Merge pull request #3574 from mxpv/cfg

Support config imports

services/server/config/config.go

@@ -17,12 +17,15 @@
 package config
 
 import (
+	"path/filepath"
 	"strings"
 
 	"github.com/BurntSushi/toml"
+	"github.com/imdario/mergo"
+	"github.com/pkg/errors"
+
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/plugin"
-	"github.com/pkg/errors"
 )
 
 // Config provides containerd configuration data for the server
@@ -59,16 +62,14 @@ type Config struct {
 	ProxyPlugins map[string]ProxyPlugin `toml:"proxy_plugins"`
 	// Timeouts specified as a duration
 	Timeouts map[string]string `toml:"timeouts"`
+	// Imports are additional file path list to config files that can overwrite main config file fields
+	Imports []string `toml:"imports"`
 
-	StreamProcessors []StreamProcessor `toml:"stream_processors"`
-
-	md toml.MetaData
+	StreamProcessors map[string]StreamProcessor `toml:"stream_processors"`
 }
 
 // StreamProcessor provides configuration for diff content processors
 type StreamProcessor struct {
-	// ID of the processor, also used to fetch the specific payload
-	ID string `toml:"id"`
 	// Accepts specific media-types
 	Accepts []string `toml:"accepts"`
 	// Returns the media-type
@@ -202,23 +203,125 @@ func (c *Config) Decode(p *plugin.Registration) (interface{}, error) {
 	if !ok {
 		return p.Config, nil
 	}
-	if err := c.md.PrimitiveDecode(data, p.Config); err != nil {
+	if err := toml.PrimitiveDecode(data, p.Config); err != nil {
 		return nil, err
 	}
 	return p.Config, nil
 }
 
 // LoadConfig loads the containerd server config from the provided path
-func LoadConfig(path string, v *Config) error {
-	if v == nil {
-		return errors.Wrapf(errdefs.ErrInvalidArgument, "argument v must not be nil")
+func LoadConfig(path string, out *Config) error {
+	if out == nil {
+		return errors.Wrapf(errdefs.ErrInvalidArgument, "argument out must not be nil")
 	}
-	md, err := toml.DecodeFile(path, v)
+
+	var (
+		loaded  = map[string]bool{}
+		pending = []string{path}
+	)
+
+	for len(pending) > 0 {
+		path, pending = pending[0], pending[1:]
+
+		// Check if a file at the given path already loaded to prevent circular imports
+		if _, ok := loaded[path]; ok {
+			continue
+		}
+
+		config, err := loadConfigFile(path)
+		if err != nil {
+			return err
+		}
+
+		if err := mergeConfig(out, config); err != nil {
+			return err
+		}
+
+		imports, err := resolveImports(path, config.Imports)
+		if err != nil {
+			return err
+		}
+
+		loaded[path] = true
+		pending = append(pending, imports...)
+	}
+
+	// Fix up the list of config files loaded
+	out.Imports = []string{}
+	for path := range loaded {
+		out.Imports = append(out.Imports, path)
+	}
+
+	return out.ValidateV2()
+}
+
+// loadConfigFile decodes a TOML file at the given path
+func loadConfigFile(path string) (*Config, error) {
+	config := &Config{}
+	_, err := toml.DecodeFile(path, &config)
+	if err != nil {
+		return nil, err
+	}
+	return config, nil
+}
+
+// resolveImports resolves import strings list to absolute paths list:
+// - If path contains *, glob pattern matching applied
+// - Non abs path is relative to parent config file directory
+// - Abs paths returned as is
+func resolveImports(parent string, imports []string) ([]string, error) {
+	var out []string
+
+	for _, path := range imports {
+		if strings.Contains(path, "*") {
+			matches, err := filepath.Glob(path)
+			if err != nil {
+				return nil, err
+			}
+
+			out = append(out, matches...)
+		} else {
+			path = filepath.Clean(path)
+			if !filepath.IsAbs(path) {
+				path = filepath.Join(filepath.Dir(parent), path)
+			}
+
+			out = append(out, path)
+		}
+	}
+
+	return out, nil
+}
+
+// mergeConfig merges Config structs with the following rules:
+// 'to'         'from'      'result'
+// ""           "value"     "value"
+// "value"      ""          "value"
+// 1            0           1
+// 0            1           1
+// []{"1"}      []{"2"}     []{"1","2"}
+// []{"1"}      []{}        []{"1"}
+// Maps merged by keys, but values are replaced entirely.
+func mergeConfig(to, from *Config) error {
+	err := mergo.Merge(to, from, mergo.WithOverride, mergo.WithAppendSlice)
 	if err != nil {
 		return err
 	}
-	v.md = md
-	return v.ValidateV2()
+
+	// Replace entire sections instead of merging map's values.
+	for k, v := range from.Plugins {
+		to.Plugins[k] = v
+	}
+
+	for k, v := range from.StreamProcessors {
+		to.StreamProcessors[k] = v
+	}
+
+	for k, v := range from.ProxyPlugins {
+		to.ProxyPlugins[k] = v
+	}
+
+	return nil
 }
 
 // V1DisabledFilter matches based on ID

services/server/config/config_test.go

@@ -0,0 +1,207 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package config
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gotest.tools/assert"
+
+	"github.com/containerd/containerd/plugin"
+)
+
+func TestMergeConfigs(t *testing.T) {
+	a := &Config{
+		Version:          2,
+		Root:             "old_root",
+		RequiredPlugins:  []string{"old_plugin"},
+		DisabledPlugins:  []string{"old_plugin"},
+		State:            "old_state",
+		OOMScore:         1,
+		Timeouts:         map[string]string{"a": "1"},
+		StreamProcessors: map[string]StreamProcessor{"1": {Path: "2", Returns: "4"}, "2": {Path: "5"}},
+	}
+
+	b := &Config{
+		Root:             "new_root",
+		RequiredPlugins:  []string{"new_plugin1", "new_plugin2"},
+		OOMScore:         2,
+		Timeouts:         map[string]string{"b": "2"},
+		StreamProcessors: map[string]StreamProcessor{"1": {Path: "3"}},
+	}
+
+	err := mergeConfig(a, b)
+	assert.NilError(t, err)
+
+	assert.Equal(t, a.Version, 2)
+	assert.Equal(t, a.Root, "new_root")
+	assert.Equal(t, a.State, "old_state")
+	assert.Equal(t, a.OOMScore, 2)
+	assert.DeepEqual(t, a.RequiredPlugins, []string{"old_plugin", "new_plugin1", "new_plugin2"})
+	assert.DeepEqual(t, a.DisabledPlugins, []string{"old_plugin"})
+	assert.DeepEqual(t, a.Timeouts, map[string]string{"a": "1", "b": "2"})
+	assert.DeepEqual(t, a.StreamProcessors, map[string]StreamProcessor{"1": {Path: "3"}, "2": {Path: "5"}})
+}
+
+func TestResolveImports(t *testing.T) {
+	tempDir, err := ioutil.TempDir("", "containerd_")
+	assert.NilError(t, err)
+	defer os.RemoveAll(tempDir)
+
+	for _, filename := range []string{"config_1.toml", "config_2.toml", "test.toml"} {
+		err = ioutil.WriteFile(filepath.Join(tempDir, filename), []byte(""), 0600)
+		assert.NilError(t, err)
+	}
+
+	imports, err := resolveImports(filepath.Join(tempDir, "root.toml"), []string{
+		filepath.Join(tempDir, "config_*.toml"), // Glob
+		filepath.Join(tempDir, "./test.toml"),   // Path clean up
+		"current.toml",                          // Resolve current working dir
+	})
+	assert.NilError(t, err)
+
+	assert.DeepEqual(t, imports, []string{
+		filepath.Join(tempDir, "config_1.toml"),
+		filepath.Join(tempDir, "config_2.toml"),
+		filepath.Join(tempDir, "test.toml"),
+		filepath.Join(tempDir, "current.toml"),
+	})
+}
+
+func TestLoadSingleConfig(t *testing.T) {
+	data := `
+version = 2
+root = "/var/lib/containerd"
+
+[stream_processors]
+  [stream_processors."io.containerd.processor.v1.pigz"]
+	accepts = ["application/vnd.docker.image.rootfs.diff.tar.gzip"]
+	path = "unpigz"
+`
+	tempDir, err := ioutil.TempDir("", "containerd_")
+	assert.NilError(t, err)
+	defer os.RemoveAll(tempDir)
+
+	path := filepath.Join(tempDir, "config.toml")
+	err = ioutil.WriteFile(path, []byte(data), 0600)
+	assert.NilError(t, err)
+
+	var out Config
+	err = LoadConfig(path, &out)
+	assert.NilError(t, err)
+	assert.Equal(t, 2, out.Version)
+	assert.Equal(t, "/var/lib/containerd", out.Root)
+	assert.DeepEqual(t, map[string]StreamProcessor{
+		"io.containerd.processor.v1.pigz": {
+			Accepts: []string{"application/vnd.docker.image.rootfs.diff.tar.gzip"},
+			Path:    "unpigz",
+		},
+	}, out.StreamProcessors)
+}
+
+func TestLoadConfigWithImports(t *testing.T) {
+	data1 := `
+version = 2
+root = "/var/lib/containerd"
+imports = ["data2.toml"]
+`
+
+	data2 := `
+disabled_plugins = ["io.containerd.v1.xyz"]
+`
+
+	tempDir, err := ioutil.TempDir("", "containerd_")
+	assert.NilError(t, err)
+	defer os.RemoveAll(tempDir)
+
+	err = ioutil.WriteFile(filepath.Join(tempDir, "data1.toml"), []byte(data1), 0600)
+	assert.NilError(t, err)
+
+	err = ioutil.WriteFile(filepath.Join(tempDir, "data2.toml"), []byte(data2), 0600)
+	assert.NilError(t, err)
+
+	var out Config
+	err = LoadConfig(filepath.Join(tempDir, "data1.toml"), &out)
+	assert.NilError(t, err)
+
+	assert.Equal(t, 2, out.Version)
+	assert.Equal(t, "/var/lib/containerd", out.Root)
+	assert.DeepEqual(t, []string{"io.containerd.v1.xyz"}, out.DisabledPlugins)
+}
+
+func TestLoadConfigWithCircularImports(t *testing.T) {
+	data1 := `
+version = 2
+root = "/var/lib/containerd"
+imports = ["data2.toml", "data1.toml"]
+`
+
+	data2 := `
+disabled_plugins = ["io.containerd.v1.xyz"]
+imports = ["data1.toml", "data2.toml"]
+`
+	tempDir, err := ioutil.TempDir("", "containerd_")
+	assert.NilError(t, err)
+	defer os.RemoveAll(tempDir)
+
+	err = ioutil.WriteFile(filepath.Join(tempDir, "data1.toml"), []byte(data1), 0600)
+	assert.NilError(t, err)
+
+	err = ioutil.WriteFile(filepath.Join(tempDir, "data2.toml"), []byte(data2), 0600)
+	assert.NilError(t, err)
+
+	var out Config
+	err = LoadConfig(filepath.Join(tempDir, "data1.toml"), &out)
+	assert.NilError(t, err)
+
+	assert.Equal(t, 2, out.Version)
+	assert.Equal(t, "/var/lib/containerd", out.Root)
+	assert.DeepEqual(t, []string{"io.containerd.v1.xyz"}, out.DisabledPlugins)
+
+	assert.DeepEqual(t, []string{
+		filepath.Join(tempDir, "data1.toml"),
+		filepath.Join(tempDir, "data2.toml"),
+	}, out.Imports)
+}
+
+func TestDecodePlugin(t *testing.T) {
+	data := `
+version = 1
+[plugins.linux]
+  shim_debug = true
+`
+
+	tempDir, err := ioutil.TempDir("", "containerd_")
+	assert.NilError(t, err)
+	defer os.RemoveAll(tempDir)
+
+	path := filepath.Join(tempDir, "config.toml")
+	err = ioutil.WriteFile(path, []byte(data), 0600)
+	assert.NilError(t, err)
+
+	var out Config
+	err = LoadConfig(path, &out)
+	assert.NilError(t, err)
+
+	pluginConfig := map[string]interface{}{}
+	_, err = out.Decode(&plugin.Registration{ID: "linux", Config: &pluginConfig})
+	assert.NilError(t, err)
+	assert.Equal(t, true, pluginConfig["shim_debug"])
+}

services/server/server.go

@@ -89,8 +89,8 @@ func New(ctx context.Context, config *srvconfig.Config) (*Server, error) {
 	if err != nil {
 		return nil, err
 	}
-	for _, p := range config.StreamProcessors {
-		diff.RegisterProcessor(diff.BinaryHandler(p.ID, p.Returns, p.Accepts, p.Path, p.Args))
+	for id, p := range config.StreamProcessors {
+		diff.RegisterProcessor(diff.BinaryHandler(id, p.Returns, p.Accepts, p.Path, p.Args))
 	}
 
 	serverOpts := []grpc.ServerOption{