------
```
- parallel +----------+ +----------+ +----------+
- stateless | sensor_1 | | sensor_2 | ... | sensor_n |
- collectors +----------+ +----------+ +----------+
- | | |
- data data data
- | | |
- V V V
- serial +-----------------------------------------+
- stateful | controller |
- observer +-----------------------------------------+
- |
- decisions
- |
- V
- serial +-----------------------------------------+
- stateless | actuator |
- executor +-----------------------------------------+
- |
- system commands
- |
- V
- ~~~~~~
- ~ OS ~
- ~~~~~~
+parallel +----------+ +----------+ +----------+
+stateless | sensor_1 | | sensor_2 | ... | sensor_n |
+collectors +----------+ +----------+ +----------+
+ | | | |
+ data data data data
+ | | | |
+ V V V V
+serial +----------------------------------------------+
+stateful | controller |
+observer +----------------------------------------------+
+ |
+ decision messages
+decision |
+messages |
+copied to |
+any number |
+of interested |
+filter/actuator |
+combinations |
+ |
+ V
+ +-------------+-+---------+---------+
+ | | | |
+ V V V V
+parallel +------------+ +------------+ +------------+
+stateless | filter_1 | | filter_2 | ... | filter_n |
+filters +------------+ +------------+ +------------+
+ | | | |
+ V V V V
+parallel +------------+ +------------+ +------------+
+stateless | actuator_1 | | actuator_2 | ... | actuator_n |
+executors +------------+ +------------+ +------------+
+ | | | |
+ commands commands commands commands
+ | | | |
+ V V V V
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ ~~~~~~~~~~~~~ operating system ~~~~~~~~~~~~~~~~~
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
### Actuator
-By default, actuator is left disconnected from the controller's output, so if
+Actuator is anything that takes action upon controller messages. A few generic
+ones are included:
+
+- `khatus_actuate_alert_to_notify_send`
+- `khatus_actuate_status_bar_to_xsetroot_name`
+
+and, by default, are left disconnected from the controller's output, so if
desired - it needs to be manually attached when starting `khatus`. For example,
in my `.xinitrc` I have:
```sh
$BIN/khatus \
-2> >($BIN/twrap.sh >> $HOME/var/log/khatus.log) \
-| $BIN/khatus_actuator \
- -v pid="$$" \
- -v display=":0" \
-2> >($BIN/twrap.sh >> $HOME/var/log/khatus-actuator.log) \
+2> >($BIN/twrap >> $HOME/var/log/khatus.log) \
+| tee \
+ >($BIN/khatus_actuate_status_bar_to_xsetroot_name) \
+ >(grep -v MpdNowPlaying | $BIN/khatus_actuate_alert_to_notify_send) \
+2> >($BIN/twrap >> $HOME/var/log/khatus-actuators.log) \
&
```
+(where `twrap` is a simple script which prefixes a timestamp to each line)
-(`twrap.sh` is a simple script which prefixes a timestamp to each line)
-
-The idea is to later have multiple, (some more-general and some more-specific)
-actuators which can be selected as needed, say for example:
+The idea is to give maximum flexibility for what to do with the controller
+output, say, for instance:
```sh
$BIN/khatus \
| tee \
->(awk '/^STATUS_BAR/ {sub("^" $1 " *", ""); system("xsetroot -name \" " $0 " \"")}') \
+... \
>(grep '^REPORT' | actuate_report_to_email) \
>(grep '^ALERT' | grep mpd | actuate_alert_to_email) \
>(grep '^ALERT' | grep IntrusionAttempt | actuate_intruder_to_iptables_drop) \
>(grep '^ALERT' | grep NewDevice | actuate_alert_to_notify_send)
>(grep '^ALERT' | grep DiskError | actuate_call_mom)
+...
```
-
-... and/or any other such fun you might imagine.
+... and so on, for any other such fun you might imagine.
### Errors
Any errors encountered by any sensor are propagated as alerts by the
controller, which are in turn actualized as desktop notifications by the
-actuator:
+`khatus_actuate_alert_to_notify_send` actuator:
![screenshot-self-error-propagation](screenshot-self-error-propagation.jpg)
+++ /dev/null
-#! /usr/bin/awk -f
-
-BEGIN {
- n_ignored = split(opt_ignore_alerts_from, ignored, "[ \t\n]+")
- for (i = 1; i <= n_ignored; i++) {
- ignored_alert_sources[ignored[i]] = 1
- }
-}
-
-/^STATUS_BAR / { shift(); handle_status_bar(); next }
-/^ALERT / { shift(); handle_alert() ; next }
-/^ERROR / { shift(); handle_error() ; next }
-
-function handle_status_bar() {
- system("xsetroot -name \" " $0 "\" ")
-}
-
-function handle_alert( src, priority, subject, sep, body, urgency, dbg) {
- src = $1
- priority = $2
- subject = $3
- shift()
- shift()
- shift()
- body = $0
- sep = body ? "\n" : ""
- body = body sep "--" src
-
- urgency = priority
- sub("hi" , "critical", urgency)
- sub("med", "normal" , urgency)
-
- dbg["priority"] = priority
- dbg["urgency"] = urgency
- dbg["subject"] = subject
- dbg["body"] = body
- debug("ALERT properties", dbg)
-
- if (src in ignored_alert_sources) {
- debug("ALERT ignoring from " src, ignored_alert_sources)
- } else {
- debug("ALERT sending from " src, ignored_alert_sources)
- notify_send(urgency, subject, body)
- }
-}
-
-function handle_error() {
- notify_send("normal", "Khatus_Error", $0)
-}
-
-function notify_send(urgency, subject, body, cmd) {
- cmd = \
- sprintf(\
- "DISPLAY=%s notify-send -u %s %s \" %s\"",
- display, urgency, subject, body \
- )
- system(cmd)
-}
-
-function shift() {
- sub("^" $1 " +", "")
-}
-
-function debug(msg, data, sep, vals, key, payload) {
- sep = ""
- vals = ""
- for (key in data) {
- vals = sprintf("%s%s%s: \"%s\"", vals, sep, key, data[key])
- sep = ", "
- }
- payload = sprintf("[%s] [%s] [%s]", pid, msg, vals)
- print payload > "/dev/stderr"
-}