test(volumes): Add test for block volumes in Linux over Qemu and FC

Add nerdctl tests to check if block-based volumes that are passed in the
container are properly mounted and unmounted inside the Linux VM. To
simulate this, a dummy block device is created from the user with dd and
mkfs. Then this device is mounted somewhere and this mountpoint is
passed as a bind mount to the container.

For that purpose, this commit:
- Adds support for defining the volumes to bind mount inside the
  container through the test description.
- Adds support for bind mounting volumes in ctr, nerdctl, crictl and docker.
  This functionality can be used for other tests too.
- Adds a new test which executes cat /proc/self/mountinfo inside the
  VM, captures the output and checks if all defined volumes in the test
  description were properly mounted inside the VM. Furthermore, it
  checks if they were unmounted correctly too.

It also changed the vm_test workflow to simulate the dummy block based
mount.

Moreover, the timeout was increased to 3 seconds for each test because
the Linux VM shows a lot of logs, exceeding 2 secs. We should definitely
change that in the future.

PR: #329
Signed-off-by: Charalampos Mainas <cmainas@nubificus.co.uk>
Reviewed-by: Anastassios Nanos <ananos@nubificus.co.uk>
Approved-by: Anastassios Nanos <ananos@nubificus.co.uk>

Author: cmainas

.github/workflows/vm_test.yml

@@ -171,6 +171,13 @@ jobs:
         EOT
         sudo systemctl restart containerd
 
+    - name: Setup block-based mountpoint
+      run: |
+        mkdir /tmp/test_mountpoint
+        dd if=/dev/zero of=/tmp/fake_block bs=1M count=200
+        mkfs.ext2 /tmp/fake_block
+        sudo mount /tmp/fake_block /tmp/test_mountpoint
+
     - name: Install CNI plugins
       env:
         CNI_VERSION: ${{ inputs.cni_version }}

docs/Sample-images.md

@@ -48,3 +48,5 @@ We plan to create and maintain multi-platform images soon, as well as enrich thi
 - harbor.nbfc.io/nubificus/urunc/block-test-spt-mirage:latest
 - harbor.nbfc.io/nubificus/urunc/whoami-qemu-linux-initrd:latest
 - harbor.nbfc.io/nubificus/urunc/whoami-firecracker-linux-initrd:latest
+- harbor.nbfc.io/nubificus/urunc/busybox-qemu-linux-raw:latest
+- harbor.nbfc.io/nubificus/urunc/busybox-firecracker-linux-raw:latest

tests/e2e/common.go

@@ -66,6 +66,9 @@ func commonNewContainerCmd(a containerTestArgs) string {
 	for _, groupID := range a.Groups {
 		cmdBase += fmt.Sprintf("--group-add %d ", groupID)
 	}
+	for _, vol := range a.Volumes {
+		cmdBase += fmt.Sprintf("--mount type=bind,src=%s,dst=%s ", vol.Source, vol.Dest)
+	}
 	cmdBase += "--name "
 	cmdBase += a.Name + " "
 	cmdBase += a.Image + " "

tests/e2e/crictl.go

@@ -84,6 +84,14 @@ func crictlNewContainerConfig(path string, a containerTestArgs) (string, error)
 	} else {
 		name = a.Name
 	}
+	var mounts []*criruntimeapi.Mount
+	for _, vol := range a.Volumes {
+		mounts = append(mounts, &criruntimeapi.Mount{
+			ContainerPath: vol.Dest,
+			HostPath:      vol.Source,
+			Readonly:      false,
+		})
+	}
 	containerConfig := criruntimeapi.ContainerConfig{
 		Metadata: &criruntimeapi.ContainerMetadata{
 			Name: name,
@@ -92,6 +100,7 @@ func crictlNewContainerConfig(path string, a containerTestArgs) (string, error)
 			Image: a.Image,
 		},
 		Command: strings.Fields(a.Cli),
+		Mounts:  mounts,
 		Linux: &criruntimeapi.LinuxContainerConfig{
 			SecurityContext: &criruntimeapi.LinuxContainerSecurityContext{},
 			Resources:       &criruntimeapi.LinuxContainerResources{},

tests/e2e/ctr.go

@@ -50,6 +50,9 @@ func ctrNewContainerCmd(a containerTestArgs) string {
 	if a.UID != 0 || a.GID != 0 {
 		cmdBase += fmt.Sprintf("-u %d:%d ", a.UID, a.GID)
 	}
+	for _, vol := range a.Volumes {
+		cmdBase += fmt.Sprintf("--mount type=bind,src=%s,dst=%s ", vol.Source, vol.Dest)
+	}
 	cmdBase += a.Image + " "
 	cmdBase += a.Name + " "
 	cmdBase += a.Cli