Ldap authenticator (bluesky#207)

* ENH: add LDAPAuthenticator

* STY: black

* Make ldap3 an optional dependency.

* Remove global imports.

* Refactor imports.

* Satisfy isort.

* Make LDAP authenticator non-blocking.

Ported from bluesky/bluesky-httpserver#38 by @dmgav

* Fix missing await.

Co-authored-by: Dan Allan <dallan@bnl.gov>

continuous_integration/docker-configs/ldap-docker-compose.yml

@@ -0,0 +1,19 @@
+version: '2'
+
+services:
+  openldap:
+    image: docker.io/bitnami/openldap:2.6
+    ports:
+      - '1389:1389'
+      - '1636:1636'
+    environment:
+      - LDAP_ADMIN_USERNAME=admin
+      - LDAP_ADMIN_PASSWORD=adminpassword
+      - LDAP_USERS=user01,user02
+      - LDAP_PASSWORDS=password1,password2
+    volumes:
+      - 'openldap_data:/bitnami/openldap'
+
+volumes:
+  openldap_data:
+    driver: local

continuous_integration/scripts/install.sh

@@ -1,6 +1,9 @@
 #!/bin/bash
 set -vxeuo pipefail
 
+# Start LDAP (in docker)
+source start_LDAP.sh
+
 # These packages are installed in the base environment but may be older
 # versions. Explicitly upgrade them because they often create
 # installation problems if out of date.

requirements-dev.txt

@@ -3,6 +3,7 @@
 codecov
 coverage
 flake8
+ldap3
 pre-commit
 pytest
 pytest-asyncio

start_LDAP.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+set -e
+
+# Start LDAP server in docker container
+sudo docker pull bitnami/openldap:latest
+sudo docker-compose -f continuous_integration/docker-configs/ldap-docker-compose.yml up -d
+sudo docker ps

tiled/_tests/test_authenticators.py

@@ -0,0 +1,30 @@
+import asyncio
+
+import pytest
+
+from ..authenticators import LDAPAuthenticator
+
+
+@pytest.mark.parametrize("use_tls,use_ssl", [(False, False)])
+def test_LDAPAuthenticator_01(use_tls, use_ssl):
+    """
+    Basic test for ``LDAPAuthenticator``.
+
+    TODO: The test could be extended with enabled TLS or SSL, but it requires configuration
+    of the LDAP server.
+    """
+    authenticator = LDAPAuthenticator(
+        "localhost",
+        1389,
+        bind_dn_template="cn={username},ou=users,dc=example,dc=org",
+        use_tls=use_tls,
+        use_ssl=use_ssl,
+    )
+
+    async def testing():
+        assert await authenticator.authenticate("user01", "password1") == "user01"
+        assert await authenticator.authenticate("user02", "password2") == "user02"
+        assert await authenticator.authenticate("user02a", "password2") is None
+        assert await authenticator.authenticate("user02", "password2a") is None
+
+    asyncio.run(testing())