Fix backwards compat with v2 containerd configs

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

cmd/containerd/command/config.go

@@ -50,6 +50,11 @@ var configCommand = cli.Command{
 				config := &Config{
 					Config: defaultConfig(),
 				}
+				// for the time being, keep the defaultConfig's version set at 1 so that
+				// when a config without a version is loaded from disk and has no version
+				// set, we assume it's a v1 config.  But when generating new configs via
+				// this command, generate the v2 config
+				config.Config.Version = 2
 				plugins, err := server.LoadPlugins(gocontext.Background(), config.Config)
 				if err != nil {
 					return err

cmd/containerd/command/config_linux.go

@@ -23,7 +23,7 @@ import (
 
 func defaultConfig() *srvconfig.Config {
 	return &srvconfig.Config{
-		Version: 2,
+		Version: 1,
 		Root:    defaults.DefaultRootDir,
 		State:   defaults.DefaultStateDir,
 		GRPC: srvconfig.GRPCConfig{

cmd/containerd/command/config_unsupported.go

@@ -25,7 +25,7 @@ import (
 
 func defaultConfig() *srvconfig.Config {
 	return &srvconfig.Config{
-		Version: 2,
+		Version: 1,
 		Root:    defaults.DefaultRootDir,
 		State:   defaults.DefaultStateDir,
 		GRPC: srvconfig.GRPCConfig{

cmd/containerd/command/config_windows.go

@@ -23,7 +23,7 @@ import (
 
 func defaultConfig() *srvconfig.Config {
 	return &srvconfig.Config{
-		Version: 2,
+		Version: 1,
 		Root:    defaults.DefaultRootDir,
 		State:   defaults.DefaultStateDir,
 		GRPC: srvconfig.GRPCConfig{