From a1f5e4c0c006e16a5047a16fc65c9b3663adb81e Mon Sep 17 00:00:00 2001
From: Ben Wolsieffer <benwolsieffer@gmail.com>
Date: Wed, 4 Dec 2019 22:19:29 -0500
Subject: [PATCH] Add cache-dir option.

---
 README.md |  4 ++++
 sanoid    | 17 +++++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index bc8ed83..d5e143d 100644
--- a/README.md
+++ b/README.md
@@ -49,6 +49,10 @@ Which would be enough to tell sanoid to take and keep 36 hourly snapshots, 30 da
 
 	Specify a location for the config file named sanoid.conf. Defaults to /etc/sanoid
 
++ --cache-dir
+
+	Specify a directory to store the zfs snapshot cache. Defaults to /var/cache/sanoid
+
 + --take-snapshots
 
 	This will process your sanoid.conf file, create snapshots, but it will NOT purge expired ones. (Note that snapshots taken are atomic in an individual dataset context, <i>not</i> a global context - snapshots of pool/dataset1 and pool/dataset2 will each be internally consistent and atomic, but one may be a few filesystem transactions "newer" than the other.)
diff --git a/sanoid b/sanoid
index 2b566ef..fd39f3a 100755
--- a/sanoid
+++ b/sanoid
@@ -11,15 +11,19 @@ use strict;
 use warnings;
 use Config::IniFiles; # read samba-style conf file
 use Data::Dumper;     # debugging - print contents of hash
-use File::Path;       # for rmtree command in use_prune
+use File::Path 'make_path';
 use Getopt::Long qw(:config auto_version auto_help);
 use Pod::Usage;       # pod2usage
 use Time::Local;      # to parse dates in reverse
 use Capture::Tiny ':all';
 
-my %args = ("configdir" => "/etc/sanoid");
+my %args = (
+	"configdir" => "/etc/sanoid",
+	"cache-dir" => "/var/cache/sanoid"
+);
 GetOptions(\%args, "verbose", "debug", "cron", "readonly", "quiet",
-                   "monitor-health", "force-update", "configdir=s",
+                   "configdir=s", "cache-dir=s",
+                   "monitor-health", "force-update",
                    "monitor-snapshots", "take-snapshots", "prune-snapshots", "force-prune",
                    "monitor-capacity"
           ) or pod2usage(2);
@@ -41,9 +45,13 @@ my $default_conf_file = "$args{'configdir'}/sanoid.defaults.conf";
 # parse config file
 my %config = init($conf_file,$default_conf_file);
 
+my $cache_dir = $args{'cache-dir'};
+
+make_path($cache_dir);
+
 # if we call getsnaps(%config,1) it will forcibly update the cache, TTL or no TTL
 my $forcecacheupdate = 0;
-my $cache = '/var/cache/sanoidsnapshots.txt';
+my $cache = "$cache_dir/snapshots.txt";
 my $cacheTTL = 900; # 15 minutes
 my %snaps = getsnaps( \%config, $cacheTTL, $forcecacheupdate );
 my %pruned;
@@ -1659,6 +1667,7 @@ Assumes --cron --verbose if no other arguments (other than configdir) are specif
 Options:
 
   --configdir=DIR       Specify a directory to find config file sanoid.conf
+  --cache-dir=DIR       Specify a directory to store the zfs snapshot cache
 
   --cron                Creates snapshots and purges expired snapshots
   --verbose             Prints out additional information during a sanoid run