Make the exporter listen on IPv6.

.gitignore

@@ -0,0 +1 @@
+exporter

exporter.c

@@ -0,0 +1,32 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define USER "odoo"
+#define HTTP_PORT 9402
+#define INTERVAL 10
+
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    fprintf(stdout, "Invalid number of arguments. Usage: %s [dbname]\n",
+            argv[0]);
+    exit(EXIT_FAILURE);
+  }
+
+  /* Setup database connection parameters */
+  char connstring[STRLEN];
+  sprintf(connstring, "database = %s, user = %s", argv[1], USER);
+
+  /* Connect to the database */
+  PGconn *conn = PQconnectdb(connstring);
+
+  if (conn == NULL) {
+    fprintf(stderr, "Out of memory connecting the PostgreSQL\n.");
+    exit(EXIT_FAILURE);
+  } else if (PQstatus(conn) != CONNECTION_OK) {
+    fprintf(stderr, PQerrorMessage(conn));
+    PQfinish(conn);
+    exit(EXIT_FAILURE);
+  }
+
+  return EXIT_SUCCESS;
+}

prometheus-odoo-license-exporter

@@ -10,6 +10,7 @@ import sys
 
 
 USER = "odoo"
+HTTP_HOST = "::"
 HTTP_PORT = 9402
 INTERVAL = 10
 
@@ -26,7 +27,7 @@ if __name__ == '__main__':
             "Remaining days before Odoo license expiration")
 
     # Serve metrics over HTTP
-    start_http_server(HTTP_PORT)
+    start_http_server(host=HTTP_HOST, port=HTTP_PORT)
 
     # Open connection
     with psycopg2.connect(database=DBNAME, user=USER) as conn: