implement init containers in podman

this is the first pass at implementing init containers for podman pods.
init containersare made popular by k8s as a way to run setup for pods
before the pods standard containers run.

unlike k8s, we support two styles of init containers: always and
oneshot.  always means the container stays in the pod and starts
whenever a pod is started.  this does not apply to pods restarting.
oneshot means the container runs onetime when the pod starts and then is
removed.

Signed-off-by: Brent Baude <bbaude@redhat.com>

1 files changed, 171 insertions, 0 deletions

diff --git a/test/e2e/pod_initcontainers_test.go b/test/e2e/pod_initcontainers_test.go
new file mode 100644
index 000000000..606294f51
--- /dev/null
+++ b/test/e2e/pod_initcontainers_test.go
@@ -0,0 +1,171 @@
+package integration
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/containers/podman/v3/libpod/define"
+	. "github.com/containers/podman/v3/test/utils"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+	. "github.com/onsi/gomega/gexec"
+)
+
+var _ = Describe("Podman init containers", func() {
+	var (
+		tempdir    string
+		err        error
+		podmanTest *PodmanTestIntegration
+	)
+
+	BeforeEach(func() {
+		tempdir, err = CreateTempDirInTempDir()
+		if err != nil {
+			os.Exit(1)
+		}
+		podmanTest = PodmanTestCreate(tempdir)
+		podmanTest.Setup()
+		podmanTest.SeedImages()
+	})
+
+	AfterEach(func() {
+		podmanTest.Cleanup()
+		f := CurrentGinkgoTestDescription()
+		processTestResult(f)
+
+	})
+
+	It("podman create init container without --pod should fail", func() {
+		session := podmanTest.Podman([]string{"create", "--init-ctr", "always", ALPINE, "top"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(125))
+	})
+
+	It("podman create init container with bad init type should fail", func() {
+		session := podmanTest.Podman([]string{"create", "--init-ctr", "unknown", "--pod", "new:foobar", ALPINE, "top"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(125))
+	})
+
+	It("podman init containers should not degrade pod status", func() {
+		// create a pod
+		topPod := podmanTest.Podman([]string{"create", "-t", "--pod", "new:foobar", ALPINE, "top"})
+		topPod.WaitWithDefaultTimeout()
+		Expect(topPod).Should(Exit(0))
+		// add an init container
+		session := podmanTest.Podman([]string{"create", "--init-ctr", "always", "--pod", "foobar", ALPINE, "date"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(0))
+		// start a pod
+		start := podmanTest.Podman([]string{"pod", "start", "foobar"})
+		start.WaitWithDefaultTimeout()
+		Expect(start).Should(Exit(0))
+
+		inspect := podmanTest.Podman([]string{"pod", "inspect", "foobar"})
+		inspect.WaitWithDefaultTimeout()
+		Expect(inspect).Should(Exit(0))
+		data := inspect.InspectPodToJSON()
+		Expect(data.State).To(Equal(define.PodStateRunning))
+	})
+
+	It("podman create init container should fail in running pod", func() {
+		// create a running pod
+		topPod := podmanTest.Podman([]string{"run", "-dt", "--pod", "new:foobar", ALPINE, "top"})
+		topPod.WaitWithDefaultTimeout()
+		Expect(topPod).Should(Exit(0))
+		// adding init-ctr to running pod should fail
+		session := podmanTest.Podman([]string{"create", "--init-ctr", "always", "--pod", "foobar", ALPINE, "date"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(125))
+	})
+
+	It("podman make sure init container runs before pod containers", func() {
+		filename := filepath.Join("/dev/shm", RandomString(12))
+		content := RandomString(16)
+		session := podmanTest.Podman([]string{"create", "--init-ctr", "always", "--pod", "new:foobar", ALPINE, "bin/sh", "-c", fmt.Sprintf("echo %s > %s", content, filename)})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(0))
+		verify := podmanTest.Podman([]string{"create", "--pod", "foobar", "-t", ALPINE, "top"})
+		verify.WaitWithDefaultTimeout()
+		Expect(verify).Should(Exit(0))
+		start := podmanTest.Podman([]string{"pod", "start", "foobar"})
+		start.WaitWithDefaultTimeout()
+		Expect(start).Should(Exit(0))
+		checkLog := podmanTest.Podman([]string{"exec", "-it", verify.OutputToString(), "cat", filename})
+		checkLog.WaitWithDefaultTimeout()
+		Expect(checkLog).Should(Exit(0))
+		Expect(checkLog.OutputToString()).To(Equal(content))
+	})
+
+	It("podman make sure oneshot container is removed", func() {
+		filename := filepath.Join("/dev/shm", RandomString(12))
+		content := RandomString(16)
+		session := podmanTest.Podman([]string{"create", "--init-ctr", "oneshot", "--pod", "new:foobar", ALPINE, "bin/sh", "-c", fmt.Sprintf("echo %s > %s", content, filename)})
+		session.WaitWithDefaultTimeout()
+		initContainerID := session.OutputToString()
+		Expect(session).Should(Exit(0))
+		verify := podmanTest.Podman([]string{"create", "--pod", "foobar", "-t", ALPINE, "top"})
+		verify.WaitWithDefaultTimeout()
+		Expect(verify).Should(Exit(0))
+		start := podmanTest.Podman([]string{"pod", "start", "foobar"})
+		start.WaitWithDefaultTimeout()
+		Expect(start).Should(Exit(0))
+		check := podmanTest.Podman([]string{"container", "exists", initContainerID})
+		check.WaitWithDefaultTimeout()
+		// Container was rm'd
+		//Expect(check).Should(Exit(1))
+		Expect(check.ExitCode()).To(Equal(1), "I dont understand why the other way does not work")
+		// Lets double check with a stop and start
+		stopPod := podmanTest.Podman([]string{"pod", "stop", "foobar"})
+		stopPod.WaitWithDefaultTimeout()
+		Expect(stopPod).Should(Exit(0))
+		startPod := podmanTest.Podman([]string{"pod", "start", "foobar"})
+		startPod.WaitWithDefaultTimeout()
+		Expect(startPod).Should(Exit(0))
+
+		// Because no init was run, the file should not even exist
+		doubleCheck := podmanTest.Podman([]string{"exec", "-it", verify.OutputToString(), "cat", filename})
+		doubleCheck.WaitWithDefaultTimeout()
+		Expect(doubleCheck).Should(Exit(1))
+
+	})
+
+	It("podman ensure always init containers always run", func() {
+		filename := filepath.Join("/dev/shm", RandomString(12))
+
+		// Write the date to a file
+		session := podmanTest.Podman([]string{"create", "--init-ctr", "always", "--pod", "new:foobar", ALPINE, "bin/sh", "-c", fmt.Sprintf("date > %s", filename)})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(Exit(0))
+		verify := podmanTest.Podman([]string{"create", "--pod", "foobar", "-t", ALPINE, "top"})
+		verify.WaitWithDefaultTimeout()
+		Expect(verify).Should(Exit(0))
+		start := podmanTest.Podman([]string{"pod", "start", "foobar"})
+		start.WaitWithDefaultTimeout()
+		Expect(start).Should(Exit(0))
+
+		// capture the date written
+		checkLog := podmanTest.Podman([]string{"exec", "-it", verify.OutputToString(), "cat", filename})
+		checkLog.WaitWithDefaultTimeout()
+		firstResult := checkLog.OutputToString()
+		Expect(checkLog).Should(Exit(0))
+
+		// Stop and start the pod
+		stopPod := podmanTest.Podman([]string{"pod", "stop", "foobar"})
+		stopPod.WaitWithDefaultTimeout()
+		Expect(stopPod).Should(Exit(0))
+		startPod := podmanTest.Podman([]string{"pod", "start", "foobar"})
+		startPod.WaitWithDefaultTimeout()
+		Expect(startPod).Should(Exit(0))
+
+		// Check the file again with exec
+		secondCheckLog := podmanTest.Podman([]string{"exec", "-it", verify.OutputToString(), "cat", filename})
+		secondCheckLog.WaitWithDefaultTimeout()
+		Expect(secondCheckLog).Should(Exit(0))
+
+		// Dates should not match
+		Expect(firstResult).ToNot(Equal(secondCheckLog.OutputToString()))
+	})
+
+})