From e039c5634cd7b7271fe38cc8b64e68e6ab0cae5c Mon Sep 17 00:00:00 2001
From: Phillip Whelan <phillip.whelan@chronosphere.io>
Date: Wed, 23 Oct 2024 11:52:27 -0300
Subject: [PATCH] in_calyptia_fleet: fix registering agent after first
 invocation.

Signed-off-by: Phillip Whelan <phillip.whelan@chronosphere.io>
---
 plugins/in_calyptia_fleet/in_calyptia_fleet.c | 97 ++++++++++++++++++-
 1 file changed, 92 insertions(+), 5 deletions(-)

diff --git a/plugins/in_calyptia_fleet/in_calyptia_fleet.c b/plugins/in_calyptia_fleet/in_calyptia_fleet.c
index 0128733aed6..f61068ceede 100644
--- a/plugins/in_calyptia_fleet/in_calyptia_fleet.c
+++ b/plugins/in_calyptia_fleet/in_calyptia_fleet.c
@@ -117,6 +117,7 @@ static flb_sds_t fleet_config_filename(struct flb_in_calyptia_fleet_config *ctx,
 #define new_fleet_config_filename(a) fleet_config_filename((a), "new")
 #define cur_fleet_config_filename(a) fleet_config_filename((a), "cur")
 #define old_fleet_config_filename(a) fleet_config_filename((a), "old")
+#define hdr_fleet_config_filename(a) fleet_config_filename((a), "header")
 
 static int get_calyptia_files(struct flb_in_calyptia_fleet_config *ctx,
                               const char *url,
@@ -388,7 +389,6 @@ static int is_timestamped_fleet_config_path(struct flb_in_calyptia_fleet_config
     errno = 0;
     val = strtol(fname, &end, 10);
     if ((errno == ERANGE && (val == LONG_MAX || val == LONG_MIN)) || (errno != 0 && val == 0)) {
-        flb_errno();
         return FLB_FALSE;
     }
 
@@ -480,6 +480,23 @@ static int exists_old_fleet_config(struct flb_in_calyptia_fleet_config *ctx)
     return ret;
 }
 
+static int exists_header_fleet_config(struct flb_in_calyptia_fleet_config *ctx)
+{
+    int ret = FLB_FALSE;
+    flb_sds_t cfgheadername;
+
+    cfgheadername = hdr_fleet_config_filename(ctx);
+    if (cfgheadername == NULL) {
+        flb_plg_error(ctx->ins, "unable to allocate configuration name");
+        return FLB_FALSE;
+    }
+
+    ret = access(cfgheadername, F_OK) == 0 ? FLB_TRUE : FLB_FALSE;
+    flb_sds_destroy(cfgheadername);
+
+    return ret;
+}
+
 static void *do_reload(void *data)
 {
     struct reload_ctx *reload = (struct reload_ctx *)data;
@@ -1665,12 +1682,68 @@ static void fleet_config_get_properties(flb_sds_t *buf, struct mk_list *props)
     }
 }
 
+static flb_sds_t get_fleet_id_from_header(struct flb_in_calyptia_fleet_config *ctx)
+{
+    struct mk_list *head;
+    struct flb_cf_section *section;
+    flb_sds_t fleet_id;
+    flb_sds_t name;
+    struct flb_cf *cf_hdr;
+
+
+    if (exists_header_fleet_config(ctx)) {
+        cf_hdr = flb_cf_create_from_file(NULL, hdr_fleet_config_filename(ctx));
+
+        if (cf_hdr == NULL) {
+            flb_cf_destroy(cf_hdr);
+            return NULL;
+        }
+
+        mk_list_foreach(head, &cf_hdr->sections) {
+            section = mk_list_entry(head, struct flb_cf_section, _head);
+
+            if (strcasecmp(section->name, "custom") != 0) {
+                continue;
+            }
+
+            name = flb_cf_section_property_get_string(cf_hdr, section, "name");
+
+            if (!name) {
+                flb_plg_error(ctx->ins, "no name in fleet header");
+                flb_cf_destroy(cf_hdr);
+                return NULL;
+            }
+
+            if (strcasecmp(name, "calyptia") != 0) {
+                flb_sds_destroy(name);
+                continue;
+            }
+            flb_sds_destroy(name);
+
+            fleet_id = flb_cf_section_property_get_string(cf_hdr, section, "fleet_id");
+
+            if (!fleet_id) {
+                flb_plg_error(ctx->ins, "no fleet_id in fleet header");
+                flb_cf_destroy(cf_hdr);
+                return NULL;
+            }
+
+            flb_cf_destroy(cf_hdr);
+            return fleet_id;
+        }
+    }
+
+    flb_cf_destroy(cf_hdr);
+    return NULL;
+}
+
 flb_sds_t fleet_config_get(struct flb_in_calyptia_fleet_config *ctx)
 {
     flb_sds_t buf;
     struct mk_list *head;
     struct flb_custom_instance *c_ins;
     flb_ctx_t *flb = flb_context_get();
+    flb_sds_t fleet_id = NULL;
 
 
     buf = flb_sds_create_size(2048);
@@ -1679,7 +1752,6 @@ flb_sds_t fleet_config_get(struct flb_in_calyptia_fleet_config *ctx)
         return NULL;
     }
 
-    /* [INPUT] */
     mk_list_foreach(head, &flb->config->customs) {
         c_ins = mk_list_entry(head, struct flb_custom_instance, _head);
         if (strcasecmp(c_ins->p->name, "calyptia")) {
@@ -1690,8 +1762,21 @@ flb_sds_t fleet_config_get(struct flb_in_calyptia_fleet_config *ctx)
 
         fleet_config_get_properties(&buf, &c_ins->properties);
 
-        if (ctx->fleet_id && flb_config_prop_get("fleet_id", &c_ins->properties) == NULL) {
-            flb_sds_printf(&buf, "    fleet_id %s\n", ctx->fleet_id);
+        if (flb_config_prop_get("fleet_id", &c_ins->properties) == NULL) {
+            if (ctx->fleet_id != NULL) {
+                flb_sds_printf(&buf, "    fleet_id %s\n", ctx->fleet_id);
+            }
+            else {
+                fleet_id = get_fleet_id_from_header(ctx);
+
+                if (fleet_id == NULL) {
+                    flb_plg_error(ctx->ins, "unable to get fleet_id from header");
+                    return NULL;
+                }
+
+                flb_sds_printf(&buf, "    fleet_id %s\n", fleet_id);
+                flb_sds_destroy(fleet_id);
+            }
         }
     }
     flb_sds_printf(&buf, "\n");
@@ -2215,7 +2300,9 @@ static int in_calyptia_fleet_init(struct flb_input_instance *in,
     /* refresh calyptia settings before attempting to load the fleet
      * configuration file.
      */
-    create_fleet_header(ctx);
+    if (exists_header_fleet_config(ctx) == FLB_TRUE) {
+        create_fleet_header(ctx);
+    }
 
     /* if we load a new configuration then we will be reloaded anyways */
     if (load_fleet_config(ctx) == FLB_TRUE) {