#!/usr/bin/env bash

# netdata
# real-time performance and health monitoring, done right!
# (C) 2016 Costa Tsaousis <costa@tsaousis.gr>
# SPDX-License-Identifier: GPL-3.0-or-later
#
# Script to find a better name for cgroups
#

export PATH="${PATH}:/sbin:/usr/sbin:/usr/local/sbin"
export LC_ALL=C

# -----------------------------------------------------------------------------

PROGRAM_NAME="$(basename "${0}")"

logdate() {
    date "+%Y-%m-%d %H:%M:%S"
}

log() {
    local status="${1}"
    shift

    echo >&2 "$(logdate): ${PROGRAM_NAME}: ${status}: ${*}"

}

warning() {
    log WARNING "${@}"
}

error() {
    log ERROR "${@}"
}

info() {
    log INFO "${@}"
}

fatal() {
    log FATAL "${@}"
    exit 1
}

debug=0
debug() {
    [ $debug -eq 1 ] && log DEBUG "${@}"
}

# -----------------------------------------------------------------------------

[ -z "${NETDATA_USER_CONFIG_DIR}"  ] && NETDATA_USER_CONFIG_DIR="@configdir_POST@"
[ -z "${NETDATA_STOCK_CONFIG_DIR}" ] && NETDATA_STOCK_CONFIG_DIR="@libconfigdir_POST@"

DOCKER_HOST="${DOCKER_HOST:=/var/run/docker.sock}"
CGROUP="${1}"
NAME=

# -----------------------------------------------------------------------------

if [ -z "${CGROUP}" ]
    then
    fatal "called without a cgroup name. Nothing to do."
fi

for CONFIG in "${NETDATA_USER_CONFIG_DIR}/cgroups-names.conf" "${NETDATA_STOCK_CONFIG_DIR}/cgroups-names.conf"
do
    if [ -f "${CONFIG}" ]
    then
        NAME="$(grep "^${CGROUP} " "${CONFIG}" | sed "s/[[:space:]]\+/ /g" | cut -d ' ' -f 2)"
        if [ -z "${NAME}" ]
            then
            info "cannot find cgroup '${CGROUP}' in '${CONFIG}'."
        else
            break
        fi
    #else
    #   info "configuration file '${CONFIG}' is not available."
    fi
done

function docker_get_name_classic {
    local id="${1}"
    info "Running command: docker ps --filter=id=\"${id}\" --format=\"{{.Names}}\""
    NAME="$( docker ps --filter=id="${id}" --format="{{.Names}}" )"
    return 0
}

function docker_get_name_api {
    local id="${1}"
    if [ ! -S "${DOCKER_HOST}" ]
        then
        warning "Can't find ${DOCKER_HOST}"
        return 1
    fi
    info "Running API command: /containers/${id}/json"
    JSON=$(echo -e "GET /containers/${id}/json HTTP/1.0\r\n" | nc -U ${DOCKER_HOST} | grep '^{.*')
    NAME=$(echo $JSON | jq -r .Name,.Config.Hostname | grep -v null | head -n1 | sed 's|^/||')
    return 0
}

function docker_get_name {
    local id="${1}"
    if hash docker 2>/dev/null
        then
        docker_get_name_classic "${id}"
    else
        docker_get_name_api "${id}" || docker_get_name_classic "${id}"
    fi
    if [ -z "${NAME}" ]
        then
        warning "cannot find the name of docker container '${id}'"
        NAME="${id:0:12}"
    else
        info "docker container '${id}' is named '${NAME}'"
    fi
}

if [ -z "${NAME}" ]
    then
    if [[ "${CGROUP}" =~ ^.*docker[-_/\.][a-fA-F0-9]+[-_\.]?.*$ ]]
        then
        # docker containers

        DOCKERID="$( echo "${CGROUP}" | sed "s|^.*docker[-_/]\([a-fA-F0-9]\+\)[-_\.]\?.*$|\1|" )"
        # echo "DOCKERID=${DOCKERID}"

        if [ ! -z "${DOCKERID}" -a \( ${#DOCKERID} -eq 64 -o ${#DOCKERID} -eq 12 \) ]
            then
            docker_get_name "${DOCKERID}"
        else
            error "a docker id cannot be extracted from docker cgroup '${CGROUP}'."
        fi
    elif [[ "${CGROUP}" =~ ^.*kubepods[_/].*[_/]pod[a-fA-F0-9-]+[_/][a-fA-F0-9]+$ ]]
        then
        # kubernetes

        DOCKERID="$( echo "${CGROUP}" | sed "s|^.*kubepods[_/].*[_/]pod[a-fA-F0-9-]\+[_/]\([a-fA-F0-9]\+\)$|\1|" )"
        # echo "DOCKERID=${DOCKERID}"

        if [ ! -z "${DOCKERID}" -a \( ${#DOCKERID} -eq 64 -o ${#DOCKERID} -eq 12 \) ]
            then
            docker_get_name "${DOCKERID}"
        else
            error "a docker id cannot be extracted from kubernetes cgroup '${CGROUP}'."
        fi
    elif [[ "${CGROUP}" =~ machine.slice[_/].*\.service ]]
        then
        # systemd-nspawn

        NAME="$(echo ${CGROUP} | sed 's/.*machine.slice[_\/]\(.*\)\.service/\1/g')"

    elif [[ "${CGROUP}" =~ machine.slice_machine.*-qemu ]]
        then
        # libvirtd / qemu virtual machines

        # NAME="$(echo ${CGROUP} | sed 's/machine.slice_machine.*-qemu//; s/\/x2d//; s/\/x2d/\-/g; s/\.scope//g')"
        NAME="qemu_$(echo ${CGROUP} | sed 's/machine.slice_machine.*-qemu//; s/\/x2d[[:digit:]]*//; s/\/x2d//g; s/\.scope//g')"

    elif [[ "${CGROUP}" =~ machine_.*\.libvirt-qemu ]]
        then
        # libvirtd / qemu virtual machines
        NAME="qemu_$(echo ${CGROUP} | sed 's/^machine_//; s/\.libvirt-qemu$//; s/-/_/;')"

    elif [[ "${CGROUP}" =~ qemu.slice_([0-9]+).scope && -d /etc/pve ]]
        then
        # Proxmox VMs

        FILENAME="/etc/pve/qemu-server/${BASH_REMATCH[1]}.conf"
        if [[ -f $FILENAME && -r $FILENAME ]]
            then
            NAME="qemu_$(grep -e '^name: ' "/etc/pve/qemu-server/${BASH_REMATCH[1]}.conf" | head -1 | sed -rn 's|\s*name\s*:\s*(.*)?$|\1|p')"
        else
            error "proxmox config file missing ${FILENAME} or netdata does not have read access.  Please ensure netdata is a member of www-data group."
        fi
    elif [[ "${CGROUP}" =~ lxc_([0-9]+) && -d /etc/pve ]]
        then
        # Proxmox Containers (LXC)

        FILENAME="/etc/pve/lxc/${BASH_REMATCH[1]}.conf"
        if [[ -f ${FILENAME} && -r ${FILENAME} ]]
            then
            NAME=$(grep -e '^hostname: ' /etc/pve/lxc/${BASH_REMATCH[1]}.conf | head -1 | sed -rn 's|\s*hostname\s*:\s*(.*)?$|\1|p')
        else
            error "proxmox config file missing ${FILENAME} or netdata does not have read access.  Please ensure netdata is a member of www-data group."
        fi
    fi

    [ -z "${NAME}" ] && NAME="${CGROUP}"
    [ ${#NAME} -gt 100 ] && NAME="${NAME:0:100}"
fi

info "cgroup '${CGROUP}' is called '${NAME}'"
echo "${NAME}"
