From 9f1305b72b577899a8ee42fa7f044d186bcae5e4 Mon Sep 17 00:00:00 2001
From: dave <dave@davepedu.com>
Date: Sun, 22 Jul 2018 15:38:42 -0700
Subject: [PATCH] check elasticsearch before starting up

---
 src/elasticsearch.c | 36 ++++++++++++++++++++++++++++++------
 src/elasticsearch.h |  4 ++--
 src/server.c        |  5 ++++-
 3 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/src/elasticsearch.c b/src/elasticsearch.c
index 4cbcdcd..d8f2628 100644
--- a/src/elasticsearch.c
+++ b/src/elasticsearch.c
@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include <string.h>
 #include <curl/curl.h>
 
@@ -8,7 +9,7 @@ size_t write_data(char *dbit, size_t size, size_t nmemb, void *user_data) {
 }
 
 
-int put_events(char* data, char* es_url) {  // es_url should be a string like 'http://192.168.1.120:8298'
+int elastic_put_events(char* data, char* es_url) {  // es_url should be a string like 'http://192.168.1.120:8298'
     CURL *curl;
     CURLcode res;
 
@@ -34,10 +35,33 @@ int put_events(char* data, char* es_url) {  // es_url should be a string like 'h
     curl_easy_cleanup(curl);
     curl_global_cleanup();
 
-    if(res != CURLE_OK) {
-        // printf("%d %s\n", res, response);
-        printf("CURL returned: %d\n", res);
-    }
+    if(res != CURLE_OK)
+        printf("CURL: %s\n", curl_easy_strerror(res));
 
-    return res == CURLE_OK ? 0 : 1;
+    return res == CURLE_OK ? EXIT_SUCCESS : EXIT_FAILURE;
+}
+
+
+int elastic_check(char* es_url) {
+    CURL *curl;
+    CURLcode res;
+
+    char* endpoint = "/_cluster/health";
+    char final_url[strlen(es_url) + strlen(endpoint) + 1];
+    sprintf(final_url, "%s%s", es_url, endpoint);
+
+    curl = curl_easy_init(); // check this and all of these curl functions
+
+    curl_easy_setopt(curl, CURLOPT_URL, final_url);
+    curl_easy_setopt(curl, CURLOPT_TIMEOUT, 15);
+    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);\
+
+    res = curl_easy_perform(curl);
+    curl_easy_cleanup(curl);
+    curl_global_cleanup();
+
+    if(res != CURLE_OK)
+        printf("CURL: %s\n", curl_easy_strerror(res));
+
+    return res == CURLE_OK ? EXIT_SUCCESS : EXIT_FAILURE;
 }
diff --git a/src/elasticsearch.h b/src/elasticsearch.h
index 7d921a9..d11bd31 100644
--- a/src/elasticsearch.h
+++ b/src/elasticsearch.h
@@ -1,2 +1,2 @@
-void test_curl();
-int put_events(char* data, char* es_url);
+int elastic_put_events(char* data, char* es_url);
+int elastic_check(char* es_url);
diff --git a/src/server.c b/src/server.c
index 12c3142..ce26e8a 100644
--- a/src/server.c
+++ b/src/server.c
@@ -41,7 +41,7 @@ void sig_handler(int signum) {
 
 
 int submit_events(char* message) {
-    if(put_events(message, es_url) == 0) {
+    if(elastic_put_events(message, es_url) == 0) {
         return 0;
     } else {
         printf("Failed to post messages!\n");
@@ -220,6 +220,9 @@ int run_server(int port, char* url) {
     signal(SIGTERM, sig_handler);
     signal(SIGINT, sig_handler);
 
+    if(elastic_check(url) != EXIT_SUCCESS)
+        die("Failed to contact elasticsearch");
+
     geo_init();
     es_url = url;