New configuration statement authentication-provide

* NEWS: Update.
* src/config.c: New statement "authentication-provider"
* src/eclat.c (authentication_provider): New variable.
(main): Select credentials depending on the value of
authentication_provider.
* src/eclat.h (authentication_provider): New enum and extern.

1 files changed, 23 insertions, 10 deletions

diff --git a/src/eclat.c b/src/eclat.c
index 5bbe7c4..67b20dd 100644
--- a/src/eclat.c
+++ b/src/eclat.c
@@ -24,6 +24,8 @@ int preprocess_only = 0;
 
 char *endpoint = "ec2.amazonaws.com";
 char *signature_version = "2";
+
+enum authentication_provider authentication_provider = authp_undefined;
 char *access_key;
 char *secret_key;
 char *security_token;
@@ -769,18 +771,29 @@ main(int argc, char **argv)
 	if (!endpoint) 			
 		die(EX_USAGE,
 		    "cannot find endpoint for region %s", region_name);
-	
-	if (!secret_key) {
+
+	if (access_key && secret_key)
+		authentication_provider = authp_immediate;
+
+	switch (authentication_provider) {
+	case authp_undefined:
+		die(EX_USAGE, "cannot find authentication credentials");
+		
+	case authp_immediate:
+		break;
+		
+	case authp_file:
 		if (get_access_creds(access_key, &access_key, &secret_key)) {
-			if (!access_key)
-				die(EX_UNAVAILABLE,
-				    "cannot find authentication credentials");
-			else
-				eclat_get_instance_creds(access_key,
-							 &access_key,
-							 &secret_key,
-							 &security_token);
+			die(EX_UNAVAILABLE,
+			    "cannot find authentication credentials");
 		}
+		break;
+		
+	case authp_instance:
+		eclat_get_instance_creds(access_key,
+					 &access_key,
+					 &secret_key,
+					 &security_token);
 	}
 	debug(ECLAT_DEBCAT_MAIN, 1, ("using access key %s", access_key));