fix some leaking mounts in tests

This should help with errors such as:

    === RUN   TestSysctlOverride
        testing.go:1090: TempDir RemoveAll cleanup: unlinkat /tmp/TestSysctlOverride3702360633/001/mounts/shm: device or resource busy
    --- FAIL: TestSysctlOverride (0.00s)

    === RUN   TestSysctlOverrideHost
        testing.go:1090: TempDir RemoveAll cleanup: unlinkat /tmp/TestSysctlOverrideHost226485533/001/mounts/shm: device or resource busy
    --- FAIL: TestSysctlOverrideHost (0.00s)

    === RUN   TestDockerSuite/TestRunWithVolumesIsRecursive
        testing.go:1090: TempDir RemoveAll cleanup: unlinkat /tmp/TestDockerSuiteTestRunWithVolumesIsRecursive1156692230/001/tmpfs: device or resource busy
        --- FAIL: TestDockerSuite/TestRunWithVolumesIsRecursive (0.49s)

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

integration-cli/docker_api_containers_test.go

@@ -1971,22 +1971,22 @@ func (s *DockerAPISuite) TestContainersAPICreateMountsCreate(c *testing.T) {
 			assert.NilError(c, err)
 			defer os.RemoveAll(tmpDir3)
 
-			assert.Assert(c, mountWrapper(tmpDir3, tmpDir3, "none", "bind,shared") == nil)
-
-			cases = append(cases, []testCase{
-				{
-					spec:     mount.Mount{Type: "bind", Source: tmpDir3, Target: destPath},
-					expected: types.MountPoint{Type: "bind", RW: true, Destination: destPath, Source: tmpDir3},
-				},
-				{
-					spec:     mount.Mount{Type: "bind", Source: tmpDir3, Target: destPath, ReadOnly: true},
-					expected: types.MountPoint{Type: "bind", RW: false, Destination: destPath, Source: tmpDir3},
-				},
-				{
-					spec:     mount.Mount{Type: "bind", Source: tmpDir3, Target: destPath, ReadOnly: true, BindOptions: &mount.BindOptions{Propagation: "shared"}},
-					expected: types.MountPoint{Type: "bind", RW: false, Destination: destPath, Source: tmpDir3, Propagation: "shared"},
-				},
-			}...)
+			if assert.Check(c, mountWrapper(c, tmpDir3, tmpDir3, "none", "bind,shared")) {
+				cases = append(cases, []testCase{
+					{
+						spec:     mount.Mount{Type: "bind", Source: tmpDir3, Target: destPath},
+						expected: types.MountPoint{Type: "bind", RW: true, Destination: destPath, Source: tmpDir3},
+					},
+					{
+						spec:     mount.Mount{Type: "bind", Source: tmpDir3, Target: destPath, ReadOnly: true},
+						expected: types.MountPoint{Type: "bind", RW: false, Destination: destPath, Source: tmpDir3},
+					},
+					{
+						spec:     mount.Mount{Type: "bind", Source: tmpDir3, Target: destPath, ReadOnly: true, BindOptions: &mount.BindOptions{Propagation: "shared"}},
+						expected: types.MountPoint{Type: "bind", RW: false, Destination: destPath, Source: tmpDir3, Propagation: "shared"},
+					},
+				}...)
+			}
 		}
 	}
 

integration-cli/docker_api_containers_unix_test.go

@@ -2,8 +2,18 @@
 
 package main
 
-import "github.com/moby/sys/mount"
+import (
+	"testing"
 
-func mountWrapper(device, target, mType, options string) error {
-	return mount.Mount(device, target, mType, options)
+	"github.com/moby/sys/mount"
+)
+
+func mountWrapper(t *testing.T, device, target, mType, options string) error {
+	t.Helper()
+	err := mount.Mount(device, target, mType, options)
+	if err != nil {
+		return err
+	}
+	t.Cleanup(func() { _ = mount.Unmount(target) })
+	return nil
 }

integration-cli/docker_api_containers_windows_test.go

@@ -73,7 +73,7 @@ func (s *DockerAPISuite) TestContainersAPICreateMountsBindNamedPipe(c *testing.T
 	assert.Check(c, is.Equal(text, strings.TrimSpace(string(b))))
 }
 
-func mountWrapper(device, target, mType, options string) error {
+func mountWrapper(t *testing.T, device, target, mType, options string) error {
 	// This should never be called.
 	return errors.Errorf("there is no implementation of Mount on this platform")
 }

integration-cli/docker_cli_run_unix_test.go

@@ -70,6 +70,7 @@ func (s *DockerCLIRunSuite) TestRunWithVolumesIsRecursive(c *testing.T) {
 	tmpfsDir := filepath.Join(tmpDir, "tmpfs")
 	assert.Assert(c, os.MkdirAll(tmpfsDir, 0o777) == nil, "failed to mkdir at %s", tmpfsDir)
 	assert.Assert(c, mount.Mount("tmpfs", tmpfsDir, "tmpfs", "") == nil, "failed to create a tmpfs mount at %s", tmpfsDir)
+	defer mount.Unmount(tmpfsDir)
 
 	f, err := os.CreateTemp(tmpfsDir, "touch-me")
 	assert.NilError(c, err)