fix building rule for "reaper"

[rrq/overlay-boot.git] / functions

diff --git a/functions b/functions
index 1d52d7439d9227bb0c86ebdea25272f8462a2839..8c1b45c048706c91a2923f451c5065040c0224f6 100644 (file)
--- a/functions
+++ b/functions
@@ -15,18 +15,22 @@ config() {
     eval echo "$1=\$$1"
 }
 
-# Unless the subhost already has a private /etc/network/interfaces,
-# install an "empty" one
+# Install a default $1/etc/network/interfaces on the subhost root $1
 setup_networking() {
-    [ -r $UPPER/etc/network/interfaces ] && return 0
-    [ "$UPPER/etc/network" = "/etc/network" ] && exit 1
-    mkdir -p $UPPER/etc/network
-    cat <<EOF > $UPPER/etc/network/interfaces
+    [ -r $1/etc/network/interfaces ] && return 0
+    mkdir -p $1/etc/network
+    cat <<EOF >> $1/etc/network/interfaces
 # Generated for $NAME subhost
 auto lo
 iface lo inet loopback
 EOF
-    return 1
+    for IF in $(ip netns exec $NAME ip link show | grep "^eth") ; do
+       cat <<EOF >> $1/etc/network/interfaces
+
+auto eth$i
+iface eth$i inet manual
+EOF
+    done
 }
 
 # Setup the network namespace for the given $CABLES
@@ -36,45 +40,94 @@ setup_veth_cables() {
     NETNS="$1"
     shift 1
     i=0
-    ADD=false
-    setup_networking || ADD=true
     for C in "$@" ; do
        IF=$NETNS$i
        MAC="${C#*=}"
        [ -z "$MAC" ] || MAC="address $MAC"
        ip link add $IF type veth peer name eth$i $MAC netns $NETNS
        ip link set $IF up
-       $ADD && cat <<EOF >> $UPPER/etc/network/interfaces
-
-auto eth$i
-iface eth$i inet manual
-EOF
        BR="${C%=*}"
-       [ -z "$BR" ] || brctl addif $BR $IF
+       if [ -z "$BR" ] ; then
+           ip link set $IF
+           ifup $IF
+       else
+           brctl addif $BR $IF
+       fi
        i=$((i+1))
     done
 }
 
-REAPER=$(dirname $(realpath $0))/reaper/reaper
 # (name live system root work)
 # Set up an overlay fmr $name on $live, with a new tmpfs on its /run,
 # and "install" a "reaper" as the upcoming pid 1
 setup_overlay() {
-    set -x
-    mkdir -p $4/run
-    mount -t tmpfs -osize=100M tmpfs $4/run
-    mkdir -p $4/run/lock
-    grep -q "$1 $2" /proc/mounts || \
-       mount -t overlay -olowerdir=$3,upperdir=$4,workdir=$5 $1 $2 || \
-       die "Cannot set up the overlay mount $2"
-    mount --bind $4/run $2/run
-    cp $REAPER $LIVE/.reaper
-}
+    local LIVE="$2" LOWER="$3" UPPER="$4" ROOT
 
+    if grep -q "$1 $2" /proc/mounts ; then
+       die "$1 is already mounted"
+    fi
 
-# Check if $SRV is "live" ; will 
-is_live() {
-    pgrep -f ".reaper $SRV" > /dev/null
+    if [ -f "${UPPER%% *}" ] ; then
+       if [ -x "${UPPER%% *}" ] ; then
+           echo "${UPPER%% *} appears to be executable" >&2
+           # Giving a program/script as UPPER= asks for running this
+           # first, to make a root filesystem available. The script takes
+           # ACTION "setup" and "teardown", and on "setup" it must tell
+           # where the ROOT is set up.
+           ROOT="$(env ACTION=setup $UPPER)"
+           if [ ! -d "$ROOT" ] ; then
+               # setup failed
+               die "root setup failed: $UPPER"
+           fi
+           UPPER="$ROOT"
+           ## Now falling down to "normal overlay" setup
+       else
+           die "${UPPER%% *} (root setup program/script) is not executable"
+       fi
+    fi
+
+    # LIVE is the same as LOWER then skip the overlay; just assume
+    # a proper chroot system exists at LIVE.
+    if [ "$LIVE" != "$LOWER" ] ; then
+       # setup $UPPER/run
+       mkdir -p "$UPPER/run"
+       mount -t tmpfs -osize=100M tmpfs "$UPPER/run"
+       mkdir -p "$UPPER/run/lock"
+       # setup $UPPER/dev
+       mkdir -p "$UPPER/dev"
+       mount -t tmpfs -osize=100M tmpfs "$UPPER/dev"
+       mknod -m 622 "$UPPER/dev/console" c 5 1
+       mknod -m 666 "$UPPER/dev/null" c 1 3
+       mknod -m 666 "$UPPER/dev/zero" c 1 5
+       mknod -m 666 "$UPPER/dev/ptmx" c 5 2
+       mknod -m 666 "$UPPER/dev/tty" c 5 0
+       mknod -m 444 "$UPPER/dev/random" c 1 8
+       mknod -m 444 "$UPPER/dev/urandom" c 1 9
+       chown root:tty "$UPPER/dev/console"
+       chown root:tty "$UPPER/dev/ptmx"
+       chown root:tty "$UPPER/dev/tty"
+       ln -sTf /proc/self/fd "$UPPER/dev/fd"
+       ln -sTf /proc/self/fd/0 "$UPPER/dev/stdin"
+       ln -sTf /proc/self/fd/1 "$UPPER/dev/stdout"
+       ln -sTf /proc/self/fd/2 "$UPPER/dev/stderr"
+       ln -sTf /proc/kcore "$UPPER/dev/core"
+       mkdir "$UPPER/dev/shm"
+       mkdir "$UPPER/dev/pts"
+       chmod 1777 "$UPPER/dev/shm"
+
+       # all good so far ; now avoid using the host's networking setup
+       setup_networking "$UPPER"
+
+       OLY="-olowerdir=$3,upperdir=$UPPER,workdir=$5"
+       if ! mount -t overlay "$OLY" $1 $2 ; then
+           umount -R "$UPPER/dev"
+           umount "$UPPER/run"
+           die "Cannot set up the overlay mount $2"
+       fi
+    fi
+
+    echo "Installing $OVERLAYDIR/reaper to $LIVE/.reaper"
+    cp -p $OVERLAYDIR/reaper $LIVE/.reaper
 }
 
 start_services() {
@@ -82,3 +135,25 @@ start_services() {
        service $S start
     done
 }
+
+# find the upperdir option for an overlay mount line
+getupper() {
+    sed 's/.*upperdir=\([^,]*\).*/\1/'
+}
+
+# Check if $1 is "live" and echo the
+# unshare and reaper process pids
+is_live() {
+    local NAME=$1
+    local USPID="$(pgrep -f "unshare.* $NAME ")"
+    [ -z "$USPID" ] && return 1
+    echo $USPID $(pgrep -f ".reaper $NAME")
+}
+
+list_running() {
+    for C in $(pgrep -a overlay-boot | awk '{print $4}') ; do
+       eval NAME="$(sed "/^NAME=.*/{s|^NAME=||;b};d" $C)"
+       [ -z "$NAME" ] && NAME=$(basename $C .conf)
+       echo $NAME
+    done
+}