From d4b9247f1470d3cd9a12b3b43a7a917830cae1c9 Mon Sep 17 00:00:00 2001
From: Chris F Ravenscroft <chris@voilaweb.com>
Date: Wed, 22 Jul 2015 20:57:59 -0700
Subject: [PATCH] Execute commands in a container

---
 bocker | 81 ++++++++++++++++++++++++----------------------------------
 1 file changed, 33 insertions(+), 48 deletions(-)

diff --git a/bocker b/bocker
index 76676f4..ab2c89a 100755
--- a/bocker
+++ b/bocker
@@ -1,20 +1,13 @@
 #!/usr/bin/env bash
 set -o errexit -o nounset -o pipefail; shopt -s nullglob
 btrfs_path='/var/bocker';
-function CHECK() {
-[[ "$1" == 'img' ]] && TYPE='image'
-[[ "$1" == 'ps' ]] && TYPE='container'
-[[ "$1" == '' ]] && TYPE='container or image'
-if [[ "$2" == "$1"* ]]; then
-	if btrfs subvolume list "$btrfs_path" | grep -qw "$2"; then
-		return 0
-	fi
-fi
-echo "No $TYPE named '$2' exists" && exit 1
+function bocker_check() {
+btrfs subvolume list "$btrfs_path" | grep -qw "$1" && echo 0 || echo 1
 }
-function INIT() {
+function bocker_init() { #HELP Create an image:\nBOCKER init <image_directory>
+uuid="img_$(shuf -i 42002-42254 -n 1)"
 if [[ -d "$1" ]]; then
-	uuid="img_$(shuf -i 10000-99999 -n 1)"
+	[[ "$(bocker_check "$uuid")" == 0 ]] && bocker_run "$@"
 	btrfs subvolume create "$btrfs_path/$uuid" > /dev/null
 	cp -rf --reflink=auto "$1"/* "$btrfs_path/$uuid" > /dev/null
 	echo "Created: $uuid"
@@ -22,75 +15,67 @@ else
 	echo "No directory named '$1' exists"
 fi
 }
-function RM() {
-CHECK '' "$1"
+function bocker_rm() { #HELP Delete an image or container:\nBOCKER rm <image_id or container_id>
+[[ "$(bocker_check "$1")" == 1 ]] && echo "No container named '$1' exists" && exit 1
 btrfs subvolume delete "$btrfs_path/$1" > /dev/null
 echo "Removed: $1"
 }
-function IMAGES() {
+function bocker_images() { #HELP List images:\nBOCKER images
 echo -e "IMAGE_ID"
 for img in "$btrfs_path"/img_*; do
 	basename "$img"
 done
 }
-function PS() {
+function bocker_ps() { #HELP List containers:\nBOCKER ps
 echo -e "CONTAINER_ID\t\tCOMMAND"
 for ps in "$btrfs_path"/ps_*; do
 	ps=$(basename "$ps")
 	echo -e "$ps\t\t$(cat "$btrfs_path/$ps/$ps.cmd")"
 done
 }
-function RUN() {
-CHECK 'img' "$1"
-uuid="ps_$(shuf -i 10000-99999 -n 1)"
+function bocker_run() { #HELP Create a container:\nBOCKER run <image_id> <command
+uuid="ps_$(shuf -i 42002-42254 -n 1)"
+[[ "$(bocker_check "$1")" == 1 ]] && echo "No image named '$1' exists" && exit 1
+[[ "$(bocker_check "$uuid")" == 0 ]] && echo "UUID conflict, retrying..." && bocker_run "$@" && return
+cmd=${@:2} && ip="$(echo "${uuid: -3}" | sed 's/0//g')" && mac="${uuid: -3:1}:${uuid: -2}"
 ip link add dev veth0_"$uuid" type veth peer name veth1_"$uuid"
 ip link set dev veth0_"$uuid" up
 ip link set veth0_"$uuid" master bridge0
 ip netns add netns_"$uuid"
 ip link set veth1_"$uuid" netns netns_"$uuid"
 ip netns exec netns_"$uuid" ip link set dev lo up
-ip netns exec netns_"$uuid" ip addr add 10.0.0.2/24 dev veth1_"$uuid"
+ip netns exec netns_"$uuid" ip link set veth1_"$uuid" address 02:42:ac:11:00"$mac"
+ip netns exec netns_"$uuid" ip addr add 10.0.0."$ip"/24 dev veth1_"$uuid"
 ip netns exec netns_"$uuid" ip link set dev veth1_"$uuid" up
 ip netns exec netns_"$uuid" ip route add default via 10.0.0.1
 btrfs subvolume snapshot "$btrfs_path/$1" "$btrfs_path/$uuid" > /dev/null
 echo 'nameserver 8.8.8.8' > "$btrfs_path/$uuid"/etc/resolv.conf
-echo "$2" > "$btrfs_path/$uuid/$uuid.cmd"
+echo "$cmd" > "$btrfs_path/$uuid/$uuid.cmd"
 ip netns exec netns_"$uuid" "unshare" -fp --mount-proc "chroot" \
-	"$btrfs_path/$uuid" /bin/sh -c "/bin/mount -t proc proc /proc && $2" \
+	"$btrfs_path/$uuid" /bin/sh -c "/bin/mount -t proc proc /proc && $cmd" \
 	2>&1 | tee "$btrfs_path/$uuid/$uuid.log" || true
 ip link del dev veth0_"$uuid"
 ip netns del netns_"$uuid"
 }
-function LOGS() {
-CHECK 'ps' "$1"
+function bocker_exec() { #HELP Run bash (default) or comnmands in a container:\nBOCKER exec <container_id> <command
+[[ "$(bocker_check "$1")" == 1 ]] && echo "No container named '$1' exists" && exit 1
+cmd=${@:2} && CID=$(ps xao ppid,pid,cmd | grep $(ps -u | grep unshare | grep "$1" | awk '{ print $2 }') | grep -v unshare | awk '{ print $2 }') && nsenter --target $CID --mount --uts --ipc --net --pid chroot "$btrfs_path/$1" $cmd
+}
+function bocker_logs() { #HELP View logs from a container:\nBOCKER logs <container_id>
+[[ "$(bocker_check "$1")" == 1 ]] && echo "No container named '$1' exists" && exit 1
 cat "$btrfs_path/$1/$1.log"
 }
-function COMMIT() {
-CHECK 'ps' "$1" && CHECK 'img' "$2" && RM "$2"
-btrfs subvolume snapshot "$btrfs_path/$1" "$btrfs_path/$2" > /dev/null
+function bocker_commit() { #HELP Commit a container to an image:\nBOCKER commit <container_id> <image_id>
+[[ "$(bocker_check "$1")" == 1 ]] && echo "No container named '$1' exists" && exit 1
+[[ "$(bocker_check "$2")" == 1 ]] && echo "No image named '$1' exists" && exit 1
+bocker_rm "$2" && btrfs subvolume snapshot "$btrfs_path/$1" "$btrfs_path/$2" > /dev/null
 echo "Created: $2"
 }
-function HELP() {
-echo -e "Create an image: \n\t./bocker init <image_directory>\n"
-echo -e "List images: \n\t./bocker images\n"
-echo -e "Create a container: \n\t./bocker run <image_id> <command>\n"
-echo -e "List containers: \n\t./bocker ps\n"
-echo -e "View logs from a container: \n\t./bocker logs <container_id>\n"
-echo -e "Delete an image or container: \n\t./bocker rm <image_or_container_id>"
-exit 0
+function bocker_help() { #HELP Display this message:\nBOCKER help
+sed -n "s/^.*#HELP\\s//p;" < "$1" | sed "s/\\\\n/\n\t/g;s/$/\n/;s!BOCKER!${1/!/\\!}!g"
 }
-[[ -z "${1-}" ]] && HELP
+[[ -z "${1-}" ]] && bocker_help "$0"
 case $1 in
-	init) INIT "$2" ;;
-	rm)	RM "$2" ;;
-	images) IMAGES ;;
-	ps) PS ;;
-	run)
-		IMAGE="$2"
-		shift && shift
-		RUN "$IMAGE" "$*"
-		;;
-	logs) LOGS "$2" ;;
-	commit) COMMIT "$2" "$3" ;;
-	*) HELP ;;
+	init|rm|images|ps|run|exec|logs|commit) bocker_"$1" "${@:2}" ;;
+	*) bocker_help "$0" ;;
 esac