rewrite podman-cp

* Add a new `pkg/copy` to centralize all container-copy related code.

* The new code is based on Buildah's `copier` package.

* The compat `/archive` endpoints use the new `copy` package.

* Update docs and an several new tests.

* Includes many fixes, most notably, the look-up of volumes and mounts.

Breaking changes:

 * Podman is now expecting that container-destination paths exist.
   Before, Podman created the paths if needed.  Docker does not do
   that and I believe Podman should not either as it's a recipe for
   masking errors.  These errors may be user induced (e.g., a path
   typo), or internal typos (e.g., when the destination may be a
   mistakenly unmounted volume).  Let's keep the magic low for such
   a security sensitive feature.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

1 files changed, 97 insertions, 225 deletions

diff --git a/test/e2e/cp_test.go b/test/e2e/cp_test.go
index c1d3be5ab..33908b60e 100644
--- a/test/e2e/cp_test.go
+++ b/test/e2e/cp_test.go
@@ -4,14 +4,18 @@ import (
 	"io/ioutil"
 	"os"
 	"os/exec"
+	"os/user"
 	"path/filepath"
-	"strings"
 
 	. "github.com/containers/podman/v2/test/utils"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 )
 
+// NOTE: Only smoke tests.  The system tests (i.e., "./test/system/*") take
+// care of function and regression tests.  Please consider adding system tests
+// rather than e2e tests.  System tests are used in RHEL gating.
+
 var _ = Describe("Podman cp", func() {
 	var (
 		tempdir    string
@@ -37,240 +41,108 @@ var _ = Describe("Podman cp", func() {
 
 	})
 
+	// Copy a file to the container, then back to the host and make sure
+	// that the contents match.
 	It("podman cp file", func() {
-		srcPath := filepath.Join(podmanTest.RunRoot, "cp_test.txt")
-		dstPath := filepath.Join(podmanTest.RunRoot, "cp_from_container")
-		fromHostToContainer := []byte("copy from host to container")
-
-		session := podmanTest.Podman([]string{"create", ALPINE, "cat", "foo"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-		name := session.OutputToString()
-
-		err := ioutil.WriteFile(srcPath, fromHostToContainer, 0644)
+		srcFile, err := ioutil.TempFile("", "")
 		Expect(err).To(BeNil())
+		defer srcFile.Close()
+		defer os.Remove(srcFile.Name())
 
-		session = podmanTest.Podman([]string{"cp", srcPath, name + ":foo/"})
-		session.WaitWithDefaultTimeout()
-		Expect(session).To(ExitWithError())
-
-		session = podmanTest.Podman([]string{"cp", srcPath, name + ":foo"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-
-		session = podmanTest.Podman([]string{"cp", name + ":foo", dstPath})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-
-		session = podmanTest.Podman([]string{"start", name})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-	})
-
-	It("podman cp file to dir", func() {
-		name := "testctr"
-		setup := podmanTest.RunTopContainer(name)
-		setup.WaitWithDefaultTimeout()
-		Expect(setup.ExitCode()).To(Equal(0))
-
-		srcPath := "/tmp/cp_test.txt"
-		fromHostToContainer := []byte("copy from host to container directory")
-		err := ioutil.WriteFile(srcPath, fromHostToContainer, 0644)
+		originalContent := []byte("podman cp file test")
+		err = ioutil.WriteFile(srcFile.Name(), originalContent, 0644)
 		Expect(err).To(BeNil())
 
-		session := podmanTest.Podman([]string{"exec", name, "mkdir", "foodir"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-
-		session = podmanTest.Podman([]string{"cp", srcPath, name + ":foodir/"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-
-		session = podmanTest.Podman([]string{"exec", name, "ls", "foodir/cp_test.txt"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-
-		os.Remove("/tmp/cp_test.txt")
-	})
-
-	It("podman cp dir to dir", func() {
-		testDirPath := filepath.Join(podmanTest.RunRoot, "TestDir1")
-
-		session := podmanTest.Podman([]string{"create", ALPINE, "ls", "/foodir"})
+		// Create a container. NOTE that container mustn't be running for copying.
+		session := podmanTest.Podman([]string{"create", ALPINE})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 		name := session.OutputToString()
 
-		err := os.Mkdir(testDirPath, 0755)
-		Expect(err).To(BeNil())
-		defer os.RemoveAll(testDirPath)
-
-		session = podmanTest.Podman([]string{"cp", testDirPath, name + ":/foodir"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-
-		session = podmanTest.Podman([]string{"cp", testDirPath, name + ":/foodir"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-
-		testctr := "testctr"
-		setup := podmanTest.RunTopContainer(testctr)
-		setup.WaitWithDefaultTimeout()
-		Expect(setup.ExitCode()).To(Equal(0))
+		// Copy TO the container.
 
-		session = podmanTest.Podman([]string{"exec", testctr, "mkdir", "foo"})
+		// Cannot copy to a non-existent path (note the trailing "/").
+		session = podmanTest.Podman([]string{"cp", srcFile.Name(), name + ":foo/"})
 		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-
-		session = podmanTest.Podman([]string{"cp", testDirPath + "/.", testctr + ":/foo"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-		session = podmanTest.Podman([]string{"exec", testctr, "ls", "foo"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-		Expect(len(session.OutputToString())).To(Equal(0))
+		Expect(session).To(ExitWithError())
 
-		session = podmanTest.Podman([]string{"cp", testctr + ":/foo/.", testDirPath})
+		// The file will now be created (and written to).
+		session = podmanTest.Podman([]string{"cp", srcFile.Name(), name + ":foo"})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
-		cmd := exec.Command("ls", testDirPath)
-		res, err := cmd.Output()
-		Expect(err).To(BeNil())
-		Expect(len(res)).To(Equal(0))
-	})
 
-	It("podman cp stdin/stdout", func() {
-		SkipIfRemote("FIXME: podman-remote cp not implemented yet")
-		session := podmanTest.Podman([]string{"create", ALPINE, "ls", "foo"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-		name := session.OutputToString()
+		// Copy FROM the container.
 
-		testDirPath := filepath.Join(podmanTest.RunRoot, "TestDir2")
-		err := os.Mkdir(testDirPath, 0755)
-		Expect(err).To(BeNil())
-		defer os.RemoveAll(testDirPath)
-		cmd := exec.Command("tar", "-zcvf", "file.tar.gz", testDirPath)
-		_, err = cmd.Output()
+		destFile, err := ioutil.TempFile("", "")
 		Expect(err).To(BeNil())
+		defer destFile.Close()
+		defer os.Remove(destFile.Name())
 
-		data, err := ioutil.ReadFile("foo.tar.gz")
-		reader := strings.NewReader(string(data))
-		cmd.Stdin = reader
-		session = podmanTest.Podman([]string{"cp", "-", name + ":/foo"})
+		session = podmanTest.Podman([]string{"cp", name + ":foo", destFile.Name()})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
-		session = podmanTest.Podman([]string{"cp", "file.tar.gz", name + ":/foo.tar.gz"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-		session = podmanTest.Podman([]string{"cp", name + ":/foo.tar.gz", "-"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-
-		os.Remove("file.tar.gz")
-	})
-
-	It("podman cp tar", func() {
-		testctr := "testctr"
-		setup := podmanTest.RunTopContainer(testctr)
-		setup.WaitWithDefaultTimeout()
-		Expect(setup.ExitCode()).To(Equal(0))
-
-		session := podmanTest.Podman([]string{"exec", testctr, "mkdir", "foo"})
+		session = podmanTest.Podman([]string{"start", name})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
-		path, err := os.Getwd()
-		Expect(err).To(BeNil())
-		testDirPath := filepath.Join(path, "TestDir3")
-		err = os.Mkdir(testDirPath, 0777)
+		// Now make sure the content matches.
+		roundtripContent, err := ioutil.ReadFile(destFile.Name())
 		Expect(err).To(BeNil())
-		defer os.RemoveAll(testDirPath)
-		cmd := exec.Command("tar", "-cvf", "file.tar", testDirPath)
-		_, err = cmd.Output()
-		Expect(err).To(BeNil())
-
-		session = podmanTest.Podman([]string{"cp", "file.tar", "testctr:/foo/"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-
-		session = podmanTest.Podman([]string{"exec", testctr, "ls", "-l", "foo"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-		Expect(session.OutputToString()).To(ContainSubstring("file.tar"))
-
-		os.Remove("file.tar")
+		Expect(roundtripContent).To(Equal(originalContent))
 	})
 
-	It("podman cp tar --extract", func() {
-		testctr := "testctr"
-		setup := podmanTest.RunTopContainer(testctr)
-		setup.WaitWithDefaultTimeout()
-		Expect(setup.ExitCode()).To(Equal(0))
-
-		session := podmanTest.Podman([]string{"exec", testctr, "mkdir", "/foo"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-
-		path, err := os.Getwd()
-		Expect(err).To(BeNil())
-		testDirPath := filepath.Join(path, "TestDir4")
-		err = os.Mkdir(testDirPath, 0777)
-		Expect(err).To(BeNil())
-		defer os.RemoveAll(testDirPath)
-		f, err := os.Create(filepath.Join(testDirPath, "a.txt"))
-		Expect(err).To(BeNil())
-		_, err = f.Write([]byte("Hello World!!!\n"))
-		f.Close()
-		cmd := exec.Command("tar", "-cvf", "file.tar", "TestDir4")
-		exec.Command("tar", "-cvf", "/home/mvasek/file.tar", testDirPath)
-		_, err = cmd.Output()
+	// Create a symlink in the container, use it as a copy destination and
+	// make sure that the link and the resolved path are accessible and
+	// give the right content.
+	It("podman cp symlink", func() {
+		srcFile, err := ioutil.TempFile("", "")
 		Expect(err).To(BeNil())
-		defer os.Remove("file.tar")
+		defer srcFile.Close()
+		defer os.Remove(srcFile.Name())
 
-		session = podmanTest.Podman([]string{"cp", "--extract", "file.tar", "testctr:/foo/"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-
-		session = podmanTest.Podman([]string{"exec", testctr, "cat", "/foo/TestDir4/a.txt"})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-		Expect(session.OutputToString()).To(ContainSubstring("Hello World!!!"))
-	})
+		originalContent := []byte("podman cp symlink test")
+		err = ioutil.WriteFile(srcFile.Name(), originalContent, 0644)
+		Expect(err).To(BeNil())
 
-	It("podman cp symlink", func() {
 		session := podmanTest.Podman([]string{"run", "-d", ALPINE, "top"})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 		name := session.OutputToString()
 
-		srcPath := filepath.Join(podmanTest.RunRoot, "cp_test.txt")
-		fromHostToContainer := []byte("copy from host to container")
-		err := ioutil.WriteFile(srcPath, fromHostToContainer, 0644)
-		Expect(err).To(BeNil())
-
 		session = podmanTest.Podman([]string{"exec", name, "ln", "-s", "/tmp", "/test"})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
-		session = podmanTest.Podman([]string{"cp", "--pause=false", srcPath, name + ":/test"})
+		session = podmanTest.Podman([]string{"cp", "--pause=false", srcFile.Name(), name + ":/test"})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
-		_, err = os.Stat("/tmp/cp_test.txt")
-		Expect(err).To(Not(BeNil()))
-
-		session = podmanTest.Podman([]string{"exec", name, "ln", "-s", "/tmp/nonesuch", "/test1"})
+		session = podmanTest.Podman([]string{"exec", name, "cat", "/tmp/" + filepath.Base(srcFile.Name())})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).To(ContainSubstring(string(originalContent)))
 
-		session = podmanTest.Podman([]string{"cp", "--pause=false", srcPath, name + ":/test1/"})
+		session = podmanTest.Podman([]string{"exec", name, "cat", "/test/" + filepath.Base(srcFile.Name())})
 		session.WaitWithDefaultTimeout()
-		Expect(session).To(ExitWithError())
-
+		Expect(session.ExitCode()).To(Equal(0))
+		Expect(session.OutputToString()).To(ContainSubstring(string(originalContent)))
 	})
+
+	// Copy a file to a volume in the container.  The tricky part is that
+	// containers mustn't be running for copying, so Podman has to do some
+	// intense Yoga and 1) detect volume paths on the container, 2) resolve
+	// the path to the volume's mount point on the host, and 3) copy the
+	// data to the volume and not the container.
 	It("podman cp volume", func() {
+		srcFile, err := ioutil.TempFile("", "")
+		Expect(err).To(BeNil())
+		defer srcFile.Close()
+		defer os.Remove(srcFile.Name())
+
+		originalContent := []byte("podman cp volume")
+		err = ioutil.WriteFile(srcFile.Name(), originalContent, 0644)
+		Expect(err).To(BeNil())
 		session := podmanTest.Podman([]string{"volume", "create", "data"})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
@@ -279,23 +151,31 @@ var _ = Describe("Podman cp", func() {
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
-		err = ioutil.WriteFile("cp_vol", []byte("copy to the volume"), 0644)
-		if err != nil {
-			os.Exit(1)
-		}
-		session = podmanTest.Podman([]string{"cp", "cp_vol", "container1" + ":/data/cp_vol1"})
+		session = podmanTest.Podman([]string{"cp", srcFile.Name(), "container1" + ":/data/file.txt"})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
-		session = podmanTest.Podman([]string{"cp", "container1" + ":/data/cp_vol1", "cp_vol2"})
+		// Now get the volume's mount point, read the file and make
+		// sure the contents match.
+		session = podmanTest.Podman([]string{"volume", "inspect", "data", "--format", "{{.Mountpoint}}"})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
-		os.Remove("cp_vol")
-		os.Remove("cp_vol2")
+		volumeMountPoint := session.OutputToString()
+		copiedContent, err := ioutil.ReadFile(filepath.Join(volumeMountPoint, "file.txt"))
+		Expect(err).To(BeNil())
+		Expect(copiedContent).To(Equal(originalContent))
 	})
 
+	// Create another user in the container, let them create a file, copy
+	// it to the host and back to the container and make sure that we can
+	// access it, and (roughly) the right users own it.
 	It("podman cp from ctr chown ", func() {
+		srcFile, err := ioutil.TempFile("", "")
+		Expect(err).To(BeNil())
+		defer srcFile.Close()
+		defer os.Remove(srcFile.Name())
+
 		setup := podmanTest.RunTopContainer("testctr")
 		setup.WaitWithDefaultTimeout()
 		Expect(setup.ExitCode()).To(Equal(0))
@@ -308,17 +188,19 @@ var _ = Describe("Podman cp", func() {
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
-		session = podmanTest.Podman([]string{"cp", "--pause=false", "testctr:/tmp/testfile", "testfile1"})
+		session = podmanTest.Podman([]string{"cp", "--pause=false", "testctr:/tmp/testfile", srcFile.Name()})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
 		// owner of the file copied to local machine is not testuser
-		cmd := exec.Command("ls", "-l", "testfile1")
+		u, err := user.Current()
+		Expect(err).To(BeNil())
+		cmd := exec.Command("ls", "-l", srcFile.Name())
 		cmdRet, err := cmd.Output()
 		Expect(err).To(BeNil())
-		Expect(strings.Contains(string(cmdRet), "testuser")).To(BeFalse())
+		Expect(string(cmdRet)).To(ContainSubstring(u.Username))
 
-		session = podmanTest.Podman([]string{"cp", "--pause=false", "testfile1", "testctr:testfile2"})
+		session = podmanTest.Podman([]string{"cp", "--pause=false", srcFile.Name(), "testctr:testfile2"})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
@@ -327,45 +209,35 @@ var _ = Describe("Podman cp", func() {
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 		Expect(session.OutputToString()).To(ContainSubstring("root"))
-
-		os.Remove("testfile1")
 	})
-	It("podman cp the root directory from the ctr to an existing directory on the host ", func() {
-		imgName := "test-cp-root-dir:latest"
-		DockerfileName := "Dockerfile.test-cp-root-dir"
-		ctrName := "test-container-cp-root"
 
-		session := podmanTest.Podman([]string{"build", "-f", "build/" + DockerfileName, "-t", imgName, "build/"})
+	// Copy the root dir "/" of a container to the host.
+	It("podman cp the root directory from the ctr to an existing directory on the host ", func() {
+		container := "copyroottohost"
+		session := podmanTest.RunTopContainer(container)
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
-		testDirPath := filepath.Join(podmanTest.RunRoot, "TestDirForCp")
-
-		session = podmanTest.Podman([]string{"create", "--name", ctrName, imgName, "dummy"})
+		session = podmanTest.Podman([]string{"exec", container, "touch", "/dummy.txt"})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
-		err := os.Mkdir(testDirPath, 0755)
+		tmpDir, err := ioutil.TempDir("", "")
 		Expect(err).To(BeNil())
-		defer os.RemoveAll(testDirPath)
 
-		// Copy the root directory of the container to an existing directory
-		session = podmanTest.Podman([]string{"cp", ctrName + ":/", testDirPath})
+		session = podmanTest.Podman([]string{"cp", container + ":/", tmpDir})
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 
-		// The file should be in the directory,
-		// not one layer too much of the directory called merged
-		checkFile := filepath.Join(testDirPath, DockerfileName)
-		_, err = os.Stat(checkFile)
+		cmd := exec.Command("ls", "-la", tmpDir)
+		output, err := cmd.Output()
+		lsOutput := string(output)
 		Expect(err).To(BeNil())
-
-		session = podmanTest.Podman([]string{"container", "rm", ctrName})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
-
-		session = podmanTest.Podman([]string{"rmi", "-f", imgName})
-		session.WaitWithDefaultTimeout()
-		Expect(session.ExitCode()).To(Equal(0))
+		Expect(lsOutput).To(ContainSubstring("dummy.txt"))
+		Expect(lsOutput).To(ContainSubstring("tmp"))
+		Expect(lsOutput).To(ContainSubstring("etc"))
+		Expect(lsOutput).To(ContainSubstring("var"))
+		Expect(lsOutput).To(ContainSubstring("bin"))
+		Expect(lsOutput).To(ContainSubstring("usr"))
 	})
 })