From 21c9e3db1852eebb88be5454137ceb23159f7dc0 Mon Sep 17 00:00:00 2001
From: Dennis Camera <dennis.camera@ssrq-sds-fds.ch>
Date: Mon, 3 Feb 2020 22:12:21 +0100
Subject: [PATCH] [explorer/init] Support more init systems
---
cdist/conf/explorer/init | 233 ++++++++++++++++++++++++++++++---------
1 file changed, 178 insertions(+), 55 deletions(-)
diff --git a/cdist/conf/explorer/init b/cdist/conf/explorer/init
index ceae2e9f..bf1736cd 100755
--- a/cdist/conf/explorer/init
+++ b/cdist/conf/explorer/init
@@ -1,7 +1,8 @@
-#!/bin/sh
+#!/bin/sh -e
#
# 2016 Daniel Heule (hda at sfs.biz)
# Copyright 2017, Philippe Gregoire <pg@pgregoire.xyz>
+# 2020 Dennis Camera (dennis.camera at ssrq-sds-fds.ch)
#
# This file is part of cdist.
#
@@ -23,59 +24,181 @@
# for example at linux this value is "init" or "systemd" in most cases
#
+set -e
+
+# Expected values:
+# Linux:
+# Gentoo:
+# sysvinit, openrc-init
+
+# GNU:
+# Debian:
+# hurd-init, sysvinit
+
+# [root@fedora-12 ~]# readlink /proc/1/exe
+# /sbin/init (deleted)
+# [root@fedora-12 ~]# ls -l /proc/1/exe
+# lrwxrwxrwx. 1 root root 0 2020-01-30 23:00 /proc/1/exe -> /sbin/init (deleted)
+
+# inspired by https://stackoverflow.com/a/33266819
+shreadlink() (
+ CDPATH=
+ target=$1 fname= targetDir=
+
+ # Resolve potential symlinks until the ultimate target is found.
+ while :
+ do
+ if ! test -e "$target"
+ then
+ printf 'ERROR: %s does not exist.\n' "'$target'" >&2
+ return 1
+ fi
+
+ # Change to target dir; necessary for correct resolution of target path.
+ cd "$(dirname -- "$target")"
+
+ fname=$(basename -- "$target") # Extract filename.
+ [ "$fname" = '/' ] && fname='' # !! curiously, `basename /` returns '/'
+
+ [ -L "$fname" ] || break
+
+ # Extract [next] target path, which may be defined
+ # *relative* to the symlink's own directory.
+ # Note: We parse `ls -l` output to find the symlink target
+ # which is the only POSIX-compliant, albeit somewhat fragile, way.
+ # FIXME: Will break if one of the filenames contain ’ -> ’
+ target=$(ls -l "$fname" | sed -e 's/^.* -> //')
+ done
+
+ # Get canonical dir. path
+ targetDir=$(pwd -P)
+
+ # Output the ultimate target's canonical path.
+ # Note that we manually resolve paths ending in /. and /.. to make sure we have a normalized path.
+ if test "$fname" = '.'
+ then
+ printf '%s\n' "${targetDir%/}"
+ elif test "$fname" = '..'
+ then
+ # Caveat: something like /var/.. will resolve to /private (assuming /var@ -> /private/var), i.e. the '..' is applied
+ # AFTER canonicalization.
+ printf '%s\n' "$(dirname -- "${targetDir}")"
+ else
+ printf '%s/%s\n' "${targetDir%/}" "$fname"
+ fi
+)
+
+
case $(uname -s) in
- Linux)
- if test -d /proc/1/
- then
- comm_name=$(cat /proc/1/comm)
- else
- # BusyBox's versions of ps and pgrep do not support some options
- # depending on which compile-time options have been used.
- # Both pgrep and ps are tried to get the command name
- comm_name=$(
- pgrep -P0 -l 2>/dev/null | awk '/^1[ \t]/ { print $2 }'
- || ps -o comm= -p 1 2>/dev/null)
- fi
-
- case $comm_name
- in
- systemd)
- echo systemd
- ;;
- init)
- # It could be anything...
-
- if test -h /proc/1/exe
- then
- init_exe=/proc/1/exe
- else
- init_exe=$(command -v "$comm_name")
- fi
-
- test -x "$comm_exe" || exit 1
-
- case $("$comm_exe" --version | head -n 1)
- in
- *SysV*)
- echo init
- ;;
- *upstart*)
- echo upstart
- ;;
- *)
- echo ""
- ;;
- esac
- esac
- ;;
- FreeBSD|OpenBSD)
- ps -o comm= -p 1 2>/dev/null || true
- ;;
- Darwin)
- basename "$(ps -o comm= -p 1 2>/dev/null)"
- ;;
- *)
- # return a empty string as unknown value
- echo ""
- ;;
+ Linux|GNU)
+ # if test -f /proc/1/comm
+ # then
+ # comm_name=$(cat /proc/1/comm)
+ # else
+ # BusyBox's versions of ps and pgrep do not support some options
+ # depending on which compile-time options have been used.
+ # Both pgrep and ps are tried to get the command name
+ # comm_name=$(
+ # pgrep -P0 -l 2>/dev/null | awk '/^1[ \t]/ { print $2 }'
+ # || ps -o comm= -p 1 2>/dev/null)
+ # fi
+
+ init_exe=$(shreadlink /proc/1/exe)
+
+ if ! test -x "$init_exe"
+ then
+ # On some rare occasions it can happen that the
+ # running init's binary has been replaced. In this
+ # case Linux adjusts the symlink to "X (deleted)"
+ case $init_exe
+ in
+ *' (deleted)')
+ init_exe=${init_exe% (deleted)}
+ test -x "$init_exe" || exit 1
+ ;;
+ *)
+ exit 1
+ ;;
+ esac
+ fi
+
+ if test "$init_exe" = '/hurd/init'
+ then
+ # XXX: Could maybe be removed
+ echo hurd-init
+ exit 0
+ fi
+
+ comm_name=$(basename "$init_exe")
+ case $comm_name
+ in
+ init)
+ : # handled below
+ ;;
+ systemd)
+ # NOTE: sd_booted(3)
+ if test -d /run/systemd/system/
+ then
+ echo systemd
+ exit 0
+ fi
+ # otherwise: treat like "init"
+ ;;
+ *)
+ echo "$comm_name"
+ exit 0
+ ;;
+ esac
+
+ # init: it could be anything...
+ case $("$init_exe" --version 2>/dev/null | head -n 1)
+ in
+ SysV*)
+ # This is a little bit more specific than init
+ echo sysvinit
+ exit 0
+ ;;
+ *'GNU Hurd'*)
+ echo hurd-init
+ ;;
+ *upstart*)
+ echo upstart
+ exit 0
+ ;;
+ esac
+ case $("$init_exe" --help 2>/dev/null | head -n 1)
+ in
+ BusyBox*)
+ echo busybox
+ exit 0
+ ;;
+ esac
+
+ echo init
+ ;;
+ FreeBSD|OpenBSD)
+ ps -o comm= -p 1 2>/dev/null || true
+ ;;
+ Darwin)
+ basename "$(ps -o comm= -p 1 2>/dev/null)"
+ ;;
+ SunOS)
+ comm_name=$(ps -o comm= -p 1 2>/dev/null)
+ if test "$(basename "$comm_name")" != 'init'
+ then
+ echo "${comm_name}"
+ exit 0
+ fi
+
+ # XXX: Is this the correct way??
+ if test -f /etc/svc/volatile/svc_nonpersist.db
+ then
+ echo smf
+ exit 0
+ fi
+ ;;
+ *)
+ # return a empty string as unknown value
+ echo ""
+ ;;
esac