use container cgroups path

When looking up a container's cgroup path, parse /proc/[PID]/cgroup.
This will work across all cgroup managers and configurations and is
supported on cgroups v1 and v2.

Fixes: #8265
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/test/e2e/stats_test.go b/test/e2e/stats_test.go
index c8f5efa9d..5e8a7a3d0 100644
--- a/test/e2e/stats_test.go
+++ b/test/e2e/stats_test.go
@@ -5,6 +5,7 @@ package integration
 import (
 	"fmt"
 	"os"
+	"strconv"
 	"time"
 
 	. "github.com/containers/podman/v2/test/utils"
@@ -126,4 +127,44 @@ var _ = Describe("Podman stats", func() {
 		session.WaitWithDefaultTimeout()
 		Expect(session.ExitCode()).To(Equal(0))
 	})
+
+	// Regression test for #8265
+	It("podman stats with custom memory limits", func() {
+		// Run thre containers. One with a memory limit.  Make sure
+		// that the limits are different and the limited one has a
+		// lower limit.
+		ctrNoLimit0 := "no-limit-0"
+		ctrNoLimit1 := "no-limit-1"
+		ctrWithLimit := "with-limit"
+
+		session := podmanTest.Podman([]string{"run", "-d", "--name", ctrNoLimit0, ALPINE, "top"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+
+		session = podmanTest.Podman([]string{"run", "-d", "--name", ctrNoLimit1, ALPINE, "top"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+
+		session = podmanTest.Podman([]string{"run", "-d", "--name", ctrWithLimit, "--memory", "50m", ALPINE, "top"})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+
+		session = podmanTest.Podman([]string{"stats", "--no-stream", "--format", "{{.MemLimit}}", ctrNoLimit0, ctrNoLimit1, ctrWithLimit})
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+
+		// We have three containers.  The unlimited ones need to have
+		// the same limit, the limited one a lower one.
+		limits := session.OutputToStringArray()
+		Expect(len(limits)).To(BeNumerically("==", 3))
+		Expect(limits[0]).To(Equal(limits[1]))
+		Expect(limits[0]).ToNot(Equal(limits[2]))
+
+		defaultLimit, err := strconv.Atoi(limits[0])
+		Expect(err).To(BeNil())
+		customLimit, err := strconv.Atoi(limits[2])
+		Expect(err).To(BeNil())
+
+		Expect(customLimit).To(BeNumerically("<", defaultLimit))
+	})
 })