initrd: add integration tests

Add integration tests for booting VMs with initrd and no rootfs.
- Functional: the VM shall boot and / should be mounted as "rootfs"
- Performance: VM shall boot in less than 400ms

Co-developed-by: Tim Deegan <tdeegan@amazon.com>
Signed-off-by: Tim Deegan <tdeegan@amazon.com>
Co-developed-by: Marco Vedovati <mvedovati@suse.com>
Signed-off-by: Marco Vedovati <mvedovati@suse.com>

tests/README.md

@@ -89,6 +89,7 @@ s3://<bucket-url>/img/
     <microvm_test_image_folder_n>/
         kernel/
             <optional_kernel_name.>vmlinux.bin
+            <optional_initrd_name.>initrd.img
         fsfiles/
             <rootfs_name>rootfs.ext4
             <other_fsfile_n>

tests/framework/microvm.py

@@ -59,6 +59,7 @@ def __init__(
         self._fsfiles_path = os.path.join(self._path, MICROVM_FSFILES_RELPATH)
         self._kernel_file = ''
         self._rootfs_file = ''
+        self._initrd_file = ''
 
         # The binaries this microvm will use to start.
         self._fc_binary_path = fc_binary_path
@@ -170,6 +171,16 @@ def kernel_file(self, path):
         """Set the path to the kernel file."""
         self._kernel_file = path
 
+    @property
+    def initrd_file(self):
+        """Return the name of the initrd file used by this microVM to boot."""
+        return self._initrd_file
+
+    @initrd_file.setter
+    def initrd_file(self, path):
+        """Set the path to the initrd file."""
+        self._initrd_file = path
+
     @property
     def rootfs_file(self):
         """Return the path to the image this microVM can boot into."""
@@ -228,6 +239,7 @@ def setup(self):
              <microvm_uuid>/
                  kernel/
                      <kernel_file_n>
+                     <initrd_file_n>
                      ....
                  fsfiles/
                      <fsfile_n>
@@ -275,7 +287,7 @@ def spawn(self):
             if self.bin_cloner_path:
                 cmd = [self.bin_cloner_path] + \
                       [self._jailer_binary_path] + \
-                      jailer_param_list
+                    jailer_param_list
                 _p = run(cmd, stdout=PIPE, stderr=PIPE, check=True)
                 # Terrible hack to make the tests fail when starting the
                 # jailer fails with a panic. This is needed because we can't
@@ -334,7 +346,8 @@ def basic_config(
         vcpu_count: int = 2,
         ht_enabled: bool = False,
         mem_size_mib: int = 256,
-        add_root_device: bool = True
+        add_root_device: bool = True,
+        use_initrd: bool = False
     ):
         """Shortcut for quickly configuring a microVM.
 
@@ -361,13 +374,18 @@ def basic_config(
                 self._memory_events_queue
             )
 
-        # Add a kernel to start booting from.
-        response = self.boot.put(
-            kernel_image_path=self.create_jailed_resource(self.kernel_file)
-        )
+        boot_source_args = {}
+        boot_source_args.update(
+            kernel_image_path=self.create_jailed_resource(self.kernel_file))
+
+        if use_initrd and self.initrd_file != '':
+            boot_source_args.update(
+                initrd_path=self.create_jailed_resource(self.initrd_file))
+
+        response = self.boot.put(**boot_source_args)
         assert self._api_session.is_status_no_content(response.status_code)
 
-        if add_root_device:
+        if add_root_device and self.rootfs_file != '':
             # Add the root file system with rw permissions.
             response = self.drive.put(
                 drive_id='rootfs',

tests/framework/resources.py

@@ -88,12 +88,15 @@ def get(cls):
     @staticmethod
     def create_json(
             boot_args=None,
-            kernel_image_path=None
+            kernel_image_path=None,
+            initrd_path=None
     ):
         """Compose the json associated to this type of API request."""
         datax = {}
         if kernel_image_path is not None:
             datax['kernel_image_path'] = kernel_image_path
+        if initrd_path is not None:
+            datax['initrd_path'] = initrd_path
         if boot_args is not None:
             datax['boot_args'] = boot_args
         return datax

tests/framework/s3fetcher.py

@@ -27,6 +27,7 @@ class MicrovmImageS3Fetcher:
         <microvm_image_folder_n>/
             kernel/
                 <optional_kernel_name>vmlinux.bin
+                <optional_initrd_name>initrd.img
             fsfiles/
                 <rootfs_file_name>rootfs.ext4
                 <other_fsfile_n>
@@ -55,6 +56,7 @@ class MicrovmImageS3Fetcher:
     MICROVM_IMAGE_KERNEL_RELPATH = 'kernel/'
     MICROVM_IMAGE_BLOCKDEV_RELPATH = 'fsfiles/'
     MICROVM_IMAGE_KERNEL_FILE_SUFFIX = r'vmlinux.bin'
+    MICROVM_IMAGE_INITRD_FILE_SUFFIX = r'initrd.img'
     MICROVM_IMAGE_ROOTFS_FILE_SUFFIX = r'rootfs.ext4'
     MICROVM_IMAGE_SSH_KEY_SUFFIX = r'.id_rsa'
 
@@ -142,13 +144,32 @@ def init_vm_resources(self, microvm_image_name, microvm):
 
             if not os.path.exists(microvm_dest_path):
                 copyfile(resource_local_path, microvm_dest_path)
+                """"
+                Disclaimer: Ugly HACK...!
+
+                While an initrd.img is missing on the S3 bucket, place a copy of
+                it in the local ubuntu_with_ssh/kernel/ image folder, and then run
+                initrd tests using the "test_microvm_with_ssh" fixture.
+                """
+                if microvm_dest_path.endswith(self.MICROVM_IMAGE_KERNEL_FILE_SUFFIX) and  \
+                   resource_local_path.find('ubuntu_with_ssh') > 0:
+                    src_initrd = resource_local_path.replace(
+                        self.MICROVM_IMAGE_KERNEL_FILE_SUFFIX, self.MICROVM_IMAGE_INITRD_FILE_SUFFIX)
+                    dest_initrd = microvm_dest_path.replace(
+                        self.MICROVM_IMAGE_KERNEL_FILE_SUFFIX, self.MICROVM_IMAGE_INITRD_FILE_SUFFIX)
+                    copyfile(src_initrd, dest_initrd)
+                    microvm.initrd_file = dest_initrd
+                """ END OF HACK """
 
             if resource_key.endswith(self.MICROVM_IMAGE_KERNEL_FILE_SUFFIX):
                 microvm.kernel_file = microvm_dest_path
 
             if resource_key.endswith(self.MICROVM_IMAGE_ROOTFS_FILE_SUFFIX):
                 microvm.rootfs_file = microvm_dest_path
 
+            if resource_key.endswith(self.MICROVM_IMAGE_INITRD_FILE_SUFFIX):
+                microvm.initrd_file = microvm_dest_path
+
             if resource_key.endswith(self.MICROVM_IMAGE_SSH_KEY_SUFFIX):
                 # Add the key path to the config dictionary and set
                 # permissions.
@@ -193,6 +214,9 @@ def hardlink_vm_resources(
             if resource_key.endswith(self.MICROVM_IMAGE_ROOTFS_FILE_SUFFIX):
                 to_microvm.rootfs_file = microvm_dest_path
 
+            if resource_key.endswith(self.MICROVM_IMAGE_INITRD_FILE_SUFFIX):
+                to_microvm.initrd_file = microvm_dest_path
+
             if resource_key.endswith(self.MICROVM_IMAGE_SSH_KEY_SUFFIX):
                 # Add the key path to the config dictionary and set
                 # permissions.

tests/integration_tests/functional/test_initrd.py

@@ -0,0 +1,31 @@
+# Copyright 2019 SUSE LLC
+# SPDX-License-Identifier: Apache-2.0
+"""Tests for initd."""
+
+from host_tools.network import SSHConnection
+
+INITRD_FILESYSTEM = "rootfs"
+
+
+def test_microvm_initrd(
+        test_microvm_with_ssh,
+        network_config):
+    """ Check microvm started with an inird has / mounted as rootfs."""
+
+    vm = test_microvm_with_ssh
+
+    vm.spawn()
+
+    vm.basic_config(
+        add_root_device=False,
+        use_initrd=True
+    )
+    _tap, _, _ = vm.ssh_network_config(network_config, '1')
+
+    vm.start()
+
+    # Find out  what is the filesystem of /, and make sure initrd is used
+    conn = SSHConnection(vm.ssh_config)
+    ecode, stdout, _ = conn.execute_command(
+        f"findmnt / | grep -q -w {INITRD_FILESYSTEM}")
+    assert ecode == 0

tests/integration_tests/performance/test_boottime.py

@@ -11,6 +11,7 @@
 
 # The maximum acceptable boot time in us.
 MAX_BOOT_TIME_US = 150000
+MAX_BOOT_TIME_INITRD_US = 400000
 # TODO: Keep a `current` boot time in S3 and validate we don't regress
 # Regex for obtaining boot time from some string.
 TIMESTAMP_LOG_REGEX = r'Guest-boot-time\s+\=\s+(\d+)\s+us'
@@ -76,7 +77,32 @@ def test_single_microvm_boottime_with_network(
     print("Boot time with network configured is: " + str(boottime_us) + " us")
 
 
-def _test_microvm_boottime(log_fifo):
+def test_single_microvm_net_initrd_boottime(
+        test_microvm_with_ssh,
+        network_config
+):
+    """Check guest boottime of microvm with network."""
+    log_fifo, _tap = _configure_vm(test_microvm_with_ssh, {
+        "config": network_config, "iface_id": "1"
+    }, initrd=True)
+    time.sleep(0.4)
+    boottime_us = _test_microvm_boottime(
+        log_fifo, max_time_us=MAX_BOOT_TIME_INITRD_US)
+    print("Boot time with initrd + network configured is: " +
+          str(boottime_us) + " us")
+
+
+def test_single_microvm_initrd_boottime(
+        test_microvm_with_ssh):
+    """Check guest boottime of microvm with network."""
+    log_fifo, _tap = _configure_vm(test_microvm_with_ssh, initrd=True)
+    time.sleep(0.4)
+    boottime_us = _test_microvm_boottime(
+        log_fifo, max_time_us=MAX_BOOT_TIME_INITRD_US)
+    print("Boot time with initrd is: " + str(boottime_us) + " us")
+
+
+def _test_microvm_boottime(log_fifo, max_time_us=MAX_BOOT_TIME_US):
     """Assert that we meet the minimum boot time.
 
     TODO: Should use a microVM with the `boottime` capability.
@@ -90,19 +116,26 @@ def _test_microvm_boottime(log_fifo):
             boot_time_us = int(timestamps[0])
 
     assert boot_time_us > 0
-    assert boot_time_us < MAX_BOOT_TIME_US
+    assert boot_time_us < max_time_us
     return boot_time_us
 
 
-def _configure_vm(microvm, network_info=None):
+def _configure_vm(microvm, network_info=None, initrd=False):
     """Auxiliary function for preparing microvm before measuring boottime."""
     microvm.spawn()
 
     # Machine configuration specified in the SLA.
-    microvm.basic_config(
-        vcpu_count=1,
-        mem_size_mib=128
-    )
+    config = {
+        'vcpu_count': 1,
+        'mem_size_mib': 128
+    }
+
+    if initrd:
+        config['add_root_device'] = False
+        config['use_initrd'] = True
+
+    microvm.basic_config(**config)
+
     if network_info:
         _tap, _, _ = microvm.ssh_network_config(
             network_info["config"],