in_calyptia_fleet: fleet config fetch ignores older-timestamped files

plugins/in_calyptia_fleet/in_calyptia_fleet.c

@@ -64,6 +64,7 @@ static int fleet_cur_chdir(struct flb_in_calyptia_fleet_config *ctx);
 static int get_calyptia_files(struct flb_in_calyptia_fleet_config *ctx,
                               time_t timestamp);
 static void in_calyptia_fleet_destroy(struct flb_in_calyptia_fleet_config *ctx);
+static struct cfl_array *read_glob(const char *path);
 
 #ifndef FLB_SYSTEM_WINDOWS
 
@@ -965,6 +966,93 @@ static int get_calyptia_fleet_id_by_name(struct flb_in_calyptia_fleet_config *ct
     return 0;
 }
 
+/**
+ * Checks for existing config files having timestamps at or after new_timestamp.
+ * @param ctx Fleet configuration context
+ * @param new_timestamp Timestamp to compare against existing files
+ * @return FLB_TRUE if new_timestamp is newer than all existing files, FLB_FALSE otherwise.
+ */
+static int check_timestamp_is_newer(struct flb_in_calyptia_fleet_config *ctx, time_t new_timestamp)
+{
+    flb_sds_t base_dir = NULL;
+    flb_sds_t glob_pattern = NULL;
+    struct cfl_array *files = NULL;
+    size_t idx;
+    int ret;
+    long file_timestamp;
+    char *ext;
+    char *fname;
+    char *path_copy = NULL;
+    const char *file_extension;
+
+    if (generate_base_fleet_directory(ctx, &base_dir) == NULL) {
+        return FLB_FALSE;
+    }
+
+    /* Create glob pattern to match all timestamped files */
+    glob_pattern = flb_sds_create_size(0);
+    if (glob_pattern == NULL) {
+        flb_sds_destroy(base_dir);
+        return FLB_FALSE;
+    }
+
+    file_extension = ctx->fleet_config_legacy_format ? "*.conf" : "*.yaml";
+    glob_pattern = flb_sds_printf(&glob_pattern, "%s" PATH_SEPARATOR "%s", base_dir, file_extension);
+
+    files = read_glob(glob_pattern);
+    if (files == NULL) {
+        /* No existing files found - could be empty directory or glob failure */
+        flb_plg_debug(ctx->ins, "no existing config files found in %s", base_dir);
+        flb_sds_destroy(base_dir);
+        flb_sds_destroy(glob_pattern);
+        return FLB_TRUE;
+    }
+
+    /* Check each existing file's timestamp */
+    ret = FLB_TRUE;
+    for (idx = 0; idx < files->entry_count; idx++) {
+        /* Create a copy to avoid basename() modifying the original path */
+        path_copy = flb_strdup(files->entries[idx]->data.as_string);
+        if (path_copy == NULL) {
+            ret = FLB_FALSE;
+            break;
+        }
+
+        fname = basename(path_copy);
+        if (fname == NULL) {
+            flb_free(path_copy);
+            ret = FLB_FALSE;
+            break;
+        }
+
+        errno = 0;
+        ext = NULL;
+        file_timestamp = strtol(fname, &ext, 10);
+        flb_free(path_copy);
+        fname = NULL;
+        if ((errno == ERANGE && (file_timestamp == LONG_MAX || file_timestamp == LONG_MIN)) ||
+            (errno != 0 && file_timestamp == 0)) {
+            /* Skip files that don't have valid timestamps */
+            continue;
+        }
+
+        /* Check if existing file timestamp is greater than or equal to new timestamp */
+        if (file_timestamp >= (long)new_timestamp) {
+            flb_plg_debug(ctx->ins,
+                          "existing file with timestamp %ld >= new timestamp %ld",
+                          file_timestamp, (long)new_timestamp);
+            ret = FLB_FALSE;
+            break;
+        }
+    }
+
+    cfl_array_destroy(files);
+    flb_sds_destroy(base_dir);
+    flb_sds_destroy(glob_pattern);
+
+    return ret;
+}
+
 static int get_calyptia_file(struct flb_in_calyptia_fleet_config *ctx,
                              flb_sds_t url,
                              const char *hdr,
@@ -1002,6 +1090,18 @@ static int get_calyptia_file(struct flb_in_calyptia_fleet_config *ctx,
         flb_strptime(fbit_last_modified, "%a, %d %B %Y %H:%M:%S GMT", &tm_last_modified);
         last_modified = mktime(&tm_last_modified.tm);
 
+        /* Check if there are existing files with timestamps >= new timestamp */
+        if (check_timestamp_is_newer(ctx, last_modified) == FLB_FALSE) {
+            flb_plg_debug(ctx->ins, "not creating file with timestamp %ld since it is not newer than existing files",
+                         (long)last_modified);
+            ret = -1;
+            goto client_error;
+        }
+        else {
+            flb_plg_info(ctx->ins, "creating config file with timestamp %ld",
+                         (long)last_modified);
+        }
+
         fname = time_fleet_config_filename(ctx, last_modified);
     }
     else {