From c51d68a7375915154a90c22e716e832f635ca878 Mon Sep 17 00:00:00 2001
From: Beni Ruef <bernhard.ruef@ssrq-sds-fds.ch>
Date: Thu, 3 Dec 2020 18:48:04 +0100
Subject: [PATCH 01/21] [type/__postgres_conf] New type based on ALTER SYSTEM
 command

---
 .../conf/type/__postgres_conf/gencode-remote  | 92 +++++++++++++++++++
 cdist/conf/type/__postgres_conf/man.rst       | 55 +++++++++++
 .../__postgres_conf/parameter/default/state   |  1 +
 .../type/__postgres_conf/parameter/optional   |  2 +
 4 files changed, 150 insertions(+)
 create mode 100755 cdist/conf/type/__postgres_conf/gencode-remote
 create mode 100644 cdist/conf/type/__postgres_conf/man.rst
 create mode 100644 cdist/conf/type/__postgres_conf/parameter/default/state
 create mode 100644 cdist/conf/type/__postgres_conf/parameter/optional

diff --git a/cdist/conf/type/__postgres_conf/gencode-remote b/cdist/conf/type/__postgres_conf/gencode-remote
new file mode 100755
index 00000000..a09e1873
--- /dev/null
+++ b/cdist/conf/type/__postgres_conf/gencode-remote
@@ -0,0 +1,92 @@
+#!/bin/sh -e
+# -*- mode: sh; indent-tabs-mode: t -*-
+#
+# 2019 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
+# 2020 Beni Ruef (bernhard.ruef at ssrq-sds-fds.ch)
+#
+# This file is part of cdist.
+#
+# cdist is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# cdist is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with cdist. If not, see <http://www.gnu.org/licenses/>.
+#
+
+os=$(cat "${__global}/explorer/os")
+state_should=$(cat "${__object}/parameter/state")
+
+if [ "${state_should}" != 'present' ] && [ "${state_should}" != 'absent' ]
+then
+	echo "Invalid state '${state_should}'." \
+	     'Only "present" and "absent" are acceptable' >&2
+	exit 1
+fi
+
+if [ "${state_should}" = 'present' ] && [ ! -f "${__object}/parameter/value" ]
+then
+	echo 'Missing required parameter "value"' >&2
+	exit 1
+fi
+
+# Parameters
+conf_name="${__object_id}"
+if [ -f "${__object}/parameter/value" ]
+then
+	conf_value=$(cat "${__object}/parameter/value")
+fi
+
+if [ "${state_should}" = 'present' ]
+then
+	set_command="ALTER SYSTEM SET ${conf_name} = '${conf_value}'"
+	check_command="SHOW ${conf_name}"
+else
+	set_command="ALTER SYSTEM SET ${conf_name} = DEFAULT"
+fi
+
+case $os
+in
+	openbsd|devuan)
+		case $os
+		in
+			openbsd)
+				postgres_user='_postgresql'
+				restart_command='/etc/rc.d/postgresql restart'
+				;;
+			devuan)
+				postgres_user='postgres'
+				restart_command='/etc/init.d/postgresql restart'
+				;;
+		esac
+		# needs two separate psql commands because ALTER SYSTEM
+		# cannot run inside a transaction block
+		cat <<-EOF
+		su - ${postgres_user} -c "psql postgres -twAc \
+			\"${set_command}\""
+		su - ${postgres_user} -c "psql postgres -twAc \
+			\"SELECT pg_reload_conf()\""
+		EOF
+		# check success (makes only sense if setting to a non-default value)
+		# and restart server if needed
+		if [ "${state_should}" = 'present' ]
+		then
+			cat <<-EOF
+			if [ \$(su - ${postgres_user} -c "psql postgres -twAc \"SHOW ${conf_name}\"") != '${conf_value}' ]
+			then
+				${restart_command}
+			fi
+			EOF
+		fi
+		;;
+	*)
+		echo "Unsupported OS: ${os}" >&2
+		exit 1
+		;;
+esac
diff --git a/cdist/conf/type/__postgres_conf/man.rst b/cdist/conf/type/__postgres_conf/man.rst
new file mode 100644
index 00000000..76016c6c
--- /dev/null
+++ b/cdist/conf/type/__postgres_conf/man.rst
@@ -0,0 +1,55 @@
+cdist-type__postgres_conf(7)
+============================
+
+Configure a PostgreSQL server.
+
+NOTE: This type might need to be run multiple times to apply all bits of the
+configuration due to ordering requirements.
+
+SSRQ <cdist--@--ssrq-sds-fds.ch>
+
+
+DESCRIPTION
+-----------
+Configure a PostgreSQL server using ALTER SYSTEM.
+
+
+REQUIRED PARAMETERS
+-------------------
+value
+    The value to setup (can be omitted when state is set to "absent").
+
+
+OPTIONAL PARAMETERS
+-------------------
+state
+    "present" or "absent". Defaults to "present".
+
+
+BOOLEAN PARAMETERS
+------------------
+None.
+
+
+EXAMPLES
+--------
+
+.. code-block:: sh
+
+	# set timezone
+    __postgres_conf timezone --value Europe/Zurich
+
+    # reset maximum number of concurrent connections to default (normally 100)
+    __postgres_conf max_connections --state absent
+
+
+SEE ALSO
+--------
+- `cdist-type(7) <cdist-type.html>`_
+
+
+COPYING
+-------
+Copyright \(C) 2020 SSRQ (www.ssrq-sds-fds.ch).
+Free use of this software is granted under the terms
+of the GNU General Public License version 3 (GPLv3).
diff --git a/cdist/conf/type/__postgres_conf/parameter/default/state b/cdist/conf/type/__postgres_conf/parameter/default/state
new file mode 100644
index 00000000..e7f6134f
--- /dev/null
+++ b/cdist/conf/type/__postgres_conf/parameter/default/state
@@ -0,0 +1 @@
+present
diff --git a/cdist/conf/type/__postgres_conf/parameter/optional b/cdist/conf/type/__postgres_conf/parameter/optional
new file mode 100644
index 00000000..d0460d86
--- /dev/null
+++ b/cdist/conf/type/__postgres_conf/parameter/optional
@@ -0,0 +1,2 @@
+state
+value

From 534d5f6bb5dd3d8e9cb2256e75ed182d6530a892 Mon Sep 17 00:00:00 2001
From: Beni Ruef <bernhard.ruef@ssrq-sds-fds.ch>
Date: Fri, 4 Dec 2020 14:31:04 +0100
Subject: [PATCH 02/21] [type/__postgres_conf] Fix errors found by ShellCheck

---
 cdist/conf/type/__postgres_conf/gencode-remote | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/cdist/conf/type/__postgres_conf/gencode-remote b/cdist/conf/type/__postgres_conf/gencode-remote
index a09e1873..e25514d0 100755
--- a/cdist/conf/type/__postgres_conf/gencode-remote
+++ b/cdist/conf/type/__postgres_conf/gencode-remote
@@ -20,8 +20,8 @@
 # along with cdist. If not, see <http://www.gnu.org/licenses/>.
 #
 
-os=$(cat "${__global}/explorer/os")
-state_should=$(cat "${__object}/parameter/state")
+os=$(cat "${__global:?}/explorer/os")
+state_should=$(cat "${__object:?}/parameter/state")
 
 if [ "${state_should}" != 'present' ] && [ "${state_should}" != 'absent' ]
 then
@@ -37,7 +37,7 @@ then
 fi
 
 # Parameters
-conf_name="${__object_id}"
+conf_name="${__object_id:?}"
 if [ -f "${__object}/parameter/value" ]
 then
 	conf_value=$(cat "${__object}/parameter/value")
@@ -46,7 +46,6 @@ fi
 if [ "${state_should}" = 'present' ]
 then
 	set_command="ALTER SYSTEM SET ${conf_name} = '${conf_value}'"
-	check_command="SHOW ${conf_name}"
 else
 	set_command="ALTER SYSTEM SET ${conf_name} = DEFAULT"
 fi

From 50bcd951055d7599ec340b4dea80a3a5d11dd9b0 Mon Sep 17 00:00:00 2001
From: Beni Ruef <bernhard.ruef@ssrq-sds-fds.ch>
Date: Thu, 10 Dec 2020 11:45:32 +0100
Subject: [PATCH 03/21] [type/__postgres_conf] Remove faulty quotes

---
 cdist/conf/type/__postgres_conf/gencode-remote | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cdist/conf/type/__postgres_conf/gencode-remote b/cdist/conf/type/__postgres_conf/gencode-remote
index e25514d0..8ccb3b42 100755
--- a/cdist/conf/type/__postgres_conf/gencode-remote
+++ b/cdist/conf/type/__postgres_conf/gencode-remote
@@ -45,7 +45,7 @@ fi
 
 if [ "${state_should}" = 'present' ]
 then
-	set_command="ALTER SYSTEM SET ${conf_name} = '${conf_value}'"
+	set_command="ALTER SYSTEM SET ${conf_name} = ${conf_value}"
 else
 	set_command="ALTER SYSTEM SET ${conf_name} = DEFAULT"
 fi

From b4060720dc3c7cc58aa992285877e4c009caa6be Mon Sep 17 00:00:00 2001
From: Beni Ruef <bernhard.ruef@ssrq-sds-fds.ch>
Date: Fri, 11 Dec 2020 11:12:16 +0100
Subject: [PATCH 04/21] [type/__postgres_conf] Fix psql options for ALTER
 command

---
 cdist/conf/type/__postgres_conf/gencode-remote | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cdist/conf/type/__postgres_conf/gencode-remote b/cdist/conf/type/__postgres_conf/gencode-remote
index 8ccb3b42..7d86028e 100755
--- a/cdist/conf/type/__postgres_conf/gencode-remote
+++ b/cdist/conf/type/__postgres_conf/gencode-remote
@@ -67,7 +67,7 @@ in
 		# needs two separate psql commands because ALTER SYSTEM
 		# cannot run inside a transaction block
 		cat <<-EOF
-		su - ${postgres_user} -c "psql postgres -twAc \
+		su - ${postgres_user} -c "psql postgres -qwc \
 			\"${set_command}\""
 		su - ${postgres_user} -c "psql postgres -twAc \
 			\"SELECT pg_reload_conf()\""

From 1b49fec972ce5f486f2794571c8e892d1fa6cb51 Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Mon, 18 Jan 2021 19:15:49 +0100
Subject: [PATCH 05/21] [type/__postgres_conf] Refactor

---
 .../type/__postgres_conf/explorer/context     |  42 ++++++
 .../conf/type/__postgres_conf/explorer/state  |  60 ++++++++
 .../conf/type/__postgres_conf/gencode-remote  | 135 ++++++++++--------
 3 files changed, 180 insertions(+), 57 deletions(-)
 create mode 100644 cdist/conf/type/__postgres_conf/explorer/context
 create mode 100644 cdist/conf/type/__postgres_conf/explorer/state

diff --git a/cdist/conf/type/__postgres_conf/explorer/context b/cdist/conf/type/__postgres_conf/explorer/context
new file mode 100644
index 00000000..3a2fa504
--- /dev/null
+++ b/cdist/conf/type/__postgres_conf/explorer/context
@@ -0,0 +1,42 @@
+#!/bin/sh -e
+# -*- mode: sh; indent-tabs-mode: t -*-
+#
+# 2021 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
+#
+# This file is part of cdist.
+#
+# cdist is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# cdist is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with cdist. If not, see <http://www.gnu.org/licenses/>.
+#
+# Returns the "context" of the configuration setting.
+# cf. also https://www.postgresql.org/docs/10/view-pg-settings.html
+
+os=$("${__explorer:?}/os")
+
+case ${os}
+in
+	(openbsd)
+		postgres_user='_postgresql'
+		;;
+	(devuan)
+		postgres_user='postgres'
+		;;
+	(*)
+		echo "Unsupported OS: ${os}" >&2
+		exit 1
+		;;
+esac
+
+conf_name=${__object_id:?}
+
+su - "${postgres_user}" -c "psql postgres -twAc \"SELECT context FROM pg_settings WHERE name = '${conf_name}'\""
diff --git a/cdist/conf/type/__postgres_conf/explorer/state b/cdist/conf/type/__postgres_conf/explorer/state
new file mode 100644
index 00000000..da904b56
--- /dev/null
+++ b/cdist/conf/type/__postgres_conf/explorer/state
@@ -0,0 +1,60 @@
+#!/bin/sh -e
+# -*- mode: sh; indent-tabs-mode: t -*-
+#
+# 2021 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
+#
+# This file is part of cdist.
+#
+# cdist is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# cdist is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with cdist. If not, see <http://www.gnu.org/licenses/>.
+#
+
+os=$("${__explorer:?}/os")
+
+case ${os}
+in
+	(openbsd)
+		postgres_user='_postgresql'
+		;;
+	(devuan)
+		postgres_user='postgres'
+		;;
+	(*)
+		echo "Unsupported OS: ${os}" >&2
+		exit 1
+		;;
+esac
+
+conf_name=${__object_id:?}
+
+if su - "${postgres_user}" -c "psql postgres -twAc 'SHOW ${conf_name}'" \
+	| cmp -s "${__object:?}/parameter/value" -
+then
+	echo present
+else
+	case $(su - "${postgres_user}" -c "psql postgres -tAwc \"SELECT source FROM pg_settings WHERE name = '${conf_name}'\"")
+	in
+		('')
+			# invalid configuration parameter
+			# (error message was already printed by SHOW command above.
+			#  Yes, it's a hack)
+			exit 1
+			;;
+		(default)
+			echo absent
+			;;
+		(*)
+			echo different
+			;;
+	esac
+fi
diff --git a/cdist/conf/type/__postgres_conf/gencode-remote b/cdist/conf/type/__postgres_conf/gencode-remote
index 7d86028e..998b8582 100755
--- a/cdist/conf/type/__postgres_conf/gencode-remote
+++ b/cdist/conf/type/__postgres_conf/gencode-remote
@@ -1,7 +1,7 @@
 #!/bin/sh -e
 # -*- mode: sh; indent-tabs-mode: t -*-
 #
-# 2019 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
+# 2019-2021 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
 # 2020 Beni Ruef (bernhard.ruef at ssrq-sds-fds.ch)
 #
 # This file is part of cdist.
@@ -21,71 +21,92 @@
 #
 
 os=$(cat "${__global:?}/explorer/os")
+state_is=$(cat "${__object:?}/explorer/state")
 state_should=$(cat "${__object:?}/parameter/state")
 
-if [ "${state_should}" != 'present' ] && [ "${state_should}" != 'absent' ]
+conf_name=${__object_id:?}
+
+if test "${state_is}" = "${state_should}"
 then
-	echo "Invalid state '${state_should}'." \
-	     'Only "present" and "absent" are acceptable' >&2
-	exit 1
+	exit 0
 fi
 
-if [ "${state_should}" = 'present' ] && [ ! -f "${__object}/parameter/value" ]
-then
-	echo 'Missing required parameter "value"' >&2
-	exit 1
-fi
-
-# Parameters
-conf_name="${__object_id:?}"
-if [ -f "${__object}/parameter/value" ]
-then
-	conf_value=$(cat "${__object}/parameter/value")
-fi
-
-if [ "${state_should}" = 'present' ]
-then
-	set_command="ALTER SYSTEM SET ${conf_name} = ${conf_value}"
-else
-	set_command="ALTER SYSTEM SET ${conf_name} = DEFAULT"
-fi
-
-case $os
-in
-	openbsd|devuan)
-		case $os
-		in
-			openbsd)
-				postgres_user='_postgresql'
-				restart_command='/etc/rc.d/postgresql restart'
-				;;
-			devuan)
-				postgres_user='postgres'
-				restart_command='/etc/init.d/postgresql restart'
-				;;
-		esac
-		# needs two separate psql commands because ALTER SYSTEM
-		# cannot run inside a transaction block
-		cat <<-EOF
-		su - ${postgres_user} -c "psql postgres -qwc \
-			\"${set_command}\""
-		su - ${postgres_user} -c "psql postgres -twAc \
-			\"SELECT pg_reload_conf()\""
-		EOF
-		# check success (makes only sense if setting to a non-default value)
-		# and restart server if needed
-		if [ "${state_should}" = 'present' ]
+quote() {
+	for _arg
+	do
+		shift
+		if test -n "$(printf '%s' "${_arg}" | tr -d -c '\t\n \042-\047\050-\052\073-\077\133\\`|~' | tr -c '' '.')"
 		then
-			cat <<-EOF
-			if [ \$(su - ${postgres_user} -c "psql postgres -twAc \"SHOW ${conf_name}\"") != '${conf_value}' ]
-			then
-				${restart_command}
-			fi
-			EOF
+			# needs quoting
+			set -- "$@" "'$(printf '%s' "${_arg}" | sed -e "s/'/'\\\\''/g")'"
+		else
+			set -- "$@" "${_arg}"
 		fi
+	done
+	unset _arg
+
+	# NOTE: Use printf because POSIX echo interprets escape sequences
+	printf '%s' "$*"
+}
+
+case ${os}
+in
+	(openbsd)
+		postgres_user='_postgresql'
+		restart_command='/etc/rc.d/postgresql restart'
 		;;
-	*)
+	(devuan)
+		postgres_user='postgres'
+		restart_command='/etc/init.d/postgresql restart'
+		;;
+	(*)
 		echo "Unsupported OS: ${os}" >&2
 		exit 1
 		;;
 esac
+
+
+psql_cmd() {
+	printf 'su - %s -c %s\n' "$(quote "${postgres_user}")" "$(quote "$(quote psql "$@")")"
+}
+
+case ${state_should}
+in
+	(present)
+		test -s "${__object:?}/parameter/value" || {
+			echo 'Missing required parameter --value' >&2
+			exit 1
+		}
+
+		cat <<-EOF
+		exec 3< "\${__object:?}/parameter/value"
+		$(psql_cmd postgres -tAw) <<'SQL'
+		\\set conf_value \`cat <&3\`
+		ALTER SYSTEM SET ${conf_name} = :'conf_value';
+		SELECT pg_reload_conf();
+		SQL
+		exec 3<&-
+		EOF
+		;;
+	(absent)
+		psql_cmd postgres -qwc "ALTER SYSTEM SET ${conf_name} TO DEFAULT"
+		;;
+	(*)
+		printf 'Invalid --state: %s\n' "${state_should}" >&2
+		printf 'Only "present" and "absent" are acceptable.\n' >&2
+		exit 1
+		;;
+esac
+
+# check success (makes only sense if setting to a non-default value)
+# and restart server if needed
+if test "${state_should}" = 'present'
+then
+	cat <<-EOF
+
+	$(psql_cmd postgres -twAc "SHOW ${conf_name}") \\
+	| cmp -s "\${__object:?}/parameter/value" - || {
+		${restart_command}
+	}
+	EOF
+fi

From 803367b316f5c72c51153172a41b7a745f2d2d83 Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Mon, 18 Jan 2021 19:29:42 +0100
Subject: [PATCH 06/21] [type/__postgres_conf] Fix default detection when
 default is also set in config file

e.g. port is usually also set to the default value in postgresql.conf
---
 cdist/conf/type/__postgres_conf/explorer/state | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cdist/conf/type/__postgres_conf/explorer/state b/cdist/conf/type/__postgres_conf/explorer/state
index da904b56..400b27e8 100644
--- a/cdist/conf/type/__postgres_conf/explorer/state
+++ b/cdist/conf/type/__postgres_conf/explorer/state
@@ -42,7 +42,7 @@ if su - "${postgres_user}" -c "psql postgres -twAc 'SHOW ${conf_name}'" \
 then
 	echo present
 else
-	case $(su - "${postgres_user}" -c "psql postgres -tAwc \"SELECT source FROM pg_settings WHERE name = '${conf_name}'\"")
+	case $(su - "${postgres_user}" -c "psql postgres -tAwc \"SELECT CASE WHEN source = 'default' OR setting = boot_val THEN 'default' ELSE source END FROM pg_settings WHERE name = '${conf_name}'\"")
 	in
 		('')
 			# invalid configuration parameter

From 891c98567e1d94577dc4f20d3ec9f73f4927fd24 Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Mon, 18 Jan 2021 19:39:56 +0100
Subject: [PATCH 07/21] [type/__postgres_conf] Compare configuration parameter
 names case insensitively

---
 cdist/conf/type/__postgres_conf/explorer/context | 3 ++-
 cdist/conf/type/__postgres_conf/explorer/state   | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/cdist/conf/type/__postgres_conf/explorer/context b/cdist/conf/type/__postgres_conf/explorer/context
index 3a2fa504..def5f676 100644
--- a/cdist/conf/type/__postgres_conf/explorer/context
+++ b/cdist/conf/type/__postgres_conf/explorer/context
@@ -39,4 +39,5 @@ esac
 
 conf_name=${__object_id:?}
 
-su - "${postgres_user}" -c "psql postgres -twAc \"SELECT context FROM pg_settings WHERE name = '${conf_name}'\""
+# NOTE: SHOW/SET are case-insentitive, so this command should also be.
+su - "${postgres_user}" -c "psql postgres -twAc \"SELECT context FROM pg_settings WHERE lower(name) = lower('${conf_name}')\""
diff --git a/cdist/conf/type/__postgres_conf/explorer/state b/cdist/conf/type/__postgres_conf/explorer/state
index 400b27e8..a4930296 100644
--- a/cdist/conf/type/__postgres_conf/explorer/state
+++ b/cdist/conf/type/__postgres_conf/explorer/state
@@ -42,7 +42,8 @@ if su - "${postgres_user}" -c "psql postgres -twAc 'SHOW ${conf_name}'" \
 then
 	echo present
 else
-	case $(su - "${postgres_user}" -c "psql postgres -tAwc \"SELECT CASE WHEN source = 'default' OR setting = boot_val THEN 'default' ELSE source END FROM pg_settings WHERE name = '${conf_name}'\"")
+	# NOTE: SHOW/SET are case-insentitive, so this command should also be.
+	case $(su - "${postgres_user}" -c "psql postgres -tAwc \"SELECT CASE WHEN source = 'default' OR setting = boot_val THEN 'default' ELSE source END FROM pg_settings WHERE lower(name) = lower('${conf_name}')\"")
 	in
 		('')
 			# invalid configuration parameter

From 5051d4f40b7097f58431ce334f9ddf5b171dbc7f Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Tue, 19 Jan 2021 16:36:44 +0100
Subject: [PATCH 08/21] [type/__postgres_conf] Catch invalid values

---
 cdist/conf/type/__postgres_conf/gencode-remote | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cdist/conf/type/__postgres_conf/gencode-remote b/cdist/conf/type/__postgres_conf/gencode-remote
index 998b8582..cc9b4e99 100755
--- a/cdist/conf/type/__postgres_conf/gencode-remote
+++ b/cdist/conf/type/__postgres_conf/gencode-remote
@@ -80,7 +80,7 @@ in
 
 		cat <<-EOF
 		exec 3< "\${__object:?}/parameter/value"
-		$(psql_cmd postgres -tAw) <<'SQL'
+		$(psql_cmd postgres -tAw -v ON_ERROR_STOP=on) <<'SQL'
 		\\set conf_value \`cat <&3\`
 		ALTER SYSTEM SET ${conf_name} = :'conf_value';
 		SELECT pg_reload_conf();

From 0f2ff477381d67de27149a92744f873322e44fd7 Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Tue, 19 Jan 2021 16:37:43 +0100
Subject: [PATCH 09/21] [type/__postgres_conf] Restart PostgreSQL server based
 on pending_restart column of pg_settings

---
 .../type/__postgres_conf/explorer/context     | 43 -------------------
 .../conf/type/__postgres_conf/gencode-remote  | 16 +++----
 2 files changed, 6 insertions(+), 53 deletions(-)
 delete mode 100644 cdist/conf/type/__postgres_conf/explorer/context

diff --git a/cdist/conf/type/__postgres_conf/explorer/context b/cdist/conf/type/__postgres_conf/explorer/context
deleted file mode 100644
index def5f676..00000000
--- a/cdist/conf/type/__postgres_conf/explorer/context
+++ /dev/null
@@ -1,43 +0,0 @@
-#!/bin/sh -e
-# -*- mode: sh; indent-tabs-mode: t -*-
-#
-# 2021 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
-#
-# This file is part of cdist.
-#
-# cdist is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# cdist is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with cdist. If not, see <http://www.gnu.org/licenses/>.
-#
-# Returns the "context" of the configuration setting.
-# cf. also https://www.postgresql.org/docs/10/view-pg-settings.html
-
-os=$("${__explorer:?}/os")
-
-case ${os}
-in
-	(openbsd)
-		postgres_user='_postgresql'
-		;;
-	(devuan)
-		postgres_user='postgres'
-		;;
-	(*)
-		echo "Unsupported OS: ${os}" >&2
-		exit 1
-		;;
-esac
-
-conf_name=${__object_id:?}
-
-# NOTE: SHOW/SET are case-insentitive, so this command should also be.
-su - "${postgres_user}" -c "psql postgres -twAc \"SELECT context FROM pg_settings WHERE lower(name) = lower('${conf_name}')\""
diff --git a/cdist/conf/type/__postgres_conf/gencode-remote b/cdist/conf/type/__postgres_conf/gencode-remote
index cc9b4e99..fa930cc4 100755
--- a/cdist/conf/type/__postgres_conf/gencode-remote
+++ b/cdist/conf/type/__postgres_conf/gencode-remote
@@ -98,15 +98,11 @@ in
 		;;
 esac
 
-# check success (makes only sense if setting to a non-default value)
-# and restart server if needed
-if test "${state_should}" = 'present'
-then
-	cat <<-EOF
+# Restart PostgreSQL server if required to apply new configuration value
+cat <<EOF
 
-	$(psql_cmd postgres -twAc "SHOW ${conf_name}") \\
-	| cmp -s "\${__object:?}/parameter/value" - || {
-		${restart_command}
-	}
-	EOF
+if test 't' = "\$($(psql_cmd postgres -twAc "SELECT pending_restart FROM pg_settings WHERE lower(name) = lower('${conf_name}')"))"
+then
+	${restart_command}
 fi
+EOF

From 3f605c31ac7538d188a11b5d9d84cf2ed485bf23 Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Tue, 19 Jan 2021 17:18:27 +0100
Subject: [PATCH 10/21] [type/__postgres_conf] Add support for more init
 systems to restart service

---
 .../conf/type/__postgres_conf/gencode-remote  | 35 +++++++++++++++++--
 1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/cdist/conf/type/__postgres_conf/gencode-remote b/cdist/conf/type/__postgres_conf/gencode-remote
index fa930cc4..15d5bb3e 100755
--- a/cdist/conf/type/__postgres_conf/gencode-remote
+++ b/cdist/conf/type/__postgres_conf/gencode-remote
@@ -53,11 +53,9 @@ case ${os}
 in
 	(openbsd)
 		postgres_user='_postgresql'
-		restart_command='/etc/rc.d/postgresql restart'
 		;;
 	(devuan)
 		postgres_user='postgres'
-		restart_command='/etc/init.d/postgresql restart'
 		;;
 	(*)
 		echo "Unsupported OS: ${os}" >&2
@@ -103,6 +101,37 @@ cat <<EOF
 
 if test 't' = "\$($(psql_cmd postgres -twAc "SELECT pending_restart FROM pg_settings WHERE lower(name) = lower('${conf_name}')"))"
 then
-	${restart_command}
+	$(
+		init=$(cat "${__global:?}/explorer/init")
+		case ${init}
+		in
+			(systemd)
+				echo 'systemctl restart postgresql.service'
+				;;
+			(*openrc*)
+				echo 'rc-service postgresql restart'
+				;;
+			(sysvinit)
+				echo '/etc/init.d/postgresql restart'
+				;;
+			(init)
+				case $(cat "${__global:?}/explorer/kernel_name")
+				in
+					(FreeBSD)
+						echo 'service postgresql restart'
+						;;
+					(OpenBSD|NetBSD)
+						echo '/etc/rc.d/postgresql restart'
+						;;
+					(*)
+						echo "Unsupported operating system. Don't know how to restart services." >&2
+						exit 1
+				esac
+				;;
+			(*)
+				printf "Don't know how to restart services with your init (%s)\n" "${init}" >&2
+				exit 1
+		esac
+	)
 fi
 EOF

From 4967c7ebbb7e98af6aa2c7f8bc91511bcbbf9820 Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Tue, 19 Jan 2021 17:20:27 +0100
Subject: [PATCH 11/21] [type/__postgres_conf] Silence psql output

---
 cdist/conf/type/__postgres_conf/gencode-remote | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cdist/conf/type/__postgres_conf/gencode-remote b/cdist/conf/type/__postgres_conf/gencode-remote
index 15d5bb3e..9b8227ee 100755
--- a/cdist/conf/type/__postgres_conf/gencode-remote
+++ b/cdist/conf/type/__postgres_conf/gencode-remote
@@ -78,7 +78,7 @@ in
 
 		cat <<-EOF
 		exec 3< "\${__object:?}/parameter/value"
-		$(psql_cmd postgres -tAw -v ON_ERROR_STOP=on) <<'SQL'
+		$(psql_cmd postgres -tAwq -o /dev/null -v ON_ERROR_STOP=on) <<'SQL'
 		\\set conf_value \`cat <&3\`
 		ALTER SYSTEM SET ${conf_name} = :'conf_value';
 		SELECT pg_reload_conf();

From f9ebb4333c85e41439635cb00a40c3e07d8a3683 Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Tue, 19 Jan 2021 17:21:50 +0100
Subject: [PATCH 12/21] [type/__postgres_conf] Add NetBSD PostgreSQL UNIX user

---
 cdist/conf/type/__postgres_conf/gencode-remote | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/cdist/conf/type/__postgres_conf/gencode-remote b/cdist/conf/type/__postgres_conf/gencode-remote
index 9b8227ee..8f8a2bfe 100755
--- a/cdist/conf/type/__postgres_conf/gencode-remote
+++ b/cdist/conf/type/__postgres_conf/gencode-remote
@@ -51,15 +51,14 @@ quote() {
 
 case ${os}
 in
+	(netbsd)
+		postgres_user='pgsql'
+		;;
 	(openbsd)
 		postgres_user='_postgresql'
 		;;
-	(devuan)
-		postgres_user='postgres'
-		;;
 	(*)
-		echo "Unsupported OS: ${os}" >&2
-		exit 1
+		postgres_user='postgres'
 		;;
 esac
 

From 6b18cace759d1345cec6c2168c3bd8f238f23bca Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Thu, 21 Jan 2021 19:29:07 +0100
Subject: [PATCH 13/21] [type/__postgres_conf] Catch connection errors early

---
 cdist/conf/type/__postgres_conf/explorer/state | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/cdist/conf/type/__postgres_conf/explorer/state b/cdist/conf/type/__postgres_conf/explorer/state
index a4930296..589925de 100644
--- a/cdist/conf/type/__postgres_conf/explorer/state
+++ b/cdist/conf/type/__postgres_conf/explorer/state
@@ -37,6 +37,11 @@ esac
 
 conf_name=${__object_id:?}
 
+su - "${postgres_user}" -c 'psql postgres -c "SELECT 1"' >/dev/null || {
+	echo 'Connection to PostgreSQL server failed' >&2
+	exit 1
+}
+
 if su - "${postgres_user}" -c "psql postgres -twAc 'SHOW ${conf_name}'" \
 	| cmp -s "${__object:?}/parameter/value" -
 then

From 0835f414a5b2ce41309ee9b265cb80abb1362563 Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Tue, 16 Feb 2021 16:03:23 +0100
Subject: [PATCH 14/21] [type/__postgres_conf] Extract PostgreSQL service user
 detection to separate explorer

---
 .../__postgres_conf/explorer/postgres_user    | 64 +++++++++++++++++++
 .../conf/type/__postgres_conf/explorer/state  | 16 +----
 .../conf/type/__postgres_conf/gencode-remote  | 17 +----
 3 files changed, 67 insertions(+), 30 deletions(-)
 create mode 100644 cdist/conf/type/__postgres_conf/explorer/postgres_user

diff --git a/cdist/conf/type/__postgres_conf/explorer/postgres_user b/cdist/conf/type/__postgres_conf/explorer/postgres_user
new file mode 100644
index 00000000..c6582dc4
--- /dev/null
+++ b/cdist/conf/type/__postgres_conf/explorer/postgres_user
@@ -0,0 +1,64 @@
+#!/bin/sh -e
+# -*- mode: sh; indent-tabs-mode: t -*-
+#
+# 2021 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
+#
+# This file is part of cdist.
+#
+# cdist is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# cdist is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with cdist. If not, see <http://www.gnu.org/licenses/>.
+#
+
+os=$("${__explorer:?}/os")
+
+case ${os}
+in
+	(alpine)
+		echo 'postgres'
+		;;
+	(centos|rhel|scientific)
+		echo 'postgres'
+		;;
+	(debian|devuan|ubuntu)
+		echo 'postgres'
+		;;
+	(freebsd)
+		test -x /usr/local/etc/rc.d/postgresql || {
+			printf 'could not find postgresql rc script./n' >&2
+			exit 1
+		}
+		pg_status=$(/usr/local/etc/rc.d/postgresql onestatus) || {
+			printf 'postgresql daemon is not running.\n' >&2
+			exit 1
+		}
+		pg_pid=$(printf '%s\n' "${pg_status}" \
+			| sed -n 's/^pg_ctl:.*(PID: *\([0-9]*\))$/\1/p')
+
+		# PostgreSQL < 9.6: pgsql
+		# PostgreSQL >= 9.6: postgres
+		ps -o user -p "${pg_pid}" | sed -n '2p'
+		;;
+	(netbsd)
+		echo 'pgsql'
+		;;
+	(openbsd)
+		echo '_postgresql'
+		;;
+	(suse)
+		echo 'postgres'
+		;;
+	(*)
+		echo "Unsupported OS: ${os}" >&2
+		exit 1
+		;;
+esac
diff --git a/cdist/conf/type/__postgres_conf/explorer/state b/cdist/conf/type/__postgres_conf/explorer/state
index 589925de..de6e8aa0 100644
--- a/cdist/conf/type/__postgres_conf/explorer/state
+++ b/cdist/conf/type/__postgres_conf/explorer/state
@@ -19,21 +19,7 @@
 # along with cdist. If not, see <http://www.gnu.org/licenses/>.
 #
 
-os=$("${__explorer:?}/os")
-
-case ${os}
-in
-	(openbsd)
-		postgres_user='_postgresql'
-		;;
-	(devuan)
-		postgres_user='postgres'
-		;;
-	(*)
-		echo "Unsupported OS: ${os}" >&2
-		exit 1
-		;;
-esac
+postgres_user=$("${__type_explorer:?}/postgres_user")
 
 conf_name=${__object_id:?}
 
diff --git a/cdist/conf/type/__postgres_conf/gencode-remote b/cdist/conf/type/__postgres_conf/gencode-remote
index 8f8a2bfe..d0d247b4 100755
--- a/cdist/conf/type/__postgres_conf/gencode-remote
+++ b/cdist/conf/type/__postgres_conf/gencode-remote
@@ -20,9 +20,9 @@
 # along with cdist. If not, see <http://www.gnu.org/licenses/>.
 #
 
-os=$(cat "${__global:?}/explorer/os")
 state_is=$(cat "${__object:?}/explorer/state")
 state_should=$(cat "${__object:?}/parameter/state")
+postgres_user=$(cat "${__object:?}/explorer/postgres_user")
 
 conf_name=${__object_id:?}
 
@@ -49,19 +49,6 @@ quote() {
 	printf '%s' "$*"
 }
 
-case ${os}
-in
-	(netbsd)
-		postgres_user='pgsql'
-		;;
-	(openbsd)
-		postgres_user='_postgresql'
-		;;
-	(*)
-		postgres_user='postgres'
-		;;
-esac
-
 
 psql_cmd() {
 	printf 'su - %s -c %s\n' "$(quote "${postgres_user}")" "$(quote "$(quote psql "$@")")"
@@ -117,7 +104,7 @@ then
 				case $(cat "${__global:?}/explorer/kernel_name")
 				in
 					(FreeBSD)
-						echo 'service postgresql restart'
+						echo '/usr/local/etc/rc.d/postgresql restart'
 						;;
 					(OpenBSD|NetBSD)
 						echo '/etc/rc.d/postgresql restart'

From 92b8942a8c37bb985ef42991f3b7aaef0cd8073f Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Thu, 15 Apr 2021 09:00:32 +0200
Subject: [PATCH 15/21] [type/__postgres_conf] Add psql_exec function to state
 explorer

---
 cdist/conf/type/__postgres_conf/explorer/state | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/cdist/conf/type/__postgres_conf/explorer/state b/cdist/conf/type/__postgres_conf/explorer/state
index de6e8aa0..1a58751a 100644
--- a/cdist/conf/type/__postgres_conf/explorer/state
+++ b/cdist/conf/type/__postgres_conf/explorer/state
@@ -20,21 +20,24 @@
 #
 
 postgres_user=$("${__type_explorer:?}/postgres_user")
-
 conf_name=${__object_id:?}
 
-su - "${postgres_user}" -c 'psql postgres -c "SELECT 1"' >/dev/null || {
+quote() { printf '%s\n' "$*" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/'/"; }
+psql_exec() {
+	su - "${postgres_user}" -c "psql postgres -twAc $(quote "$*")"
+}
+
+psql_exec 'SELECT 1' >/dev/null || {
 	echo 'Connection to PostgreSQL server failed' >&2
 	exit 1
 }
 
-if su - "${postgres_user}" -c "psql postgres -twAc 'SHOW ${conf_name}'" \
-	| cmp -s "${__object:?}/parameter/value" -
+if psql_exec "SHOW ${conf_name}" | cmp -s "${__object:?}/parameter/value" -
 then
 	echo present
 else
 	# NOTE: SHOW/SET are case-insentitive, so this command should also be.
-	case $(su - "${postgres_user}" -c "psql postgres -tAwc \"SELECT CASE WHEN source = 'default' OR setting = boot_val THEN 'default' ELSE source END FROM pg_settings WHERE lower(name) = lower('${conf_name}')\"")
+	case $(psql_exec "SELECT CASE WHEN source = 'default' OR setting = boot_val THEN 'default' ELSE source END FROM pg_settings WHERE lower(name) = lower('${conf_name}')")
 	in
 		('')
 			# invalid configuration parameter

From 2ccc03fef1e28c759a7918fa00ffcb45c76dc57a Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Thu, 15 Apr 2021 09:02:40 +0200
Subject: [PATCH 16/21] [type/__postgres_conf] Add psql_conf_cmp function to
 state explorer

---
 cdist/conf/type/__postgres_conf/explorer/state | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/cdist/conf/type/__postgres_conf/explorer/state b/cdist/conf/type/__postgres_conf/explorer/state
index 1a58751a..be881be6 100644
--- a/cdist/conf/type/__postgres_conf/explorer/state
+++ b/cdist/conf/type/__postgres_conf/explorer/state
@@ -27,12 +27,16 @@ psql_exec() {
 	su - "${postgres_user}" -c "psql postgres -twAc $(quote "$*")"
 }
 
+psql_conf_cmp() {
+	test "$(psql_exec "SHOW $1")" = "$2"
+}
+
 psql_exec 'SELECT 1' >/dev/null || {
 	echo 'Connection to PostgreSQL server failed' >&2
 	exit 1
 }
 
-if psql_exec "SHOW ${conf_name}" | cmp -s "${__object:?}/parameter/value" -
+if psql_conf_cmp "${conf_name}" "$(cat "${__object:?}/parameter/value")"
 then
 	echo present
 else

From e0416403c4862cb8bc0f41a7c6f8a33d1a8656a5 Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Thu, 15 Apr 2021 09:04:07 +0200
Subject: [PATCH 17/21] [type/__postgres_conf] Add psql_conf_source function to
 state explorer

---
 cdist/conf/type/__postgres_conf/explorer/state | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/cdist/conf/type/__postgres_conf/explorer/state b/cdist/conf/type/__postgres_conf/explorer/state
index be881be6..9f54724a 100644
--- a/cdist/conf/type/__postgres_conf/explorer/state
+++ b/cdist/conf/type/__postgres_conf/explorer/state
@@ -27,6 +27,10 @@ psql_exec() {
 	su - "${postgres_user}" -c "psql postgres -twAc $(quote "$*")"
 }
 
+psql_conf_source() {
+	# NOTE: SHOW/SET are case-insentitive, so this command should also be.
+	psql_exec "SELECT CASE WHEN source = 'default' OR setting = boot_val THEN 'default' ELSE source END FROM pg_settings WHERE lower(name) = lower('$1')"
+}
 psql_conf_cmp() {
 	test "$(psql_exec "SHOW $1")" = "$2"
 }
@@ -40,8 +44,7 @@ if psql_conf_cmp "${conf_name}" "$(cat "${__object:?}/parameter/value")"
 then
 	echo present
 else
-	# NOTE: SHOW/SET are case-insentitive, so this command should also be.
-	case $(psql_exec "SELECT CASE WHEN source = 'default' OR setting = boot_val THEN 'default' ELSE source END FROM pg_settings WHERE lower(name) = lower('${conf_name}')")
+	case $(psql_conf_source "${conf_name}")
 	in
 		('')
 			# invalid configuration parameter

From 12c2995494ce582cb3adf1d942b36f6df035370a Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Thu, 15 Apr 2021 14:46:36 +0200
Subject: [PATCH 18/21] [type/__postgres_conf] Implement complex state compare
 logic

---
 .../conf/type/__postgres_conf/explorer/state  | 166 +++++++++++++++++-
 1 file changed, 163 insertions(+), 3 deletions(-)

diff --git a/cdist/conf/type/__postgres_conf/explorer/state b/cdist/conf/type/__postgres_conf/explorer/state
index 9f54724a..e76540c5 100644
--- a/cdist/conf/type/__postgres_conf/explorer/state
+++ b/cdist/conf/type/__postgres_conf/explorer/state
@@ -22,6 +22,52 @@
 postgres_user=$("${__type_explorer:?}/postgres_user")
 conf_name=${__object_id:?}
 
+tolower() { printf '%s' "$*" | tr '[:upper:]' '[:lower:]'; }
+
+tobytes() {
+	# NOTE: This function treats everything as base 2.
+	#       It is not compatible with SI units.
+	awk 'BEGIN { FS = "\n" }
+	/TB$/ { $0 = ($0 * 1024) "GB" }
+	/GB$/ { $0 = ($0 * 1024) "MB" }
+	/MB$/ { $0 = ($0 * 1024) "kB" }
+	/kB$/ { $0 = ($0 * 1024) "B" }
+	 /B?$/ { sub(/ *B?$/, "") }
+	($0*1) == $0  # is number
+	' <<-EOF
+	$1
+	EOF
+}
+
+tomillisecs() {
+	awk 'BEGIN { FS = "\n" }
+	    /d$/ { $0 = ($0 * 24) "h" }
+	    /h$/ { $0 = ($0 * 60) "min" }
+	  /min$/ { $0 = ($0 * 60) "s" }
+	/[^m]s$/ { $0 = ($0 * 1000) "ms" }
+	   /ms$/ { $0 *= 1 }
+	($0*1) == $0  # is number
+	' <<-EOF
+	$1
+	EOF
+}
+
+tobool() {
+	# prints either 'on' or 'off'
+	case $(tolower "$1")
+	in
+		(t|true|y|yes|on|1)
+			echo 'on' ;;
+		(f|false|n|no|off|0)
+			echo 'off' ;;
+		(*)
+			printf 'Inavlid bool value: %s\n' "$2" >&2
+			return 1
+			;;
+	esac
+	return 0
+}
+
 quote() { printf '%s\n' "$*" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/'/"; }
 psql_exec() {
 	su - "${postgres_user}" -c "psql postgres -twAc $(quote "$*")"
@@ -31,9 +77,123 @@ psql_conf_source() {
 	# NOTE: SHOW/SET are case-insentitive, so this command should also be.
 	psql_exec "SELECT CASE WHEN source = 'default' OR setting = boot_val THEN 'default' ELSE source END FROM pg_settings WHERE lower(name) = lower('$1')"
 }
-psql_conf_cmp() {
-	test "$(psql_exec "SHOW $1")" = "$2"
-}
+psql_conf_cmp() (
+	IFS='|' read -r lower_name vartype setting unit <<-EOF
+	$(psql_exec "SELECT lower(name), vartype, setting, unit FROM pg_settings WHERE lower(name) = lower('$1')")
+	EOF
+
+	should_value=$2
+	is_value=${setting}
+
+	# The following case contains special cases for special settings.
+	case ${lower_name}
+	in
+		(archive_command)
+			if test "${setting}" = '(disabled)'
+			then
+				# DAFUQ PostgreSQL?!
+				# PostgreSQL returns (disabled) if the feature is inactive.
+				# We cannot compare the values unless it is enabled, first.
+				return 0
+			fi
+			;;
+		(archive_mode|backslash_quote|constraint_exclusion|force_parallel_mode|huge_pages|synchronous_commit)
+			# Although only 'on', 'off' are documented, PostgreSQL accepts all
+			# the "likely" variants of "on" and "off".
+			case $(tolower "${should_value}")
+			in
+				(on|off|true|false|yes|no|1|0)
+					should_value=$(tobool "${should_value}")
+					;;
+			esac
+			;;
+	esac
+
+	case ${vartype}
+	in
+		(bool)
+			test -z "${unit}" || {
+				# please fix the explorer if this error occurs.
+				printf 'units are not supported for vartype: %s\n' "${vartype}" >&2
+				exit 1
+			}
+
+			should_value=$(tobool "${should_value}")
+
+			test "${is_value}" = "${should_value}"
+			;;
+		(enum)
+			test -z "${unit}" || {
+				# please fix the explorer if this error occurs.
+				printf 'units are not supported with vartype: %s\n' "${vartype}" >&2
+				exit 1
+			}
+
+			# NOTE: All enums that are currently defined are lower case, but
+			#       PostgreSQL also accepts upper case spelling.
+			should_value=$(tolower "$2")
+
+			test "${is_value}" = "${should_value}"
+			;;
+		(integer)
+			# split multiples from unit, first (e.g. 8kB -> 8, kB)
+			case ${unit}
+			in
+				([0-9]*)
+					multiple=${unit%%[!0-9]*}
+					unit=${unit##*[0-9 ]}
+					;;
+				(*) multiple=1 ;;
+			esac
+
+			is_value=$((setting * multiple))${unit}
+
+			if expr "${should_value}" : '-\{0,1\}[0-9]*$' >/dev/null
+			then
+				# default unit
+				should_value=$((should_value * multiple))${unit}
+			fi
+
+			# then, do conversion
+			# NOTE: these conversions work for integers only!
+			case ${unit}
+			in
+				(B|[kMGT]B)
+					# bytes
+					is_bytes=$(tobytes "${is_value}")
+					should_bytes=$(tobytes "${should_value}")
+
+					test $((is_bytes)) -eq $((should_bytes))
+					;;
+				(ms|s|min|h|d)
+					# seconds
+					is_ms=$(tomillisecs "${is_value}")
+					should_ms=$(tomillisecs "${should_value}")
+
+					test $((is_ms)) -eq $((should_ms))
+					;;
+				('')
+					# no unit
+					is_int=${is_value}
+					should_int=${should_value}
+
+					test $((is_int)) -eq $((should_int))
+					;;
+			esac
+			;;
+		(real|string)
+			# NOTE: reals could possibly have units, but currently there none.
+
+			test -z "${unit}" || {
+				# please fix the explorer if this error occurs.
+				printf 'units are not supported with vartype: %s\n' "${vartype}" >&2
+				exit 1
+			}
+
+			test "${is_value}" = "${should_value}"
+			;;
+	esac
+)
 
 psql_exec 'SELECT 1' >/dev/null || {
 	echo 'Connection to PostgreSQL server failed' >&2

From bef1433ba3adb022f8b50eb9df0fbbbf90757d76 Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Thu, 15 Apr 2021 14:46:50 +0200
Subject: [PATCH 19/21] [type/__postgres_conf] Accept empty values

---
 cdist/conf/type/__postgres_conf/gencode-remote | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cdist/conf/type/__postgres_conf/gencode-remote b/cdist/conf/type/__postgres_conf/gencode-remote
index d0d247b4..27651600 100755
--- a/cdist/conf/type/__postgres_conf/gencode-remote
+++ b/cdist/conf/type/__postgres_conf/gencode-remote
@@ -57,7 +57,7 @@ psql_cmd() {
 case ${state_should}
 in
 	(present)
-		test -s "${__object:?}/parameter/value" || {
+		test -n "${__object:?}/parameter/value" || {
 			echo 'Missing required parameter --value' >&2
 			exit 1
 		}

From 686e4f0f2d498ee39a69e43f7535171f16f5fcbc Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Thu, 15 Apr 2021 15:01:38 +0200
Subject: [PATCH 20/21] [type/__postgres_conf] Reverse state logic (decide
 based on source first)

---
 .../conf/type/__postgres_conf/explorer/state  | 39 ++++++++++---------
 1 file changed, 20 insertions(+), 19 deletions(-)

diff --git a/cdist/conf/type/__postgres_conf/explorer/state b/cdist/conf/type/__postgres_conf/explorer/state
index e76540c5..4b7b0a43 100644
--- a/cdist/conf/type/__postgres_conf/explorer/state
+++ b/cdist/conf/type/__postgres_conf/explorer/state
@@ -200,23 +200,24 @@ psql_exec 'SELECT 1' >/dev/null || {
 	exit 1
 }
 
-if psql_conf_cmp "${conf_name}" "$(cat "${__object:?}/parameter/value")"
-then
-	echo present
-else
-	case $(psql_conf_source "${conf_name}")
-	in
-		('')
-			# invalid configuration parameter
-			# (error message was already printed by SHOW command above.
-			#  Yes, it's a hack)
-			exit 1
-			;;
-		(default)
-			echo absent
-			;;
-		(*)
+case $(psql_conf_source "${conf_name}")
+in
+	('')
+		printf 'Invalid configuration parameter: %s\n' "${conf_name}" >&2
+		exit 1
+		;;
+	(default)
+		echo absent
+		;;
+	(*)
+		if ! test -f "${__object:?}/parameter/value"
+		then
+			echo present
+		elif psql_conf_cmp "${conf_name}" "$(cat "${__object:?}/parameter/value")"
+		then
+			echo present
+		else
 			echo different
-			;;
-	esac
-fi
+		fi
+		;;
+esac

From 19bf37be1a8b0b099a7199d1565b74598010f614 Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Thu, 15 Apr 2021 15:55:52 +0200
Subject: [PATCH 21/21] [type/__postgres_conf] Update man.rst

---
 cdist/conf/type/__postgres_conf/man.rst | 39 ++++++++++++++-----------
 1 file changed, 22 insertions(+), 17 deletions(-)

diff --git a/cdist/conf/type/__postgres_conf/man.rst b/cdist/conf/type/__postgres_conf/man.rst
index 76016c6c..e035f080 100644
--- a/cdist/conf/type/__postgres_conf/man.rst
+++ b/cdist/conf/type/__postgres_conf/man.rst
@@ -1,29 +1,27 @@
 cdist-type__postgres_conf(7)
 ============================
 
-Configure a PostgreSQL server.
-
-NOTE: This type might need to be run multiple times to apply all bits of the
-configuration due to ordering requirements.
-
-SSRQ <cdist--@--ssrq-sds-fds.ch>
+NAME
+----
+cdist-type__postgres_conf - Alter PostgreSQL configuration
 
 
 DESCRIPTION
 -----------
-Configure a PostgreSQL server using ALTER SYSTEM.
+Configure a running PostgreSQL server using ``ALTER SYSTEM``.
 
 
 REQUIRED PARAMETERS
 -------------------
 value
-    The value to setup (can be omitted when state is set to "absent").
+   The value to set (can be omitted if ``--state`` is set to ``absent``).
 
 
 OPTIONAL PARAMETERS
 -------------------
 state
-    "present" or "absent". Defaults to "present".
+   ``present`` or ``absent``.
+   Defaults to ``present``.
 
 
 BOOLEAN PARAMETERS
@@ -36,20 +34,27 @@ EXAMPLES
 
 .. code-block:: sh
 
-	# set timezone
-    __postgres_conf timezone --value Europe/Zurich
+   # set timezone
+   __postgres_conf timezone --value Europe/Zurich
 
-    # reset maximum number of concurrent connections to default (normally 100)
-    __postgres_conf max_connections --state absent
+   # reset maximum number of concurrent connections to default (normally 100)
+   __postgres_conf max_connections --state absent
 
 
 SEE ALSO
 --------
-- `cdist-type(7) <cdist-type.html>`_
+None.
+
+
+AUTHORS
+-------
+Beni Ruef (bernhard.ruef--@--ssrq-sds-fds.ch)
+Dennis Camera (dennis.camera--@--ssrq-sds-fds.ch)
 
 
 COPYING
 -------
-Copyright \(C) 2020 SSRQ (www.ssrq-sds-fds.ch).
-Free use of this software is granted under the terms
-of the GNU General Public License version 3 (GPLv3).
+Copyright \(C) 2019-2021 SSRQ (www.ssrq-sds-fds.ch).
+You can redistribute it and/or modify it under the terms of the GNU General
+Public License as published by the Free Software Foundation, either version 3 of
+the License, or (at your option) any later version.