First commit

Author: gregneagle

LICENSE.md

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+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this source code except in compliance with the License.
+You may obtain a copy of the License at
+
+   https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

README.md

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+macadmin-scripts
+
+Some scripts that might be of use to macOS admins. Might be related to Munki;
+might not.

createbootvolfromautonbi.py

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+#!/usr/bin/python
+# encoding: utf-8
+#
+# Copyright 2017 Greg Neagle.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+'''A tool to make bootable disk volumes from the output of autonbi. Especially
+useful to make bootable disks containing Imagr and the 'SIP-ignoring' kernel,
+which allows Imagr to run scripts that affect SIP state, set UAKEL options, and
+run the `startosinstall` component, all of which might otherwise require network
+booting from a NetInstall-style nbi.'''
+
+import argparse
+import os
+import plistlib
+import subprocess
+import sys
+import urlparse
+
+
+# dmg helpers
+def mountdmg(dmgpath):
+    """
+    Attempts to mount the dmg at dmgpath and returns first mountpoint
+    """
+    mountpoints = []
+    dmgname = os.path.basename(dmgpath)
+    cmd = ['/usr/bin/hdiutil', 'attach', dmgpath,
+           '-mountRandom', '/tmp', '-nobrowse', '-plist',
+           '-owners', 'on']
+    proc = subprocess.Popen(cmd, bufsize=-1,
+                            stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    (pliststr, err) = proc.communicate()
+    if proc.returncode:
+        print >> sys.stderr, 'Error: "%s" while mounting %s.' % (err, dmgname)
+        return None
+    if pliststr:
+        plist = plistlib.readPlistFromString(pliststr)
+        for entity in plist['system-entities']:
+            if 'mount-point' in entity:
+                mountpoints.append(entity['mount-point'])
+
+    return mountpoints[0]
+
+
+def unmountdmg(mountpoint):
+    """
+    Unmounts the dmg at mountpoint
+    """
+    proc = subprocess.Popen(['/usr/bin/hdiutil', 'detach', mountpoint],
+                            bufsize=-1, stdout=subprocess.PIPE,
+                            stderr=subprocess.PIPE)
+    (dummy_output, err) = proc.communicate()
+    if proc.returncode:
+        print >> sys.stderr, 'Polite unmount failed: %s' % err
+        print >> sys.stderr, 'Attempting to force unmount %s' % mountpoint
+        # try forcing the unmount
+        retcode = subprocess.call(['/usr/bin/hdiutil', 'detach', mountpoint,
+                                   '-force'])
+        if retcode:
+            print >> sys.stderr, 'Failed to unmount %s' % mountpoint
+
+
+def locate_basesystem_dmg(nbi):
+    '''Finds and returns the relative path to the BaseSystem.dmg within the
+    NetInstall.dmg'''
+    source_boot_plist = os.path.join(nbi, 'i386/com.apple.Boot.plist')
+    try:
+        boot_args = plistlib.readPlist(source_boot_plist)
+    except Exception, err:
+        print >> sys.stderr, err
+        sys.exit(-1)
+    kernel_flags = boot_args.get('Kernel Flags')
+    if not kernel_flags:
+        print >> sys.stderr, 'i386/com.apple.Boot.plist is missing Kernel Flags'
+        sys.exit(-1)
+    # kernel flags should in the form 'root-dmg=file:///path'
+    if not kernel_flags.startswith('root-dmg='):
+        print >> sys.stderr, 'Unexpected Kernel Flags: %s' % kernel_flags
+        sys.exit(-1)
+    file_url = kernel_flags[9:]
+    dmg_path = urlparse.unquote(urlparse.urlparse(file_url).path)
+    # return path minus leading slash
+    return dmg_path.lstrip('/')
+
+
+def copy_system_version_plist(nbi, target_volume):
+    '''Copies System/Library/CoreServices/SystemVersion.plist from the
+    BaseSystem.dmg to the target volume.'''
+    netinstall_dmg = os.path.join(nbi, 'NetInstall.dmg')
+    if not os.path.exists(netinstall_dmg):
+        print >> sys.stderr, "Missing NetInstall.dmg from nbi folder"
+        sys.exit(-1)
+    print 'Mounting %s...' % netinstall_dmg
+    netinstall_mount = mountdmg(netinstall_dmg)
+    if not netinstall_mount:
+        sys.exit(-1)
+    basesystem_dmg = os.path.join(netinstall_mount, locate_basesystem_dmg(nbi))
+    print 'Mounting %s...' % basesystem_dmg
+    basesystem_mount = mountdmg(basesystem_dmg)
+    if not basesystem_mount:
+        unmountdmg(netinstall_mount)
+        sys.exit(-1)
+    source = os.path.join(
+        basesystem_mount, 'System/Library/CoreServices/SystemVersion.plist')
+    dest = os.path.join(
+        target_volume, 'System/Library/CoreServices/SystemVersion.plist')
+    try:
+        subprocess.check_call(
+            ['/usr/bin/ditto', '-V', source, dest])
+    except subprocess.CalledProcessError, err:
+        print >> sys.stderr, err
+        unmountdmg(basesystem_mount)
+        unmountdmg(netinstall_mount)
+        sys.exit(-1)
+
+    unmountdmg(basesystem_mount)
+    unmountdmg(netinstall_mount)
+
+
+def copy_boot_files(nbi, target_volume):
+    '''Copies some boot files, yo'''
+    files_to_copy = [
+        ['NetInstall.dmg', 'NetInstall.dmg'],
+        ['i386/PlatformSupport.plist',
+         'System/Library/CoreServices/PlatformSupport.plist'],
+        ['i386/booter', 'System/Library/CoreServices/boot.efi'],
+        ['i386/booter', 'usr/standalone/i386/boot.efi'],
+        ['i386/x86_64/kernelcache',
+         'System/Library/PrelinkedKernels/prelinkedkernel']
+    ]
+    for source, dest in files_to_copy:
+        full_source = os.path.join(nbi, source)
+        full_dest = os.path.join(target_volume, dest)
+        try:
+            subprocess.check_call(
+                ['/usr/bin/ditto', '-V', full_source, full_dest])
+        except subprocess.CalledProcessError, err:
+            print >> sys.stderr, err
+            sys.exit(-1)
+
+
+def make_boot_plist(nbi, target_volume):
+    '''Creates our com.apple.Boot.plist'''
+    source_boot_plist = os.path.join(nbi, 'i386/com.apple.Boot.plist')
+    try:
+        boot_args = plistlib.readPlist(source_boot_plist)
+    except Exception, err:
+        print >> sys.stderr, err
+        sys.exit(-1)
+    kernel_flags = boot_args.get('Kernel Flags')
+    if not kernel_flags:
+        print >> sys.stderr, 'i386/com.apple.Boot.plist is missing Kernel Flags'
+        sys.exit(-1)
+    # prepend the container-dmg path
+    boot_args['Kernel Flags'] = (
+        'container-dmg=file:///NetInstall.dmg ' + kernel_flags)
+    boot_plist = os.path.join(
+        target_volume,
+        'Library/Preferences/SystemConfiguration/com.apple.Boot.plist')
+    plist_dir = os.path.dirname(boot_plist)
+    if not os.path.exists(plist_dir):
+        os.makedirs(plist_dir)
+    try:
+        plistlib.writePlist(boot_args, boot_plist)
+    except Exception, err:
+        print >> sys.stderr, err
+        sys.exit(-1)
+
+
+def bless(target_volume, label=None):
+    '''Bless the target volume'''
+    blessfolder = os.path.join(target_volume, 'System/Library/CoreServices')
+    if not label:
+        label = os.path.basename(target_volume)
+    try:
+        subprocess.check_call(
+            ['/usr/sbin/bless', '--folder', blessfolder, '--label', label])
+    except subprocess.CalledProcessError, err:
+        print >> sys.stderr, err
+        sys.exit(-1)
+
+
+def main():
+    '''Do the thing we were made for'''
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--nbi', required=True, metavar='path_to_nbi',
+                        help='Path to nbi folder created by autonbi.')
+    parser.add_argument('--volume', required=True, 
+                        metavar='path_to_disk_volume',
+                        help='Path to disk volume.')
+    args = parser.parse_args()
+    copy_system_version_plist(args.nbi, args.volume)
+    copy_boot_files(args.nbi, args.volume)
+    make_boot_plist(args.nbi, args.volume)
+    bless(args.volume)
+
+
+if __name__ == '__main__':
+    main()