From 94220037c444919fb59020b03f71449186976e12 Mon Sep 17 00:00:00 2001
From: Artyom Kartasov <agneum@gmail.com>
Date: Mon, 7 Feb 2022 08:58:37 +0000
Subject: [PATCH] fix: skip connection if the DLE container is already
 connected to an internal network

---
 pkg/util/networks/networks.go      | 32 ++++++++++++++++++++++--------
 pkg/util/networks/networks_test.go | 28 ++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 8 deletions(-)

diff --git a/pkg/util/networks/networks.go b/pkg/util/networks/networks.go
index d45bc8c6..261a41de 100644
--- a/pkg/util/networks/networks.go
+++ b/pkg/util/networks/networks.go
@@ -28,15 +28,19 @@ const (
 )
 
 // Setup creates a new internal Docker network and connects container to it.
-func Setup(ctx context.Context, dockerCLI *client.Client, instanceID, containerID string) (string, error) {
+func Setup(ctx context.Context, dockerCLI *client.Client, instanceID, containerName string) (string, error) {
 	networkName := getNetworkName(instanceID)
 
 	log.Dbg("Discovering internal network:", networkName)
 
 	networkResource, err := dockerCLI.NetworkInspect(ctx, networkName, types.NetworkInspectOptions{})
 	if err == nil {
-		if err := dockerCLI.NetworkConnect(ctx, networkResource.ID, containerID, &network.EndpointSettings{}); err != nil {
-			return "", err
+		if !hasContainerConnected(networkResource, containerName) {
+			if err := dockerCLI.NetworkConnect(ctx, networkResource.ID, containerName, &network.EndpointSettings{}); err != nil {
+				return "", err
+			}
+
+			log.Dbg(fmt.Sprintf("Container %s has been connected to %s", containerName, networkName))
 		}
 
 		return networkResource.ID, nil
@@ -61,7 +65,7 @@ func Setup(ctx context.Context, dockerCLI *client.Client, instanceID, containerI
 
 	log.Dbg("A new internal network has been created:", internalNetwork.ID)
 
-	if err := dockerCLI.NetworkConnect(ctx, internalNetwork.ID, containerID, &network.EndpointSettings{}); err != nil {
+	if err := dockerCLI.NetworkConnect(ctx, internalNetwork.ID, containerName, &network.EndpointSettings{}); err != nil {
 		return "", err
 	}
 
@@ -108,11 +112,13 @@ func Connect(ctx context.Context, dockerCLI *client.Client, instanceID, containe
 		return fmt.Errorf("internal network not found: %w", err)
 	}
 
-	if err := dockerCLI.NetworkConnect(ctx, networkResource.ID, containerID, &network.EndpointSettings{}); err != nil {
-		return err
-	}
+	if !hasContainerConnected(networkResource, containerID) {
+		if err := dockerCLI.NetworkConnect(ctx, networkResource.ID, containerID, &network.EndpointSettings{}); err != nil {
+			return err
+		}
 
-	log.Dbg(fmt.Sprintf("Container %s has been connected to %s", instanceID, networkName))
+		log.Dbg(fmt.Sprintf("Container %s has been connected to %s", instanceID, networkName))
+	}
 
 	return nil
 }
@@ -147,6 +153,16 @@ func Reconnect(ctx context.Context, dockerCLI *client.Client, instanceID, contai
 	return nil
 }
 
+func hasContainerConnected(networkResource types.NetworkResource, containerID string) bool {
+	for _, container := range networkResource.Containers {
+		if container.Name == containerID {
+			return true
+		}
+	}
+
+	return false
+}
+
 func getNetworkName(instanceID string) string {
 	return networkPrefix + instanceID
 }
diff --git a/pkg/util/networks/networks_test.go b/pkg/util/networks/networks_test.go
index 869bf75b..8b8393fb 100644
--- a/pkg/util/networks/networks_test.go
+++ b/pkg/util/networks/networks_test.go
@@ -7,6 +7,7 @@ package networks
 import (
 	"testing"
 
+	"github.com/docker/docker/api/types"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -17,3 +18,30 @@ func TestInternalNetworks(t *testing.T) {
 		assert.Equal(t, "dle_network_testInstanceID", getNetworkName(instanceID))
 	})
 }
+
+func TestIfContainerConnected(t *testing.T) {
+	t.Run("test if container connected", func(t *testing.T) {
+		resource := types.NetworkResource{
+			Containers: map[string]types.EndpointResource{
+				"testID": {Name: "test_server"},
+			},
+		}
+		testCases := []struct {
+			containerName string
+			result        bool
+		}{
+			{
+				containerName: "test_server",
+				result:        true,
+			},
+			{
+				containerName: "not_connected_server",
+				result:        false,
+			},
+		}
+
+		for _, tc := range testCases {
+			assert.Equal(t, tc.result, hasContainerConnected(resource, tc.containerName))
+		}
+	})
+}