Dvc remote default in list validation

dvc/command/remote.py

@@ -85,7 +85,18 @@ def run(self):
                 if self.args.unset:
                     conf["core"].pop("remote", None)
                 else:
-                    conf["core"]["remote"] = self.args.name
+                    merged_conf = self.config.load_config_to_level(
+                        self.args.level
+                    )
+                    if (
+                        self.args.name in conf["remote"]
+                        or self.args.name in merged_conf["remote"]
+                    ):
+                        conf["core"]["remote"] = self.args.name
+                    else:
+                        raise ConfigError(
+                            "default remote must be present in remote list."
+                        )
         return 0
 
 

dvc/config.py

@@ -278,7 +278,7 @@ def load(self, validate=True):
         Raises:
             ConfigError: thrown if config has an invalid format.
         """
-        conf = self._load_config_to_level()
+        conf = self.load_config_to_level()
 
         if validate:
             conf = self.validate(conf)
@@ -330,7 +330,7 @@ def _map_dirs(conf, func):
         dirs_schema = {"cache": {"dir": func}, "remote": {str: {"url": func}}}
         return Schema(dirs_schema, extra=ALLOW_EXTRA)(conf)
 
-    def _load_config_to_level(self, level=None):
+    def load_config_to_level(self, level=None):
         merged_conf = {}
         for merge_level in self.LEVELS:
             if merge_level == level:
@@ -349,7 +349,7 @@ def edit(self, level="repo"):
 
         conf = self._save_paths(conf, self.files[level])
 
-        merged_conf = self._load_config_to_level(level)
+        merged_conf = self.load_config_to_level(level)
         _merge(merged_conf, conf)
         self.validate(merged_conf)
 

tests/func/test_remote.py

@@ -121,6 +121,7 @@ def test(self):
 
 
 def test_show_default(dvc, capsys):
+    assert main(["remote", "add", "foo", "s3://bucket/name"]) == 0
     assert main(["remote", "default", "foo"]) == 0
     assert main(["remote", "default"]) == 0
     out, _ = capsys.readouterr()
@@ -270,3 +271,21 @@ def test_remote_modify_validation(dvc):
     )
     config = configobj.ConfigObj(dvc.config.files["repo"])
     assert unsupported_config not in config['remote "{}"'.format(remote_name)]
+
+
+def test_remote_modify_default(dvc):
+    remote_repo = "repo_level"
+    remote_local = "local_level"
+    wrong_name = "anything"
+    assert main(["remote", "add", remote_repo, "s3://bucket/repo"]) == 0
+    assert main(["remote", "add", remote_local, "s3://bucket/local"]) == 0
+
+    assert main(["remote", "default", wrong_name]) == 251
+    assert main(["remote", "default", remote_repo]) == 0
+    assert main(["remote", "default", "--local", remote_local]) == 0
+
+    repo_config = configobj.ConfigObj(dvc.config.files["repo"])
+    local_config = configobj.ConfigObj(dvc.config.files["local"])
+
+    assert repo_config["core"]["remote"] == remote_repo
+    assert local_config["core"]["remote"] == remote_local