pythonprobe: don't use inotify

Don't wait for new payload via inotify, let systemd path unit
detect any new payloads in /usr/lib/telemetry/python and start
the pythonprobe service.
Also set the sticky bit for the above folder, preventing users to
modify permissions.

Signed-off-by: Juro Bystricky <juro.bystricky@intel.com>

scripts/telemctl

@@ -6,7 +6,7 @@ declare -a SPECIAL_UNITS=(
   telempostd.path
   klogscanner.service
   journal-probe.service
-  python-probe.service
+  python-probe.path
 )
 
 declare -a SERVICES=(

src/data/local.mk

@@ -17,6 +17,7 @@ EXTRA_DIST += \
 	%D%/bert-probe.service.in \
 	%D%/journal-probe.service.in \
 	%D%/python-probe.service.in \
+	%D%/python-probe.path.in \
 	%D%/pstore-probe.service.in \
 	%D%/klogscanner.service.in \
 	%D%/pstore-clean.service.in \
@@ -54,6 +55,7 @@ systemdunit_DATA = \
 	%D%/bert-probe.service \
 	%D%/journal-probe.service \
 	%D%/python-probe.service \
+	%D%/python-probe.path \
 	%D%/pstore-probe.service \
 	%D%/klogscanner.service \
 	%D%/pstore-clean.service \
@@ -90,6 +92,9 @@ systemdunit_DATA = \
 %D%/python-probe.service: %D%/python-probe.service.in
 	$(pathfix) < $< > $@
 
+%D%/python-probe.path: %D%/python-probe.path.in
+	$(pathfix) < $< > $@
+
 %D%/telemprobd.service: %D%/telemprobd.service.in
 	$(pathfix) < $< > $@
 
@@ -114,6 +119,7 @@ clean-local:
 		%D%/telempostd.service \
 		%D%/telempostd.path \
 		%D%/python-probe.service \
+		%D%/python-probe.path \
 		%D%/telemprobd-update-trigger.service \
 		%D%/telemetrics.conf \
 		%D%/telemetrics-dirs.conf \

src/data/python-probe.path.in

@@ -0,0 +1,9 @@
+[Unit]
+Description=Python Probe Daemon Staging
+ConditionPathExists=!/etc/telemetrics/opt-out
+
+[Path]
+DirectoryNotEmpty=@localstatedir@/lib/telemetry/python
+
+[Install]
+WantedBy=multi-user.target

src/data/telemetrics-dirs.conf.in

@@ -1,5 +1,5 @@
 d @localstatedir@/lib/telemetry 0755 telemetry telemetry -
-d @localstatedir@/lib/telemetry/python 0777 telemetry telemetry -
+d @localstatedir@/lib/telemetry/python 01777 telemetry telemetry -
 d @localstatedir@/spool/telemetry 0750 telemetry telemetry -
 d @localstatedir@/log/telemetry 0750 telemetry telemetry -
 d @localstatedir@/log/telemetry/records 0750 telemetry telemetry -

src/probes/python-probe.c

@@ -221,71 +221,6 @@ static void drop_privs(void)
         assert(getegid() == pw->pw_gid);
 }
 
-static void handle_inotify_event(const struct inotify_event *event)
-{
-        if (!event) {
-                telem_perror("Null event received");
-                return;
-        }
-
-        if (event->len == 0) {
-                telem_perror("inotify event received with no file.");
-                return;
-        }
-
-        if (event->mask & IN_MOVED_TO) {
-                if (event->mask & IN_ISDIR) {
-                        return;
-                }
-
-                #ifdef DEBUG
-                telem_log(LOG_DEBUG, "New file moved to the monitored location: %s\n", event->name);
-                #endif
-                deliver_payload(event->name);
-        }
-}
-
-static void wait_for_payload(void)
-{
-        int inotify_fd;
-        char buf[4096];
-        char *ptr = NULL;
-        ssize_t len;
-        const struct inotify_event *event;
-
-        inotify_fd = inotify_init();
-        if (inotify_fd == -1) {
-                telem_log(LOG_ERR, "Failed to create inotify instance: %s\n", strerror(errno));
-                exit(EXIT_FAILURE);
-        }
-
-        if (inotify_add_watch(inotify_fd, PYTHON_TELEMETRY_DIR, IN_MOVED_TO) == -1) {
-                telem_perror("Error adding watch to the inotify instance");
-        }
-
-        while (true) {
-                len = read(inotify_fd, buf, sizeof buf);
-                if (len <= 0) {
-                        telem_perror("error reading event");
-                        continue;
-                }
-
-                if (len < sizeof(struct inotify_event)) {
-                        telem_perror("Incomplete event received");
-                        continue;
-                }
-
-                /* Loop over all events in the buffer */
-                for (ptr = buf; ptr < buf + len;
-                     ptr += sizeof(struct inotify_event) + event->len) {
-
-                        event = (const struct inotify_event *)ptr;
-                        /* handle the event */
-                        handle_inotify_event(event);
-                }
-        }
-}
-
 static void print_usage(char *prog)
 {
         printf("%s: Usage\n", prog);
@@ -354,8 +289,5 @@ int main(int argc, char **argv)
         }
 
         closedir(dir);
-
-        /* Wait for any new python exception files to appear */
-        wait_for_payload();
         exit(EXIT_SUCCESS);
 }