| #!/bin/sh |
| # shellcheck disable=SC2039 |
| # zed-functions.sh |
| # |
| # ZED helper functions for use in ZEDLETs |
| |
| |
| # Variable Defaults |
| # |
| : "${ZED_LOCKDIR:="/var/lock"}" |
| : "${ZED_NOTIFY_INTERVAL_SECS:=3600}" |
| : "${ZED_NOTIFY_VERBOSE:=0}" |
| : "${ZED_RUNDIR:="/var/run"}" |
| : "${ZED_SYSLOG_PRIORITY:="daemon.notice"}" |
| : "${ZED_SYSLOG_TAG:="zed"}" |
| |
| ZED_FLOCK_FD=8 |
| |
| |
| # zed_check_cmd (cmd, ...) |
| # |
| # For each argument given, search PATH for the executable command [cmd]. |
| # Log a message if [cmd] is not found. |
| # |
| # Arguments |
| # cmd: name of executable command for which to search |
| # |
| # Return |
| # 0 if all commands are found in PATH and are executable |
| # n for a count of the command executables that are not found |
| # |
| zed_check_cmd() |
| { |
| local cmd |
| local rv=0 |
| |
| for cmd; do |
| if ! command -v "${cmd}" >/dev/null 2>&1; then |
| zed_log_err "\"${cmd}\" not installed" |
| rv=$((rv + 1)) |
| fi |
| done |
| return "${rv}" |
| } |
| |
| |
| # zed_log_msg (msg, ...) |
| # |
| # Write all argument strings to the system log. |
| # |
| # Globals |
| # ZED_SYSLOG_PRIORITY |
| # ZED_SYSLOG_TAG |
| # |
| # Return |
| # nothing |
| # |
| zed_log_msg() |
| { |
| logger -p "${ZED_SYSLOG_PRIORITY}" -t "${ZED_SYSLOG_TAG}" -- "$@" |
| } |
| |
| |
| # zed_log_err (msg, ...) |
| # |
| # Write an error message to the system log. This message will contain the |
| # script name, EID, and all argument strings. |
| # |
| # Globals |
| # ZED_SYSLOG_PRIORITY |
| # ZED_SYSLOG_TAG |
| # ZEVENT_EID |
| # |
| # Return |
| # nothing |
| # |
| zed_log_err() |
| { |
| logger -p "${ZED_SYSLOG_PRIORITY}" -t "${ZED_SYSLOG_TAG}" -- "error:" \ |
| "$(basename -- "$0"):""${ZEVENT_EID:+" eid=${ZEVENT_EID}:"}" "$@" |
| } |
| |
| |
| # zed_lock (lockfile, [fd]) |
| # |
| # Obtain an exclusive (write) lock on [lockfile]. If the lock cannot be |
| # immediately acquired, wait until it becomes available. |
| # |
| # Every zed_lock() must be paired with a corresponding zed_unlock(). |
| # |
| # By default, flock-style locks associate the lockfile with file descriptor 8. |
| # The bash manpage warns that file descriptors >9 should be used with care as |
| # they may conflict with file descriptors used internally by the shell. File |
| # descriptor 9 is reserved for zed_rate_limit(). If concurrent locks are held |
| # within the same process, they must use different file descriptors (preferably |
| # decrementing from 8); otherwise, obtaining a new lock with a given file |
| # descriptor will release the previous lock associated with that descriptor. |
| # |
| # Arguments |
| # lockfile: pathname of the lock file; the lock will be stored in |
| # ZED_LOCKDIR unless the pathname contains a "/". |
| # fd: integer for the file descriptor used by flock (OPTIONAL unless holding |
| # concurrent locks) |
| # |
| # Globals |
| # ZED_FLOCK_FD |
| # ZED_LOCKDIR |
| # |
| # Return |
| # nothing |
| # |
| zed_lock() |
| { |
| local lockfile="$1" |
| local fd="${2:-${ZED_FLOCK_FD}}" |
| local umask_bak |
| local err |
| |
| [ -n "${lockfile}" ] || return |
| if ! expr "${lockfile}" : '.*/' >/dev/null 2>&1; then |
| lockfile="${ZED_LOCKDIR}/${lockfile}" |
| fi |
| |
| umask_bak="$(umask)" |
| umask 077 |
| |
| # Obtain a lock on the file bound to the given file descriptor. |
| # |
| eval "exec ${fd}> '${lockfile}'" |
| err="$(flock --exclusive "${fd}" 2>&1)" |
| # shellcheck disable=SC2181 |
| if [ $? -ne 0 ]; then |
| zed_log_err "failed to lock \"${lockfile}\": ${err}" |
| fi |
| |
| umask "${umask_bak}" |
| } |
| |
| |
| # zed_unlock (lockfile, [fd]) |
| # |
| # Release the lock on [lockfile]. |
| # |
| # Arguments |
| # lockfile: pathname of the lock file |
| # fd: integer for the file descriptor used by flock (must match the file |
| # descriptor passed to the zed_lock function call) |
| # |
| # Globals |
| # ZED_FLOCK_FD |
| # ZED_LOCKDIR |
| # |
| # Return |
| # nothing |
| # |
| zed_unlock() |
| { |
| local lockfile="$1" |
| local fd="${2:-${ZED_FLOCK_FD}}" |
| local err |
| |
| [ -n "${lockfile}" ] || return |
| if ! expr "${lockfile}" : '.*/' >/dev/null 2>&1; then |
| lockfile="${ZED_LOCKDIR}/${lockfile}" |
| fi |
| |
| # Release the lock and close the file descriptor. |
| err="$(flock --unlock "${fd}" 2>&1)" |
| # shellcheck disable=SC2181 |
| if [ $? -ne 0 ]; then |
| zed_log_err "failed to unlock \"${lockfile}\": ${err}" |
| fi |
| eval "exec ${fd}>&-" |
| } |
| |
| |
| # zed_notify (subject, pathname) |
| # |
| # Send a notification via all available methods. |
| # |
| # Arguments |
| # subject: notification subject |
| # pathname: pathname containing the notification message (OPTIONAL) |
| # |
| # Return |
| # 0: notification succeeded via at least one method |
| # 1: notification failed |
| # 2: no notification methods configured |
| # |
| zed_notify() |
| { |
| local subject="$1" |
| local pathname="$2" |
| local num_success=0 |
| local num_failure=0 |
| |
| zed_notify_email "${subject}" "${pathname}"; rv=$? |
| [ "${rv}" -eq 0 ] && num_success=$((num_success + 1)) |
| [ "${rv}" -eq 1 ] && num_failure=$((num_failure + 1)) |
| |
| zed_notify_pushbullet "${subject}" "${pathname}"; rv=$? |
| [ "${rv}" -eq 0 ] && num_success=$((num_success + 1)) |
| [ "${rv}" -eq 1 ] && num_failure=$((num_failure + 1)) |
| |
| [ "${num_success}" -gt 0 ] && return 0 |
| [ "${num_failure}" -gt 0 ] && return 1 |
| return 2 |
| } |
| |
| |
| # zed_notify_email (subject, pathname) |
| # |
| # Send a notification via email to the address specified by ZED_EMAIL_ADDR. |
| # |
| # Requires the mail executable to be installed in the standard PATH, or |
| # ZED_EMAIL_PROG to be defined with the pathname of an executable capable of |
| # reading a message body from stdin. |
| # |
| # Command-line options to the mail executable can be specified in |
| # ZED_EMAIL_OPTS. This undergoes the following keyword substitutions: |
| # - @ADDRESS@ is replaced with the space-delimited recipient email address(es) |
| # - @SUBJECT@ is replaced with the notification subject |
| # |
| # Arguments |
| # subject: notification subject |
| # pathname: pathname containing the notification message (OPTIONAL) |
| # |
| # Globals |
| # ZED_EMAIL_PROG |
| # ZED_EMAIL_OPTS |
| # ZED_EMAIL_ADDR |
| # |
| # Return |
| # 0: notification sent |
| # 1: notification failed |
| # 2: not configured |
| # |
| zed_notify_email() |
| { |
| local subject="$1" |
| local pathname="${2:-"/dev/null"}" |
| |
| : "${ZED_EMAIL_PROG:="mail"}" |
| : "${ZED_EMAIL_OPTS:="-s '@SUBJECT@' @ADDRESS@"}" |
| |
| # For backward compatibility with ZED_EMAIL. |
| if [ -n "${ZED_EMAIL}" ] && [ -z "${ZED_EMAIL_ADDR}" ]; then |
| ZED_EMAIL_ADDR="${ZED_EMAIL}" |
| fi |
| [ -n "${ZED_EMAIL_ADDR}" ] || return 2 |
| |
| zed_check_cmd "${ZED_EMAIL_PROG}" || return 1 |
| |
| [ -n "${subject}" ] || return 1 |
| if [ ! -r "${pathname}" ]; then |
| zed_log_err \ |
| "$(basename "${ZED_EMAIL_PROG}") cannot read \"${pathname}\"" |
| return 1 |
| fi |
| |
| ZED_EMAIL_OPTS="$(echo "${ZED_EMAIL_OPTS}" \ |
| | sed -e "s/@ADDRESS@/${ZED_EMAIL_ADDR}/g" \ |
| -e "s/@SUBJECT@/${subject}/g")" |
| |
| # shellcheck disable=SC2086 |
| eval "${ZED_EMAIL_PROG}" ${ZED_EMAIL_OPTS} < "${pathname}" >/dev/null 2>&1 |
| rv=$? |
| if [ "${rv}" -ne 0 ]; then |
| zed_log_err "$(basename "${ZED_EMAIL_PROG}") exit=${rv}" |
| return 1 |
| fi |
| return 0 |
| } |
| |
| |
| # zed_notify_pushbullet (subject, pathname) |
| # |
| # Send a notification via Pushbullet <https://www.pushbullet.com/>. |
| # The access token (ZED_PUSHBULLET_ACCESS_TOKEN) identifies this client to the |
| # Pushbullet server. The optional channel tag (ZED_PUSHBULLET_CHANNEL_TAG) is |
| # for pushing to notification feeds that can be subscribed to; if a channel is |
| # not defined, push notifications will instead be sent to all devices |
| # associated with the account specified by the access token. |
| # |
| # Requires awk, curl, and sed executables to be installed in the standard PATH. |
| # |
| # References |
| # https://docs.pushbullet.com/ |
| # https://www.pushbullet.com/security |
| # |
| # Arguments |
| # subject: notification subject |
| # pathname: pathname containing the notification message (OPTIONAL) |
| # |
| # Globals |
| # ZED_PUSHBULLET_ACCESS_TOKEN |
| # ZED_PUSHBULLET_CHANNEL_TAG |
| # |
| # Return |
| # 0: notification sent |
| # 1: notification failed |
| # 2: not configured |
| # |
| zed_notify_pushbullet() |
| { |
| local subject="$1" |
| local pathname="${2:-"/dev/null"}" |
| local msg_body |
| local msg_tag |
| local msg_json |
| local msg_out |
| local msg_err |
| local url="https://api.pushbullet.com/v2/pushes" |
| |
| [ -n "${ZED_PUSHBULLET_ACCESS_TOKEN}" ] || return 2 |
| |
| [ -n "${subject}" ] || return 1 |
| if [ ! -r "${pathname}" ]; then |
| zed_log_err "pushbullet cannot read \"${pathname}\"" |
| return 1 |
| fi |
| |
| zed_check_cmd "awk" "curl" "sed" || return 1 |
| |
| # Escape the following characters in the message body for JSON: |
| # newline, backslash, double quote, horizontal tab, vertical tab, |
| # and carriage return. |
| # |
| msg_body="$(awk '{ ORS="\\n" } { gsub(/\\/, "\\\\"); gsub(/"/, "\\\""); |
| gsub(/\t/, "\\t"); gsub(/\f/, "\\f"); gsub(/\r/, "\\r"); print }' \ |
| "${pathname}")" |
| |
| # Push to a channel if one is configured. |
| # |
| [ -n "${ZED_PUSHBULLET_CHANNEL_TAG}" ] && msg_tag="$(printf \ |
| '"channel_tag": "%s", ' "${ZED_PUSHBULLET_CHANNEL_TAG}")" |
| |
| # Construct the JSON message for pushing a note. |
| # |
| msg_json="$(printf '{%s"type": "note", "title": "%s", "body": "%s"}' \ |
| "${msg_tag}" "${subject}" "${msg_body}")" |
| |
| # Send the POST request and check for errors. |
| # |
| msg_out="$(curl -u "${ZED_PUSHBULLET_ACCESS_TOKEN}:" -X POST "${url}" \ |
| --header "Content-Type: application/json" --data-binary "${msg_json}" \ |
| 2>/dev/null)"; rv=$? |
| if [ "${rv}" -ne 0 ]; then |
| zed_log_err "curl exit=${rv}" |
| return 1 |
| fi |
| msg_err="$(echo "${msg_out}" \ |
| | sed -n -e 's/.*"error" *:.*"message" *: *"\([^"]*\)".*/\1/p')" |
| if [ -n "${msg_err}" ]; then |
| zed_log_err "pushbullet \"${msg_err}"\" |
| return 1 |
| fi |
| return 0 |
| } |
| |
| |
| # zed_rate_limit (tag, [interval]) |
| # |
| # Check whether an event of a given type [tag] has already occurred within the |
| # last [interval] seconds. |
| # |
| # This function obtains a lock on the statefile using file descriptor 9. |
| # |
| # Arguments |
| # tag: arbitrary string for grouping related events to rate-limit |
| # interval: time interval in seconds (OPTIONAL) |
| # |
| # Globals |
| # ZED_NOTIFY_INTERVAL_SECS |
| # ZED_RUNDIR |
| # |
| # Return |
| # 0 if the event should be processed |
| # 1 if the event should be dropped |
| # |
| # State File Format |
| # time;tag |
| # |
| zed_rate_limit() |
| { |
| local tag="$1" |
| local interval="${2:-${ZED_NOTIFY_INTERVAL_SECS}}" |
| local lockfile="zed.zedlet.state.lock" |
| local lockfile_fd=9 |
| local statefile="${ZED_RUNDIR}/zed.zedlet.state" |
| local time_now |
| local time_prev |
| local umask_bak |
| local rv=0 |
| |
| [ -n "${tag}" ] || return 0 |
| |
| zed_lock "${lockfile}" "${lockfile_fd}" |
| time_now="$(date +%s)" |
| time_prev="$(grep -E "^[0-9]+;${tag}\$" "${statefile}" 2>/dev/null \ |
| | tail -1 | cut -d\; -f1)" |
| |
| if [ -n "${time_prev}" ] \ |
| && [ "$((time_now - time_prev))" -lt "${interval}" ]; then |
| rv=1 |
| else |
| umask_bak="$(umask)" |
| umask 077 |
| grep -E -v "^[0-9]+;${tag}\$" "${statefile}" 2>/dev/null \ |
| > "${statefile}.$$" |
| echo "${time_now};${tag}" >> "${statefile}.$$" |
| mv -f "${statefile}.$$" "${statefile}" |
| umask "${umask_bak}" |
| fi |
| |
| zed_unlock "${lockfile}" "${lockfile_fd}" |
| return "${rv}" |
| } |
| |
| |
| # zed_guid_to_pool (guid) |
| # |
| # Convert a pool GUID into its pool name (like "tank") |
| # Arguments |
| # guid: pool GUID (decimal or hex) |
| # |
| # Return |
| # Pool name |
| # |
| zed_guid_to_pool() |
| { |
| if [ -z "$1" ] ; then |
| return |
| fi |
| |
| guid=$(printf "%llu" "$1") |
| if [ -n "$guid" ] ; then |
| $ZPOOL get -H -ovalue,name guid | awk '$1=='"$guid"' {print $2}' |
| fi |
| } |
| |
| # zed_exit_if_ignoring_this_event |
| # |
| # Exit the script if we should ignore this event, as determined by |
| # $ZED_SYSLOG_SUBCLASS_INCLUDE and $ZED_SYSLOG_SUBCLASS_EXCLUDE in zed.rc. |
| # This function assumes you've imported the normal zed variables. |
| zed_exit_if_ignoring_this_event() |
| { |
| if [ -n "${ZED_SYSLOG_SUBCLASS_INCLUDE}" ]; then |
| eval "case ${ZEVENT_SUBCLASS} in |
| ${ZED_SYSLOG_SUBCLASS_INCLUDE});; |
| *) exit 0;; |
| esac" |
| elif [ -n "${ZED_SYSLOG_SUBCLASS_EXCLUDE}" ]; then |
| eval "case ${ZEVENT_SUBCLASS} in |
| ${ZED_SYSLOG_SUBCLASS_EXCLUDE}) exit 0;; |
| *);; |
| esac" |
| fi |
| } |