From 6fbb76296fb3f8980c16b59bf14be345e3b1eeda Mon Sep 17 00:00:00 2001
From: Anton Novojilov <andy@essentialkaos.com>
Date: Tue, 7 Feb 2023 14:53:41 +0300
Subject: [PATCH] [system/container] Add container sub-package with methods for
 checking container engine info

---
 system/container/container.go      | 47 +++++++++++++++++++++++++++++
 system/container/container_test.go | 48 ++++++++++++++++++++++++++++++
 2 files changed, 95 insertions(+)
 create mode 100644 system/container/container.go
 create mode 100644 system/container/container_test.go

diff --git a/system/container/container.go b/system/container/container.go
new file mode 100644
index 00000000..2b3cb8c9
--- /dev/null
+++ b/system/container/container.go
@@ -0,0 +1,47 @@
+// Package container provides methods for checking container engine info
+package container
+
+// ////////////////////////////////////////////////////////////////////////////////// //
+//                                                                                    //
+//                         Copyright (c) 2023 ESSENTIAL KAOS                          //
+//      Apache License, Version 2.0 <https://www.apache.org/licenses/LICENSE-2.0>     //
+//                                                                                    //
+// ////////////////////////////////////////////////////////////////////////////////// //
+
+import (
+	"os"
+)
+
+// ////////////////////////////////////////////////////////////////////////////////// //
+
+const (
+	DOCKER = "docker" // Docker
+	PODMAN = "podman" // Podman
+)
+
+// ////////////////////////////////////////////////////////////////////////////////// //
+
+var dockerEnv = "/.dockerenv"
+var podmanEnv = "/run/.containerenv"
+
+// ////////////////////////////////////////////////////////////////////////////////// //
+
+// GetEngine returns container engine name if used
+func GetEngine() string {
+	switch {
+	case isFileExist(dockerEnv):
+		return DOCKER
+	case isFileExist(podmanEnv):
+		return PODMAN
+	}
+
+	return ""
+}
+
+// ////////////////////////////////////////////////////////////////////////////////// //
+
+// isFileExist returns true if given file exist
+func isFileExist(file string) bool {
+	_, err := os.Stat(file)
+	return !os.IsNotExist(err)
+}
diff --git a/system/container/container_test.go b/system/container/container_test.go
new file mode 100644
index 00000000..9987603d
--- /dev/null
+++ b/system/container/container_test.go
@@ -0,0 +1,48 @@
+package container
+
+// ////////////////////////////////////////////////////////////////////////////////// //
+//                                                                                    //
+//                         Copyright (c) 2023 ESSENTIAL KAOS                          //
+//      Apache License, Version 2.0 <https://www.apache.org/licenses/LICENSE-2.0>     //
+//                                                                                    //
+// ////////////////////////////////////////////////////////////////////////////////// //
+
+import (
+	"os"
+	"testing"
+
+	. "github.com/essentialkaos/check"
+)
+
+// ////////////////////////////////////////////////////////////////////////////////// //
+
+func Test(t *testing.T) { TestingT(t) }
+
+type ContainerSuite struct{}
+
+// ////////////////////////////////////////////////////////////////////////////////// //
+
+var _ = Suite(&ContainerSuite{})
+
+// ////////////////////////////////////////////////////////////////////////////////// //
+
+func (s *ContainerSuite) TestGetEngine(c *C) {
+	testEnv := c.MkDir() + "/test"
+
+	dockerEnv = "/_unknown_"
+	podmanEnv = "/_unknown_"
+
+	c.Assert(GetEngine(), Equals, "")
+
+	os.WriteFile(testEnv, []byte("TEST"), 0644)
+
+	dockerEnv = testEnv
+	podmanEnv = "/_unknown_"
+
+	c.Assert(GetEngine(), Equals, DOCKER)
+
+	dockerEnv = "/_unknown_"
+	podmanEnv = testEnv
+
+	c.Assert(GetEngine(), Equals, PODMAN)
+}