Add a Debian package and bash completion

make deb builds dist/jarl_<version>_<arch>.deb with dpkg-deb alone (no
root), for the host or another architecture (DEB_ARCH=arm64). The package
creates the jarl user and directories and an example jarl.yaml on the
first install, restarts a running jarld on upgrades, never touches
/etc/jarl/jarl.yaml, stops jarld on removal, and keeps Jarl's data even
on purge.

make install and the package install bash completion for jarl and jarld.
Besides commands and flags it completes server and group names from the
CLI configuration, zone, view, ACL, TSIG key and user names from the
server, and record types. make dist includes the completion scripts.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scripts/mkdeb.sh

@@ -0,0 +1,77 @@
+#!/bin/sh
+# Builds a Debian package of Jarl: dist/jarl_<version>_<arch>.deb.
+# Run through 'make deb' (which sets the variables below); needs only
+# dpkg-deb, no root and no debhelper.
+#
+# The package installs, with Debian's paths:
+#   /usr/bin/jarld, /usr/bin/jarl
+#   /usr/share/bash-completion/completions/{jarl,jarld}
+#   /usr/lib/systemd/system/jarl.service
+#   /usr/lib/sysusers.d/jarl.conf, /usr/lib/tmpfiles.d/jarl.conf
+#   /usr/share/doc/jarl/ (README, CHANGELOG, docs, contrib)
+# and its scripts (deploy/debian) create the jarl user and directories and
+# /etc/jarl/jarl.yaml on the first install, restart a running jarld on
+# upgrades, and stop it on removal. No file in /etc belongs to the package,
+# so an upgrade never asks about configuration files.
+#
+# Variables: DEB_ARCH (Debian architecture, e.g. amd64, arm64, armhf),
+# DEB_VERSION, VERSION, LDFLAGS, GOFLAGS, and DEB_MAINTAINER (default: your
+# git name and email).
+set -eu
+
+: "${DEB_ARCH:?}" "${DEB_VERSION:?}" "${VERSION:?}" "${LDFLAGS:?}"
+GOFLAGS=${GOFLAGS:-}
+
+# Debian architecture -> Go architecture.
+goarm=
+case "$DEB_ARCH" in
+amd64) goarch=amd64 ;;
+arm64) goarch=arm64 ;;
+armhf) goarch=arm goarm=7 ;;
+i386) goarch=386 ;;
+ppc64el) goarch=ppc64le ;;
+riscv64) goarch=riscv64 ;;
+s390x) goarch=s390x ;;
+*) echo "mkdeb: unsupported architecture $DEB_ARCH" >&2; exit 1 ;;
+esac
+
+if [ -z "${DEB_MAINTAINER:-}" ]; then
+	name=$(git config user.name 2>/dev/null || true)
+	email=$(git config user.email 2>/dev/null || true)
+	DEB_MAINTAINER="${name:-Jarl packager} <${email:-root@localhost}>"
+fi
+
+work=dist/deb/jarl_${DEB_VERSION}_${DEB_ARCH}
+root=$work/root
+out=dist/jarl_${DEB_VERSION}_${DEB_ARCH}.deb
+rm -rf "$work"
+mkdir -p "$root/DEBIAN"
+
+# Binaries for the package's architecture (bin/ holds the host's, which
+# also generated the completion scripts).
+echo "mkdeb: building for linux/$goarch"
+# go reads GOFLAGS (-trimpath) from the environment.
+export GOFLAGS
+GOOS=linux GOARCH=$goarch GOARM=$goarm CGO_ENABLED=0 go build -ldflags "$LDFLAGS" -o "$work/jarld" ./cmd/jarld
+GOOS=linux GOARCH=$goarch GOARM=$goarm CGO_ENABLED=0 go build -ldflags "$LDFLAGS" -o "$work/jarl" ./cmd/jarl
+
+make --no-print-directory install-files DESTDIR="$root" PREFIX=/usr \
+	UNITDIR=/usr/lib/systemd/system JARLD_BIN="$work/jarld" JARL_BIN="$work/jarl" >/dev/null
+
+for f in postinst prerm postrm; do
+	install -m 0755 "deploy/debian/$f" "$root/DEBIAN/$f"
+done
+# Directories 0755 and no group/other write, whatever the build's umask.
+find "$root" -type d -exec chmod 0755 {} +
+chmod -R go-w "$root"
+size=$(du -sk --exclude=DEBIAN "$root" | cut -f1)
+sed -e "s/@VERSION@/$DEB_VERSION/" -e "s/@ARCH@/$DEB_ARCH/" -e "s/@SIZE@/$size/" \
+	-e "s|@MAINTAINER@|$DEB_MAINTAINER|" deploy/debian/control.in > "$root/DEBIAN/control"
+(cd "$root" && find . -path ./DEBIAN -prune -o -type f -print | sed 's|^\./||' | sort | xargs md5sum) > "$root/DEBIAN/md5sums"
+chmod 0644 "$root/DEBIAN/control" "$root/DEBIAN/md5sums"
+
+# Files belong to root in the package, whoever builds it.
+dpkg-deb --root-owner-group -Zxz --build "$root" "$out" >/dev/null
+rm -rf dist/deb
+echo "mkdeb: wrote $out"
+dpkg-deb --info "$out" | sed -n 's/^ \(Package\|Version\|Architecture\|Installed-Size\):/  \1:/p'