Add v2 server config support with plugin URIs

Closes #3210

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

services/server/config/config.go

@@ -17,13 +17,18 @@
 package config
 
 import (
+	"strings"
+
 	"github.com/BurntSushi/toml"
 	"github.com/containerd/containerd/errdefs"
+	"github.com/containerd/containerd/plugin"
 	"github.com/pkg/errors"
 )
 
 // Config provides containerd configuration data for the server
 type Config struct {
+	// Version of the config file
+	Version int `toml:"version"`
 	// Root is the path to a directory where containerd will store persistent data
 	Root string `toml:"root"`
 	// State is the path to a directory where containerd will store transient data
@@ -54,6 +59,42 @@ type Config struct {
 	md toml.MetaData
 }
 
+// GetVersion returns the config file's version
+func (c *Config) GetVersion() int {
+	if c.Version == 0 {
+		return 1
+	}
+	return c.Version
+}
+
+// ValidateV2 validates the config for a v2 file
+func (c *Config) ValidateV2() error {
+	if c.GetVersion() != 2 {
+		return nil
+	}
+	for _, p := range c.DisabledPlugins {
+		if len(strings.Split(p, ".")) < 4 {
+			return errors.Errorf("invalid disabled plugin URI %q expect io.containerd.x.vx", p)
+		}
+	}
+	for _, p := range c.RequiredPlugins {
+		if len(strings.Split(p, ".")) < 4 {
+			return errors.Errorf("invalid required plugin URI %q expect io.containerd.x.vx", p)
+		}
+	}
+	for p := range c.Plugins {
+		if len(strings.Split(p, ".")) < 4 {
+			return errors.Errorf("invalid plugin key URI %q expect io.containerd.x.vx", p)
+		}
+	}
+	for p := range c.ProxyPlugins {
+		if len(strings.Split(p, ".")) < 4 {
+			return errors.Errorf("invalid proxy plugin key URI %q expect io.containerd.x.vx", p)
+		}
+	}
+	return nil
+}
+
 // GRPCConfig provides GRPC configuration for the socket
 type GRPCConfig struct {
 	Address        string `toml:"address"`
@@ -130,15 +171,19 @@ func (bc *BoltConfig) Validate() error {
 }
 
 // Decode unmarshals a plugin specific configuration by plugin id
-func (c *Config) Decode(id string, v interface{}) (interface{}, error) {
+func (c *Config) Decode(p *plugin.Registration) (interface{}, error) {
+	id := p.URI()
+	if c.GetVersion() == 1 {
+		id = p.ID
+	}
 	data, ok := c.Plugins[id]
 	if !ok {
-		return v, nil
+		return p.Config, nil
 	}
-	if err := c.md.PrimitiveDecode(data, v); err != nil {
+	if err := c.md.PrimitiveDecode(data, p.Config); err != nil {
 		return nil, err
 	}
-	return v, nil
+	return p.Config, nil
 }
 
 // LoadConfig loads the containerd server config from the provided path
@@ -151,5 +196,29 @@ func LoadConfig(path string, v *Config) error {
 		return err
 	}
 	v.md = md
-	return nil
+	return v.ValidateV2()
+}
+
+// V1DisabledFilter matches based on ID
+func V1DisabledFilter(list []string) plugin.DisableFilter {
+	set := make(map[string]struct{}, len(list))
+	for _, l := range list {
+		set[l] = struct{}{}
+	}
+	return func(r *plugin.Registration) bool {
+		_, ok := set[r.ID]
+		return ok
+	}
+}
+
+// V2DisabledFilter matches based on URI
+func V2DisabledFilter(list []string) plugin.DisableFilter {
+	set := make(map[string]struct{}, len(list))
+	for _, l := range list {
+		set[l] = struct{}{}
+	}
+	return func(r *plugin.Registration) bool {
+		_, ok := set[r.URI()]
+		return ok
+	}
 }