From 0766417065bfec9747bf0f41f9b68c27e378f817 Mon Sep 17 00:00:00 2001
From: Sergey Poznyakoff <gray@gnu.org.ua>
Date: Sun, 18 Jan 2015 13:29:25 +0200
Subject: If no region is specified, get it from the instance store

* src/eclat.c: If no region is specified, try to get it
from the instance store.
* src/eclat.h (eclat_trace_fun): New proto.
(eclat_get_instance_zone): New proto.
* src/io.c (eclat_trace_fun): Remove static qualifier.
* src/util.c (eclat_get_instance_meta_data): New function.
(eclat_get_instance_zone): New function.
---
 src/util.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)

(limited to 'src/util.c')

diff --git a/src/util.c b/src/util.c
index 641d304..f70f70a 100644
--- a/src/util.c
+++ b/src/util.c
@@ -367,3 +367,104 @@ canonattrname(char **attrs, const char *arg, char *delim, size_t *plen)
 	return NULL;
 }
 	
+static size_t
+get_meta_data_cb(void *ptr, size_t size, size_t nmemb, void *data)
+{
+	size_t realsize = size * nmemb;
+	char *v;
+
+	if (debug_level(ECLAT_DEBCAT_MAIN) >= 10)
+		debug_printf("Got %*.*s", realsize, realsize, ptr);
+
+	v = grecs_malloc(realsize + 1);
+	memcpy(v, ptr, realsize);
+	v[realsize] = 0;
+	*(char**)data = v;
+	return realsize;
+}
+
+char *
+eclat_get_instance_meta_data(char *url)
+{
+	CURLcode res;
+	CURL *curl = curl_easy_init();
+	char *retval = NULL;
+	long http_resp;
+		
+	if (!curl)
+		die(EX_UNAVAILABLE, "curl_easy_init failed");
+	
+	if (debug_level(ECLAT_DEBCAT_CURL)) {
+		curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
+		if (debug_level(ECLAT_DEBCAT_CURL) > 1)
+			curl_easy_setopt(curl, CURLOPT_DEBUGFUNCTION,
+					 eclat_trace_fun);
+	}
+
+	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, get_meta_data_cb);
+	curl_easy_setopt(curl, CURLOPT_WRITEDATA, &retval);
+
+	curl_easy_setopt(curl, CURLOPT_URL, url);
+	
+	res = curl_easy_perform(curl);
+
+	if (res != CURLE_OK)
+		die(EX_UNAVAILABLE, "CURL: %s", curl_easy_strerror(res));
+
+	res = curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &http_resp);
+	if (res != CURLE_OK)
+		die(EX_UNAVAILABLE, "CURL: %s", curl_easy_strerror(res));
+
+	if (http_resp != 200)
+		die(EX_UNAVAILABLE, "CURL: unexpected error code %3ld", res);
+
+	curl_easy_cleanup(curl);
+
+	return retval;
+}
+
+#define URL_INST_DOCUMENT\
+	"http://169.254.169.254/latest/dynamic/instance-identity/document"
+
+char *
+eclat_get_instance_zone()
+{
+	char *doc;
+	char *retval = NULL;
+	struct wordsplit ws;
+	size_t i;
+	int lev;
+	
+	doc = eclat_get_instance_meta_data(URL_INST_DOCUMENT);
+	
+	if (wordsplit(doc, &ws,
+		      WRDSF_NOVAR | WRDSF_NOCMD |
+		      WRDSF_SQUEEZE_DELIMS |
+		      WRDSF_DQUOTE)) {
+		die(EX_UNAVAILABLE, "wordsplit: %s", wordsplit_strerror(&ws));
+	}
+	free(doc);
+	
+	lev = 0;
+	for (i = 0; i < ws.ws_wordc; i++) {
+		if (strcmp(ws.ws_wordv[i], "{") == 0)
+			++lev;
+		else if (strcmp(ws.ws_wordv[i], "}") == 0)
+			--lev;
+		else if (lev == 1 && strcmp(ws.ws_wordv[i], "region") == 0) {
+			if (i + 2 < ws.ws_wordc &&
+			    strcmp(ws.ws_wordv[i+1], ":") == 0) {
+				size_t len;
+
+				retval = grecs_strdup(ws.ws_wordv[i+2]);
+				len = strlen(retval);
+				if (retval[len-1] == ',')
+					retval[len-1] = 0;
+				break;
+			}
+		}
+	}
+	wordsplit_free(&ws);
+	
+	return retval;
+}
-- 
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