Use built in duplicity encryption (GPG) for backups, closes #362
This commit is contained in:
David Piggott
parent
298e19598b
commit
2726b15764
|
|
@ -36,10 +36,10 @@ def backup_status(env):
|
|||
return "%d hours, %d minutes" % (rd.hours, rd.minutes)
|
||||
|
||||
backups = { }
|
||||
basedir = os.path.join(env['STORAGE_ROOT'], 'backup/duplicity/')
|
||||
encdir = os.path.join(env['STORAGE_ROOT'], 'backup/encrypted/')
|
||||
os.makedirs(basedir, exist_ok=True) # os.listdir fails if directory does not exist
|
||||
for fn in os.listdir(basedir):
|
||||
backup_dir = os.path.join(env["STORAGE_ROOT"], 'backup')
|
||||
backup_encrypted_dir = os.path.join(backup_dir, 'encrypted')
|
||||
os.makedirs(backup_encrypted_dir, exist_ok=True) # os.listdir fails if directory does not exist
|
||||
for fn in os.listdir(backup_encrypted_dir):
|
||||
m = re.match(r"duplicity-(full|full-signatures|(inc|new-signatures)\.(?P<incbase>\d+T\d+Z)\.to)\.(?P<date>\d+T\d+Z)\.", fn)
|
||||
if not m: raise ValueError(fn)
|
||||
|
||||
|
|
@ -53,15 +53,9 @@ def backup_status(env):
|
|||
"full": m.group("incbase") is None,
|
||||
"previous": m.group("incbase"),
|
||||
"size": 0,
|
||||
"encsize": 0,
|
||||
}
|
||||
|
||||
backups[key]["size"] += os.path.getsize(os.path.join(basedir, fn))
|
||||
|
||||
# Also check encrypted size.
|
||||
encfn = os.path.join(encdir, fn + ".enc")
|
||||
if os.path.exists(encfn):
|
||||
backups[key]["encsize"] += os.path.getsize(encfn)
|
||||
backups[key]["size"] += os.path.getsize(os.path.join(backup_encrypted_dir, fn))
|
||||
|
||||
# Ensure the rows are sorted reverse chronologically.
|
||||
# This is relied on by should_force_full() and the next step.
|
||||
|
|
@ -106,9 +100,8 @@ def backup_status(env):
|
|||
bak["deleted_in"] = deleted_in
|
||||
|
||||
return {
|
||||
"directory": basedir,
|
||||
"encpwfile": os.path.join(env['STORAGE_ROOT'], 'backup/secret_key.txt'),
|
||||
"encdirectory": encdir,
|
||||
"directory": backup_encrypted_dir,
|
||||
"encpwfile": os.path.join(backup_dir, 'secret_key.txt'),
|
||||
"tz": now.tzname(),
|
||||
"backups": backups,
|
||||
}
|
||||
|
|
@ -137,10 +130,61 @@ def perform_backup(full_backup):
|
|||
|
||||
exclusive_process("backup")
|
||||
|
||||
# Ensure the backup directory exists.
|
||||
backup_dir = os.path.join(env["STORAGE_ROOT"], 'backup')
|
||||
backup_encrypted_dir = os.path.join(backup_dir, 'encrypted')
|
||||
|
||||
# In an older version of this script, duplicity was called
|
||||
# such that it did not encrypt the backups it created (in
|
||||
# backup/duplicity), and instead openssl was called separately
|
||||
# after each backup run, creating AES256 encrypted copies of
|
||||
# each file created by duplicity in backup/encrypted.
|
||||
#
|
||||
# We detect the transition by the presence of backup/duplicity
|
||||
# and handle it by 'dupliception': we move all the old *un*encrypted
|
||||
# duplicity files up out of the backup/duplicity directory (as
|
||||
# backup/ is excluded from duplicity runs) in order that it is
|
||||
# included in the next run, and we delete backup/encrypted (which
|
||||
# duplicity will output files directly to, post-transition).
|
||||
#
|
||||
# This achieves two things:
|
||||
# 1. It preserves the pre-transition unencrypted backup files
|
||||
# within the encrypted backups we will immediately create, so
|
||||
# that they are kept until the next full backup is triggered.
|
||||
# (it is because those backups will be encrypted that we take
|
||||
# the old *un*encrypted backups, not the duplicates encrypted
|
||||
# with openssl).
|
||||
# 2. It results in backup_status() being called on a non-existant
|
||||
# backup/encrypted directory, which will trigger a full backup
|
||||
# (though duplicity ought to do one anyway as it ought not
|
||||
# recognise the old openssl encrypted .enc files, if we *had*
|
||||
# left them there). More to the point it clears out those .enc
|
||||
# files which are now redundant, thereby gaining disk space and
|
||||
# preventing backup_status() getting terribly confused by their
|
||||
# presence.
|
||||
#
|
||||
# A note about disk use:
|
||||
# At no point in the transition will we use more disk space than
|
||||
# was used pre-transition, because by deleting the openssl
|
||||
# encrypted duplicates we decrease by more* than half the disk
|
||||
# space used, while the addition by 'dupliception' of the old
|
||||
# *un*encrypted backups takes less space than we gained from
|
||||
# dropping the openssl encrypted duplicates.
|
||||
#
|
||||
# A note about the status page post-upgrade but pre-transition:
|
||||
# Between the point that the new code is deployed and when the first
|
||||
# daily backup is run, there will be a subtle change in the
|
||||
# behaviour of the web control panel's backup status page, in that
|
||||
# it will only sum the size of the encrypted backups when reporting
|
||||
# the total size on disk i.e. it will not consider the unencrypted
|
||||
# originals.
|
||||
#
|
||||
# *the openssl encrypted duplicates were base64 encrypted, hence
|
||||
# accounting for more than half of the space used.
|
||||
backup_duplicity_dir = os.path.join(backup_dir, 'duplicity')
|
||||
os.makedirs(backup_duplicity_dir, exist_ok=True)
|
||||
migrated_unencrypted_backup_dir = os.path.join(env["STORAGE_ROOT"], "migrated_unencrypted_backup")
|
||||
if os.path.isdir(backup_duplicity_dir):
|
||||
shutil.move(backup_duplicity_dir, migrated_unencrypted_backup_dir)
|
||||
shutil.rmtree(backup_encrypted_dir)
|
||||
|
||||
# On the first run, always do a full backup. Incremental
|
||||
# will fail. Otherwise do a full backup when the size of
|
||||
|
|
@ -158,65 +202,41 @@ def perform_backup(full_backup):
|
|||
shell('check_call', [
|
||||
"/usr/bin/duplicity",
|
||||
"full" if full_backup else "incr",
|
||||
"--no-encryption",
|
||||
"--archive-dir", "/tmp/duplicity-archive-dir",
|
||||
"--name", "mailinabox",
|
||||
"--exclude", backup_dir,
|
||||
"--volsize", "100",
|
||||
"--verbosity", "warning",
|
||||
env["STORAGE_ROOT"],
|
||||
"file://" + backup_duplicity_dir
|
||||
])
|
||||
"file://" + backup_encrypted_dir
|
||||
],
|
||||
env={ "PASSPHRASE" : open(
|
||||
os.path.join(backup_dir, 'secret_key.txt')
|
||||
).read() }
|
||||
)
|
||||
finally:
|
||||
# Start services again.
|
||||
shell('check_call', ["/usr/sbin/service", "dovecot", "start"])
|
||||
shell('check_call', ["/usr/sbin/service", "postfix", "start"])
|
||||
|
||||
if os.path.isdir(migrated_unencrypted_backup_dir):
|
||||
shutil.rmtree(migrated_unencrypted_backup_dir)
|
||||
|
||||
# Remove old backups. This deletes all backup data no longer needed
|
||||
# from more than 31 days ago. Must do this before destroying the
|
||||
# from more than 3 days ago. Must do this before destroying the
|
||||
# cache directory or else this command will re-create it.
|
||||
shell('check_call', [
|
||||
"/usr/bin/duplicity",
|
||||
"remove-older-than",
|
||||
"%dD" % keep_backups_for_days,
|
||||
"--archive-dir", "/tmp/duplicity-archive-dir",
|
||||
"--name", "mailinabox",
|
||||
"--force",
|
||||
"--verbosity", "warning",
|
||||
"file://" + backup_duplicity_dir
|
||||
"file://" + backup_encrypted_dir
|
||||
])
|
||||
|
||||
# Remove duplicity's cache directory because it's redundant with our backup directory.
|
||||
shutil.rmtree("/tmp/duplicity-archive-dir")
|
||||
|
||||
# Encrypt all of the new files.
|
||||
backup_encrypted_dir = os.path.join(backup_dir, 'encrypted')
|
||||
os.makedirs(backup_encrypted_dir, exist_ok=True)
|
||||
for fn in os.listdir(backup_duplicity_dir):
|
||||
fn2 = os.path.join(backup_encrypted_dir, fn) + ".enc"
|
||||
if os.path.exists(fn2): continue
|
||||
|
||||
# Encrypt the backup using the backup private key.
|
||||
shell('check_call', [
|
||||
"/usr/bin/openssl",
|
||||
"enc",
|
||||
"-aes-256-cbc",
|
||||
"-a",
|
||||
"-salt",
|
||||
"-in", os.path.join(backup_duplicity_dir, fn),
|
||||
"-out", fn2,
|
||||
"-pass", "file:%s" % os.path.join(backup_dir, "secret_key.txt"),
|
||||
])
|
||||
|
||||
# The backup can be decrypted with:
|
||||
# openssl enc -d -aes-256-cbc -a -in latest.tgz.enc -out /dev/stdout -pass file:secret_key.txt | tar -z
|
||||
|
||||
# Remove encrypted backups that are no longer needed.
|
||||
for fn in os.listdir(backup_encrypted_dir):
|
||||
fn2 = os.path.join(backup_duplicity_dir, fn.replace(".enc", ""))
|
||||
if os.path.exists(fn2): continue
|
||||
os.unlink(os.path.join(backup_encrypted_dir, fn))
|
||||
|
||||
# Execute a post-backup script that does the copying to a remote server.
|
||||
# Run as the STORAGE_USER user, not as root. Pass our settings in
|
||||
# environment variables so the script has access to STORAGE_ROOT.
|
||||
|
|
|
|||
|
|
@ -54,7 +54,7 @@ function show_system_backup() {
|
|||
"GET",
|
||||
{ },
|
||||
function(r) {
|
||||
$('#backup-location').text(r.encdirectory);
|
||||
$('#backup-location').text(r.directory);
|
||||
$('#backup-encpassword-file').text(r.encpwfile);
|
||||
|
||||
$('#backup-status tbody').html("");
|
||||
|
|
@ -72,7 +72,7 @@ function show_system_backup() {
|
|||
tr.append( $('<td/>').text(b.date_str + " " + r.tz) );
|
||||
tr.append( $('<td/>').text(b.date_delta + " ago") );
|
||||
tr.append( $('<td/>').text(b.full ? "full" : "increment") );
|
||||
tr.append( $('<td style="text-align: right"/>').text( nice_size(b.encsize)) );
|
||||
tr.append( $('<td style="text-align: right"/>').text( nice_size(b.size)) );
|
||||
if (b.deleted_in)
|
||||
tr.append( $('<td/>').text(b.deleted_in) );
|
||||
else
|
||||
|
|
@ -80,7 +80,6 @@ function show_system_backup() {
|
|||
$('#backup-status tbody').append(tr);
|
||||
|
||||
total_disk_size += b.size;
|
||||
total_disk_size += b.encsize;
|
||||
}
|
||||
|
||||
$('#backup-total-size').text(nice_size(total_disk_size));
|
||||
|
|
|
|||
Loading…
Reference in New Issue