Re: [arch-projects] [mkinitcpio][PATCH] functions: add_udev_rules and add_systemd_unit

14 Apr 2013

On Sat, Apr 13, 2013 at 03:43:35AM +0200, Tom Gundersen wrote:
...
add_udev_rules() adds a rules file and pulls in the necessary binaries udev
rules by automatically pulling in the necessary binaries.
add_systemd_unit() pulls in the necessary binaries, and also Requires= and
OnFailure= units.
Moreover, it pulls in any symlinks to the unit in any .wants or .requires
directories.
---
It'd be great if you could also prepare some doc for these in mkinitcpio(8).
...
functions | 98 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)

diff --git a/functions b/functions
index 432d700..12df3cd 100644
--- a/functions
+++ b/functions
@@ -569,6 +569,104 @@ add_binary() {
     return 0
 }
+add_udev_rules() {
+    # Add an udev rules file to the initcpio image. Dependencies on binaries
+    # will be discovered and added.
+    #   $1: path to rules file (or name of rules file)
+
+    local udevdir= rules= rule= entry= key= value= binary=
+    udevdir=$(pkg-config --variable=udevdir udev)
I'd like to avoid pkg-config as a dependency here. We can use a
hardcoded (sane) PATH and do something like...

  rules=$(PATH=/usr/lib/udev/rules.d:/lib/udev/rules.d type -P "$1")
  if [[ -z $rules ]]; then
    # complain about not found rules
    return 1
  fi
...
+
+    if [[ ${1:0:1} != '/' ]]; then
+        rules="${udevdir}/rules.d/${1}"
+    else
+        rules=$1
+    fi
+
+    add_file "${rules}"
+
+    while read rule; do
+        if [[ ${rule:0:1} == '#' ]]; then
+            continue
+        fi
+
+        IFS=', '
There's no support for multibyte field separators. What this actually
does is split lines on both ',' and ' ', which I suspect  breaks a lot
of the logic below here. I suspect you want to just split on commas in
the outer while loop:

  while IFS=, read -ra rule; do
    for pair in "${rule[@]}"; do
      IFS='=' read -ra key values <<<"$rule"
...
+        for entry in ${rule}; do
+
+            IFS='=' read key value <<< "${entry}"
+
+            if [[ ( ${key:0:3} == "RUN" &&
+                    ${key:4:7} != "builtin" ) ||
+                  ${key:0:7} == "PROGRAM" ||
+                  ${key:0:15} == "IMPORT{program}" ||
+                  ${key:0:15} == "ENV{REMOVE_CMD}" ]]; then
Perhaps a case statement? Taking my advice above gives you a nice array
of key/value pairs for each entry in the rule:

  case $key in
    RUN|RUN+|IMPORT{@(builtin|program)}|ENV{REMOVE_CMD})
      binary=${value[0]#\"}
      if [[ ${binary:0:1} = / ]]; then
        add_binary "$binary"
      else
        add_binary "$udevdir/$binary"
      fi
    ;;
  esac
...
+
+                binary=${value//\"/}
+                if [[ ${binary:0:1} != '/' ]]; then
+                    binary="${udevdir}/${binary}"
+                fi
+
+                read -d ' ' binary <<< "${binary} "
+                add_binary "${binary}"
+            fi
+        done
+    done < "$rules"
+}
+
+add_systemd_unit() {
+    # Add a systemd unit file to the initcpio image. Dependencies on binaries
+    # and other unit files will be discovered and added.
+    #   $1: path to rules file (or name of rules file)
+
+    local unitdir= unit= rule= entry= key= value= binary= dep=
+
+    unitdir=$(pkg-config --variable=systemdsystemunitdir systemd)
+
+    if [[ ${1:0:1} != '/' ]]; then
+        unit="${unitdir}/${1}"
+    else
+        unit=$1
+    fi
+
+    add_file "${unit}"
+
+    while read entry; do
You should split the line here instead of splitting again below. You
need to make sure to pass the -r flag as well:

  while IFS='=' read -r key values; do
    read -ra values <<<"$values"

    # now values is split on whitespace into an array

    ...
  done
...
+        if [[ ${entry:0:1} == '#' ]]; then
+            continue
+        fi
+
+        IFS='=' read key value <<< "${entry}"
+
+	if [[ ${key:0:4} == 'Exec' ]]; then
+        binary=${value//\"/}
+        if [[ ${binary:0:1} != '-' ]]; then
+            read -d ' ' binary <<< "${binary} "
+            add_binary "${binary}"
+        fi
+    fi
+
+	if [[ ${key} == 'Requires' || ${key} == 'OnFailure' ]]; then
+		for dep in ${value}; do
+			add_systemd_unit ${dep}
+		done
+	fi
The per-key behavior is probably better expressed in a case statement:

  case $key in
    Requires|OnFailure)
      map add_systemd_unit "${values[@]}"
      ;;
    Exec)
      add_binary "${values[0]#-}"
      ;;
    ...
  esac
...
+
+    done < "$unit"
+
+    for dep in "${unitdir}"/*.{wants,requires}/$(basename $unit); do
+	if [[ -h "${dep}" ]]; then
+		add_symlink "${dep}"
+	fi
+    done
+
+    if [[ -d "${unit}.requires" ]]; then
+	    for dep in "${unit}".requires/*; do
+		add_systemd_unit $(basename $dep)
+	    done
+    fi
+}
+
 parse_config() {
     # parse key global variables set by the config file.
--
1.8.2.1

    

Re: [arch-projects] [mkinitcpio][PATCH] functions: add_udev_rules and add_systemd_unit

Dave Reisner