replace target: Add a target to replace part of an identifier..

..using regular expressions.

Possible future improvements: Use submatches in the replacement string,
similar to sed's \1, \2, ... back-references.

diff --git a/configure.in b/configure.in
index b7d989d8ce00d0511b114698fdc889cc7dee2680..3c7f9df278848a18d254fefd69a1c39b9844384c 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -3023,6 +3023,7 @@ AC_PLUGIN([swap],        [$plugin_swap],       [Swap usage statistics])
 AC_PLUGIN([syslog],      [$have_syslog],       [Syslog logging plugin])
 AC_PLUGIN([tail],        [yes],                [Parsing of logfiles])
 AC_PLUGIN([tape],        [$plugin_tape],       [Tape drive statistics])
+AC_PLUGIN([target_replace], [yes],             [The replace target])
 AC_PLUGIN([target_set],  [yes],                [The set target])
 AC_PLUGIN([tcpconns],    [$plugin_tcpconns],   [TCP connection statistics])
 AC_PLUGIN([teamspeak2],  [yes],                [TeamSpeak2 server statistics])
@@ -3201,6 +3202,7 @@ Configuration:
     syslog  . . . . . . . $enable_syslog
     tail  . . . . . . . . $enable_tail
     tape  . . . . . . . . $enable_tape
+    target_replace  . . . $enable_target_replace
     target_set  . . . . . $enable_target_set
     tcpconns  . . . . . . $enable_tcpconns
     teamspeak2  . . . . . $enable_teamspeak2

diff --git a/src/Makefile.am b/src/Makefile.am
index 35747e76b3f72587cfd2d180b07268eace325227..60b1cfb4e1e305d6767a342edc8a7542728d5d37 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -742,6 +742,14 @@ collectd_LDADD += "-dlopen" tape.la
 collectd_DEPENDENCIES += tape.la
 endif
 
+if BUILD_PLUGIN_TARGET_REPLACE
+pkglib_LTLIBRARIES += target_replace.la
+target_replace_la_SOURCES = target_replace.c
+target_replace_la_LDFLAGS = -module -avoid-version
+collectd_LDADD += "-dlopen" target_replace.la
+collectd_DEPENDENCIES += target_replace.la
+endif
+
 if BUILD_PLUGIN_TARGET_SET
 pkglib_LTLIBRARIES += target_set.la
 target_set_la_SOURCES = target_set.c

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index 55aa69b60345e7650781ff13ac1959529db312ba..0ffd48540ea1e782450cce1cd1d92c27f8bd059a 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -2787,6 +2787,42 @@ Example:
 
 =over 4
 
+=item B<replace>
+
+Replaces parts of the identifier using regular expressions.
+
+Available options:
+
+=over 4
+
+=item B<Host> I<Regex> I<Replacement>
+
+=item B<Plugin> I<Regex> I<Replacement>
+
+=item B<PluginInstance> I<Regex> I<Replacement>
+
+=item B<TypeInstance> I<Regex> I<Replacement>
+
+Match the appropriate field with the given regular expression I<Regex>. If the
+regular expression matches, that part that matches is replaced with
+I<Replacement>. If multiple places of the input buffer match a given regular
+expression, only the first occurrence will be replaced.
+
+You can specify each option multiple times to use multiple regular expressions
+one after another.
+
+=back
+
+Example:
+
+ <Target "replace">
+   # Replace "example.net" with "example.com"
+   Host "\\<example.net\\>" "example.com"
+ 
+   # Strip "www." from hostnames
+   Host "\\<www\\." ""
+ </Target>
+
 =item B<set>
 
 Sets part of the identifier of a value to a given string.

diff --git a/src/target_replace.c b/src/target_replace.c
new file mode 100644 (file)
index 0000000..6e72f31
--- /dev/null
+++ b/src/target_replace.c
@@ -0,0 +1,394 @@
+/**
+ * collectd - src/target_replace.c
+ * Copyright (C) 2008  Florian Forster
+ *
+ * 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:
+ *   Florian Forster <octo at verplant.org>
+ **/
+
+/*
+ * First tell the compiler to stick to the C99 and POSIX standards as close as
+ * possible.
+ */
+#ifndef __STRICT_ANSI__ /* {{{ */
+# define __STRICT_ANSI__
+#endif
+
+#ifndef _ISOC99_SOURCE
+# define _ISOC99_SOURCE
+#endif
+
+#ifdef _POSIX_C_SOURCE
+# undef _POSIX_C_SOURCE
+#endif
+#define _POSIX_C_SOURCE 200112L
+
+#if 0
+/* Single UNIX needed for strdup. */
+#ifdef _XOPEN_SOURCE
+# undef _XOPEN_SOURCE
+#endif
+#define _XOPEN_SOURCE 500
+#endif
+
+#ifndef _REENTRANT
+# define _REENTRANT
+#endif
+
+#ifndef _THREAD_SAFE
+# define _THREAD_SAFE
+#endif
+
+#ifdef _GNU_SOURCE
+# undef _GNU_SOURCE
+#endif
+/* }}} */
+
+#include "collectd.h"
+#include "common.h"
+#include "filter_chain.h"
+#include "utils_subst.h"
+
+#include <regex.h>
+
+struct tr_action_s;
+typedef struct tr_action_s tr_action_t;
+struct tr_action_s
+{
+  regex_t re;
+  char *replacement;
+  int may_be_empty;
+
+  tr_action_t *next;
+};
+
+struct tr_data_s
+{
+  tr_action_t *host;
+  tr_action_t *plugin;
+  tr_action_t *plugin_instance;
+  /* tr_action_t *type; */
+  tr_action_t *type_instance;
+};
+typedef struct tr_data_s tr_data_t;
+
+static char *tr_strdup (const char *orig) /* {{{ */
+{
+  size_t sz;
+  char *dest;
+
+  if (orig == NULL)
+    return (NULL);
+
+  sz = strlen (orig) + 1;
+  dest = (char *) malloc (sz);
+  if (dest == NULL)
+    return (NULL);
+
+  memcpy (dest, orig, sz);
+
+  return (dest);
+} /* }}} char *tr_strdup */
+
+static void tr_action_destroy (tr_action_t *act) /* {{{ */
+{
+  if (act == NULL)
+    return;
+
+  regfree (&act->re);
+  sfree (act->replacement);
+
+  if (act->next != NULL)
+    tr_action_destroy (act->next);
+
+  sfree (act);
+} /* }}} void tr_action_destroy */
+
+static int tr_config_add_action (tr_action_t **dest, /* {{{ */
+    const oconfig_item_t *ci, int may_be_empty)
+{
+  tr_action_t *act;
+  int status;
+
+  if (dest == NULL)
+    return (-EINVAL);
+
+  if ((ci->values_num != 2)
+      || (ci->values[0].type != OCONFIG_TYPE_STRING)
+      || (ci->values[1].type != OCONFIG_TYPE_STRING))
+  {
+    ERROR ("Target `replace': The `%s' option requires exactly two string "
+        "arguments.", ci->key);
+    return (-1);
+  }
+
+  act = (tr_action_t *) malloc (sizeof (*act));
+  if (act == NULL)
+  {
+    ERROR ("tr_config_add_action: malloc failed.");
+    return (-ENOMEM);
+  }
+  memset (act, 0, sizeof (*act));
+
+  act->replacement = NULL;
+  act->may_be_empty = may_be_empty;
+
+  status = regcomp (&act->re, ci->values[0].value.string, REG_EXTENDED);
+  if (status != 0)
+  {
+    char errbuf[1024] = "";
+
+    /* regerror assures null termination. */
+    regerror (status, &act->re, errbuf, sizeof (errbuf));
+    ERROR ("Target `replace': Compiling the regular expression `%s' "
+        "failed: %s.",
+        ci->values[0].value.string, errbuf);
+    sfree (act);
+    return (-EINVAL);
+  }
+
+  act->replacement = tr_strdup (ci->values[1].value.string);
+  if (act->replacement == NULL)
+  {
+    ERROR ("tr_config_add_action: tr_strdup failed.");
+    regfree (&act->re);
+    sfree (act);
+    return (-ENOMEM);
+  }
+
+  /* Insert action at end of list. */
+  if (*dest == NULL)
+    *dest = act;
+  else
+  {
+    tr_action_t *prev;
+
+    prev = *dest;
+    while (prev->next != NULL)
+      prev = prev->next;
+
+    prev->next = act;
+  }
+
+  return (0);
+} /* }}} int tr_config_add_action */
+
+static int tr_action_invoke (tr_action_t *act_head, /* {{{ */
+    char *buffer_in, size_t buffer_in_size, int may_be_empty)
+{
+  tr_action_t *act;
+  int status;
+  char buffer[DATA_MAX_NAME_LEN];
+  regmatch_t matches[8];
+
+  if (act_head == NULL)
+    return (-EINVAL);
+
+  sstrncpy (buffer, buffer_in, sizeof (buffer));
+  memset (matches, 0, sizeof (matches));
+
+  DEBUG ("target_replace plugin: tr_action_invoke: <- buffer = %s;", buffer);
+
+  for (act = act_head; act != NULL; act = act->next)
+  {
+    char temp[DATA_MAX_NAME_LEN];
+    char *subst_status;
+
+    status = regexec (&act->re, buffer,
+        STATIC_ARRAY_SIZE (matches), matches,
+        /* flags = */ 0);
+    if (status == REG_NOMATCH)
+      continue;
+    else if (status != 0)
+    {
+      char errbuf[1024] = "";
+
+      regerror (status, &act->re, errbuf, sizeof (errbuf));
+      ERROR ("Target `replace': Executing a regular expression failed: %s.",
+          errbuf);
+      continue;
+    }
+
+    subst_status = subst (temp, sizeof (temp), buffer,
+        matches[0].rm_so, matches[0].rm_eo, act->replacement);
+    if (subst_status == NULL)
+    {
+      ERROR ("Target `replace': subst (buffer = %s, start = %zu, end = %zu, "
+          "replacement = %s) failed.",
+          buffer, (size_t) matches[0].rm_so, (size_t) matches[0].rm_eo,
+          act->replacement);
+      continue;
+    }
+    sstrncpy (buffer, temp, sizeof (buffer));
+
+    DEBUG ("target_replace plugin: tr_action_invoke: -- buffer = %s;", buffer);
+  } /* for (act = act_head; act != NULL; act = act->next) */
+
+  if ((may_be_empty == 0) && (buffer[0] == 0))
+  {
+    WARNING ("Target `replace': Replacement resulted in an empty string, "
+        "which is not allowed for this buffer (`host' or `plugin').");
+    return (0);
+  }
+
+  DEBUG ("target_replace plugin: tr_action_invoke: -> buffer = %s;", buffer);
+  sstrncpy (buffer_in, buffer, buffer_in_size);
+
+  return (0);
+} /* }}} int tr_action_invoke */
+
+static int tr_destroy (void **user_data) /* {{{ */
+{
+  tr_data_t *data;
+
+  if (user_data == NULL)
+    return (-EINVAL);
+
+  data = *user_data;
+  if (data == NULL)
+    return (0);
+
+  tr_action_destroy (data->host);
+  tr_action_destroy (data->plugin);
+  tr_action_destroy (data->plugin_instance);
+  /* tr_action_destroy (data->type); */
+  tr_action_destroy (data->type_instance);
+  sfree (data);
+
+  return (0);
+} /* }}} int tr_destroy */
+
+static int tr_create (const oconfig_item_t *ci, void **user_data) /* {{{ */
+{
+  tr_data_t *data;
+  int status;
+  int i;
+
+  data = (tr_data_t *) malloc (sizeof (*data));
+  if (data == NULL)
+  {
+    ERROR ("tr_create: malloc failed.");
+    return (-ENOMEM);
+  }
+  memset (data, 0, sizeof (*data));
+
+  data->host = NULL;
+  data->plugin = NULL;
+  data->plugin_instance = NULL;
+  /* data->type = NULL; */
+  data->type_instance = NULL;
+
+  status = 0;
+  for (i = 0; i < ci->children_num; i++)
+  {
+    oconfig_item_t *child = ci->children + i;
+
+    if ((strcasecmp ("Host", child->key) == 0)
+        || (strcasecmp ("Hostname", child->key) == 0))
+      status = tr_config_add_action (&data->host, child,
+          /* may be empty = */ 0);
+    else if (strcasecmp ("Plugin", child->key) == 0)
+      status = tr_config_add_action (&data->plugin, child,
+          /* may be empty = */ 0);
+    else if (strcasecmp ("PluginInstance", child->key) == 0)
+      status = tr_config_add_action (&data->plugin_instance, child,
+          /* may be empty = */ 1);
+#if 0
+    else if (strcasecmp ("Type", child->key) == 0)
+      status = tr_config_add_action (&data->type, child,
+          /* may be empty = */ 0);
+#endif
+    else if (strcasecmp ("TypeInstance", child->key) == 0)
+      status = tr_config_add_action (&data->type_instance, child,
+          /* may be empty = */ 1);
+    else
+    {
+      ERROR ("Target `replace': The `%s' configuration option is not understood "
+          "and will be ignored.", child->key);
+      status = 0;
+    }
+
+    if (status != 0)
+      break;
+  }
+
+  /* Additional sanity-checking */
+  while (status == 0)
+  {
+    if ((data->host == NULL)
+        && (data->plugin == NULL)
+        && (data->plugin_instance == NULL)
+        /* && (data->type == NULL) */
+        && (data->type_instance == NULL))
+    {
+      ERROR ("Target `replace': You need to set at lease one of `Host', "
+          "`Plugin', `PluginInstance', `Type', or `TypeInstance'.");
+      status = -1;
+    }
+
+    break;
+  }
+
+  if (status != 0)
+  {
+    tr_destroy ((void *) &data);
+    return (status);
+  }
+
+  *user_data = data;
+  return (0);
+} /* }}} int tr_create */
+
+static int tr_invoke (const data_set_t *ds, value_list_t *vl, /* {{{ */
+    notification_meta_t **meta, void **user_data)
+{
+  tr_data_t *data;
+
+  if ((ds == NULL) || (vl == NULL) || (user_data == NULL))
+    return (-EINVAL);
+
+  data = *user_data;
+  if (data == NULL)
+  {
+    ERROR ("Target `replace': Invoke: `data' is NULL.");
+    return (-EINVAL);
+  }
+
+#define HANDLE_FIELD(f,e) \
+  if (data->f != NULL) \
+    tr_action_invoke (data->f, vl->f, sizeof (vl->f), e)
+  HANDLE_FIELD (host, 0);
+  HANDLE_FIELD (plugin, 0);
+  HANDLE_FIELD (plugin_instance, 1);
+  /* HANDLE_FIELD (type); */
+  HANDLE_FIELD (type_instance, 1);
+
+  return (FC_TARGET_CONTINUE);
+} /* }}} int tr_invoke */
+
+void module_register (void)
+{
+       target_proc_t tproc;
+
+       memset (&tproc, 0, sizeof (tproc));
+       tproc.create  = tr_create;
+       tproc.destroy = tr_destroy;
+       tproc.invoke  = tr_invoke;
+       fc_register_target ("replace", tproc);
+} /* module_register */
+
+/* vim: set sw=2 sts=2 tw=78 et fdm=marker : */
+