Fix the wrong symlinks when using the custom docker engine

cmd/control/console_init.go

@@ -137,7 +137,7 @@ func consoleInitFunc() error {
 		}
 	}
 
-	baseSymlink := symLinkEngineBinary(cfg.Rancher.Docker.Engine)
+	baseSymlink := symLinkEngineBinary()
 
 	if _, err := os.Stat(dockerCompletionFile); err == nil {
 		baseSymlink = append(baseSymlink, symlink{

cmd/control/docker_init.go

@@ -86,14 +86,15 @@ func dockerInitAction(c *cli.Context) error {
 	}
 
 	cfg := config.LoadConfig()
-	baseSymlink := symLinkEngineBinary(cfg.Rancher.Docker.Engine)
 
-	for _, link := range baseSymlink {
+	for _, link := range symLinkEngineBinary() {
 		syscall.Unlink(link.newname)
+		if _, err := os.Stat(link.oldname); err == nil {
 			if err := os.Symlink(link.oldname, link.newname); err != nil {
 				log.Error(err)
 			}
 		}
+	}
 
 	err = checkZfsBackingFS(cfg.Rancher.Docker.StorageDriver, cfg.Rancher.Docker.Graph)
 	if err != nil {

cmd/control/util.go

@@ -10,7 +10,6 @@ import (
 
 	"github.com/rancher/os/config"
 	"github.com/rancher/os/pkg/log"
-	"github.com/rancher/os/pkg/util/versions"
 
 	"github.com/pkg/errors"
 )
@@ -34,30 +33,27 @@ func formatImage(image string, cfg *config.CloudConfig) string {
 	return image
 }
 
-func symLinkEngineBinary(version string) []symlink {
-	versionNum := strings.Replace(strings.Replace(version, "docker-", "", -1), "-ce", "", -1)
+func symLinkEngineBinary() []symlink {
 	baseSymlink := []symlink{
+		{"/usr/share/ros/os-release", "/usr/lib/os-release"},
+		{"/usr/share/ros/os-release", "/etc/os-release"},
+
 		{"/var/lib/rancher/engine/docker", "/usr/bin/docker"},
 		{"/var/lib/rancher/engine/dockerd", "/usr/bin/dockerd"},
 		{"/var/lib/rancher/engine/docker-init", "/usr/bin/docker-init"},
 		{"/var/lib/rancher/engine/docker-proxy", "/usr/bin/docker-proxy"},
-		{"/usr/share/ros/os-release", "/usr/lib/os-release"},
-		{"/usr/share/ros/os-release", "/etc/os-release"},
-	}
-	if versions.GreaterThanOrEqualTo(versionNum, "18.09.0") {
-		baseSymlink = append(baseSymlink, []symlink{
+
+		// >= 18.09.0
 		{"/var/lib/rancher/engine/containerd", "/usr/bin/containerd"},
 		{"/var/lib/rancher/engine/ctr", "/usr/bin/ctr"},
 		{"/var/lib/rancher/engine/containerd-shim", "/usr/bin/containerd-shim"},
 		{"/var/lib/rancher/engine/runc", "/usr/bin/runc"},
-		}...)
-	} else {
-		baseSymlink = append(baseSymlink, []symlink{
+
+		// < 18.09.0
 		{"/var/lib/rancher/engine/docker-containerd", "/usr/bin/docker-containerd"},
 		{"/var/lib/rancher/engine/docker-containerd-ctr", "/usr/bin/docker-containerd-ctr"},
 		{"/var/lib/rancher/engine/docker-containerd-shim", "/usr/bin/docker-containerd-shim"},
 		{"/var/lib/rancher/engine/docker-runc", "/usr/bin/docker-runc"},
-		}...)
 	}
 	return baseSymlink
 }