Add test for Apertis update manager error conditions

Add test to check proper behavior in the following circumstances:
- Power cut during an update
- USB mass storage unplug during an update
- The disk is full during an update

Signed-off-by: Denis Pynkin <denis.pynkin@collabora.com>
Signed-off-by: Frédéric Dalleau <frederic.dalleau@collabora.com>

test-cases/apertis-update-manager-diskfull.yaml

+metadata:
+  name: apertis-update-manager-diskfull
+  format: "Apertis Test Definition 1.0"
+  image-type: any
+  image-arch: armhf
+  type: functional
+  exec-type: manual
+  priority: medium
+  maintainer: "Apertis Project"
+  description: "Ensure that failures due to disk full errors during updates have no effect on the system"
+
+  resources:
+    - "A Fat32 USB flash drive, preloaded with an update bundle named static-update.bundle at the root of the disk"
+    - "The DUT u-boot environment must be clean: in u-boot, run: `env default -a` followed by `saveenv`"
+    - "A PC must be connected to DUT serial port"
+
+  expected:
+    - "The update wasn't applied"
+    - "System boots using the initial deployment"
+
+run:
+  steps:
+    - "Check the current deployment"
+    - $ sudo ostree admin status
+    - "Need to monitor the journal log"
+    - $ sudo journalctl -ef --unit apertis-update-manager &
+    - "Check the free space on rootfs, calculate the size of file to leave only 3% of free space.
+      For instance,  NUM=2604620 for case below -- just round to lesser value the result of calculation: 2716616-(3733136/100*3)"
+    - $ sudo df -B 512 /
+    - | 
+        >Filesystem         512B-blocks      Used Available Use% Mounted on
+        /dev/mmcblk0p2         3733136    790784   2716616  23% /
+    - $ sudo dd if=/dev/zero of=/var/bigfile bs=512 count=<NUM>
+    - "Plug the USB flash drive in the device"
+    - "The update should fail with some error message related to disk space, for instance:"
+    - |
+        >Dec 19 22:55:10 apertis apertis-update-[319]: Ostree upgrade failed: mkdir(boot/loader.0/entries): Input/output error
+        Dec 19 22:43:46 apertis apertis-update-[794]: Ostree upgrade failed: Error writing to file descriptor: No space left on device
+    - "Remove the USB flash drive"
+    - "Remove temporary file"
+    - $ sudo rm -f /var/bigfile
+    - "Fill the disk with root filesystem to 100%"
+    - $ sudo dd if=/dev/zero of=/var/bigfile bs=1M
+    - "Plug the USB flash drive in the device"
+    - "The update should fail with error message"
+    - |
+        >Dec 19 22:53:33 apertis apertis-update-[348]: Ostree upgrade failed: min-free-space-percent '3%' would be exceeded, 16.8 MB available
+    - "Remove the USB flash drive"
+    - "Remove temporary file"
+    - $ sudo rm -f /var/bigfile
+    - "Reboot the system"
+    - $ sudo reboot
+    - "Check that the status is the same than at the beginning of the test"
+    - $ sudo ostree admin status

test-cases/apertis-update-manager-powercut.yaml

+metadata:
+  name: apertis-update-manager-powercut
+  format: "Apertis Test Definition 1.0"
+  image-type: any
+  image-arch: armhf
+  type: functional
+  exec-type: manual
+  priority: medium
+  maintainer: "Apertis Project"
+  description: "Ensure that failures due to power losses during updates have no effect on the system"
+
+  resources:
+    - "A Fat32 USB flash drive, preloaded with an update bundle named static-update.bundle at the root of the disk"
+    - "The DUT u-boot environment must be clean: in u-boot, run: `env default -a` followed by `saveenv`"
+    - "A PC must be connected to DUT serial port"
+
+  expected:
+    - "The update wasn't applied"
+    - "System boots using the initial deployment"
+    - "Possible corruption of root file system which should not affect to boot into initial OSTree deployment"
+
+run:
+  steps:
+    - "Check the current deployment"
+    - $ sudo ostree admin status
+    - "Need to monitor the journal log to catch events in time"
+    - $ sudo journalctl -ef --unit apertis-update-manager &
+    - "Plug the USB flash drive into the device"
+    - "The update starts automatically"
+    - "Wait while the upgrade starts"
+    - |
+        >Dec 19 22:31:46 apertis apertis-update-[390]: mount added : /media/test
+        Dec 19 22:31:46 apertis apertis-update-[390]: Ostree static delta starting
+        Dec 19 22:31:46 apertis apertis-update-[390]: Cannot check the ID in black list: No such file or directory
+    - "Wait for message similar to below in log and immediately unplug the power"
+    - |
+        >Dec 19 22:46:59 apertis apertis-update-managerd[887]: Copying /etc changes: 5 modified, 0 removed, 16 added
+    - "Plug the power back and let the device boot"
+    - "Check the current deployment is the same that at the beginning of the test"
+    - $ sudo ostree admin status

test-cases/apertis-update-manager-usb-unplug.yaml

+metadata:
+  name: apertis-update-manager-usb-unplug
+  format: "Apertis Test Definition 1.0"
+  image-type: any
+  image-arch: armhf
+  type: functional
+  exec-type: manual
+  priority: medium
+  maintainer: "Apertis Project"
+  description: "Test the apertis-update-manager automatic update interrupted by mass storage removing."
+
+  resources:
+    - "A Fat32 USB flash drive, preloaded with an update bundle named static-update.bundle at the root of the disk"
+    - "The DUT u-boot environment must be clean: in u-boot, run: `env default -a` followed by `saveenv`"
+    - "A PC must be connected to DUT serial port"
+
+  expected:
+    - "The update wasn't applied"
+    - "System boots using the initial deployment"
+
+run:
+  steps:
+    - "Check the current deployment"
+    - $ sudo ostree admin status
+    - "Need to monitor the journal log to catch events in time"
+    - $ sudo journalctl -ef --unit apertis-update-manager &
+    - "Plug the USB flash drive into the device"
+    - "The update starts automatically"
+    - "Wait while the upgrade starts"
+    - |
+        >Dec 19 22:31:46 apertis apertis-update-[390]: mount added : /media/test
+        Dec 19 22:31:46 apertis apertis-update-[390]: Ostree static delta starting
+        Dec 19 22:31:46 apertis apertis-update-[390]: Cannot check the ID in black list: No such file or directory
+    - "Wait 10-20 seconds (depending on your HW) and remove the USB flash drive"
+    - "Update should be interrupted with error messages similar to"
+    - |
+        >[   59.542717] scsi 1:0:0:0: rejecting I/O to offline device
+        [   59.548183] scsi 1:0:0:0: rejecting I/O to offline device
+        [   59.553633] scsi 1:0:0:0: rejecting I/O to dead device
+        [   59.558840] scsi 1:0:0:0: rejecting I/O to dead device
+        [   59.564239] print_req_error: I/O error, dev sda, sector 24393
+        [   59.570120] print_req_error: I/O error, dev sda, sector 24633
+        Dec 19 22:31:49 apertis systemd[1]: apertis-update-manager.service: Main process exited, code=killed, status=7/BUS
+        Dec 19 22:31:49 apertis systemd[1]: apertis-update-manager.service: Unit entered failed state.
+        Dec 19 22:31:49 apertis systemd[1]: apertis-update-manager.service: Failed with result 'signal'.
+        Dec 19 22:31:49 apertis systemd[1]: apertis-update-manager.service: Service hold-off time over, scheduling restart.
+        Dec 19 22:31:49 apertis systemd[1]: Stopped Apertis update manager.
+        Dec 19 22:31:49 apertis systemd[1]: Starting Apertis update manager...
+    - "Check the current deployment is the same that at the beginning of the test"
+    - $ sudo ostree admin status
+    - "Repeat the test several times by plug and unplug the USB stick"
+    - "Reboot the system"
+    - $ sudo reboot
+    - "Check the current deployment is the same that at the beginning of the test"
+    - $ sudo ostree admin status
+