Have libexec scripts be able to communicate with a docker container

start-target creates and starts a docker container from the image created
by make-base-vm

stop-target stops and removes the docker container from start-target

copy-from-target, copy-to-target, and on-target can execute commands
and copy files to and from the docker container started by start-target.

make-clean-vm does nothing because nothing needs to be done to make a
clean docker container.

Author: achow101

libexec/copy-from-target

@@ -46,7 +46,9 @@ if [ $# = 0 ] ; then
   exit 1
 fi
 
-if [ -z "$USE_LXC" ]; then
+if [ -n "$USE_DOCKER" ]; then
+    docker cp gitian-target:"/home/$TUSER/$1" $2
+elif [ -z "$USE_LXC" ]; then
     src="${1%/}"  # remove trailing / which triggers special rsync behaviour
     rsync --checksum -a $QUIET_FLAG -e "ssh -oConnectTimeout=30 -oNoHostAuthenticationForLocalhost=yes -i ${GITIAN_BASE:-.}/var/id_rsa -p $VM_SSH_PORT" "$TUSER@localhost:${src}" "$2"
 else

libexec/copy-to-target

@@ -46,7 +46,10 @@ if [ $# = 0 ] ; then
   exit 1
 fi
 
-if [ -z "$USE_LXC" ]; then
+if [ -n "$USE_DOCKER" ]; then
+    docker exec -u $TUSER gitian-target mkdir -p "/home/$TUSER/$2"
+    docker cp "$1" gitian-target:"/home/$TUSER/$2"
+elif [ -z "$USE_LXC" ]; then
     src="${1%/}"  # remove trailing / which triggers special rsync behaviour
     rsync --checksum -a $QUIET_FLAG -e "ssh -oConnectTimeout=30 -oNoHostAuthenticationForLocalhost=yes -i ${GITIAN_BASE:-.}/var/id_rsa -p $VM_SSH_PORT" "${src}" "$TUSER@localhost:$2"
 else

libexec/make-clean-vm

@@ -9,6 +9,8 @@ if [ -n "$USE_LXC" ]; then
     VMSW=LXC
 elif [ -n "$USE_VBOX" ]; then
     VMSW=VBOX
+elif [ -n "$USE_DOCKER" ]; then
+    VMSW=DOCKER
 fi
 
 usage() {
@@ -66,4 +68,7 @@ case $VMSW in
   VBOX)
     VBoxManage snapshot "Gitian-${SUITE}-${ARCH}" restore "Gitian-Clean"
     ;;
+  DOCKER)
+    true #Docker doesn't need to do anything
+    ;;
 esac

libexec/on-target

@@ -46,7 +46,9 @@ fi
 #  exit 1
 #fi
 
-if [ -z "$USE_LXC" ]; then
+if [ -n "$USE_DOCKER" ]; then
+    docker exec -u $TUSER -i gitian-target $*
+elif [ -z "$USE_LXC" ]; then
     ssh -oConnectTimeout=30 -oNoHostAuthenticationForLocalhost=yes -i ${GITIAN_BASE:-.}/var/id_rsa -p $VM_SSH_PORT $TUSER@localhost $*
 else
     config-lxc

libexec/start-target

@@ -10,6 +10,8 @@ if [ -n "$USE_LXC" ]; then
     VMSW=LXC
 elif [ -n "$USE_VBOX" ]; then
     VMSW=VBOX
+elif [ -n "$USE_DOCKER" ]; then
+    VMSW=DOCKER
 fi
 
 case $VMSW in
@@ -34,4 +36,7 @@ case $VMSW in
     VBoxManage startvm "Gitian-${2}" --type headless
     echo "Gitian-${2}" > var/target.vmname
     ;;
+  DOCKER)
+    docker run -d --name gitian-target base-$SUFFIX:latest > /dev/null
+    ;;
 esac

libexec/stop-target

@@ -5,6 +5,8 @@ if [ -n "$USE_LXC" ]; then
     VMSW=LXC
 elif [ -n "$USE_VBOX" ]; then
     VMSW=VBOX
+elif [ -n "$USE_DOCKER" ]; then
+    VMSW=DOCKER
 fi
 
 case $VMSW in
@@ -30,4 +32,8 @@ case $VMSW in
     VBoxManage controlvm `cat var/target.vmname` savestate
     rm var/target.vmname
     ;;
+  DOCKER)
+    docker container stop gitian-target > /dev/null
+    docker container rm gitian-target > /dev/null
+    ;;
 esac