From d92d0afd23b5882437bb1cafff23a7034add15d7 Mon Sep 17 00:00:00 2001
From: Wolfgang Bumiller <w.bumiller@proxmox.com>
Date: Tue, 5 Nov 2019 13:58:01 +0100
Subject: [PATCH] add PVE::LXC::Tools

Will contain lxc/container specific tools which should also
be accessible within our lxc hook scripts.

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
---
 src/PVE/LXC/Makefile |  7 +++-
 src/PVE/LXC/Tools.pm | 82 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 src/PVE/LXC/Tools.pm

diff --git a/src/PVE/LXC/Makefile b/src/PVE/LXC/Makefile
index 8a0224b..d889204 100644
--- a/src/PVE/LXC/Makefile
+++ b/src/PVE/LXC/Makefile
@@ -1,4 +1,9 @@
-SOURCES=Setup.pm Create.pm Migrate.pm Config.pm
+SOURCES= \
+	Config.pm \
+	Create.pm \
+	Migrate.pm \
+	Setup.pm \
+	Tools.pm
 
 .PHONY: install
 install: ${SOURCES} 
diff --git a/src/PVE/LXC/Tools.pm b/src/PVE/LXC/Tools.pm
new file mode 100644
index 0000000..18a1a22
--- /dev/null
+++ b/src/PVE/LXC/Tools.pm
@@ -0,0 +1,82 @@
+# Module for lxc related functionality used mostly by our hooks.
+
+package PVE::LXC::Tools;
+
+use PVE::SafeSyslog;
+
+# LXC introduced an `lxc.hook.version` property which allows hooks to be executed in different
+# manners. The old way passes a lot of stuff as command line parameter, the new way passes
+# environment variables.
+#
+# This is supposed to be a common entry point for hooks, consuming the parameters passed by lxc and
+# passing them on to a subroutine in a defined way.
+sub lxc_hook($$&) {
+    my ($expected_type, $expected_section, $code) = @_;
+
+    my ($ct_name, $section, $type);
+    my $namespaces = {};
+    my $args;
+
+    my $version = $ENV{LXC_HOOK_VERSION} // '0';
+    if ($version eq '0') {
+	# Old style hook:
+	$ct_name = shift @ARGV;
+	$section = shift @ARGV;
+	$type = shift @ARGV;
+
+	if (!defined($ct_name) || !defined($section) || !defined($type)) {
+	    die "missing hook parameters, expected to be called by lxc as hook\n";
+	}
+
+	if ($ct_name !~ /^\d+$/ || $section ne $expected_section || $type ne $expected_type) {
+	    return;
+	}
+
+	if ($type eq 'stop') {
+	    foreach my $ns (@ARGV) {
+		if ($ns =~ /^([^:]+):(.+)$/) {
+		    $namespaces->{$1} = $2;
+		} else {
+		    die "unrecognized 'stop' hook parameter: $ns\n";
+		}
+	    }
+	} elsif ($type eq 'clone') {
+	    $args = [@ARGV];
+	}
+    } elsif ($version eq '1') {
+	$ct_name = $ENV{LXC_NAME}
+	    or die "missing LXC_NAME environment variable\n";
+	$section = $ENV{LXC_HOOK_SECTION}
+	    or die "missing LXC_HOOK_SECTION environment variable\n";
+	$type = $ENV{LXC_HOOK_TYPE}
+	    or die "missing LXC_HOOK_TYPE environment variable\n";
+
+	if ($ct_name !~ /^\d+$/ || $section ne $expected_section || $type ne $expected_type) {
+	    return;
+	}
+
+	foreach my $var (keys %$ENV) {
+	    if ($var =~ /^LXC_([A-Z]+)_NS$/) {
+		$namespaces->{lc($1)} = $ENV{$1};
+	    }
+	}
+    } else {
+	die "lxc.hook.version $version not supported!\n";
+    }
+
+    my $logid = $ENV{PVE_LOG_ID} || "pve-lxc-hook-$section-$type";
+    initlog($logid);
+
+    my $common_vars = {
+	ROOTFS_MOUNT => ($ENV{LXC_ROOTFS_MOUNT} or die "missing LXC_ROOTFS_MOUNT env var\n"),
+	ROOTFS_PATH => ($ENV{LXC_ROOTFS_PATH} or die "missing LXC_ROOTFS_PATH env var\n"),
+	CONFIG_FILE => ($ENV{LXC_CONFIG_FILE} or die "missing LXC_CONFIG_FILE env var\n"),
+    };
+    if (defined(my $target = $ENV{LXC_TARGET})) {
+	$common_vars->{TARGET} = $target;
+    }
+
+    $code->($ct_name, $common_vars, $namespaces, $args);
+}
+
+1;
-- 
2.39.2