datasource: Move datasources into their own packages.

datasource/url/url.go

@@ -0,0 +1,38 @@
+package url
+
+import "github.com/coreos/coreos-cloudinit/pkg"
+
+type remoteFile struct {
+	url string
+}
+
+func NewDatasource(url string) *remoteFile {
+	return &remoteFile{url}
+}
+
+func (f *remoteFile) IsAvailable() bool {
+	client := pkg.NewHttpClient()
+	_, err := client.Get(f.url)
+	return (err == nil)
+}
+
+func (f *remoteFile) AvailabilityChanges() bool {
+	return true
+}
+
+func (f *remoteFile) ConfigRoot() string {
+	return ""
+}
+
+func (f *remoteFile) FetchMetadata() ([]byte, error) {
+	return []byte{}, nil
+}
+
+func (f *remoteFile) FetchUserdata() ([]byte, error) {
+	client := pkg.NewHttpClient()
+	return client.GetRetry(f.url)
+}
+
+func (f *remoteFile) Type() string {
+	return "url"
+}