Merge pull request #41168 from thaJeztah/raise_minimum_memory_limit

Set minimum memory limit to 6M, to account for higher startup memory use

daemon/daemon_unix.go

@@ -68,8 +68,8 @@ const (
 	linuxMinCPUShares = 2
 	linuxMaxCPUShares = 262144
 	platformSupported = true
-	// It's not kernel limit, we want this 4M limit to supply a reasonable functional container
-	linuxMinMemory = 4194304
+	// It's not kernel limit, we want this 6M limit to account for overhead during startup, and to supply a reasonable functional container
+	linuxMinMemory = 6291456
 	// constants for remapped root settings
 	defaultIDSpecifier = "default"
 	defaultRemappedID  = "dockremap"
@@ -433,7 +433,7 @@ func verifyPlatformContainerResources(resources *containertypes.Resources, sysIn
 
 	// memory subsystem checks and adjustments
 	if resources.Memory != 0 && resources.Memory < linuxMinMemory {
-		return warnings, fmt.Errorf("Minimum memory limit allowed is 4MB")
+		return warnings, fmt.Errorf("Minimum memory limit allowed is 6MB")
 	}
 	if resources.Memory > 0 && !sysInfo.MemoryLimit {
 		warnings = append(warnings, "Your kernel does not support memory limit capabilities or the cgroup is not mounted. Limitation discarded.")

integration-cli/docker_api_containers_test.go

@@ -871,7 +871,7 @@ func (s *DockerSuite) TestCreateWithTooLowMemoryLimit(c *testing.T) {
 	} else {
 		assert.Assert(c, res.StatusCode != http.StatusOK)
 	}
-	assert.Assert(c, strings.Contains(string(b), "Minimum memory limit allowed is 4MB"))
+	assert.Assert(c, strings.Contains(string(b), "Minimum memory limit allowed is 6MB"))
 }
 
 func (s *DockerSuite) TestContainerAPIRename(c *testing.T) {

integration-cli/docker_cli_run_test.go

@@ -2826,13 +2826,11 @@ func (s *DockerSuite) TestRunPIDHostWithChildIsKillable(c *testing.T) {
 }
 
 func (s *DockerSuite) TestRunWithTooSmallMemoryLimit(c *testing.T) {
-	// TODO Windows. This may be possible to enable once Windows supports
-	// memory limits on containers
+	// TODO Windows. This may be possible to enable once Windows supports memory limits on containers
 	testRequires(c, DaemonIsLinux)
-	// this memory limit is 1 byte less than the min, which is 4MB
-	// https://github.com/docker/docker/blob/v1.5.0/daemon/create.go#L22
-	out, _, err := dockerCmdWithError("run", "-m", "4194303", "busybox")
-	if err == nil || !strings.Contains(out, "Minimum memory limit allowed is 4MB") {
+	// this memory limit is 1 byte less than the min (daemon.linuxMinMemory), which is 6MB (6291456 bytes)
+	out, _, err := dockerCmdWithError("create", "-m", "6291455", "busybox")
+	if err == nil || !strings.Contains(out, "Minimum memory limit allowed is 6MB") {
 		c.Fatalf("expected run to fail when using too low a memory limit: %q", out)
 	}
 }

integration-cli/docker_cli_update_unix_test.go

@@ -108,7 +108,7 @@ func (s *DockerSuite) TestUpdateContainerInvalidValue(c *testing.T) {
 	dockerCmd(c, "run", "-d", "--name", name, "-m", "300M", "busybox", "true")
 	out, _, err := dockerCmdWithError("update", "-m", "2M", name)
 	assert.ErrorContains(c, err, "")
-	expected := "Minimum memory limit allowed is 4MB"
+	expected := "Minimum memory limit allowed is 6MB"
 	assert.Assert(c, strings.Contains(out, expected))
 }
 

integration-cli/docker_deprecated_api_v124_test.go

@@ -175,7 +175,7 @@ func (s *DockerSuite) TestDeprecatedStartWithTooLowMemoryLimit(c *testing.T) {
 	} else {
 		assert.Equal(c, res.StatusCode, http.StatusBadRequest)
 	}
-	assert.Assert(c, is.Contains(string(b), "Minimum memory limit allowed is 4MB"))
+	assert.Assert(c, is.Contains(string(b), "Minimum memory limit allowed is 6MB"))
 }
 
 // #14640