in_systemd: add 'lowercase' option (#4908)

* in_systemd: add 'lowercase' option Signed-off-by: Chitoku <[email protected]>
fluent · Mar 4, 2022 · 6ab7380 · 6ab7380
1 parent a9b8753
commit 6ab7380
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Showing 3 changed files with 55 additions and 5 deletions.
diff --git a/plugins/in_systemd/systemd.c b/plugins/in_systemd/systemd.c
@@ -25,6 +25,8 @@
 #include "systemd_config.h"
 #include "systemd_db.h"
 
+#include <ctype.h>
+
 /* msgpack helpers to pack unsigned ints (it takes care of endianness */
 #define pack_uint16(buf, d) _msgpack_store16(buf, (uint16_t) d)
 #define pack_uint32(buf, d) _msgpack_store32(buf, (uint32_t) d)
@@ -73,6 +75,7 @@ static int in_systemd_collect(struct flb_input_instance *ins,
 {
     int ret;
     int ret_j;
+    int i;
     int len;
     int entries = 0;
     int skip_entries = 0;
@@ -82,10 +85,12 @@ static int in_systemd_collect(struct flb_input_instance *ins,
     uint8_t h;
     uint64_t usec;
     size_t length;
+    size_t threshold;
     const char *sep;
     const char *key;
     const char *val;
     char *tmp;
+    char *buf = NULL;
 #ifdef FLB_HAVE_SQLDB
     char *cursor = NULL;
 #endif
@@ -125,6 +130,17 @@ static int in_systemd_collect(struct flb_input_instance *ins,
         }
     }
 
+    if (ctx->lowercase == FLB_TRUE) {
+        ret = sd_journal_get_data_threshold(ctx->j, &threshold);
+        if (ret != 0) {
+            flb_plg_error(ctx->ins,
+                          "error setting up systemd data. "
+                          "sd_journal_get_data_threshold() return value '%i'",
+                          ret);
+            return FLB_SYSTEMD_ERROR;
+        }
+    }
+
     while ((ret_j = sd_journal_next(ctx->j)) > 0) {
         /* If the tag is composed dynamically, gather the Systemd Unit name */
         if (ctx->dynamic_tag) {
@@ -211,14 +227,36 @@ static int in_systemd_collect(struct flb_input_instance *ins,
                 key++;
                 length--;
             }
+
             sep = strchr(key, '=');
             if (sep == NULL) {
                 skip_entries++;
                 continue;
             }
+
             len = (sep - key);
             msgpack_pack_str(&mp_pck, len);
-            msgpack_pack_str_body(&mp_pck, key, len);
+
+            if (ctx->lowercase == FLB_TRUE) {
+                /*
+                 * Ensure buf to have enough space for the key because the libsystemd
+                 * might return larger data than the threshold.
+                 */
+                if (buf == NULL) {
+                    buf = flb_sds_create_len(NULL, threshold);
+                }
+                if (flb_sds_alloc(buf) < len) {
+                    buf = flb_sds_increase(buf, len - flb_sds_alloc(buf));
+                }
+                for (i = 0; i < len; i++) {
+                    buf[i] = tolower(key[i]);
+                }
+
+                msgpack_pack_str_body(&mp_pck, buf, len);
+            }
+            else {
+                msgpack_pack_str_body(&mp_pck, key, len);
+            }
 
             val = sep + 1;
             len = length - (sep - key) - 1;
@@ -276,6 +314,8 @@ static int in_systemd_collect(struct flb_input_instance *ins,
         }
     }
 
+    flb_sds_destroy(buf);
+
 #ifdef FLB_HAVE_SQLDB
     /* Save cursor */
     if (ctx->db) {
@@ -493,6 +533,11 @@ static struct flb_config_map config_map[] = {
       0, FLB_TRUE, offsetof(struct flb_systemd_config, read_from_tail),
       "Read the journal from the end (tail)"
     },
+    {
+      FLB_CONFIG_MAP_BOOL, "lowercase", "false",
+      0, FLB_TRUE, offsetof(struct flb_systemd_config, lowercase),
+      "Lowercase the fields"
+    },
     {
       FLB_CONFIG_MAP_BOOL, "strip_underscores", "false",
       0, FLB_TRUE, offsetof(struct flb_systemd_config, strip_underscores),

diff --git a/plugins/in_systemd/systemd_config.c b/plugins/in_systemd/systemd_config.c
@@ -151,16 +151,19 @@ struct flb_systemd_config *flb_systemd_config_create(struct flb_input_instance *
     if (ctx->filter_type) {
         if (strcasecmp(ctx->filter_type, "and") == 0) {
             journal_filter_is_and = FLB_TRUE;
-        } else if (strcasecmp(ctx->filter_type, "or") == 0) {
+        }
+        else if (strcasecmp(ctx->filter_type, "or") == 0) {
             journal_filter_is_and = FLB_FALSE;
-        } else {
+        }
+        else {
             flb_plg_error(ctx->ins,
                           "systemd_filter_type must be 'and' or 'or'. Got %s",
                           ctx->filter_type);
             flb_free(ctx);
             return NULL;
         }
-    } else {
+    }
+    else {
         journal_filter_is_and = FLB_FALSE;
     }
 
@@ -172,7 +175,8 @@ struct flb_systemd_config *flb_systemd_config_create(struct flb_input_instance *
             sd_journal_add_match(ctx->j, mv->val.str, 0);
             if (journal_filter_is_and) {
                 sd_journal_add_conjunction(ctx->j);
-            } else {
+            }
+            else {
                 sd_journal_add_disjunction(ctx->j);
             }
         }

diff --git a/plugins/in_systemd/systemd_config.h b/plugins/in_systemd/systemd_config.h
@@ -51,6 +51,7 @@ struct flb_systemd_config {
     struct mk_list *systemd_filters;
     int pending_records;
     int read_from_tail;  /* read_from_tail option */
+    int lowercase;
     int strip_underscores;
 
     /* Internal */