From 44d2cc15f7e69f6810eb0198253d8473c9e6c9c4 Mon Sep 17 00:00:00 2001
From: Andrew Gaul <andrew@gaul.org>
Date: Fri, 18 Sep 2020 08:12:47 +0900
Subject: [PATCH] Ensure environment variable is set when using ECS

Previously s3fs crashed when AWS_CONTAINER_CREDENTIALS_RELATIVE_URI
was not set.  References #1162.
---
 src/curl.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/curl.cpp b/src/curl.cpp
index b67142c..1e99519 100644
--- a/src/curl.cpp
+++ b/src/curl.cpp
@@ -2678,7 +2678,12 @@ int S3fsCurl::GetIAMCredentials()
 
     // url
     if(is_ecs){
-        url = std::string(S3fsCurl::IAM_cred_url) + std::getenv(ECS_IAM_ENV_VAR.c_str());
+        const char *env = std::getenv(ECS_IAM_ENV_VAR.c_str());
+        if(env == NULL){
+            S3FS_PRN_ERR("%s is not set.", ECS_IAM_ENV_VAR.c_str());
+            return -EIO;
+        }
+        url = std::string(S3fsCurl::IAM_cred_url) + env;
     }else{
         url = std::string(S3fsCurl::IAM_cred_url) + S3fsCurl::IAM_role;
     }