#!/bin/bash
set -e -o pipefail

# shellcheck source=jenkins-helpers.sh
. "$(dirname $0)"/jenkins-helpers.sh

# Start a local docker instance with the requested arch and distro

# This script is meant to be executed from Jenkins jobs inside TCWG
# lab. It prints shell commands meant to be executed in the parent
# shell, consisting in:
# - definition of ${CONTAINER}, used to prefix commands that you want
#   to run inside the container.
# - definition of ${CONTAINER_CLEANUP}, a cleanup statement remove the
#   container on exit for instance
# - definition of ${session_host}, ${session_port}, and ${session_opts[@]}
#   can be used for a remote connection to the container
usage() {
    echo "Usage: $0 [--arch container-arch] --distro flavour [--dryrun true/false] [--label label] [--newuser username:[uid]] [--node node] [--prefix prefix] [--secondary true/false] [--session-host host] [--session-name name] [--ssh_info true/false] [--task {build|test|bench}] [--user user] [--weight weight] [--verbose true/false] [--security options]"
    echo
    echo "  container-arch: architecture (eg: amd64, i386, arm64, armhf)"
    echo "  distro: distribution (eg: lts_1)"
    echo "  dryrun: boolean, just print commands if true"
    echo "  label: jenkins label; container is started on least-busy node; also sets container architecture"
    echo "  newuser: new user to create inside container, <username>[:<uid>] specification."
    echo "  node: jenkins node; container is started on host mapped to the node"
    echo "  prefix: prefix to prepend to output variables and functions"
    echo "  secondary: create a secondary container that will use the same workspace"
    echo "  session-host: hostname where the container will run, defaults to localhost"
    echo "    useful if the name resolution does not work correctly"
    echo "  session-name: session, in case the default '\$BUILD_NUMBER-\$JOB_NAME' is not suitable"
    echo "  ssh_info: set \$ssh_host and \$ssh_port env variables in the container"
    echo "  task: type of container (build, test or bench, default=build)"
    echo "  user: remote user to use in the container."
    echo "  weight: container weight, reserves resources. Default=1"
    echo "  security: override the default container security options (currently CAP_SYS_PTRACE and unconfined seccomp)."
    echo "  verbose: whether enable verbose output. Default=false"
    exit 1
}

ssh_error()
{
    echo "ERROR: ssh returned with code: $1, date: $(date). Trying another ssh connexion to $session_host to get debug logs:"
    ssh -v $session_host true
    return $1
}

# Save stdout/stderr file descriptors
exec 3>&1 4>&2

# Make sure all output goes to stderr
exec 1>&2

container_arch="default"
distro="default"
dryrun=false
label=
node=
newuser=
prefix=
secondary=false
session_host=
session_name=
ssh_info=false
task="build"
weight=1
user=
verbose="false"
security=""

while [ $# -ge 1 ]
do
    case $1 in
	--arch)
	    container_arch=$2
	    [ x${container_arch} = x ] && usage
	    shift 2
	    ;;
	--distro)
	    distro=$2
	    [ x${distro} = x ] && usage
	    shift 2
	    ;;
	--dryrun)
	    dryrun=$2
	    [ x${dryrun} = x ] && usage
	    [ $dryrun != false ] && [ $dryrun != true ] && usage
	    shift 2
	    ;;
	--label)
	    label=$2
	    [ x${label} = x ] && usage
	    shift 2
	    ;;
	--node)
	    node=$2
	    [ x${node} = x ] && usage
	    shift 2
	    ;;
	--newuser)
	    newuser="$2"
	    [ x${newuser} = x ] && usage
	    shift 2
	    ;;
	--prefix)
	    prefix=$2
	    [ x${prefix} = x ] && usage
	    shift 2
	    ;;
	--secondary)
	    secondary=$2
	    [ x$secondary = x ] && usage
	    shift 2
	    ;;
	--session-host)
	    session_host=$2
	    [ x${session_host} = x ] && usage
	    shift 2
	    ;;
	--session-name)
	    session_name=$2
	    [ x${session_name} = x ] && usage
	    shift 2
	    ;;
	--ssh_info)
	    ssh_info=$2
	    [ x$ssh_info = x ] && usage
	    shift 2
	    ;;
	--task)
	    task=$2
	    case "${task}" in
	        build|precommit|bench|test) ;;
		*) usage ;;
	    esac
	    shift 2
	    ;;
	--user)
	    user="$2"@
	    [ x${user} = x@ ] && usage
	    shift 2
	    ;;
	--weight)
	    weight=$2
	    [ x${weight} = x ] && usage
	    shift 2
	    ;;
	--verbose)
	    verbose=$2
	    [ x${verbose} = x ] && usage
	    shift 2
	    ;;
	--security)
	    security="$2"
	    shift 2
	    ;;
	*)
	    echo "Unsupported option: $1"
	    usage
	    ;;
    esac
done

if $verbose; then set -x; fi

dryruncmd=""
if $dryrun; then
    dryruncmd="echo"
fi

if [ x"$node" = x"" ] && [ x"$session_host" = x"" ] && [ x"$label" != x"" ]; then
    node=$(print_node_with_least_containers "$label")
    if [ x"$node" = x"" ]; then
        echo "ERROR: Cannot find node for $label"
        exit 1
    fi
fi

if [ x"$node" != x"" ]; then
    if [ x"$session_host" != x"" ]; then
	echo "--session_host conflicts with --node"
	usage
    fi
    session_host=$(print_host_for_node $node)
fi

if [ x"$session_host" = x"" ]; then
    # Get first FQDN.  This name needs to have .tcwglab suffix for VPN'ed
    # machines and entries in .ssh/config for external machines.
    session_host=$(hostname -A | cut -d" " -f 1)
    if [ "$session_host" = "" ]; then
	# WSL environment return empty string for "hostname -A", but outputs
	# a proper hostname (set in /etc/wsl.conf) for "hostname".
	session_host=$(hostname)
	assert_with_msg "Cannot get hostname" \
			[ x"$session_host" != x"" ]
    fi

    arch_host="localhost"
else
    arch_host="$session_host"
fi

if [ x"${container_arch}" = x"default" ]; then
    if [ x"$label" != x"" ]; then
	container_arch=$(print_arch_for_label "$label")
    else
	container_arch=$(print_arch_for_host "$arch_host")
    fi
elif [ x"$label" != x"" ]; then
    echo "--arch conflicts with --label"
    usage
fi

if [ x"$session_name" = x ]; then
    # Set the default session_name, using BUILD_NUMBER and JOB_NAME,
    # as set by Jenkins.
    # shellcheck disable=SC2153
    if [ "x$BUILD_NUMBER" != "x" ] && [ "x$JOB_NAME" != "x" ]; then
	session_name="$BUILD_NUMBER-$JOB_NAME-$task"
    else
	session_name="$USER-$(date +%Y%m%d-%H_%M_%S)"
    fi
    session_name=$(print_docker_name "$session_name")
fi

# Resolve LTS and LTS-1 values to Ubuntu distros.
case "$distro" in
    lts_1) distro=focal ;;
    lts|default) distro=jammy ;;
esac

image=linaro/ci-${container_arch}-tcwg-build-ubuntu:${distro}

# Avoid connection sharing because of race conditions with parallel builds.
# Also, we don't really need ssh agent forwarding here, so, since precommit
# testing takes this path, disable it for extra caution.  Also see note
# about ssh agent forward at wait_for_ssh_server below.
SSH="ssh -Snone -oForwardAgent=no"

pwd_translate=(cat)

# Configure container for precommit testing:
# - use tcwg-build user instead of tcwg-buildslave;
# - disable ssh agent forwarding;
# - use scratch docker volume for $WORKSPACE instead of bind-mounting from host;
#   -- use container_rsync() to transfer data to and from precommit container;
# - mount everything else as read-only (e.g., ccache, snapshots-ref, etc.);
# - translate absolute /home/* paths
if [ "$task" = "precommit" ]; then
    if [ "$newuser" = "" ]; then
	newuser=tcwg-build
    fi
    if [ "$user" = "" ]; then
	user="$newuser"
    fi

    if [ "${WORKSPACE+set}" = "set" ]; then
	# Translate $WORKSPACE/* paths from $USER to $user.  Or, specifically,
	# from /home/tcwg-buildslave/workspace/* to
	# /home/tcwg-build/workspace/*.
	dst_workspace=$(echo "$WORKSPACE" | sed -e "s#^$HOME#/home/$user#")
	pwd_translate=(sed -e "s#^$WORKSPACE#$dst_workspace#")
    fi
fi

assert_with_msg "user and USER variables should not be set to the same value" \
		[ x"$user" != x"$USER" ]

# Note that when we use this we *want* it to split on spaces
# So that the shell runs:
# foo bar docker <...>
# Instead of:
# "foo bar docker" <...>
# Note: use "ssh -n" to avoid consuming stdin.  This is especially important
#       in "while read $i;" loops we use to cleanup containers.  Without this
#       we cleanup the first container, and entries for all other containers
#       are swallowed by ssh.
DOCKER="$dryruncmd $SSH -n $session_host docker-wrapper"

$DOCKER maybepull $image || ssh_error $?

# If the configuration does not override the security options, use the default.
if [ -z "$security" ]; then
   security="--cap-add=SYS_PTRACE"
   # We need this because of a bug in libgo's configure script:
   # it would crash when testing "whether setcontext clobbers TLS
   # variables", and report neither "no" nor "yes", later making
   # configure fail.
   # Also, because the sanitizers need to disable ASLR during the tests
   # and docker needs to explicitly enable the process to do that on all
   # architectures.
   security="${security} --security-opt seccomp:unconfined"

   case "$container_arch:$distro:$($DOCKER --version | cut -d" " -f3)" in
	armhf:focal:18*)
	    # To run armhf focal images on old docker we need to disable
	    # seccomp via --privileged option.  We can't upgrade docker to
	    # a newer version on TK1s as we will loose bridge network (presumably,
	    # due to incompatibility with old 3.10 kernel), which we use in
	    # jenkins CI builds.
	    security="--privileged"
	;;
   esac
fi

# Reserve resources according to weight and task
nproc=$($SSH $session_host nproc --all)
memlimit=$($SSH $session_host free -m | awk '/^Mem/ { print $2 }')

pids=$(print_pids_limit "$task" "$weight")
cpus=$(print_cpu_shares "$task" "$weight")
memory=$(print_memory_limit "$task" "$weight" "$nproc" "$memlimit")

memory_opt=""
if [ x"$memory" != x"unlimited" ]; then
    memory_opt="--memory=${memory}M"
fi

if [ x"${JOB_NAME:+set}" = x"set" ]; then
    job_name="$JOB_NAME"
fi

wsl=false
case "$($SSH $session_host uname -r)" in
    *"-WSL2") wsl=true ;;
esac

lock_workspace=false
mounts_opt=()
chown_mounts=()
git_mounts=()
force_port=()

readarray -t mounts < <(print_mounts "$task" "$job_name" \
				     "-$container_arch-$distro" \
				     $SSH "$session_host")

if $wsl; then
    # Enable WSL-Interop inside containers.  This allows us to build toolchains
    # inside docker containers inside WSL2 environments, and still have ability
    # to run generated win32 executables.
    # If this doesn't work, make sure WSL2 version is 2.0.14 or later;
    # WSL 2.0.9 has a bug preventing interop outside of the "main init"
    # process tree.
    mounts+=(/init:/init:ro /run/WSL:/run/WSL)

    # FIXME: WSL VM is on a private network, and we have several
    # ports -- 22, 2222, and 32768 -- proxied inside it.  I couldn't
    # figure out how to proxy a port range, so it's simpler to configure
    # docker to use a fixed port.
    # We should try to configure bridged network for WSL VM, so that no port
    # forwarding is necessary.
    force_port=(-p 32768:22)
fi

echo "MOUNTS: ${mounts[*]}"

for mount in "${mounts[@]}"; do
    # Disassemble the mount
    ro=$(echo "$mount" | cut -s -d: -f 3)
    if [ "$ro" != "" ]; then
	assert [ "$ro" = "ro" ]

	# This is a read-only bind-mount or volume mount, e.g.,
	# - ssh host keys,
	# - $WORKSPACE/base-artifacts/ for task==precommit,
	# - ccache-* for task==precommit.
	dst=$(echo "$mount" | cut -s -d: -f 2)
	src=$(echo "$mount" | cut -s -d: -f 1)
    else
	dst=$(echo "$mount" | cut -s -d: -f 2)
	if [ "$dst" != "" ]; then
	    # This is a read-write bind-mount or volume mount, e.g.,
	    # - $WORKSPACE for task==build,
	    # - ccache-* for task==build.
	    src=$(echo "$mount" | cut -s -d: -f 1)
	    assert_with_msg "Non-readonly mount for precommit task" \
		            [ "$task" != "precommit" -o "$wsl" = "true" ]
	else
	    # This is a read-write scratch mount, e.g.,
	    # - $WORKSPACE for task==precommit.
	    dst="$mount"
	    src=""
	fi
    fi

    if [ "${WORKSPACE+set}" = "set" ] && [ "$dst" = "$WORKSPACE" ]; then
	lock_workspace=true
    fi

    dst=$(echo "$dst" | "${pwd_translate[@]}")

    # ccache-* volumes are owned by tcwg-buildslave, so don't let
    # anyone else write into them.  It's fine, though, to use them
    # as read-only ccache for other users and for precommit testing.
    # Also see round-robin.sh:setup_ccache().
    case "$src" in
	ccache-*)
	    if [ "$user" != "" ] && [ "$user" != "tcwg-buildslave" ]; then
		dst="/home/$user/.ccache"
		ro="ro"
	    fi
	    ;;
    esac

    case "$src" in
	"/home/"*)
	    # Make sure all bind-mount /home/* directories exist.
	    # If a host bind-mount dir doesn't exist, then docker creates
	    # it on the host with root:root owner, which can't be removed
	    # by cleanup job.
	    $dryruncmd $SSH $session_host mkdir -p "$src"
	    ;;
	"")
	    case "$dst:$ro" in
		*":ro") ;; # This is a read-only mount
		"/home/"*)
		    # Similarly to above "mkdir -p", chown scratch volumes
		    # under /home to to $user.
		    chown_mounts+=("$dst")
		    ;;
	    esac
	    ;;
    esac

    # See processing of git_mounts below.
    if [ "$src" != "" ] && git -C "$src" status >/dev/null 2>&1; then
	git_mounts+=("$dst")
    fi

    # Re-assemble the mount
    mount="$dst"
    if [ "$src" != "" ]; then
	mount="$src:$mount"
	if [ "$ro" != "" ]; then
	    mount="$mount:ro"
	fi
    fi
    mounts_opt+=("-v" "$mount")
done

# For CI builds make sure to kill previous build, which might have been
# aborted by jenkins, but processes could have survived.  Otherwise old
# build can start writing to files of the current build.
if $lock_workspace; then
    # We may have several containers (one primary and several secondary)
    # sharing the same workspace, and we list these in $WORKSPACE/.lock.
    # Helpers stop_all_containers() and clean_all_containers() use this .lock
    # file to stop/cleanup all containers created in the current session.
    # We keep the .lock file, so that the primary container in the next
    # build can confirm that all containers are indeed removed.
    #
    # When cleanup routine is triggered by aborted jenkins build, we
    # often no longer have access to ssh-agent.  Therefore, $SSH command
    # will likely fail.  However, sometimes $SSH just hangs indefinitely,
    # which causes problems in tcwg-benchmark_backend job -- the shell hanging
    # in "trap" waits on $SSH and does not release the board lock file.
    # To avoid this we put a "timeout 10m" on the container cleanup.
    # Docker daemon will finish removing the container even if the caller
    # docker client is killed by timeout.
    if ! $secondary; then
	while read prev_container; do
	    # Container may have been cleaned up by something else
	    if $DOCKER stats --no-stream "$prev_container" &>/dev/null; then
		echo "NOTE: Removing previous container for $WORKSPACE"
		$DOCKER rm -vf "$prev_container" \
		    || echo "WARNING: Could not remove $prev_container"
	    fi
	done < <($SSH $session_host flock "$WORKSPACE/.lock" \
			   cat "$WORKSPACE/.lock" || true)
	$SSH $session_host rm -f "$WORKSPACE/.lock"
    fi
fi

# Give access to all CPUs to container.
# This happens by default on most machines, but on machines that can put
# unused cores offline (TK1s and TX1s) it can happen that docker cpuset
# cgroup gets configured to use only a subset of cores.  If this happens,
# then we have a bug in our HW scripts, and here is the best place
# to detect this problem -- docker run will fail if it can't provide
# any of the CPUs to the new container.
cpuset_opt="--cpuset-cpus 0-$(($nproc - 1))"

echo "DEBUG: starting docker on $session_host from $(hostname), date $(date)"
# shellcheck disable=SC2206
docker_run=($DOCKER run --name $session_name -dtP "${force_port[@]}" \
		 "${mounts_opt[@]}" \
		 ${memory_opt} \
		 "--pids-limit=${pids}" \
		 "--cpu-shares=${cpus}" \
		 $cpuset_opt \
		 ${security} \
		 $image)
echo "${docker_run[@]}"

# FIXME: It seems in some cases $DOCKER run generates a session_id but
# returns an error code. Try to get more information
ret=0
session_id=$("${docker_run[@]}") || ret=$?

if [ $ret -ne 0 ]; then
    ssh_error $ret
    if [ $ret -eq 255 ]; then
	echo "WARNING: $SSH $session_host returned an error ($ret). Trying another ssh connexion to get debug logs"
	$SSH -v $session_host true
    else
	echo "WARNING: docker run returned an error: $ret, trying to continue nonetheless..."
    fi
fi

if [ x"$session_id" = x ]; then
    echo "ERROR: could not create session_id"
    exit 1
fi

# Remove the docker instance we have just created in case something
# goes wrong.
CONTAINER_CLEANUP="$DOCKER rm -fv ${session_id}"
# shellcheck disable=SC2064
trap "exec 1>&3 2>&4 ; ${CONTAINER_CLEANUP}" EXIT

if [ x"$newuser" != x"" ]; then
    $DOCKER exec "$session_id" \
	    new-user.sh --user "$newuser" --verbose "$verbose"
fi

if [ "$user" != "" ]; then
    for dir in "${chown_mounts[@]}"; do
	$DOCKER exec "$session_id" chown $user "$dir"
    done

    # Mark git mounts as safe git directories,so that git does not complain
    # about dubious ownership.  This is important for get_git_history()
    # fetching sumfiles/flaky.xfail files.
    for dir in "${git_mounts[@]}"; do
	$DOCKER exec "$session_id" sudo -i -u $user \
		git config --global --add safe.directory "$dir"
    done

    if [ "$user" = "tcwg-build" ]; then
	# FIXME: Hack -- use tcwg-buildslave's key while tcwg-build's
	#        is unavailable.
	$DOCKER exec "$session_id" cp \
		/home/tcwg-buildslave/.ssh/authorized_keys \
		/home/tcwg-build/.ssh/authorized_keys
	$DOCKER exec "$session_id" chown $user \
		/home/tcwg-build/.ssh/authorized_keys
    fi

    # Below $user is used as a prefix for $session_host
    user="$user@"
fi

session_port=$($DOCKER port $session_id 22 | cut -d: -f 2) || ssh_error $?

session_opts=("-p$session_port")

# SECURITY NOTE: this is the first time we are establishing ssh connection
# to the container, and, provided we are using connection sharing, settings
# specified for this connection may affect many or all of the subsequent
# connections.  In particular, if ssh agent forwarding is enabled for the
# below connection, then it will be part of the master connection, and it
# may persist through the whole lifetime of the container.
if [ "$task" = "precommit" ]; then
    # FIXME: We should be OK to disable agent forwarding for most of our
    # jobs, but, for now, keep the previous state as the default.

    # Disable agent forwarding for precommit testing.
    session_opts+=("-oForwardAgent=no")
fi

# Wait until the ssh server is ready to serve connexions
# Make sure connexion messages go to stderr, so that in case of
# success stdout contains only the connexion info expected by the
# caller.
ret=0
$dryruncmd wait_for_ssh_server ${user}$session_host "" "${session_opts[@]}" \
    || ret=$?

if [ $ret != 0 ]; then
    echo SSH server did not respond, exiting
    exit $ret
fi

# Create the lock for the workspace, which will allow subsequent builds
# to remove our container in case it's not cleaned up gracefully.
if $lock_workspace; then
    $SSH $session_host bash -c "\"mkdir -p $WORKSPACE && echo $session_id | flock $WORKSPACE/.lock tee -a $WORKSPACE/.lock\""
fi

# Do not remove the container upon exit: it is now ready
trap EXIT

ssh_info_opt=""
if $ssh_info; then
    assert_with_msg "ssh_info is not supported for task==precommit" \
		    [ "$task" != "precommit" ]
    # FIXME: One of the things to fix for precommit benchmarking is to pass
    # all ${session_opts[@]} to the benchmarking container.  Benchmarking
    # precommit workflow is tricky because precommit container needs to trigger
    # benchmarking job on ci.linaro.org, and then the benchmarking will
    # connect via ssh to the [precommit] build container.  This connection
    # needs to happen with ssh agent DISABLED, so that processes inside
    # precommit container can't escape.  To disable ssh agent forwarding
    # when connecting to this container -- we need to pass all
    # ${session_opts[@]}, which have -oForwardAgent=no.
    #
    # Triggering of the benchmarking job on ci.linaro.org can be arranged
    # by allowing tcwg-build's ssh key to trigger tcwg-benchmark job.  This
    # relies on Jenkins ssh interface to be robust against
    # privileged-escalation attacks.
    #
    # Additionally, we should disable ssh agent forwarding by default,
    # and enable it only by request.
    ssh_info_opt="ssh_host=${user}$session_host ssh_port=$session_port"
fi

# Restore stdout/stderr
exec 1>&3 2>&4

cat <<EOF
#!/bin/bash
# The vars are used when this script is sourced
# shellcheck disable=SC2034
# v1 interface
CONTAINER="${dryruncmd} $SSH ${session_opts[@]} ${user}${session_host}"
CONTAINER_CLEANUP="${CONTAINER_CLEANUP}"
session_host=${session_host}
session_port=${session_port}
session_opts=(${session_opts[@]})

# v2 interface

# Source jenkins-helpers.sh for remote_exec
. "$(dirname "$(readlink -f "$0")")/jenkins-helpers.sh"

${prefix}CONTAINER_RSH="${dryruncmd} $SSH ${session_opts[@]} ${user}${session_host}"
${prefix}container_cleanup ()
{
  timeout 10m ${CONTAINER_CLEANUP}
}
${prefix}container_stop ()
{
  $DOCKER stop $session_id
}
${prefix}container_exec ()
{
  (
  # Avoid logging of option processing, which may include secret tokens.
  set +x
  $dryruncmd remote_exec "${user}${session_host}::\$(pwd | ${pwd_translate[@]}):${session_opts[@]}:$ssh_info_opt" "\$@"
  )
}

${prefix}container_host=${session_host}
${prefix}container_port=${session_port}
${prefix}container_opts=(${session_opts[@]})
${prefix}container_id=${session_id}

${prefix}container_rsync ()
{
  local opt
  local -a opts
  for opt in "\$@"; do
    case "\$opt" in
      ":"*) opt="${user}${session_host}\$opt"
    esac
    opts+=("\$opt")
  done

  $dryruncmd rsync -e "ssh ${session_opts[@]}" --rsync-path="cd \$(pwd | ${pwd_translate[@]}); rsync" "\${opts[@]}"
}
EOF

if $lock_workspace && ! $secondary; then
    cat <<EOF

stop_all_containers ()
{
  local i
  while read i; do
    $DOCKER stop "\$i" || echo "WARNING: Could not stop \$i"
  done < <($SSH $session_host flock "$WORKSPACE/.lock" \
			        cat "$WORKSPACE/.lock")
}

cleanup_all_containers ()
{
  local i
  while read i; do
    timeout 10m $DOCKER rm -vf "\$i" || echo "WARNING: Could not cleanup \$i"
  done < <(timeout 10m $SSH $session_host flock "$WORKSPACE/.lock" \
			        cat "$WORKSPACE/.lock")
}
EOF
fi