From 24b9e2c1a0a72a7ad302cdce7da3abbc4e6295cb Mon Sep 17 00:00:00 2001
From: Maksym Pavlenko <makpav@amazon.com>
Date: Fri, 23 Aug 2019 15:49:02 -0700
Subject: [PATCH] Merge configs section by section

Signed-off-by: Maksym Pavlenko <makpav@amazon.com>
---
 services/server/config/config.go      | 21 ++++++++++++++++++++-
 services/server/config/config_test.go | 25 ++++++++++++++-----------
 2 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/services/server/config/config.go b/services/server/config/config.go
index bc9520fea..98fef816e 100644
--- a/services/server/config/config.go
+++ b/services/server/config/config.go
@@ -297,8 +297,27 @@ func resolveImports(parent string, imports []string) ([]string, error) {
 // 0            1           1
 // []{"1"}      []{"2"}     []{"1","2"}
 // []{"1"}      []{}        []{"1"}
+// Maps merged by keys, but values are replaced entirely.
 func mergeConfig(to, from *Config) error {
-	return mergo.Merge(to, from, mergo.WithOverride, mergo.WithAppendSlice)
+	err := mergo.Merge(to, from, mergo.WithOverride, mergo.WithAppendSlice)
+	if err != nil {
+		return err
+	}
+
+	// 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
diff --git a/services/server/config/config_test.go b/services/server/config/config_test.go
index 90cba46f2..8660105d4 100644
--- a/services/server/config/config_test.go
+++ b/services/server/config/config_test.go
@@ -29,20 +29,22 @@ import (
 
 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"},
+		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"},
+		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)
@@ -55,6 +57,7 @@ func TestMergeConfigs(t *testing.T) {
 	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) {