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Diffstat (limited to '')
| -rwxr-xr-x | collectors/cgroups.plugin/cgroup-network-helper.sh | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/collectors/cgroups.plugin/cgroup-network-helper.sh b/collectors/cgroups.plugin/cgroup-network-helper.sh new file mode 100755 index 0000000..666f02f --- /dev/null +++ b/collectors/cgroups.plugin/cgroup-network-helper.sh @@ -0,0 +1,258 @@ +#!/usr/bin/env bash +# shellcheck disable=SC1117 + +# cgroup-network-helper.sh +# detect container and virtual machine interfaces +# +# (C) 2017 Costa Tsaousis +# SPDX-License-Identifier: GPL-3.0-or-later +# +# This script is called as root (by cgroup-network), with either a pid, or a cgroup path. +# It tries to find all the network interfaces that belong to the same cgroup. +# +# It supports several method for this detection: +# +# 1. cgroup-network (the binary father of this script) detects veth network interfaces, +# by examining iflink and ifindex IDs and switching namespaces +# (it also detects the interface name as it is used by the container). +# +# 2. this script, uses /proc/PID/fdinfo to find tun/tap network interfaces. +# +# 3. this script, calls virsh to find libvirt network interfaces. +# + +# ----------------------------------------------------------------------------- + +# the system path is cleared by cgroup-network +# shellcheck source=/dev/null +[ -f /etc/profile ] && source /etc/profile + +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}" = "1" ] && log DEBUG "${@}" +} + +# ----------------------------------------------------------------------------- +# check for BASH v4+ (required for associative arrays) + +[ $(( BASH_VERSINFO[0] )) -lt 4 ] && \ + fatal "BASH version 4 or later is required (this is ${BASH_VERSION})." + +# ----------------------------------------------------------------------------- +# parse the arguments + +pid= +cgroup= +while [ ! -z "${1}" ] +do + case "${1}" in + --cgroup) cgroup="${2}"; shift 1;; + --pid|-p) pid="${2}"; shift 1;; + --debug|debug) debug=1;; + *) fatal "Cannot understand argument '${1}'";; + esac + + shift +done + +if [ -z "${pid}" ] && [ -z "${cgroup}" ] +then + fatal "Either --pid or --cgroup is required" +fi + +# ----------------------------------------------------------------------------- + +set_source() { + [ ${debug} -eq 1 ] && echo "SRC ${*}" +} + + +# ----------------------------------------------------------------------------- +# veth interfaces via cgroup + +# cgroup-network can detect veth interfaces by itself (written in C). +# If you seek for a shell version of what it does, check this: +# https://github.com/netdata/netdata/issues/474#issuecomment-317866709 + + +# ----------------------------------------------------------------------------- +# tun/tap interfaces via /proc/PID/fdinfo + +# find any tun/tap devices linked to a pid +proc_pid_fdinfo_iff() { + local p="${1}" # the pid + + debug "Searching for tun/tap interfaces for pid ${p}..." + set_source "fdinfo" + grep "^iff:.*" "${NETDATA_HOST_PREFIX}/proc/${p}/fdinfo"/* 2>/dev/null | cut -f 2 +} + +find_tun_tap_interfaces_for_cgroup() { + local c="${1}" # the cgroup path + + # for each pid of the cgroup + # find any tun/tap devices linked to the pid + if [ -f "${c}/emulator/cgroup.procs" ] + then + local p + for p in $(< "${c}/emulator/cgroup.procs" ) + do + proc_pid_fdinfo_iff "${p}" + done + fi +} + + +# ----------------------------------------------------------------------------- +# virsh domain network interfaces + +virsh_cgroup_to_domain_name() { + local c="${1}" # the cgroup path + + debug "extracting a possible virsh domain from cgroup ${c}..." + + # extract for the cgroup path + sed -n -e "s|.*/machine-qemu\\\\x2d[0-9]\+\\\\x2d\(.*\)\.scope$|\1|p" \ + -e "s|.*/machine/\(.*\)\.libvirt-qemu$|\1|p" \ + <<EOF +${c} +EOF +} + +virsh_find_all_interfaces_for_cgroup() { + local c="${1}" # the cgroup path + + # the virsh command + local virsh + # shellcheck disable=SC2230 + virsh="$(which virsh 2>/dev/null || command -v virsh 2>/dev/null)" + + if [ ! -z "${virsh}" ] + then + local d + d="$(virsh_cgroup_to_domain_name "${c}")" + + if [ ! -z "${d}" ] + then + debug "running: virsh domiflist ${d}; to find the network interfaces" + + # match only 'network' interfaces from virsh output + + set_source "virsh" + "${virsh}" -r domiflist "${d}" |\ + sed -n \ + -e "s|^\([^[:space:]]\+\)[[:space:]]\+network[[:space:]]\+\([^[:space:]]\+\)[[:space:]]\+[^[:space:]]\+[[:space:]]\+[^[:space:]]\+$|\1 \1_\2|p" \ + -e "s|^\([^[:space:]]\+\)[[:space:]]\+bridge[[:space:]]\+\([^[:space:]]\+\)[[:space:]]\+[^[:space:]]\+[[:space:]]\+[^[:space:]]\+$|\1 \1_\2|p" + else + debug "no virsh domain extracted from cgroup ${c}" + fi + else + debug "virsh command is not available" + fi +} + +# ----------------------------------------------------------------------------- + +find_all_interfaces_of_pid_or_cgroup() { + local p="${1}" c="${2}" # the pid and the cgroup path + + if [ ! -z "${pid}" ] + then + # we have been called with a pid + + proc_pid_fdinfo_iff "${p}" + + elif [ ! -z "${c}" ] + then + # we have been called with a cgroup + + info "searching for network interfaces of cgroup '${c}'" + + find_tun_tap_interfaces_for_cgroup "${c}" + virsh_find_all_interfaces_for_cgroup "${c}" + + else + + error "Either a pid or a cgroup path is needed" + return 1 + + fi + + return 0 +} + +# ----------------------------------------------------------------------------- + +# an associative array to store the interfaces +# the index is the interface name as seen by the host +# the value is the interface name as seen by the guest / container +declare -A devs=() + +# store all interfaces found in the associative array +# this will also give the unique devices, as seen by the host +last_src= +# shellcheck disable=SC2162 +while read host_device guest_device +do + [ -z "${host_device}" ] && continue + + [ "${host_device}" = "SRC" ] && last_src="${guest_device}" && continue + + # the default guest_device is the host_device + [ -z "${guest_device}" ] && guest_device="${host_device}" + + # when we run in debug, show the source + debug "Found host device '${host_device}', guest device '${guest_device}', detected via '${last_src}'" + + if [ -z "${devs[${host_device}]}" ] || [ "${devs[${host_device}]}" = "${host_device}" ]; then + devs[${host_device}]="${guest_device}" + fi + +done < <( find_all_interfaces_of_pid_or_cgroup "${pid}" "${cgroup}" ) + +# print the interfaces found, in the format netdata expects them +found=0 +for x in "${!devs[@]}" +do + found=$((found + 1)) + echo "${x} ${devs[${x}]}" +done + +debug "found ${found} network interfaces for pid '${pid}', cgroup '${cgroup}', run as ${USER}, ${UID}" + +# let netdata know if we found any +[ ${found} -eq 0 ] && exit 1 +exit 0 |