rewrite minio runtime checks

runtime-checks.go

@@ -0,0 +1,65 @@
+/*
+ * Minio Cloud Storage, (C) 2015, 2016 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"runtime"
+	"strings"
+
+	"github.com/hashicorp/go-version"
+)
+
+// isContainerized returns true if we are inside a containerized environment.
+func isContainerized() bool {
+	// Docker containers contain ".dockerinit" at its root path.
+	if _, e := os.Stat("/.dockerinit"); os.IsNotExist(e) {
+		return true
+	}
+
+	// Check if cgroup policies for init process contains docker string.
+	if cgroupData, e := ioutil.ReadFile("/proc/1/cgroup"); e != nil {
+		if strings.Contains(string(cgroupData), "/docker-") {
+			return true
+		}
+	}
+
+	/* Add checks for non-docker containers here. */
+	return false
+}
+
+// check if minimum Go version is met.
+func checkGoVersion() {
+	// Current version.
+	curVersion, e := version.NewVersion(runtime.Version()[2:])
+	if e != nil {
+		Fatalln("Unable to determine current go version.", e)
+	}
+
+	// Prepare version constraint.
+	constraints, e := version.NewConstraint(minGoVersion)
+	if e != nil {
+		Fatalln("Unable to check go version.")
+	}
+
+	// Check for minimum version.
+	if !constraints.Check(curVersion) {
+		Fatalln(fmt.Sprintf("Please recompile Minio with Golang version %s.", minGoVersion))
+	}
+}