[__sensible_editor] Add support for RedHat derivatives

They have added sensible-utils lately.
select-editor(1) does not work because their alternatives system is broken,
but sensible-editor(1) works just fine, so we can support it.

cdist/conf/type/__sensible_editor/explorer/editor_path

@@ -22,76 +22,92 @@
 # absolute path.
 #
 
+die() {
+	echo "$@" >&2
+	exit 1
+}
+
+editor_missing() { die "Editor '$1' is missing on the target system."; }
+editor_no_alternative() { die "Editor '$1' is not in the alternatives list of the target system."; }
+
+
 case $("${__explorer}/os")
 in
 	debian|devuan|ubuntu)
-		:  # supported
+		has_alternatives=true
+		editors=$(update-alternatives --list editor)
 		;;
 	*)
-		exit 0  # will produce an error message in the manifest
+		# NOTE: RedHat has an alternatives system but it doesn't usually track
+		#       editors and it is a pain to extract the list.
+		has_alternatives=false
 		;;
 esac
 
-
 editor=$(cat "${__object}/parameter/editor")
-editors=$(update-alternatives --list editor)
-
-if test $(echo "${editors}" | wc -l) -lt 1
-then
-	echo 'No editors have been found on this system.' >&2
-	exit 1
-fi
 
 case $editor
 in
 	/*)
-		is_path=true
+		is_abspath=true
 		;;
 	*/*)
-		echo 'Relative editor paths are not supported' >&2
+		die 'Relative editor paths are not supported'
-		exit 1
 		;;
 	*)
-		is_path=false
+		is_abspath=false
 		;;
 esac
 
 
+if $has_alternatives && test "$(echo "${editors}" | wc -l)" -gt 0
+then
 	IFS='
 '
-if $is_path
+	if ! $is_abspath
 	then
-	if ! test -f "${editor}"
+		# First, try to resolve the absolute path using $editors.
+		for e in $editors
+		do
+			if test "$(basename "${e}")" = "${editor}"
 			then
-		echo "Editor ${editor} is missing on the target system." >&2
+				editor="${e}"
-		exit 1
+				break
 			fi
+		done
+	fi
+
+	# Check if path is present
+	test -f "${editor}" || editor_missing "${editor}"
 
 	for e in $editors
 	do
 		if test "${editor}" = "${e}"
 		then
-			# Editor is present and part of the alternatives list -> use it!
+			# Editor is part of the alternatives list -> use it!
 			echo "${editor}"
 			exit 0
 		fi
 	done
 
-	echo "Editor ${editor} is not in the alternatives list of the target system." >&2
+	editor_no_alternative "${editor}"
-	exit 1
 else
-	for e in $editors
+	# NOTE: This branch is mostly for RedHat-based systems which do
-	do
+	#       not track editor alternatives.  To make this type useful
-		if test "$(basename "${e}")" = "${editor}"
+	#       on RedHat at all we allow an absoloute path to be provided
+	#       in any case.
+
+	if $is_abspath
 	then
-			# Editor could be found by basename in the alternatives list -> use it!
+		test -x "${editor}" || editor_missing "${editor}"
-			echo "${e}"
+
+		echo "${editor}"
 		exit 0
+	else
+		die "The target doesn't list any editor alternatives. " \
+		    "Please specify an absolute path or populate the alternatives list."
 	fi
-	done
-
-	echo "Editor ${editor} is missing on the target system." >&2
-	exit 1
 fi
 
+# The script should never reach this statement!
 exit 1

cdist/conf/type/__sensible_editor/man.rst

@@ -8,14 +8,15 @@ cdist-type__sensible_editor - Select the sensible-editor
 
 DESCRIPTION
 -----------
-This cdist type allows you to select the sensible-editor on Debian-based systems
+This cdist type allows you to select the :strong:`sensible-editor` for
-for a given user.
+a given user.
 
 
 REQUIRED PARAMETERS
 -------------------
 editor
     Name or path of the editor to be selected.
+    On systems other than Debian derivatives an absolute path is required.
 
 
 OPTIONAL PARAMETERS
@@ -33,9 +34,17 @@ EXAMPLES
     __sensible_editor noob --editor nano
 
 
+LIMITATIONS
+-----------
+This type only works on operating systems on which the sensible-utils package
+is available.
+
+Hint: On RedHat-based systems setting up the EPEL repo might be necessary.
+
+
 SEE ALSO
 --------
-none
+:strong:`select-editor`\ (1), :strong:`sensible-editor`\ (1).
 
 
 AUTHOR

cdist/conf/type/__sensible_editor/manifest

@@ -27,14 +27,28 @@ user=$__object_id
 case $os
 in
 	debian|devuan|ubuntu)
-		test "${state}" = 'present' && __package_apt sensible-utils --state present
+		test "${state}" != 'absent' \
+			&& __package sensible-utils --state present --type apt
+		;;
+	centos|fedora|redhat|scientific)
+		test "${state}" != 'absent' \
+			&& __package sensible-utils --state present --type yum
 		;;
 	*)
-		echo "OS ${os} does not support select-editor." >&2
+		echo "OS ${os} does not support sensible-editor." >&2
+		echo "If it does, please provide a patch." >&2
 		exit 1
 		;;
 esac
 
+if test "${state}" != 'present' && test "${state}" != 'absent'
+then
+	echo 'Only "present" and "absent" are allowed for --state' >&2
+	exit 1
+fi
+
+test "${state}" = 'absent' || export __require='__package/sensible-utils'
+
 editor_path=$(cat "${__object}/explorer/editor_path")
 user_home=$(cat "${__object}/explorer/user_home")
 group=$(cat "${__object}/explorer/group")