From ad437292ab296409cab8d46316de1af5f367867d Mon Sep 17 00:00:00 2001
From: Disassembler <disassembler@dasm.cz>
Date: Sat, 11 Apr 2020 14:55:18 +0200
Subject: [PATCH] Rewrite extend-disk in python and move vmtty back to basic vm
 setup

---
 apk/vmmgr           |   2 +-
 vm/etc/inittab      |   1 -
 vm/sbin/extend-disk | 117 ++++++++++++++++++++++++++++++--------------
 vm/sbin/vmtty       |  17 +++++++
 4 files changed, 97 insertions(+), 40 deletions(-)
 create mode 100755 vm/sbin/vmtty

diff --git a/apk/vmmgr b/apk/vmmgr
index 7c9ed8c..ff9a12a 160000
--- a/apk/vmmgr
+++ b/apk/vmmgr
@@ -1 +1 @@
-Subproject commit 7c9ed8c17a1ef9b403fbf899915ed2f16bf67459
+Subproject commit ff9a12af65ad6e0a036a74006c7d85578d4be746
diff --git a/vm/etc/inittab b/vm/etc/inittab
index 811da22..1547c8d 100644
--- a/vm/etc/inittab
+++ b/vm/etc/inittab
@@ -2,7 +2,6 @@
 
 ::sysinit:/sbin/openrc sysinit >/dev/null 2>&1
 ::sysinit:/sbin/openrc boot >/dev/null 2>&1
-::wait:/sbin/extend-disk >/dev/null 2>&1
 ::wait:/sbin/openrc default >/dev/null 2>&1
 
 # Set up getty
diff --git a/vm/sbin/extend-disk b/vm/sbin/extend-disk
index d0bd841..750693c 100755
--- a/vm/sbin/extend-disk
+++ b/vm/sbin/extend-disk
@@ -1,46 +1,87 @@
-#!/bin/sh
-set -e
+#!/usr/bin/python3
+# -*- coding: utf-8 -*-
 
-# Determine partition and hard drive paths
-UUID=$(/usr/bin/awk '{print substr($2,6)}' /etc/crypttab)
-PART=$(/sbin/blkid -U ${UUID})
-DISK=${PART%?}
-DEV=$(/usr/bin/basename ${DISK})
+import os
+import subprocess
 
-# No resizing with less than 10k unused blocks
-BLOCKS_FREE=$(/usr/bin/awk -v dev="${DEV}" '{if ($0 ~ dev "$") blocks = $3} {if ($0 ~ dev "[0-9]") blocks -= $3} END {print blocks}' /proc/partitions)
-[ ${BLOCKS_FREE} -lt 10240 ] && exit 0
+message_printed = False
 
-# Resize physical partition
-# Force busybox fdisk as util-linux fdisk breaks subsequent partx command
-cat <<EOF | /bin/busybox fdisk ${DISK} || /bin/true
-d
-2
-n
-p
-2
+def print_message():
+    # Print user-friendly message
+    global message_printed
+    if not message_printed:
+        print()
+        print('Bylo detekováno zvětšení virtuálního disku.')
+        print('Systém nyní upraví nastavení diskových oddílů.')
+        print()
+        message_printed = True
 
+def get_sizes():
+    # Returns device sizes in MB
+    sizes = {}
+    lsblk = subprocess.run(['/bin/lsblk', '-bnro', 'PATH,SIZE'], capture_output=True, check=True).stdout.decode()
+    for line in lsblk.splitlines():
+        line = line.split()
+        sizes[line[0]] = int(line[1])//1024**2
+    return sizes
 
-t
-2
-8e
-w
-EOF
+# Determine partition and disk paths
+with open('/etc/crypttab') as f:
+    crypttab = dict(line.split()[:2] for line in f.read().splitlines())
+partition = subprocess.run(['/sbin/findfs', crypttab['system']], capture_output=True, check=True).stdout.decode().strip()
+disk = partition.rstrip('0123456789')
 
-# Re-read partition table
-/usr/sbin/partx -u ${PART}
+# Resize physical partition when there is more than 10M unallocated
+sizes = get_sizes()
+free_space = sizes[disk] - sum([size for part,size in sizes.items() if part.startswith(disk) and part[len(disk):].isdigit()])
+if free_space > 10:
+    print_message()
+    try:
+        # Force busybox fdisk as util-linux fdisk breaks the subsequent partx command by notifying kernel too hard
+        input = 'd\n2\nn\np\n2\n\n\nt\n2\n8e\nw'.encode()
+        subprocess.run(['/bin/busybox', 'fdisk', disk], input=input, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, check=True)
+    except subprocess.CalledProcessError as e:
+        # Returns code 1  because of the nofication failure, but the resize is successful anyway
+        if e.returncode != 1:
+            raise
+    # Re-read partition (partx is from util-linux, issues BLKPG_RESIZE_PARTITION ioctl to update the kernel partition table)
+    subprocess.run(['/usr/sbin/partx', '-u', partition], stdout=subprocess.DEVNULL, check=True)
+    sizes = get_sizes()
 
-# Resize dmcrypt and LVM PV
-/sbin/cryptsetup resize system
-/sbin/pvresize /dev/mapper/system
+# Resize dmcrypt when there is more than 10M of free space (16M is consumed by dmcrypt)
+free_space = sizes[partition] - sizes['/dev/mapper/system'] - 16
+if free_space > 10:
+    print_message()
+    # Create locking dir for cryptsetup to suppress warning
+    try:
+        os.mkdir('/run/cryptsetup', 0o700)
+    except FileExistsError:
+        pass
+    # Ask for password 3 times, then fail
+    fails = 0
+    while True:
+        try:
+            subprocess.run(['/sbin/cryptsetup', 'resize', 'system'], check=True)
+            break
+        except (subprocess.CalledProcessError, KeyboardInterrupt):
+            fails += 1
+            if fails == 3:
+                raise
+    sizes = get_sizes()
 
-# Create swap if it doesn't exist
-if [ ! -e /dev/vg0/swap ]; then
-    /sbin/lvcreate -L 4G vg0 -n swap
-    /sbin/mkswap /dev/vg0/swap
-    /sbin/swapon /dev/vg0/swap
-fi
-
-# Extend LV and underlying filesystem
-/sbin/lvextend -l +100%FREE vg0/root
-/usr/sbin/resize2fs /dev/vg0/root
+# Resize LVM PV when there is more than 10M of free space
+free_space = sizes['/dev/mapper/system'] - sum(size for part,size in sizes.items() if part.startswith('/dev/mapper/vg0'))
+if free_space > 10:
+    print_message()
+    subprocess.run(['/sbin/pvresize', '/dev/mapper/system'], stdout=subprocess.DEVNULL, check=True)
+# Create swap if it doesn't exist yet and there's at least 4 GB of free space
+if '/dev/mapper/vg0-swap' not in sizes and free_space > 4*1024:
+    subprocess.run(['/sbin/lvcreate', '-L', '4G', 'vg0', '-n', 'swap'], stdout=subprocess.DEVNULL, check=True)
+    subprocess.run(['/sbin/mkswap', '/dev/mapper/vg0-swap'], stdout=subprocess.DEVNULL, check=True)
+    subprocess.run(['/sbin/swapon', '/dev/mapper/vg0-swap'], stdout=subprocess.DEVNULL, check=True)
+    sizes = get_sizes()
+    free_space = sizes['/dev/mapper/system'] - sum(size for part,size in sizes.items() if part.startswith('/dev/mapper/vg0'))
+# Resize LVM LV when there is more than 10M of free space
+if free_space > 10:
+    subprocess.run(['/sbin/lvextend', '-l', '+100%FREE', '/dev/mapper/vg0-root'], stdout=subprocess.DEVNULL, check=True)
+    subprocess.run(['/usr/sbin/resize2fs', '/dev/mapper/vg0-root'], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, check=True)
diff --git a/vm/sbin/vmtty b/vm/sbin/vmtty
new file mode 100755
index 0000000..a75d314
--- /dev/null
+++ b/vm/sbin/vmtty
@@ -0,0 +1,17 @@
+#!/bin/sh
+
+# Check if virtual disk has been resized and partitions needs extending
+if [ -x /sbin/extend-disk ]; then
+    /sbin/extend-disk
+fi
+
+# Rebuild /etc/issue
+if [ -x /usr/bin/vmmgr ]; then
+    /usr/bin/vmmgr rebuild-issue
+fi
+
+# Print /etc/issue
+/bin/cat /etc/issue
+
+# Wait for key press
+read a