From bca0857530d1ead52d03595b1558bfe98112d187 Mon Sep 17 00:00:00 2001
From: Maksym Pavlenko <makpav@amazon.com>
Date: Thu, 22 Aug 2019 17:22:25 -0700
Subject: [PATCH] Fix toml plugin decoding

Do not rely on toml metadata when decoding plugin's configs as it's not possible to merge toml.MetaData structs during import.

Signed-off-by: Maksym Pavlenko <makpav@amazon.com>
---
 services/server/config/config.go      |  7 ++-----
 services/server/config/config_test.go | 27 +++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/services/server/config/config.go b/services/server/config/config.go
index 7c47cd745..57dc71585 100644
--- a/services/server/config/config.go
+++ b/services/server/config/config.go
@@ -64,8 +64,6 @@ type Config struct {
 	Imports []string `toml:"imports"`
 
 	StreamProcessors []StreamProcessor `toml:"stream_processors"`
-
-	md toml.MetaData
 }
 
 // StreamProcessor provides configuration for diff content processors
@@ -203,7 +201,7 @@ 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
@@ -258,11 +256,10 @@ func LoadConfig(path string, out *Config) error {
 // loadConfigFile decodes a TOML file at the given path
 func loadConfigFile(path string) (*Config, error) {
 	config := &Config{}
-	md, err := toml.DecodeFile(path, &config)
+	_, err := toml.DecodeFile(path, &config)
 	if err != nil {
 		return nil, err
 	}
-	config.md = md
 	return config, nil
 }
 
diff --git a/services/server/config/config_test.go b/services/server/config/config_test.go
index 56f9cb030..8e65a4630 100644
--- a/services/server/config/config_test.go
+++ b/services/server/config/config_test.go
@@ -23,6 +23,8 @@ import (
 	"testing"
 
 	"gotest.tools/assert"
+
+	"github.com/containerd/containerd/plugin"
 )
 
 func TestMergeConfigs(t *testing.T) {
@@ -161,3 +163,28 @@ imports = ["data1.toml", "data2.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"])
+}