metadata: simplify merging of metadata

Add an internal field for CloudConfig to make it easier to distinguish.
Instead of creating two CloudConfigs and merging them, just merge the
metadata into the existing CloudConfig.

initialize/config.go

@@ -170,9 +170,9 @@ func Apply(cfg config.CloudConfig, env *Environment) error {
 		var err error
 		switch env.NetconfType() {
 		case "debian":
-			interfaces, err = network.ProcessDebianNetconf(cfg.NetworkConfig)
+			interfaces, err = network.ProcessDebianNetconf(cfg.Internal.NetworkConfig)
 		case "digitalocean":
-			interfaces, err = network.ProcessDigitalOceanNetconf(cfg.NetworkConfig)
+			interfaces, err = network.ProcessDigitalOceanNetconf(cfg.Internal.NetworkConfig)
 		default:
 			err = fmt.Errorf("Unsupported network config format %q", env.NetconfType())
 		}

initialize/meta_data.go

@@ -17,25 +17,9 @@ package initialize
 import (
 	"sort"
 
-	"github.com/coreos/coreos-cloudinit/config"
 	"github.com/coreos/coreos-cloudinit/datasource"
 )
 
-// ParseMetaData parses a JSON blob in the OpenStack metadata service format,
-// and converts it to a partially hydrated CloudConfig.
-func ParseMetaData(metadata datasource.Metadata) *config.CloudConfig {
-	var cfg config.CloudConfig
-	if len(metadata.SSHPublicKeys) > 0 {
-		cfg.SSHAuthorizedKeys = make([]string, 0, len(metadata.SSHPublicKeys))
-		for _, name := range sortedKeys(metadata.SSHPublicKeys) {
-			cfg.SSHAuthorizedKeys = append(cfg.SSHAuthorizedKeys, metadata.SSHPublicKeys[name])
-		}
-	}
-	cfg.Hostname = metadata.Hostname
-	cfg.NetworkConfigPath = metadata.NetworkConfigPath
-	return &cfg
-}
-
 // ExtractIPsFromMetaData parses a JSON blob in the OpenStack metadata service
 // format and returns a substitution map possibly containing private_ipv4,
 // public_ipv4, private_ipv6, and public_ipv6 addresses.