diff --git a/swh/search/api/server.py b/swh/search/api/server.py
--- a/swh/search/api/server.py
+++ b/swh/search/api/server.py
@@ -1,10 +1,11 @@
-# Copyright (C) 2019-2020  The Software Heritage developers
+# Copyright (C) 2019-2021  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import logging
 import os
+from typing import Any, Dict
 
 from swh.core import config
 from swh.core.api import RPCServerApp
@@ -43,13 +44,13 @@
 api_cfg = None
 
 
-def load_and_check_config(config_file, type="elasticsearch"):
+def load_and_check_config(config_file: str) -> Dict[str, Any]:
     """Check the minimal configuration is set to run the api or raise an
        error explanation.
 
     Args:
-        config_file (str): Path to the configuration file to load
-        type (str): configuration type. For 'local' type, more
+        config_file: Path to the configuration file to load
+        type: configuration type. For 'local' type, more
                     checks are done.
 
     Raises:
diff --git a/swh/search/cli.py b/swh/search/cli.py
--- a/swh/search/cli.py
+++ b/swh/search/cli.py
@@ -125,6 +125,6 @@
     """Starts a Software Heritage Indexer RPC HTTP server."""
     from .api.server import app, load_and_check_config
 
-    api_cfg = load_and_check_config(config_path, type="any")
+    api_cfg = load_and_check_config(config_path)
     app.config.update(api_cfg)
     app.run(host, port=int(port), index_prefix=index_prefix, debug=bool(debug))
diff --git a/swh/search/tests/test_server.py b/swh/search/tests/test_server.py
new file mode 100644
--- /dev/null
+++ b/swh/search/tests/test_server.py
@@ -0,0 +1,88 @@
+# Copyright (C) 2021  The Software Heritage developers
+# See the AUTHORS file at the top-level directory of this distribution
+# License: GNU General Public License version 3, or any later version
+# See top-level LICENSE file for more information
+
+import os
+from typing import Any, Dict
+
+import pytest
+import yaml
+
+from swh.core.api import RPCServerApp
+from swh.core.config import load_from_envvar
+from swh.search.api.server import load_and_check_config, make_app_from_configfile
+
+
+@pytest.fixture
+def swh_search_server_config() -> Dict[str, Any]:
+    return {"search": {"cls": "elasticsearch", "hosts": ["es1"],}}
+
+
+@pytest.fixture
+def swh_search_config(monkeypatch, swh_search_server_config, tmp_path):
+    conf_path = os.path.join(str(tmp_path), "search.yml")
+    with open(conf_path, "w") as f:
+        f.write(yaml.dump(swh_search_server_config))
+    monkeypatch.setenv("SWH_CONFIG_FILENAME", conf_path)
+    return conf_path
+
+
+def prepare_config_file(tmpdir, config_dict: Dict, name: str = "config.yml") -> str:
+    """Prepare configuration file in `$tmpdir/name` with content `content`.
+
+    Args:
+        tmpdir (LocalPath): root directory
+        content: Content of the file either as string or as a dict.
+                            If a dict, converts the dict into a yaml string.
+        name: configuration filename
+
+    Returns
+        path of the configuration file prepared.
+
+    """
+    config_path = tmpdir / name
+    config_path.write_text(yaml.dump(config_dict), encoding="utf-8")
+    # pytest on python3.5 does not support LocalPath manipulation, so
+    # convert path to string
+    return str(config_path)
+
+
+@pytest.mark.parametrize("config_file", [None, ""])
+def test_load_and_check_config_no_configuration(config_file):
+    """Inexistent configuration files raises"""
+    with pytest.raises(EnvironmentError, match="Configuration file must be defined"):
+        load_and_check_config(config_file)
+
+
+def test_load_and_check_config_inexistent_file():
+    config_path = "/some/inexistent/config.yml"
+    expected_error = f"Configuration file {config_path} does not exist"
+    with pytest.raises(EnvironmentError, match=expected_error):
+        load_and_check_config(config_path)
+
+
+def test_load_and_check_config_wrong_configuration(tmpdir):
+    """Wrong configuration raises"""
+    config_path = prepare_config_file(tmpdir, {"something": "useless"})
+    with pytest.raises(KeyError, match="Missing 'search' configuration"):
+        load_and_check_config(config_path)
+
+
+def test_load_and_check_config_local_config_fine(swh_search_server_config, tmpdir):
+    """'local' complete configuration is fine"""
+    config_path = prepare_config_file(tmpdir, swh_search_server_config)
+    cfg = load_and_check_config(config_path)
+    assert cfg == swh_search_server_config
+
+
+def test_server_make_app_from_config_file(swh_search_config):
+    app = make_app_from_configfile()
+    expected_cfg = load_from_envvar()
+
+    assert app is not None
+    assert isinstance(app, RPCServerApp)
+    assert app.config["search"] == expected_cfg["search"]
+
+    app2 = make_app_from_configfile()
+    assert app is app2