#!/usr/bin/env sh

# Configurable Variables
DOCKER_SOCK_PATH="${DOCKER_SOCK_PATH:-/tmp/docker.sock}"
NETWORK_NAME="${NETWORK_NAME:-proxy}"
TEMPLATER_PATH="${TEMPLATER_PATH:-/docker-templater.sh}"
TEMPLATE_FOLDER_PATH="${TEMPLATE_FOLDER_PATH:-/templates}"

get_date() {
    printf '%s' "$(date +'%Y.%m.%d_%H:%M:%S')"
}

query_docker () {
    curl --unix-socket $DOCKER_SOCK_PATH --silent -g http://v1.41/$1$2
}

update_templates() {
    CONTAINER_LIST=$(query_docker "containers/json" "?filters={%22network%22:[%22${NETWORK_NAME}%22],%22status%22:[%22running%22]}")
    LABELS_NEW="$(echo "${CONTAINER_LIST}" | jq '.[].Labels | @base64' | sort)"
    if [ "${LABELS_NEW}" != "${LABELS_OLD}" ]
    then
        if [ -n "${LABELS_OLD}" ]
        then
            printf '%s | Container label list change detected.\n' "$(get_date)"
        fi
        LABELS_OLD="${LABELS_NEW}"
        for template in "${TEMPLATE_FOLDER_PATH}"/*
        do
            if ! "${TEMPLATER_PATH}" "${template}" "${CONTAINER_LIST}"
            then
                printf '%s | Error Processing Template: %s\n' "$(get_date)" "${template}"
            fi
        done
    fi
}

# Initial Generation
update_templates

# cannot filter because reailine no longer recognized lines otherwise (check how IFS changes)
query_docker "events" | while  true
do
    printf '%s | Listening for docker events\n' "$(get_date)"
    read -r;
    # wait for related events to finish
    printf '%s | Waiting for event messages to settle.\n' "$(get_date)"
    while [ $? -eq 0 ]
    do
        read -t 8 -r
    done
    printf '%s | Checking for changes in container label list.\n' "$(get_date)"
    update_templates
done