]>
Commit | Line | Data |
---|---|---|
cae5b340 AX |
1 | #!/bin/sh |
2 | # shellcheck disable=SC2039 | |
e10b0808 AX |
3 | # zed-functions.sh |
4 | # | |
5 | # ZED helper functions for use in ZEDLETs | |
6 | ||
7 | ||
8 | # Variable Defaults | |
9 | # | |
10 | : "${ZED_LOCKDIR:="/var/lock"}" | |
11 | : "${ZED_NOTIFY_INTERVAL_SECS:=3600}" | |
12 | : "${ZED_NOTIFY_VERBOSE:=0}" | |
13 | : "${ZED_RUNDIR:="/var/run"}" | |
14 | : "${ZED_SYSLOG_PRIORITY:="daemon.notice"}" | |
15 | : "${ZED_SYSLOG_TAG:="zed"}" | |
16 | ||
17 | ZED_FLOCK_FD=8 | |
18 | ||
19 | ||
20 | # zed_check_cmd (cmd, ...) | |
21 | # | |
22 | # For each argument given, search PATH for the executable command [cmd]. | |
23 | # Log a message if [cmd] is not found. | |
24 | # | |
25 | # Arguments | |
26 | # cmd: name of executable command for which to search | |
27 | # | |
28 | # Return | |
29 | # 0 if all commands are found in PATH and are executable | |
30 | # n for a count of the command executables that are not found | |
31 | # | |
32 | zed_check_cmd() | |
33 | { | |
34 | local cmd | |
35 | local rv=0 | |
36 | ||
37 | for cmd; do | |
38 | if ! command -v "${cmd}" >/dev/null 2>&1; then | |
39 | zed_log_err "\"${cmd}\" not installed" | |
40 | rv=$((rv + 1)) | |
41 | fi | |
42 | done | |
43 | return "${rv}" | |
44 | } | |
45 | ||
46 | ||
47 | # zed_log_msg (msg, ...) | |
48 | # | |
49 | # Write all argument strings to the system log. | |
50 | # | |
51 | # Globals | |
52 | # ZED_SYSLOG_PRIORITY | |
53 | # ZED_SYSLOG_TAG | |
54 | # | |
55 | # Return | |
56 | # nothing | |
57 | # | |
58 | zed_log_msg() | |
59 | { | |
60 | logger -p "${ZED_SYSLOG_PRIORITY}" -t "${ZED_SYSLOG_TAG}" -- "$@" | |
61 | } | |
62 | ||
63 | ||
64 | # zed_log_err (msg, ...) | |
65 | # | |
66 | # Write an error message to the system log. This message will contain the | |
67 | # script name, EID, and all argument strings. | |
68 | # | |
69 | # Globals | |
70 | # ZED_SYSLOG_PRIORITY | |
71 | # ZED_SYSLOG_TAG | |
72 | # ZEVENT_EID | |
73 | # | |
74 | # Return | |
75 | # nothing | |
76 | # | |
77 | zed_log_err() | |
78 | { | |
79 | logger -p "${ZED_SYSLOG_PRIORITY}" -t "${ZED_SYSLOG_TAG}" -- "error:" \ | |
80 | "$(basename -- "$0"):""${ZEVENT_EID:+" eid=${ZEVENT_EID}:"}" "$@" | |
81 | } | |
82 | ||
83 | ||
84 | # zed_lock (lockfile, [fd]) | |
85 | # | |
86 | # Obtain an exclusive (write) lock on [lockfile]. If the lock cannot be | |
87 | # immediately acquired, wait until it becomes available. | |
88 | # | |
89 | # Every zed_lock() must be paired with a corresponding zed_unlock(). | |
90 | # | |
91 | # By default, flock-style locks associate the lockfile with file descriptor 8. | |
92 | # The bash manpage warns that file descriptors >9 should be used with care as | |
93 | # they may conflict with file descriptors used internally by the shell. File | |
94 | # descriptor 9 is reserved for zed_rate_limit(). If concurrent locks are held | |
95 | # within the same process, they must use different file descriptors (preferably | |
96 | # decrementing from 8); otherwise, obtaining a new lock with a given file | |
97 | # descriptor will release the previous lock associated with that descriptor. | |
98 | # | |
99 | # Arguments | |
100 | # lockfile: pathname of the lock file; the lock will be stored in | |
101 | # ZED_LOCKDIR unless the pathname contains a "/". | |
102 | # fd: integer for the file descriptor used by flock (OPTIONAL unless holding | |
103 | # concurrent locks) | |
104 | # | |
105 | # Globals | |
106 | # ZED_FLOCK_FD | |
107 | # ZED_LOCKDIR | |
108 | # | |
109 | # Return | |
110 | # nothing | |
111 | # | |
112 | zed_lock() | |
113 | { | |
114 | local lockfile="$1" | |
115 | local fd="${2:-${ZED_FLOCK_FD}}" | |
116 | local umask_bak | |
117 | local err | |
118 | ||
119 | [ -n "${lockfile}" ] || return | |
120 | if ! expr "${lockfile}" : '.*/' >/dev/null 2>&1; then | |
121 | lockfile="${ZED_LOCKDIR}/${lockfile}" | |
122 | fi | |
123 | ||
124 | umask_bak="$(umask)" | |
125 | umask 077 | |
126 | ||
127 | # Obtain a lock on the file bound to the given file descriptor. | |
128 | # | |
129 | eval "exec ${fd}> '${lockfile}'" | |
130 | err="$(flock --exclusive "${fd}" 2>&1)" | |
cae5b340 | 131 | # shellcheck disable=SC2181 |
e10b0808 AX |
132 | if [ $? -ne 0 ]; then |
133 | zed_log_err "failed to lock \"${lockfile}\": ${err}" | |
134 | fi | |
135 | ||
136 | umask "${umask_bak}" | |
137 | } | |
138 | ||
139 | ||
140 | # zed_unlock (lockfile, [fd]) | |
141 | # | |
142 | # Release the lock on [lockfile]. | |
143 | # | |
144 | # Arguments | |
145 | # lockfile: pathname of the lock file | |
146 | # fd: integer for the file descriptor used by flock (must match the file | |
147 | # descriptor passed to the zed_lock function call) | |
148 | # | |
149 | # Globals | |
150 | # ZED_FLOCK_FD | |
151 | # ZED_LOCKDIR | |
152 | # | |
153 | # Return | |
154 | # nothing | |
155 | # | |
156 | zed_unlock() | |
157 | { | |
158 | local lockfile="$1" | |
159 | local fd="${2:-${ZED_FLOCK_FD}}" | |
160 | local err | |
161 | ||
162 | [ -n "${lockfile}" ] || return | |
163 | if ! expr "${lockfile}" : '.*/' >/dev/null 2>&1; then | |
164 | lockfile="${ZED_LOCKDIR}/${lockfile}" | |
165 | fi | |
166 | ||
167 | # Release the lock and close the file descriptor. | |
e10b0808 | 168 | err="$(flock --unlock "${fd}" 2>&1)" |
cae5b340 | 169 | # shellcheck disable=SC2181 |
e10b0808 AX |
170 | if [ $? -ne 0 ]; then |
171 | zed_log_err "failed to unlock \"${lockfile}\": ${err}" | |
172 | fi | |
173 | eval "exec ${fd}>&-" | |
174 | } | |
175 | ||
176 | ||
177 | # zed_notify (subject, pathname) | |
178 | # | |
179 | # Send a notification via all available methods. | |
180 | # | |
181 | # Arguments | |
182 | # subject: notification subject | |
183 | # pathname: pathname containing the notification message (OPTIONAL) | |
184 | # | |
185 | # Return | |
186 | # 0: notification succeeded via at least one method | |
187 | # 1: notification failed | |
188 | # 2: no notification methods configured | |
189 | # | |
190 | zed_notify() | |
191 | { | |
192 | local subject="$1" | |
193 | local pathname="$2" | |
194 | local num_success=0 | |
195 | local num_failure=0 | |
196 | ||
197 | zed_notify_email "${subject}" "${pathname}"; rv=$? | |
198 | [ "${rv}" -eq 0 ] && num_success=$((num_success + 1)) | |
199 | [ "${rv}" -eq 1 ] && num_failure=$((num_failure + 1)) | |
200 | ||
201 | zed_notify_pushbullet "${subject}" "${pathname}"; rv=$? | |
202 | [ "${rv}" -eq 0 ] && num_success=$((num_success + 1)) | |
203 | [ "${rv}" -eq 1 ] && num_failure=$((num_failure + 1)) | |
204 | ||
205 | [ "${num_success}" -gt 0 ] && return 0 | |
206 | [ "${num_failure}" -gt 0 ] && return 1 | |
207 | return 2 | |
208 | } | |
209 | ||
210 | ||
211 | # zed_notify_email (subject, pathname) | |
212 | # | |
213 | # Send a notification via email to the address specified by ZED_EMAIL_ADDR. | |
214 | # | |
215 | # Requires the mail executable to be installed in the standard PATH, or | |
216 | # ZED_EMAIL_PROG to be defined with the pathname of an executable capable of | |
217 | # reading a message body from stdin. | |
218 | # | |
219 | # Command-line options to the mail executable can be specified in | |
220 | # ZED_EMAIL_OPTS. This undergoes the following keyword substitutions: | |
221 | # - @ADDRESS@ is replaced with the space-delimited recipient email address(es) | |
222 | # - @SUBJECT@ is replaced with the notification subject | |
223 | # | |
224 | # Arguments | |
225 | # subject: notification subject | |
226 | # pathname: pathname containing the notification message (OPTIONAL) | |
227 | # | |
228 | # Globals | |
229 | # ZED_EMAIL_PROG | |
230 | # ZED_EMAIL_OPTS | |
231 | # ZED_EMAIL_ADDR | |
232 | # | |
233 | # Return | |
234 | # 0: notification sent | |
235 | # 1: notification failed | |
236 | # 2: not configured | |
237 | # | |
238 | zed_notify_email() | |
239 | { | |
240 | local subject="$1" | |
241 | local pathname="${2:-"/dev/null"}" | |
242 | ||
243 | : "${ZED_EMAIL_PROG:="mail"}" | |
244 | : "${ZED_EMAIL_OPTS:="-s '@SUBJECT@' @ADDRESS@"}" | |
245 | ||
246 | # For backward compatibility with ZED_EMAIL. | |
247 | if [ -n "${ZED_EMAIL}" ] && [ -z "${ZED_EMAIL_ADDR}" ]; then | |
248 | ZED_EMAIL_ADDR="${ZED_EMAIL}" | |
249 | fi | |
250 | [ -n "${ZED_EMAIL_ADDR}" ] || return 2 | |
251 | ||
252 | zed_check_cmd "${ZED_EMAIL_PROG}" || return 1 | |
253 | ||
254 | [ -n "${subject}" ] || return 1 | |
255 | if [ ! -r "${pathname}" ]; then | |
256 | zed_log_err \ | |
257 | "$(basename "${ZED_EMAIL_PROG}") cannot read \"${pathname}\"" | |
258 | return 1 | |
259 | fi | |
260 | ||
261 | ZED_EMAIL_OPTS="$(echo "${ZED_EMAIL_OPTS}" \ | |
262 | | sed -e "s/@ADDRESS@/${ZED_EMAIL_ADDR}/g" \ | |
263 | -e "s/@SUBJECT@/${subject}/g")" | |
264 | ||
265 | # shellcheck disable=SC2086 | |
266 | eval "${ZED_EMAIL_PROG}" ${ZED_EMAIL_OPTS} < "${pathname}" >/dev/null 2>&1 | |
267 | rv=$? | |
268 | if [ "${rv}" -ne 0 ]; then | |
269 | zed_log_err "$(basename "${ZED_EMAIL_PROG}") exit=${rv}" | |
270 | return 1 | |
271 | fi | |
272 | return 0 | |
273 | } | |
274 | ||
275 | ||
276 | # zed_notify_pushbullet (subject, pathname) | |
277 | # | |
278 | # Send a notification via Pushbullet <https://www.pushbullet.com/>. | |
279 | # The access token (ZED_PUSHBULLET_ACCESS_TOKEN) identifies this client to the | |
280 | # Pushbullet server. The optional channel tag (ZED_PUSHBULLET_CHANNEL_TAG) is | |
281 | # for pushing to notification feeds that can be subscribed to; if a channel is | |
282 | # not defined, push notifications will instead be sent to all devices | |
283 | # associated with the account specified by the access token. | |
284 | # | |
285 | # Requires awk, curl, and sed executables to be installed in the standard PATH. | |
286 | # | |
287 | # References | |
288 | # https://docs.pushbullet.com/ | |
289 | # https://www.pushbullet.com/security | |
290 | # | |
291 | # Arguments | |
292 | # subject: notification subject | |
293 | # pathname: pathname containing the notification message (OPTIONAL) | |
294 | # | |
295 | # Globals | |
296 | # ZED_PUSHBULLET_ACCESS_TOKEN | |
297 | # ZED_PUSHBULLET_CHANNEL_TAG | |
298 | # | |
299 | # Return | |
300 | # 0: notification sent | |
301 | # 1: notification failed | |
302 | # 2: not configured | |
303 | # | |
304 | zed_notify_pushbullet() | |
305 | { | |
306 | local subject="$1" | |
307 | local pathname="${2:-"/dev/null"}" | |
308 | local msg_body | |
309 | local msg_tag | |
310 | local msg_json | |
311 | local msg_out | |
312 | local msg_err | |
313 | local url="https://api.pushbullet.com/v2/pushes" | |
314 | ||
315 | [ -n "${ZED_PUSHBULLET_ACCESS_TOKEN}" ] || return 2 | |
316 | ||
317 | [ -n "${subject}" ] || return 1 | |
318 | if [ ! -r "${pathname}" ]; then | |
319 | zed_log_err "pushbullet cannot read \"${pathname}\"" | |
320 | return 1 | |
321 | fi | |
322 | ||
323 | zed_check_cmd "awk" "curl" "sed" || return 1 | |
324 | ||
325 | # Escape the following characters in the message body for JSON: | |
326 | # newline, backslash, double quote, horizontal tab, vertical tab, | |
327 | # and carriage return. | |
328 | # | |
329 | msg_body="$(awk '{ ORS="\\n" } { gsub(/\\/, "\\\\"); gsub(/"/, "\\\""); | |
330 | gsub(/\t/, "\\t"); gsub(/\f/, "\\f"); gsub(/\r/, "\\r"); print }' \ | |
331 | "${pathname}")" | |
332 | ||
333 | # Push to a channel if one is configured. | |
334 | # | |
335 | [ -n "${ZED_PUSHBULLET_CHANNEL_TAG}" ] && msg_tag="$(printf \ | |
336 | '"channel_tag": "%s", ' "${ZED_PUSHBULLET_CHANNEL_TAG}")" | |
337 | ||
338 | # Construct the JSON message for pushing a note. | |
339 | # | |
340 | msg_json="$(printf '{%s"type": "note", "title": "%s", "body": "%s"}' \ | |
341 | "${msg_tag}" "${subject}" "${msg_body}")" | |
342 | ||
343 | # Send the POST request and check for errors. | |
344 | # | |
345 | msg_out="$(curl -u "${ZED_PUSHBULLET_ACCESS_TOKEN}:" -X POST "${url}" \ | |
346 | --header "Content-Type: application/json" --data-binary "${msg_json}" \ | |
347 | 2>/dev/null)"; rv=$? | |
348 | if [ "${rv}" -ne 0 ]; then | |
349 | zed_log_err "curl exit=${rv}" | |
350 | return 1 | |
351 | fi | |
352 | msg_err="$(echo "${msg_out}" \ | |
353 | | sed -n -e 's/.*"error" *:.*"message" *: *"\([^"]*\)".*/\1/p')" | |
354 | if [ -n "${msg_err}" ]; then | |
355 | zed_log_err "pushbullet \"${msg_err}"\" | |
356 | return 1 | |
357 | fi | |
358 | return 0 | |
359 | } | |
360 | ||
361 | ||
362 | # zed_rate_limit (tag, [interval]) | |
363 | # | |
364 | # Check whether an event of a given type [tag] has already occurred within the | |
365 | # last [interval] seconds. | |
366 | # | |
367 | # This function obtains a lock on the statefile using file descriptor 9. | |
368 | # | |
369 | # Arguments | |
370 | # tag: arbitrary string for grouping related events to rate-limit | |
371 | # interval: time interval in seconds (OPTIONAL) | |
372 | # | |
373 | # Globals | |
374 | # ZED_NOTIFY_INTERVAL_SECS | |
375 | # ZED_RUNDIR | |
376 | # | |
377 | # Return | |
378 | # 0 if the event should be processed | |
379 | # 1 if the event should be dropped | |
380 | # | |
381 | # State File Format | |
382 | # time;tag | |
383 | # | |
384 | zed_rate_limit() | |
385 | { | |
386 | local tag="$1" | |
387 | local interval="${2:-${ZED_NOTIFY_INTERVAL_SECS}}" | |
388 | local lockfile="zed.zedlet.state.lock" | |
389 | local lockfile_fd=9 | |
390 | local statefile="${ZED_RUNDIR}/zed.zedlet.state" | |
391 | local time_now | |
392 | local time_prev | |
393 | local umask_bak | |
394 | local rv=0 | |
395 | ||
396 | [ -n "${tag}" ] || return 0 | |
397 | ||
398 | zed_lock "${lockfile}" "${lockfile_fd}" | |
399 | time_now="$(date +%s)" | |
047218e2 | 400 | time_prev="$(grep -E "^[0-9]+;${tag}\$" "${statefile}" 2>/dev/null \ |
e10b0808 AX |
401 | | tail -1 | cut -d\; -f1)" |
402 | ||
403 | if [ -n "${time_prev}" ] \ | |
404 | && [ "$((time_now - time_prev))" -lt "${interval}" ]; then | |
405 | rv=1 | |
406 | else | |
407 | umask_bak="$(umask)" | |
408 | umask 077 | |
047218e2 | 409 | grep -E -v "^[0-9]+;${tag}\$" "${statefile}" 2>/dev/null \ |
e10b0808 AX |
410 | > "${statefile}.$$" |
411 | echo "${time_now};${tag}" >> "${statefile}.$$" | |
412 | mv -f "${statefile}.$$" "${statefile}" | |
413 | umask "${umask_bak}" | |
414 | fi | |
415 | ||
416 | zed_unlock "${lockfile}" "${lockfile_fd}" | |
417 | return "${rv}" | |
418 | } | |
cae5b340 AX |
419 | |
420 | ||
421 | # zed_guid_to_pool (guid) | |
422 | # | |
423 | # Convert a pool GUID into its pool name (like "tank") | |
424 | # Arguments | |
425 | # guid: pool GUID (decimal or hex) | |
426 | # | |
427 | # Return | |
428 | # Pool name | |
429 | # | |
430 | zed_guid_to_pool() | |
431 | { | |
432 | if [ -z "$1" ] ; then | |
433 | return | |
434 | fi | |
435 | ||
436 | guid=$(printf "%llu" "$1") | |
437 | if [ ! -z "$guid" ] ; then | |
438 | $ZPOOL get -H -ovalue,name guid | awk '$1=='"$guid"' {print $2}' | |
439 | fi | |
440 | } | |
42f7b73b AX |
441 | |
442 | # zed_exit_if_ignoring_this_event | |
443 | # | |
444 | # Exit the script if we should ignore this event, as determined by | |
445 | # $ZED_SYSLOG_SUBCLASS_INCLUDE and $ZED_SYSLOG_SUBCLASS_EXCLUDE in zed.rc. | |
446 | # This function assumes you've imported the normal zed variables. | |
447 | zed_exit_if_ignoring_this_event() | |
448 | { | |
449 | if [ -n "${ZED_SYSLOG_SUBCLASS_INCLUDE}" ]; then | |
450 | eval "case ${ZEVENT_SUBCLASS} in | |
451 | ${ZED_SYSLOG_SUBCLASS_INCLUDE});; | |
452 | *) exit 0;; | |
453 | esac" | |
454 | elif [ -n "${ZED_SYSLOG_SUBCLASS_EXCLUDE}" ]; then | |
455 | eval "case ${ZEVENT_SUBCLASS} in | |
456 | ${ZED_SYSLOG_SUBCLASS_EXCLUDE}) exit 0;; | |
457 | *);; | |
458 | esac" | |
459 | fi | |
460 | } |