[PATCH v2 02/49] kdump-lib.sh: add a config format and read helper

[Kairui Song]

Add a helper `kdump_read_conf` to replace read_strip_comments.
`kdump_read_conf` does a few more things:

  - remove tailing spaces.
  - format the content, remove duplicated spaces between name and value.
  - read from KDUMP_CONFIG_FILE (/etc/kdump.conf) directly, avoid pasting
    "/etc/kdump.conf" path everywhere in the code.
  - check if config file exists, just in case.

Also unify the environmental variable, now KDUMP_CONFIG_FILE stands for
the default config location.

This helps avoid some shell pitfalls about spaces when reading config.

Signed-off-by: Kairui Song <kasong(a)redhat.com&gt;
---
 dracut-kdump.sh        | 10 +++++-----
 dracut-module-setup.sh |  5 +++--
 kdump-lib-initramfs.sh |  3 +--
 kdump-lib.sh           | 11 ++++++-----
 kdumpctl               |  7 +++----
 mkdumprd               |  2 +-
 6 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/dracut-kdump.sh b/dracut-kdump.sh
index 3e65c447..3c165b3a 100755
--- a/dracut-kdump.sh
+++ b/dracut-kdump.sh
@@ -246,10 +246,10 @@ get_host_ip()
     return 0
 }
 
-read_kdump_conf()
+read_kdump_confs()
 {
-    if [ ! -f "$KDUMP_CONF" ]; then
-        derror "$KDUMP_CONF not found"
+    if [ ! -f "$KDUMP_CONFIG_FILE" ]; then
+        derror "$KDUMP_CONFIG_FILE not found"
         return
     fi
 
@@ -278,7 +278,7 @@ read_kdump_conf()
             add_dump_code "dump_ssh $SSH_KEY_LOCATION $config_val"
             ;;
         esac
-    done <<< "$(read_strip_comments $KDUMP_CONF)"
+    done <<< "$(kdump_read_conf)"
 }
 
 fence_kdump_notify()
@@ -288,7 +288,7 @@ fence_kdump_notify()
     fi
 }
 
-read_kdump_conf
+read_kdump_confs
 fence_kdump_notify
 
 get_host_ip
diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
index a1f33e8c..ff9f7fee 100755
--- a/dracut-module-setup.sh
+++ b/dracut-module-setup.sh
@@ -682,7 +682,8 @@ default_dump_target_install_conf()
 #install kdump.conf and what user specifies in kdump.conf
 kdump_install_conf() {
     local _opt _val _pdev
-    (read_strip_comments /etc/kdump.conf) > ${initdir}/tmp/$$-kdump.conf
+
+    kdump_read_conf > "${initdir}/tmp/$$-kdump.conf"
 
     while read _opt _val;
     do
@@ -711,7 +712,7 @@ kdump_install_conf() {
             dracut_install "${_val%%[[:blank:]]*}"
             ;;
         esac
-    done <<< "$(read_strip_comments /etc/kdump.conf)"
+    done <<< "$(kdump_read_conf)"
 
     kdump_install_pre_post_conf
 
diff --git a/kdump-lib-initramfs.sh b/kdump-lib-initramfs.sh
index 319f9a07..50443e55 100755
--- a/kdump-lib-initramfs.sh
+++ b/kdump-lib-initramfs.sh
@@ -16,7 +16,6 @@ SSH_KEY_LOCATION="/root/.ssh/kdump_id_rsa"
 KDUMP_SCRIPT_DIR="/kdumpscripts"
 DD_BLKSIZE=512
 FINAL_ACTION="systemctl reboot -f"
-KDUMP_CONF="/etc/kdump.conf"
 KDUMP_PRE=""
 KDUMP_POST=""
 NEWROOT="/sysroot"
@@ -93,7 +92,7 @@ get_kdump_confs()
                 esac
             ;;
         esac
-    done <<< "$(read_strip_comments $KDUMP_CONF)"
+    done <<< "$(kdump_read_conf)"
 
     if [ -z "$CORE_COLLECTOR" ]; then
         CORE_COLLECTOR="$DEFAULT_CORE_COLLECTOR"
diff --git a/kdump-lib.sh b/kdump-lib.sh
index 4bd9751b..6ed4f5a9 100755
--- a/kdump-lib.sh
+++ b/kdump-lib.sh
@@ -7,6 +7,7 @@ DEFAULT_PATH="/var/crash/"
 FENCE_KDUMP_CONFIG_FILE="/etc/sysconfig/fence_kdump"
 FENCE_KDUMP_SEND="/usr/libexec/fence_kdump_send"
 FADUMP_ENABLED_SYS_NODE="/sys/kernel/fadump_enabled"
+KDUMP_CONFIG_FILE="/etc/kdump.conf"
 
 is_fadump_capable()
 {
@@ -80,12 +81,12 @@ strip_comments()
     echo $@ | sed -e 's/\(.*\)#.*/\1/'
 }
 
-# Read from kdump config file stripping all comments
-read_strip_comments()
+# Read kdump config in well formatted style
+kdump_read_conf()
 {
-    # strip heading spaces, and print any content starting with
-    # neither space or #, and strip everything after #
-    sed -n -e "s/^\s*\([^# \t][^#]\+\).*/\1/gp" $1
+    # Following steps are applied in order: strip tailing comment, strip tailing space,
+    # strip heading space, match non-empty line, remove duplicated spaces between conf
name and value
+    [ -f "$KDUMP_CONFIG_FILE" ] && sed -n -e
"s/#.*//;s/\s*$//;s/^\s*//;s/\(\S\+\)\s*\(.*\)/\1 \2/p" $KDUMP_CONFIG_FILE
 }
 
 # Check if fence kdump is configured in Pacemaker cluster
diff --git a/kdumpctl b/kdumpctl
index c2f0b3f2..5d9420da 100755
--- a/kdumpctl
+++ b/kdumpctl
@@ -5,7 +5,6 @@ KDUMP_KERNELVER=""
 KDUMP_KERNEL=""
 KDUMP_COMMANDLINE=""
 KEXEC_ARGS=""
-KDUMP_CONFIG_FILE="/etc/kdump.conf"
 KDUMP_LOG_PATH="/var/log"
 MKDUMPRD="/sbin/mkdumprd -f"
 MKFADUMPRD="/sbin/mkfadumprd"
@@ -272,7 +271,7 @@ check_config()
 			return 1
 		fi
 		_opt_rec[$config_opt]="$config_val"
-	done <<< "$(read_strip_comments $KDUMP_CONFIG_FILE)"
+	done <<< "$(kdump_read_conf)"
 
 	check_failure_action_config || return 1
 	check_final_action_config || return 1
@@ -731,7 +730,7 @@ check_ssh_config()
 		*)
 			;;
 		esac
-	done <<< "$(read_strip_comments $KDUMP_CONFIG_FILE)"
+	done <<< "$(kdump_read_conf)"
 
 	#make sure they've configured kdump.conf for ssh dumps
 	local SSH_TARGET=`echo -n $DUMP_TARGET | sed -n '/.*@/p'`
@@ -1362,7 +1361,7 @@ reset_crashkernel() {
 		grubby --args "$crashkernel_default" --update-kernel "$entry"
$zipl_arg
 		[[ $zipl_arg ]] && zipl > /dev/null
 	fi
-    }
+}
 
 if [ ! -f "$KDUMP_CONFIG_FILE" ]; then
 	derror "Error: No kdump config file found!"
diff --git a/mkdumprd b/mkdumprd
index 89a160d1..d5545114 100644
--- a/mkdumprd
+++ b/mkdumprd
@@ -443,7 +443,7 @@ do
     *)
         ;;
     esac
-done <<< "$(read_strip_comments $conf_file)"
+done <<< "$(kdump_read_conf)"
 
 handle_default_dump_target
 
-- 
2.31.1