feat(offload-build): create or reuse a shared SSH socket with ControlMaster=auto

src/lib/common.sh

@@ -34,8 +34,18 @@ export PACKAGING_REPO_RELEASE_HOST=repos.archlinux.org
 export PKGBASE_MAINTAINER_URL=https://archlinux.org/packages/pkgbase-maintainer
 export AUR_URL_SSH=aur@aur.archlinux.org
 
+# Create or reuse a shared SSH control socket with ControlMaster=auto. The
+# connection is initialized on the first use and persisted for some time, so
+# multiple invokations of devtools can share it.
+# shellcheck disable=SC2016
+export SSH_OPTS=(
+  -o ControlMaster=auto
+  -o ControlPersist=60s
+  -o ControlPath='${XDG_RUNTIME_DIR}/devtools-%r@%h:%p'
+)
+
 export RSYNC_OPTS=(
-  --rsh=ssh
+  --rsh="ssh ${SSH_OPTS[*]}"
   --checksum
   --copy-links
   --human-readable

src/offload-build.in

@@ -24,14 +24,6 @@ repo=extra
 arch=x86_64
 server=build.archlinux.org
 
-# remove --rsh=ssh from the default rsync opts because it will be replaced below
-rsyncopts=()
-for opt in "${RSYNC_OPTS[@]}"; do
-    if [[ "$opt" != "--rsh=ssh" ]]; then
-        rsyncopts+=("$opt")
-    fi
-done
-
 usage() {
     cat <<- _EOF_
 		Usage: ${BASH_SOURCE[0]##*/} [--repo REPO] [--arch ARCHITECTURE] [--server SERVER] -- [ARCHBUILD_ARGS]
@@ -101,22 +93,9 @@ makepkg_source_package || die "unable to make source package"
 # but an empty src dir is created in PWD. Remove once fixed in makepkg.
 rmdir --ignore-fail-on-non-empty src 2>/dev/null || true
 
-# Create an SSH master connection and use its control socket with
-# ControlMaster=no in all following SSH commands, including rsync.
-# Quoting for OpenSSH options: simple backslash escaping https://anongit.mindrot.org/openssh.git/tree/misc.c?h=V_9_7#n2011
-ssh_socket_path="${TEMPDIR//[\"\'\\]/\\&}/ssh.socket"
-sshopts_master=(-o ControlMaster=yes -o ControlPersist=yes -o ControlPath="$ssh_socket_path" -N)
-sshopts=(-o ControlMaster=no -o ControlPath="$ssh_socket_path")
-# Quoting for rsync --rsh: replace all single quotes in the arguments with two single quotes each, then surround all arguments with single quotes
-rsyncopts+=(--rsh="ssh$(printf " '%s'" "${sshopts[@]//\'/\'\'}")")
-# lib/common.sh sets up traps for cleanup, the following will override them
-trap 'ssh "${sshopts[@]}" -O exit -q -- "$server"; trap_abort' INT QUIT TERM HUP
-trap 'ssh "${sshopts[@]}" -O exit -q -- "$server"; trap_exit' EXIT
-ssh "${sshopts_master[@]}" -- "$server" &
-
 # Create a temporary directory on the server
 remote_temp=$(
-    ssh "${sshopts[@]}" -- "$server" '
+    ssh "${SSH_OPTS[@]}" -- "$server" '
         temp="${XDG_CACHE_HOME:-$HOME/.cache}/offload-build" &&
         mkdir -p "$temp" &&
         mktemp --directory --tmpdir="$temp"
@@ -126,21 +105,21 @@ remote_temp=$(
 msg "Transferring source package to the server..."
 _srcpkg=("$SRCPKGDEST"/*"$SRCEXT")
 srcpkg="${_srcpkg[0]}"
-rsync "${rsyncopts[@]}" -- "$srcpkg" "$server":"$remote_temp" || die
+rsync "${RSYNC_OPTS[@]}" -- "$srcpkg" "$server":"$remote_temp" || die
 
 # Prepare the srcpkg on the server
 msg "Extracting srcpkg"
-ssh "${sshopts[@]}" -- "$server" "cd ${remote_temp@Q} && bsdtar --strip-components 1 -xvf $(basename "$srcpkg")" || die
+ssh "${SSH_OPTS[@]}" -- "$server" "cd ${remote_temp@Q} && bsdtar --strip-components 1 -xvf $(basename "$srcpkg")" || die
 
 # Run the build command on the server
 msg "Running archbuild"
 # shellcheck disable=SC2145
-ssh "${sshopts[@]}" -t -- "$server" "cd ${remote_temp@Q} && export LOGDEST="" && ${archbuild_cmd[@]@Q}" || die
+ssh "${SSH_OPTS[@]}" -t -- "$server" "cd ${remote_temp@Q} && export LOGDEST="" && ${archbuild_cmd[@]@Q}" || die
 msg "Build complete"
 
 # Get an array of files that should be downloaded from the server
 mapfile -t files < <(
-    ssh "${sshopts[@]}" -- "$server" "
+    ssh "${SSH_OPTS[@]}" -- "$server" "
         cd ${remote_temp@Q}"' &&
         makepkg_user_config="${XDG_CONFIG_HOME:-$HOME/.config}/pacman/makepkg.conf" &&
         makepkg_config="/usr/share/devtools/makepkg.conf.d/'"${arch}"'.conf" &&
@@ -158,7 +137,7 @@ mapfile -t files < <(
 
 if (( ${#files[@]} )); then
     msg 'Downloading files...'
-    rsync "${rsyncopts[@]}" -- "${files[@]/#/$server:}" "${TEMPDIR}/" || die
+    rsync "${RSYNC_OPTS[@]}" -- "${files[@]/#/$server:}" "${TEMPDIR}/" || die
 
     if is_globfile "${TEMPDIR}"/*.log; then
         mv "${TEMPDIR}"/*.log "${LOGDEST:-${PWD}}/"