Send Podman ps to MQTT broker to watch containers status in HomeAssistant

podman2mqtt.sh

#!/bin/bash
#            _               ___           _   _   
#  ___ ___ _| |_____ ___ ___|_  |_____ ___| |_| |_ 
# | . | . | . |     | .'|   |  _|     | . |  _|  _|
# |  _|___|___|_|_|_|__,|_|_|___|_|_|_|_  |_| |_|  
# |_|                                   |_|        
#
# Copyright (C) 2026 Cyril Bosselut
#
# podman2mqtt is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# podman2mqtt is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with podman2mqtt  If not, see <http://www.gnu.org/licenses/>.

PID="$$"
DAEMON=false
v_major=1
v_minor=1
v_patch=0
VERSION="$v_major.$v_minor.$v_patch"

function print_help {
   echo "This script watch the podman containers status and update MQTT topics."
   echo
   echo "Syntax:" 
   echo " podman2mqtt.sh [-d|h|v]"
   echo "options:"
   echo " -d     Run as a daemon."
   echo " -h     Print this Help."
   echo " -v     Print software version and exit."
   echo
}

while getopts ":dvh" option; do
    case $option in
        d)  #daemon
            DAEMON=true;;
        v)  #display version
            echo $VERSION
            exit;;
        h)  #display help
            print_help
            exit;;
    esac
done

function cwords {
	local input="$1"
	echo "$input" | sed 's/_/ /g' | sed 's/\b\w/\U&/g'
}

function onexit {
	podman2mqtt_running=false
	log "Bye !"
	exit
}

function log {
	local now=$(date +"%x %T")
	if [[ $DAEMON == false ]]; then
		echo "$now - $1" 1>&2
	fi
	logger --id="$PID" -t "podman2mqtt" "$1"
}

function contains {
	local value=$1
	shift
	local arr=("$@")
	for element in "${arr[@]}"; do
		if [[ "$element" == "$value" ]]; then
			echo true
		fi
	done
	echo false
}

function main {
	podman2mqtt_running=true
	local registered_containers=()
	if [[ $DAEMON == false ]]; then
		echo "#####################################################"
		echo "#            _               ___           _   _    #"
		echo "#  ___ ___ _| |_____ ___ ___|_  |_____ ___| |_| |_  #"
		echo "# | . | . | . |     | .'|   |  _|     | . |  _|  _| #"
		echo "# |  _|___|___|_|_|_|__,|_|_|___|_|_|_|_  |_| |_|   #"
		echo "# |_|                                   |_|         #"
		echo "#                                                   #"
		echo "#####################################################"
		echo "Ver: $VERSION"
		echo ""
	fi
	log "Starting podman2mqtt with PID: $PID"
	log "Reverse DNS: $PODMAN2MQTT_RDNS"

	local podman_state="OFF"
	local first_run=true
	while $podman2mqtt_running == true; do
		log "### Updating containers status ###"
		local check_state=`systemctl status podman.socket | grep 'active (running)'`
		if [[ $check_state != "" ]]; then
			podman_state="ON"
		fi
		if [[ $first_run == true ]]; then
			log "Registering Podman"
			mosquitto_pub -r -t "homeassistant/binary_sensor/podman/state/config" -m "{\"name\":\"state\",\"dev\":{\"name\":\"Podman\",\"ids\":[\"podman_$HOSTNAME\"]},\"uniq_id\":\"sensors.podman.state\",\"dev_cla\":\"running\",\"stat_t\":\"$HOSTNAME/podman/state\",\"val_tpl\":\"{{ value_json.state }}\",\"json_attr_t\":\"$HOSTNAME/podman/state\",\"ic\":\"mdi:docker\"}" --insecure
		fi
		first_run=false
		local json=`podman ps -a --format=json`

		local l=$(expr `echo $json | jq 'length'` - 1)

		if [ $l > 0 ]; then
			local running_containers=()
			for (( i=0; i<=$l; i++ )); do
				local data=`echo $json | jq ".[$i]"`
				local container_id=`echo $data | jq -r ".Id"`
				local name=`echo $data | jq -r ".Names[0]"`
				running_containers+=("$name")
				local registered=`contains $name "${registered_containers[@]}"`
				local state="OFF"
				local state_str=`echo $data | jq -r ".State"`
				local id="podman2mqtt.$HOSTNAME.$name"
				if [[ $state_str == "running" ]]; then
					state="ON"
				fi
				local status_str=`echo $data | jq -r ".Status"`
				local startedAt=`echo $data | jq -r ".StartedAt"`
				local createdAt=`echo $data | jq -r ".Created"`
				local cu=""
				local support_url=""
				local sw=""
				local labels=`echo $data | jq -r ".Labels"`
				if [ $PODMAN2MQTT_RDNS ]; then
					local host_key="$PODMAN2MQTT_RDNS.host"
					cu=`echo $labels | jq -r ".[\"$host_key\"]"`
					log "cu: $cu"
					if [[ $cu == "null" ]]; then
						cu=`echo $labels | jq -r ".[\"org.opencontainers.image.url\"]"`
						if [[ $cu == "null" ]]; then
							cu="https://podman.io"
						fi
					fi
				fi
				support_url=`echo $labels | jq -r ".[\"org.opencontainers.image.documentation\"]"`
				if [[ $support_url == "null" ]]; then
					support_url="https://podman.io"
				fi
				sw=`echo $labels | jq -r ".[\"org.opencontainers.image.version\"]"`
				if [[ $sw == "null" ]]; then
					sw=""
				fi
				if [[ $registered == false ]]; then
					log "Registering device `cwords $name`"
					local dev="\"ids\":\"$id\", \"name\":\"`cwords $name`\",\"cu\":\"$cu\",\"mf\":\"podman2mqtt\",\"sw\":\"$sw\""
					local o="\"name\":\"podman2mqtt\",\"url\":\"$support_url\",\"sw\":\"$sw\""
					local state_cmp="\"state\":{\"name\":\"State\",\"p\":\"binary_sensor\",\"dev_cla\":\"running\",\"uniq_id\":\"sensors.podman.$name.state\",\"def_ent_id\":\"sensors.podman.$name.state\",\"val_tpl\":\"{{ 'ON' if value_json.State == 'running' else 'OFF' }}\",\"json_attr_t\":\"$HOSTNAME/podman/$name/data\",\"ic\":\"mdi:run\"}"
					local create_cmp="\"createdAt\":{\"name\":\"createdAt\",\"p\":\"sensor\",\"uniq_id\":\"sensors.podman.$name.createdat\",\"def_ent_id\":\"sensors.podman.$name.createdat\",\"val_tpl\":\"{{ as_datetime(value_json.Created|int).isoformat() }}\",\"dev_cla\":\"timestamp\",\"ic\":\"mdi:calendar\"}"
					local start_cmp="\"startedAt\":{\"name\":\"startedAt\",\"p\":\"sensor\",\"dev_cla\":\"timestamp\",\"uniq_id\":\"sensors.podman.$name.startedat\",\"def_ent_id\":\"sensors.podman.$name.startedat\",\"val_tpl\":\"{{ as_datetime(value_json.StartedAt|int).isoformat() }}\",\"ic\":\"mdi:calendar\"}"

					mosquitto_pub -r -t "homeassistant/device/podman/$name/config" -m "{\"dev\":{$dev}, \"o\":{$o}, \"cmps\":{$state_cmp, $create_cmp, $start_cmp}, \"stat_t\":\"$HOSTNAME/podman/$name/data\", \"qos\":2}" --insecure
					registered_containers+=("$name")
				fi

				mosquitto_pub -r -t "$HOSTNAME/podman/$name/state" -m "$state" --insecure &
				mosquitto_pub -r -t "$HOSTNAME/podman/$name/createdAt" -m "$createdAt" --insecure &
				mosquitto_pub -r -t "$HOSTNAME/podman/$name/startedAt" -m "$startedAt" --insecure &
				mosquitto_pub -r -t "$HOSTNAME/podman/$name/data" -m "$data" --insecure &
				mosquitto_pub -r -t "$HOSTNAME/podman/$name/status" -m "$status_str" --insecure &
			done
			for item in "${registered_containers[@]}"; do
				local running=`contains $item "${running_containers[@]}"`
				if [[ $running == false ]]; then
					mosquitto_pub -r -t "$HOSTNAME/podman/$item/state" -m "exited" --insecure &
					mosquitto_pub -r -t "$HOSTNAME/podman/$item/createdAt" -m "" --insecure &
					mosquitto_pub -r -t "$HOSTNAME/podman/$item/startedAt" -m "" --insecure &
					mosquitto_pub -r -t "$HOSTNAME/podman/$item/data" -m "{\"State\":\"exited\"}" --insecure &
					mosquitto_pub -r -t "$HOSTNAME/podman/$item/status" -m "Not launched" --insecure &
				fi
			done
			log "${#running_containers[@]}/${#registered_containers[@]} running containers"
		fi
		mosquitto_pub -r -t "$HOSTNAME/podman/state" -m "{\"state\":\"$podman_state\", \"registered\":\"${#registered_containers[@]} \", \"running\":\"${#running_containers[@]}\"}" --insecure &
		sleep 120
	done
}

LOCK_FILE=/tmp/podman2mqtt-$UID
lockfile-create --retry 0 --use-pid $LOCK_FILE || exit
trap onexit EXIT INT TERM KILL QUIT HUP
main