diff --git a/swh/objstorage/api/server.py b/swh/objstorage/api/server.py
--- a/swh/objstorage/api/server.py
+++ b/swh/objstorage/api/server.py
@@ -206,8 +206,6 @@
 
     Args:
         config_file (str): Path to the configuration file to load
-        type (str): configuration type. For 'local' type, more
-                    checks are done.
 
     Raises:
         Error if the setup is not as expected
@@ -223,7 +221,23 @@
         raise FileNotFoundError("Configuration file %s does not exist" % (config_file,))
 
     cfg = config_read(config_file)
+    return validate_config(cfg)
 
+
+def validate_config(cfg):
+    """Check the minimal configuration is set to run the api or raise an
+       error explanation.
+
+    Args:
+        cfg (dict): Loaded configuration.
+
+    Raises:
+        Error if the setup is not as expected
+
+    Returns:
+        configuration as a dict
+
+    """
     if "objstorage" not in cfg:
         raise KeyError("Invalid configuration; missing objstorage config entry")
 
diff --git a/swh/objstorage/cli.py b/swh/objstorage/cli.py
--- a/swh/objstorage/cli.py
+++ b/swh/objstorage/cli.py
@@ -10,10 +10,11 @@
 import click
 import aiohttp.web
 
+from swh.core import config
 from swh.core.cli import CONTEXT_SETTINGS
 
-from swh.objstorage.api.server import load_and_check_config, make_app
 from swh.objstorage.factory import get_objstorage
+from swh.objstorage.api.server import validate_config, make_app
 
 
 @click.group(name="objstorage", context_settings=CONTEXT_SETTINGS)
@@ -28,9 +29,19 @@
 def cli(ctx, config_file):
     """Software Heritage Objstorage tools.
     """
+    if not config_file:
+        config_file = os.environ.get("SWH_CONFIG_FILENAME")
+
+    if config_file:
+        if not os.path.exists(config_file):
+            raise ValueError("%s does not exist" % config_file)
+        conf = config.read(config_file)
+    else:
+        conf = {}
+
     ctx.ensure_object(dict)
-    cfg = load_and_check_config(config_file)
-    ctx.obj["config"] = cfg
+
+    ctx.obj["config"] = conf
 
 
 @cli.command("rpc-serve")
@@ -56,7 +67,7 @@
 
     This is not meant to be run on production systems.
     """
-    app = make_app(ctx.obj["config"])
+    app = make_app(validate_config(ctx.obj["config"]))
     if ctx.obj["log_level"] == "DEBUG":
         app.update(debug=True)
     aiohttp.web.run_app(app, host=host, port=int(port))