gzip+base64"}` |
+| `coreos.config.url`                   | `URL`                           |
 
 Note: "n", "m", "l", and "x" are 0-indexed, incrementing integers. The
 identifier for the interfaces does not correspond to anything outside of this

datasource/vmware/vmware.go

@@ -21,17 +21,25 @@ import (
 
 	"github.com/coreos/coreos-cloudinit/config"
 	"github.com/coreos/coreos-cloudinit/datasource"
+	"github.com/coreos/coreos-cloudinit/pkg"
 
 	"github.com/coreos/coreos-cloudinit/Godeps/_workspace/src/github.com/sigma/vmw-guestinfo/rpcvmx"
 	"github.com/coreos/coreos-cloudinit/Godeps/_workspace/src/github.com/sigma/vmw-guestinfo/vmcheck"
 )
 
+type readConfigFunction func(key string) (string, error)
+type urlDownloadFunction func(url string) ([]byte, error)
+
 type vmware struct {
-	readConfig func(key string) (string, error)
+	readConfig  readConfigFunction
+	urlDownload urlDownloadFunction
 }
 
 func NewDatasource() *vmware {
-	return &vmware{readConfig}
+	return &vmware{
+		readConfig:  readConfig,
+		urlDownload: urlDownload,
+	}
 }
 
 func (v vmware) IsAvailable() bool {
@@ -133,6 +141,22 @@ func (v vmware) FetchUserdata() ([]byte, error) {
 		return nil, err
 	}
 
+	// Try to fallback to url if no explicit data
+	if data == "" {
+		url, err := v.readConfig("coreos.config.url")
+		if err != nil {
+			return nil, err
+		}
+
+		if url != "" {
+			rawData, err := v.urlDownload(url)
+			if err != nil {
+				return nil, err
+			}
+			data = string(rawData)
+		}
+	}
+
 	if encoding != "" {
 		return config.DecodeContent(data, encoding)
 	}
@@ -143,6 +167,11 @@ func (v vmware) Type() string {
 	return "vmware"
 }
 
+func urlDownload(url string) ([]byte, error) {
+	client := pkg.NewHttpClient()
+	return client.GetRetry(url)
+}
+
 func readConfig(key string) (string, error) {
 	data, err := rpcvmx.NewConfig().GetString(key, "")
 	if err == nil {

datasource/vmware/vmware_test.go

@@ -115,7 +115,7 @@ func TestFetchMetadata(t *testing.T) {
 	}
 
 	for i, tt := range tests {
-		v := vmware{tt.variables.ReadConfig}
+		v := vmware{readConfig: tt.variables.ReadConfig}
 		metadata, err := v.FetchMetadata()
 		if !reflect.DeepEqual(tt.err, err) {
 			t.Errorf("bad error (#%d): want %v, got %v", i, tt.err, err)
@@ -165,10 +165,37 @@ func TestFetchUserdata(t *testing.T) {
 			},
 			err: errors.New(`Unsupported encoding "test encoding"`),
 		},
+		{
+			variables: map[string]string{
+				"coreos.config.url": "http://good.example.com",
+			},
+			userdata: "test config",
+		},
+		{
+			variables: map[string]string{
+				"coreos.config.url": "http://bad.example.com",
+			},
+			err: errors.New("Not found"),
+		},
+	}
+
+	var downloader urlDownloadFunction = func(url string) ([]byte, error) {
+		mapping := map[string]struct {
+			data []byte
+			err  error
+		}{
+			"http://good.example.com": {[]byte("test config"), nil},
+			"http://bad.example.com":  {nil, errors.New("Not found")},
+		}
+		val := mapping[url]
+		return val.data, val.err
 	}
 
 	for i, tt := range tests {
-		v := vmware{tt.variables.ReadConfig}
+		v := vmware{
+			readConfig:  tt.variables.ReadConfig,
+			urlDownload: downloader,
+		}
 		userdata, err := v.FetchUserdata()
 		if !reflect.DeepEqual(tt.err, err) {
 			t.Errorf("bad error (#%d): want %v, got %v", i, nil, err)
@@ -181,7 +208,7 @@ func TestFetchUserdata(t *testing.T) {
 
 func TestFetchUserdataError(t *testing.T) {
 	testErr := errors.New("test error")
-	_, err := vmware{func(_ string) (string, error) { return "", testErr }}.FetchUserdata()
+	_, err := vmware{readConfig: func(_ string) (string, error) { return "", testErr }}.FetchUserdata()
 
 	if testErr != err {
 		t.Errorf("bad error: want %v, got %v", testErr, err)