From 267e520fce68fa262f1c478c41ac92c82efca13f Mon Sep 17 00:00:00 2001
From: iwilltry42 <iwilltry42@gmail.com>
Date: Mon, 18 Jan 2021 15:35:57 +0100
Subject: [PATCH] registry: basic merge of existing registry with generated
 registry config

---
 pkg/client/cluster.go             | 2 ++
 pkg/client/registry.go            | 9 +++++++++
 tests/assets/test_registries.yaml | 4 ++++
 3 files changed, 15 insertions(+)
 create mode 100644 tests/assets/test_registries.yaml

diff --git a/pkg/client/cluster.go b/pkg/client/cluster.go
index 4ce4950d..4920ecc1 100644
--- a/pkg/client/cluster.go
+++ b/pkg/client/cluster.go
@@ -188,6 +188,8 @@ func ClusterPrep(ctx context.Context, runtime k3drt.Runtime, clusterConfig *conf
 		if err != nil {
 			return fmt.Errorf("Failed to generate registry config file for k3s: %+v", err)
 		}
+		RegistryMergeConfig(ctx, regConf, clusterConfig.ClusterCreateOpts.Registries.Config)
+		log.Tracef("Merged registry config: %+v", regConf)
 		regConfBytes, err := yaml.Marshal(&regConf)
 		if err != nil {
 			return fmt.Errorf("Failed to marshal registry configuration: %+v", err)
diff --git a/pkg/client/registry.go b/pkg/client/registry.go
index 05a8f557..f14d79ca 100644
--- a/pkg/client/registry.go
+++ b/pkg/client/registry.go
@@ -26,6 +26,7 @@ import (
 	"fmt"
 
 	"github.com/docker/go-connections/nat"
+	"github.com/imdario/mergo"
 	"github.com/rancher/k3d/v4/pkg/runtimes"
 	k3d "github.com/rancher/k3d/v4/pkg/types"
 	"github.com/rancher/k3d/v4/pkg/types/k3s"
@@ -305,3 +306,11 @@ func RegistryGenerateLocalRegistryHostingConfigMapYAML(ctx context.Context, regi
 
 	return cmYaml, nil
 }
+
+// RegistryMergeConfig merges a source registry config into an existing dest registry cofnig
+func RegistryMergeConfig(ctx context.Context, dest, src *k3s.Registry) error {
+	if err := mergo.MergeWithOverwrite(dest, src); err != nil {
+		return fmt.Errorf("Failed to merge registry configs: %+v", err)
+	}
+	return nil
+}
diff --git a/tests/assets/test_registries.yaml b/tests/assets/test_registries.yaml
new file mode 100644
index 00000000..c9fa033a
--- /dev/null
+++ b/tests/assets/test_registries.yaml
@@ -0,0 +1,4 @@
+mirrors:
+  "my.company.registry":
+    endpoint:
+      - http://my.company.registry:5000
\ No newline at end of file