qmail plugin: Added a plugin to count messages in qmail queues.

Hello.
Here is my first collectd plugin.
It shows the two values of qmail queues, messages and todo.
The latter should be zero in normal cases. I included it because it
may help diagnose problems.
Maybe a config parameter could be added for it.

It supports a parameter for the Qmail base directory:

<Plugin qmail_queue>
       QmailDir "/var/qmail"
</Plugin>

Feel free to modify it if you need.
Alessandro

diff --git a/src/qmail.c b/src/qmail.c
new file mode 100644 (file)
index 0000000..5ae8d60
--- /dev/null
+++ b/src/qmail.c
@@ -0,0 +1,222 @@
+/**
+ * src/qmail_queue.c
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * Authors:
+ *   Alessandro Iurlano <alessandro.iurlano@gmail.com>
+ **/
+
+#include "collectd.h"
+#include "common.h"
+#include "plugin.h"       
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <dirent.h>
+
+
+
+static char * qmail_base_dir;
+
+static const char *config_keys[] =
+{
+        "QmailDir"
+};
+static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
+
+
+static void qmail_queue_submit (gauge_t queued_messages, gauge_t todo_messages)
+{
+  value_t values[1];
+  value_list_t vl = VALUE_LIST_INIT;
+
+  values[0].gauge = queued_messages;
+
+  vl.values = values;
+  vl.values_len = STATIC_ARRAY_SIZE (values);
+  vl.time = time (NULL);
+  strcpy (vl.host, hostname_g);
+  strcpy (vl.plugin, "qmail_queue");
+  strncpy (vl.plugin_instance, "messages",
+          sizeof (vl.plugin_instance));
+
+
+  plugin_dispatch_values ("gauge", &vl);
+
+  values[0].gauge = todo_messages;
+
+  vl.values = values;
+  vl.values_len = STATIC_ARRAY_SIZE (values);
+  vl.time = time (NULL);
+  strcpy (vl.host, hostname_g);
+  strcpy (vl.plugin, "qmail_queue");
+  strncpy (vl.plugin_instance, "todo",
+          sizeof (vl.plugin_instance));
+
+  plugin_dispatch_values ("gauge", &vl);
+}
+
+#define MAX_PATH_LEN 4096
+
+static int count_files_in_dir(char * path) {
+  char *buf, *ebuf, *cp;
+  off_t base;
+  size_t bufsize;
+  int fd, nbytes;
+  struct stat sb;
+  struct dirent *dp;
+  int count=0;
+
+  if ((fd = open(path, O_RDONLY)) < 0) {
+    ERROR("cannot open %s", path);
+    return -1;
+  }
+  if (fstat(fd, &sb) < 0) {
+    ERROR("fstat");
+    return -1;
+  }
+  bufsize = sb.st_size;
+  if (bufsize < sb.st_blksize)
+    bufsize = sb.st_blksize;
+  if ((buf = malloc(bufsize)) == NULL) {
+    ERROR("cannot malloc %lu bytes", (unsigned long)bufsize);
+    return -1;
+  }
+  while ((nbytes = getdirentries(fd, buf, bufsize, &base)) > 0) {
+    ebuf = buf + nbytes;
+    cp = buf;
+    while (cp < ebuf) {
+      dp = (struct dirent *)cp;
+      if ( (dp->d_fileno!=0) && (dp->d_type!=DT_DIR) ) {
+       count++;
+      }
+      /*
+       if (dp->d_fileno != 0)
+       printf("%s\n", dp->d_name);*/
+      cp += dp->d_reclen;
+    }
+  }
+  if (nbytes < 0) {
+    ERROR("getdirentries");
+    return -1;
+  }
+  free(buf);
+  close(fd);
+
+  return count;
+}
+static int count_files_in_tree(char * path) {
+
+  char *buf, *ebuf, *cp;
+  off_t base;
+  size_t bufsize;
+  int fd, nbytes;
+  struct stat sb;
+  struct dirent *dp;
+  int files_in_tree=0;
+  int path_len=strlen(path);
+  if ((fd = open(path, O_RDONLY)) < 0) {
+    WARNING("cannot open %s", path);
+    return -1;
+  }
+  if (fstat(fd, &sb) < 0) {
+    WARNING( "fstat");
+    return -1;
+  }
+  bufsize = sb.st_size;
+  if (bufsize < sb.st_blksize)
+    bufsize = sb.st_blksize;
+  if ((buf = malloc(bufsize)) == NULL) {
+    ERROR("cannot malloc %lu bytes", (unsigned long)bufsize);
+    return -1;
+  }
+  while ((nbytes = getdirentries(fd, buf, bufsize, &base)) > 0) {
+    ebuf = buf + nbytes;
+    cp = buf;
+    while (cp < ebuf) {
+      int ret_value;
+      dp = (struct dirent *)cp;
+      //WARNING("Looking file %s\n", dp->d_name);
+      if ((dp->d_fileno!=0) && (dp->d_type==DT_DIR) && strcmp(dp->d_name,".") && strcmp(dp->d_name,"..") ) {
+       snprintf(path+path_len,MAX_PATH_LEN-path_len,"%s",dp->d_name);
+       ret_value=count_files_in_dir(path);
+       if (ret_value!=-1)
+         files_in_tree+=ret_value;
+       else
+         return -1;
+      }
+      /*
+       if (dp->d_fileno != 0)
+       printf("%s\n", dp->d_name);*/
+      cp += dp->d_reclen;
+    }
+  }
+  if (nbytes < 0) {
+    ERROR("getdirentries");
+    return -1;
+  }
+  free(buf);
+  close(fd);
+  return files_in_tree;  
+}
+
+static int queue_len_read (void)
+{
+  char path[MAX_PATH_LEN];
+  int path_len;
+  //  struct dirent *root_entry, *node_entry;
+  int messages_in_queue, messages_todo;
+  
+  messages_in_queue=0;
+  messages_todo=0;
+  snprintf(path,MAX_PATH_LEN,"%s/queue/mess/",qmail_base_dir);
+  //WARNING("PATH TO READ: %s\n",path);
+  path_len=strlen(path);
+  if (path[path_len]!='/') {
+    strcat(path,"/");
+    path_len=strlen(path);
+  }
+
+  messages_in_queue=count_files_in_tree(path);
+
+  snprintf(path,MAX_PATH_LEN,"%s/queue/todo/",qmail_base_dir);
+  //WARNING("PATH TO READ: %s\n",path);
+  messages_todo=count_files_in_tree(path);
+  if ( (messages_todo!=-1) && (messages_in_queue!=-1) ) {
+    qmail_queue_submit(messages_in_queue,messages_todo);
+    return 0;
+  }
+  else return -1;
+}
+
+static int qmail_config (const char *key, const char *val)
+{
+   if (strcasecmp ("QmailDir", key) == 0)
+     {
+        free(qmail_base_dir);
+        qmail_base_dir=strdup(val);
+       WARNING("Setting Qmail base dir to %s\n", qmail_base_dir);
+     }
+}
+
+void module_register (void)
+{
+  qmail_base_dir=strdup("/var/qmail");
+  plugin_register_config ("qmail_queue", qmail_config,
+                        config_keys, config_keys_num);
+ 
+  plugin_register_read ("qmail_queue", queue_len_read);
+} /* void module_register */