1 files changed, 121 insertions, 0 deletions
diff --git a/pkg/test/dockerutil/dockerutil.go b/pkg/test/dockerutil/dockerutil.go
new file mode 100644
index 000000000..f95ae3cd1
--- /dev/null
+++ b/pkg/test/dockerutil/dockerutil.go
@@ -0,0 +1,121 @@
+// Copyright 2018 The gVisor Authors.
+//
+// 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 dockerutil is a collection of utility functions.
+package dockerutil
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"os/exec"
+	"regexp"
+	"strconv"
+
+	"gvisor.dev/gvisor/pkg/test/testutil"
+)
+
+var (
+	// runtime is the runtime to use for tests. This will be applied to all
+	// containers. Note that the default here ("runsc") corresponds to the
+	// default used by the installations. This is important, because the
+	// default installer for vm_tests (in tools/installers:head, invoked
+	// via tools/vm:defs.bzl) will install with this name. So without
+	// changing anything, tests should have a runsc runtime available to
+	// them. Otherwise installers should update the existing runtime
+	// instead of installing a new one.
+	runtime = flag.String("runtime", "runsc", "specify which runtime to use")
+
+	// config is the default Docker daemon configuration path.
+	config = flag.String("config_path", "/etc/docker/daemon.json", "configuration file for reading paths")
+)
+
+// EnsureSupportedDockerVersion checks if correct docker is installed.
+//
+// This logs directly to stderr, as it is typically called from a Main wrapper.
+func EnsureSupportedDockerVersion() {
+	cmd := exec.Command("docker", "version")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		log.Fatalf("error running %q: %v", "docker version", err)
+	}
+	re := regexp.MustCompile(`Version:\s+(\d+)\.(\d+)\.\d.*`)
+	matches := re.FindStringSubmatch(string(out))
+	if len(matches) != 3 {
+		log.Fatalf("Invalid docker output: %s", out)
+	}
+	major, _ := strconv.Atoi(matches[1])
+	minor, _ := strconv.Atoi(matches[2])
+	if major < 17 || (major == 17 && minor < 9) {
+		log.Fatalf("Docker version 17.09.0 or greater is required, found: %02d.%02d", major, minor)
+	}
+}
+
+// RuntimePath returns the binary path for the current runtime.
+func RuntimePath() (string, error) {
+	// Read the configuration data; the file must exist.
+	configBytes, err := ioutil.ReadFile(*config)
+	if err != nil {
+		return "", err
+	}
+
+	// Unmarshal the configuration.
+	c := make(map[string]interface{})
+	if err := json.Unmarshal(configBytes, &c); err != nil {
+		return "", err
+	}
+
+	// Decode the expected configuration.
+	r, ok := c["runtimes"]
+	if !ok {
+		return "", fmt.Errorf("no runtimes declared: %v", c)
+	}
+	rs, ok := r.(map[string]interface{})
+	if !ok {
+		// The runtimes are not a map.
+		return "", fmt.Errorf("unexpected format: %v", c)
+	}
+	r, ok = rs[*runtime]
+	if !ok {
+		// The expected runtime is not declared.
+		return "", fmt.Errorf("runtime %q not found: %v", *runtime, c)
+	}
+	rs, ok = r.(map[string]interface{})
+	if !ok {
+		// The runtime is not a map.
+		return "", fmt.Errorf("unexpected format: %v", c)
+	}
+	p, ok := rs["path"].(string)
+	if !ok {
+		// The runtime does not declare a path.
+		return "", fmt.Errorf("unexpected format: %v", c)
+	}
+	return p, nil
+}
+
+// Save exports a container image to the given Writer.
+//
+// Note that the writer should be actively consuming the output, otherwise it
+// is not guaranteed that the Save will make any progress and the call may
+// stall indefinitely.
+//
+// This is called by criutil in order to import imports.
+func Save(logger testutil.Logger, image string, w io.Writer) error {
+	cmd := testutil.Command(logger, "docker", "save", testutil.ImageByName(image))
+	cmd.Stdout = w // Send directly to the writer.
+	return cmd.Run()
+}