boot messages during `podman machine start` (qemu)

bootstrap_podman_machine.sh

#!/bin/bash

set -o errexit -o nounset -o pipefail

bootstrap_podman() {
	if ! podman system info &>/dev/null; then
		echo "!!podman not initialized: doing that" >&2

		if ! podman machine inspect &>/dev/null; then
			podman machine init --user-mode-networking
		fi

		if [[ -z "$(podman machine inspect --format='{{ .State }}')" ]]; then
			podman_machine_start_but_with_boot_logs
		fi

	else
		echo "Podman VM looks good to go"
	fi
}

podman_machine_start_but_with_boot_logs() {
	declare podman_machine_console_log_file
	patch_podman_vm_qemu_config_to_log_boot_messages

	local tailer_cmd
	local podman_start_pid
	local watcher_pid

	tailer_cmd="$(if [[ -t 0 ]]; then echo "less -R +F"; else echo "tail -F"; fi)"
	rm -f "$podman_machine_console_log_file"

	set -m
        podman machine start &
	podman_start_pid=$!

	echo "About to start streaming console logs... (will auto-exit when reaches login prompt)"
	file_existance_busychecker "$podman_machine_console_log_file"
	podman_machine_boot_messages_tail_busywatcher "$$" "$tailer_cmd" "$podman_machine_console_log_file" &
	watcher_pid=$!

	$tailer_cmd "$podman_machine_console_log_file" || :

	if ! wait $watcher_pid; then
		kill "$podman_start_pid"
		die "You didn't wait for the machine to finish booting before killing the log viewer"
	else
		echo "... and now we wail a little more"
	fi

	wait "$podman_start_pid"
}

patch_podman_vm_qemu_config_to_log_boot_messages() {
	local podman_machine_config
  	local pmc_dirname
  	local pmc_basename

  	podman_machine_config="$(podman machine inspect --format='{{ .ConfigPath.Path }}')"
 	pmc_dirname="$(dirname "$podman_machine_config")"
  	pmc_basename="$(basename "${podman_machine_config}" .json)"

	podman_machine_console_log_file="${pmc_dirname}/${pmc_basename}-console.log"

	local chatty_params=()
	local script_add_chatty_params
	
	chatty_params+=('-chardev')
	chatty_params+=("socket,id=char-console,path=${podman_machine_console_log_file/.log/.sock},server=on,wait=off,logfile=${podman_machine_console_log_file}")
	chatty_params+=('-serial')
	chatty_params+=('chardev:char-console')

	# shellcheck disable=SC2059
	printf -v script_add_chatty_params "$(cat <<-'EOS'
		jq \\
			\t'if .CmdLine[-1] == $ARGS.positional[-1] then . else .CmdLine += $ARGS.positional end' \\
			\t%s.json \\
			\t  --args -- \\
			%s
			\t> %s.json.chatty
	EOS
	)" "$pmc_basename" "$(printf '\t\t"%s" \\\n' "${chatty_params[@]}")" "$pmc_basename"

  	cd "$pmc_dirname"
	bash -c "$script_add_chatty_params"
	mv "${pmc_basename}.json.chatty" "${pmc_basename}.json"
	cd -
}


file_existance_busychecker() {
	local file
	file=$1

	while true; do
		if [[ -f "$file" ]]; then
			return 0
		fi
		sleep 3
	done
}

podman_machine_boot_messages_tail_busywatcher() {
	local ppid
	local tailer_cmd
	local tailer_pid
	local file

	ppid="$1"
	# shellcheck disable=SC2206
	tailer_cmd=( $2 )
	file="$3"

	set +e
	while true; do
		if [[ -z "${tailer_pid:-}" ]]; then
			tailer_pid=$(pgrep -P "$ppid" "${tailer_cmd[0]}")
		else
			if ! kill -0 "$tailer_pid" 2>/dev/null; then
				return  1
			fi
		fi

		if tail -1 "$file" | grep -q '^localhost login:'; then
			[[ -n "${tailer_pid:-}" ]] && kill "$tailer_pid"
			return 0
		fi

		sleep 2
	done
}

bootstrap_podman

If for some reason you want to use this script and care, consider it under the MIT License

Copyright 2024 Donald Guy

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Not how laws/licenses generally work, but informally speaking I'mma say I have no plans to be picky about that their single condition. ... but the all caps part, yeah; I'm not gonna sue you, you don't sue me, deal? 🤝