From e79b26a61f790108b90c3625d554f6df4086d616 Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Sun, 21 Jun 2020 13:15:38 +0200
Subject: [PATCH] [type/__package_opkg] Also lock execution of code-remote

---
 .../type/__package_opkg/explorer/pkg_status   | 11 ++-
 cdist/conf/type/__package_opkg/gencode-remote | 94 +++++++++++++------
 2 files changed, 73 insertions(+), 32 deletions(-)

diff --git a/cdist/conf/type/__package_opkg/explorer/pkg_status b/cdist/conf/type/__package_opkg/explorer/pkg_status
index 1ba88e81..f5a6f098 100755
--- a/cdist/conf/type/__package_opkg/explorer/pkg_status
+++ b/cdist/conf/type/__package_opkg/explorer/pkg_status
@@ -23,7 +23,9 @@
 # Retrieve the status of a package - parses opkg output
 #
 
-LOCKFILE="${__type_explorer}/cdist_opkg.lock"
+__type_path=${__object%%${__object_id}*}
+
+LOCKFILE="${__type_path}/cdist_opkg.lock"
 _lock() (
 	set -o noclobber
 	until echo $$>"${LOCKFILE}"
@@ -48,9 +50,10 @@ else
 fi
 
 
-# NOTE: We need to lock parallel execution of this explorer because opkg will
-# try to acquire the OPKG lock (usually /var/lock/opkg.lock) using lockf(2) for
-# every operation. It will not wait for the lock but terminate with an error.
+# NOTE: We need to lock parallel execution of type explorers and code-remote
+# because opkg will try to acquire the OPKG lock (usually /var/lock/opkg.lock)
+# using lockf(2) for every operation.
+# It will not wait for the lock but terminate with an error.
 # This leads to incorrect 'absent notpresent' statuses when parallel execution
 # is enabled.
 trap _unlock EXIT
diff --git a/cdist/conf/type/__package_opkg/gencode-remote b/cdist/conf/type/__package_opkg/gencode-remote
index 269d5f49..ad90dc24 100755
--- a/cdist/conf/type/__package_opkg/gencode-remote
+++ b/cdist/conf/type/__package_opkg/gencode-remote
@@ -2,6 +2,7 @@
 #
 # 2011,2013 Nico Schottelius (nico-cdist at schottelius.org)
 # 2012 Giel van Schijndel (giel plus cdist at mortis dot eu)
+# 2020 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
 #
 # This file is part of cdist.
 #
@@ -19,41 +20,78 @@
 # along with cdist. If not, see <http://www.gnu.org/licenses/>.
 #
 #
-# Manage packages on OpenWRT and co.
+# Manage packages on OpenWrt, optware, and co.
 #
 
-if [ -f "$__object/parameter/name" ]; then
-   name="$(cat "$__object/parameter/name")"
+if test -f "${__object}/parameter/name"
+then
+   name=$(cat "${__object}/parameter/name")
 else
-   name="$__object_id"
+   name=$__object_id
 fi
 
-state_should="$(cat "$__object/parameter/state")"
+state_should=$(cat "${__object}/parameter/state")
+state_is=$(cat "${__object}/explorer/pkg_status")
 
-state_is="$(cat "$__object/explorer/pkg_status")"
-case "$state_is" in
-    absent*)
-       present="$(echo "$state_is" | cut -d ' ' -f 2)"
-       state_is="absent"
-    ;;
+case $state_is
+in
+	(absent*)
+		presence=$(echo "${state_is}" | cut -d ' ' -f 2)
+		state_is='absent'
+		;;
 esac
 
-[ "$state_is" = "$state_should" ] && exit 0
+if test "${state_is}" = "${state_should}"
+then
+	exit 0
+fi
 
-case "$state_should" in
-    present)
-        if [ "$present" = "notpresent" ]; then
-            echo "opkg --verbosity=0 update"
-        fi
-        echo "opkg --verbosity=0 install '$name'"
-        echo "installed" >> "$__messages_out"
-    ;;
-    absent)
-        echo "opkg --verbosity=0 remove '$name'"
-        echo "removed" >> "$__messages_out"
-    ;;
-    *)
-        echo "Unknown state: ${state_should}" >&2
-        exit 1
-    ;;
+cat <<'EOF'
+__type_path=${__object%%${__object_id}*}
+
+LOCKFILE="${__type_path}/cdist_opkg.lock"
+_lock() (
+	set -o noclobber
+	until echo $$>"${LOCKFILE}"
+	do
+		while test -f "${LOCKFILE}"; do sleep 1; done
+	done
+
+) 2>/dev/null
+_unlock() {
+	if test -s "${LOCKFILE}" && test "$(cat "${LOCKFILE}")" = $$
+	then
+		rm "${LOCKFILE}"
+	fi
+}
+EOF
+
+# NOTE: We need to lock parallel execution of code-remote to ensure that it is
+# not executed concurrently with a type explorer.
+# opkg will try to acquire the OPKG lock (usually /var/lock/opkg.lock) using
+# lockf(2) for every operation.
+# It will not wait for the lock but terminate with an error leading to an
+# incorrect outcome.
+echo 'trap _unlock EXIT'
+echo '_lock'
+
+case $state_should
+in
+	(present)
+		if test "${presence}" = 'notpresent'
+		then
+			echo 'opkg --verbosity=0 update'
+		fi
+
+		printf "opkg --verbosity=0 install '%s'\n" "${name}"
+		echo 'installed' >>"${__messages_out}"
+		;;
+	(absent)
+		printf "opkg --verbosity=0 remove '%s'" "${name}"
+		echo 'removed' >>"${__messages_out}"
+		;;
+	(*)
+		printf 'Unknown state: %s\n' "${state_should}" >&2
+		exit 1
+		;;
 esac