diff --git a/docker/tests/conftest.py b/docker/tests/conftest.py
--- a/docker/tests/conftest.py
+++ b/docker/tests/conftest.py
@@ -1,4 +1,4 @@
-# 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
@@ -17,9 +17,9 @@
 import testinfra
 
 
-APIURL = 'http://127.0.0.1:5080/api/1/'
+APIURL = "http://127.0.0.1:5080/api/1/"
 
-SAMPLE_METADATA = '''\
+SAMPLE_METADATA = """\
 <?xml version="1.0" encoding="utf-8"?>
 <entry xmlns="http://www.w3.org/2005/Atom"
        xmlns:codemeta="https://doi.org/10.5063/SCHEMA/CODEMETA-2.0">
@@ -30,20 +30,20 @@
     <codemeta:name>No One</codemeta:name>
   </codemeta:author>
 </entry>
-'''
+"""
 
 
 # scope='session' so we use the same container for all the tests;
-@pytest.fixture(scope='session')
+@pytest.fixture(scope="session")
 def docker_compose(request):
     # start the whole cluster
-    subprocess.check_output(['docker-compose', 'up', '-d'])
+    subprocess.check_output(["docker-compose", "up", "-d"])
     yield
     # and strop it
-    subprocess.check_call(['docker-compose', 'down'])
+    subprocess.check_call(["docker-compose", "down"])
 
 
-@pytest.fixture(scope='session')
+@pytest.fixture(scope="session")
 def wfi_timeout():
     """
     wait-for-it timeout in seconds
@@ -51,95 +51,98 @@
     return 60
 
 
-@pytest.fixture(scope='session')
+@pytest.fixture(scope="session")
 def scheduler_host(request, docker_compose, wfi_timeout):
     # run a container in which test commands are executed
-    docker_id = subprocess.check_output(
-        ['docker-compose', 'run', '-d',
-         'swh-scheduler', 'shell', 'sleep', '1h']).decode().strip()
+    docker_id = (
+        subprocess.check_output(
+            ["docker-compose", "run", "-d", "swh-scheduler", "shell", "sleep", "1h"]
+        )
+        .decode()
+        .strip()
+    )
     scheduler_host = testinfra.get_host("docker://" + docker_id)
-    scheduler_host.check_output(
-        f'wait-for-it swh-scheduler:5008 -t {wfi_timeout}')
-    scheduler_host.check_output(
-        f'wait-for-it swh-storage:5002 -t {wfi_timeout}')
+    scheduler_host.check_output(f"wait-for-it swh-scheduler:5008 -t {wfi_timeout}")
+    scheduler_host.check_output(f"wait-for-it swh-storage:5002 -t {wfi_timeout}")
 
     # return a testinfra connection to the container
     yield scheduler_host
 
     # at the end of the test suite, destroy the container
-    subprocess.check_call(['docker', 'rm', '-f', docker_id])
+    subprocess.check_call(["docker", "rm", "-f", docker_id])
 
 
 # scope='session' so we use the same container for all the tests;
-@pytest.fixture(scope='session')
+@pytest.fixture(scope="session")
 def deposit_host(request, docker_compose, wfi_timeout):
     # run a container in which test commands are executed
-    docker_id = subprocess.check_output(
-        ['docker-compose', 'run', '-d',
-         'swh-deposit', 'shell', 'sleep', '1h']).decode().strip()
+    docker_id = (
+        subprocess.check_output(
+            ["docker-compose", "run", "-d", "swh-deposit", "shell", "sleep", "1h"]
+        )
+        .decode()
+        .strip()
+    )
     deposit_host = testinfra.get_host("docker://" + docker_id)
-    deposit_host.check_output(
-        'echo \'print("Hello World!")\n\' > /tmp/hello.py')
-    deposit_host.check_output(
-        'tar -C /tmp -czf /tmp/archive.tgz /tmp/hello.py')
-    deposit_host.check_output(
-        f'echo \'{SAMPLE_METADATA}\' > /tmp/metadata.xml')
-    deposit_host.check_output(
-        f'wait-for-it swh-deposit:5006 -t {wfi_timeout}')
+    deposit_host.check_output("echo 'print(\"Hello World!\")\n' > /tmp/hello.py")
+    deposit_host.check_output("tar -C /tmp -czf /tmp/archive.tgz /tmp/hello.py")
+    deposit_host.check_output(f"echo '{SAMPLE_METADATA}' > /tmp/metadata.xml")
+    deposit_host.check_output(f"wait-for-it swh-deposit:5006 -t {wfi_timeout}")
     # return a testinfra connection to the container
     yield deposit_host
 
     # at the end of the test suite, destroy the container
-    subprocess.check_call(['docker', 'rm', '-f', docker_id])
+    subprocess.check_call(["docker", "rm", "-f", docker_id])
 
 
-@pytest.fixture(scope='session')
+@pytest.fixture(scope="session")
 def git_url():
-    return 'https://forge.softwareheritage.org/source/swh-core'
+    return "https://forge.softwareheritage.org/source/swh-core"
 
 
-@pytest.fixture(scope='session')
+@pytest.fixture(scope="session")
 def git_origin(scheduler_host, git_url):
-    task = scheduler_host.check_output(
-        f'swh scheduler task add load-git url={git_url}'
-    )
-    taskid = re.search(r'^Task (?P<id>\d+)$', task,
-                       flags=re.MULTILINE).group('id')
+    task = scheduler_host.check_output(f"swh scheduler task add load-git url={git_url}")
+    taskid = re.search(r"^Task (?P<id>\d+)$", task, flags=re.MULTILINE).group("id")
     assert int(taskid) > 0
 
     for i in range(60):
         status = scheduler_host.check_output(
-            f'swh scheduler task list --list-runs --task-id {taskid}')
-        if 'Executions:' in status:
-            if '[eventful]' in status:
+            f"swh scheduler task list --list-runs --task-id {taskid}"
+        )
+        if "Executions:" in status:
+            if "[eventful]" in status:
                 break
-            if '[started]' in status or '[scheduled]' in status:
+            if "[started]" in status or "[scheduled]" in status:
                 time.sleep(1)
                 continue
-            if '[failed]' in status:
+            if "[failed]" in status:
                 loader_logs = subprocess.check_output(
-                    ['docker-compose', 'logs', 'swh-loader'])
-                assert False, ('Loading execution failed\n'
-                               f'status: {status}\n'
-                               f'loader logs: '
-                               + loader_logs.decode(errors='replace'))
-            assert False, f'Loading execution failed, task status is {status}'
+                    ["docker-compose", "logs", "swh-loader"]
+                )
+                assert False, (
+                    "Loading execution failed\n"
+                    f"status: {status}\n"
+                    f"loader logs: " + loader_logs.decode(errors="replace")
+                )
+            assert False, f"Loading execution failed, task status is {status}"
     return git_url
 
 
 # Utility functions
 
-def apiget(path: str, verb: str = 'GET', **kwargs):
+
+def apiget(path: str, verb: str = "GET", **kwargs):
     """Query the API at path and return the json result or raise an
     AssertionError"""
 
     url = urljoin(APIURL, path)
     resp = requests.request(verb, url, **kwargs)
-    assert resp.status_code == 200, f'failed to retrieve {url}: {resp.text}'
+    assert resp.status_code == 200, f"failed to retrieve {url}: {resp.text}"
     return resp.json()
 
 
-def pollapi(path: str, verb: str = 'GET', **kwargs):
+def pollapi(path: str, verb: str = "GET", **kwargs):
     """Poll the API at path until it returns an OK result"""
     url = urljoin(APIURL, path)
     for i in range(60):
@@ -152,13 +155,14 @@
     return resp
 
 
-def getdirectory(dirid: str, currentpath: str = '') \
-        -> Generator[Tuple[str, Mapping], None, None]:
+def getdirectory(
+    dirid: str, currentpath: str = ""
+) -> Generator[Tuple[str, Mapping], None, None]:
     """Recursively retrieve directory description from the archive"""
-    directory = apiget(f'directory/{dirid}')
+    directory = apiget(f"directory/{dirid}")
     for direntry in directory:
-        path = join(currentpath, direntry['name'])
-        if direntry['type'] != 'dir':
+        path = join(currentpath, direntry["name"])
+        if direntry["type"] != "dir":
             yield (path, direntry)
         else:
-            yield from getdirectory(direntry['target'], path)
+            yield from getdirectory(direntry["target"], path)
diff --git a/docker/tests/test_deposit.py b/docker/tests/test_deposit.py
--- a/docker/tests/test_deposit.py
+++ b/docker/tests/test_deposit.py
@@ -1,4 +1,4 @@
-# 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
@@ -9,32 +9,39 @@
 
 def test_admin_collection(deposit_host):
     # 'deposit_host' binds to the container
-    assert deposit_host.check_output(
-        'swh deposit admin collection list') == 'test'
+    assert deposit_host.check_output("swh deposit admin collection list") == "test"
 
 
 def test_admin_user(deposit_host):
-    assert deposit_host.check_output('swh deposit admin user list') == 'test'
+    assert deposit_host.check_output("swh deposit admin user list") == "test"
 
 
 def test_create_deposit_simple(deposit_host):
     deposit = deposit_host.check_output(
-        'swh deposit upload --format json --username test --password test '
-        '--url http://nginx:5080/deposit/1 '
-        '--archive /tmp/archive.tgz '
-        '--name test_deposit --author somebody')
+        "swh deposit upload --format json --username test --password test "
+        "--url http://nginx:5080/deposit/1 "
+        "--archive /tmp/archive.tgz "
+        "--name test_deposit --author somebody"
+    )
     deposit = json.loads(deposit)
 
-    assert set(deposit.keys()) == {'deposit_id', 'deposit_status',
-                                   'deposit_status_detail', 'deposit_date'}
-    assert deposit['deposit_status'] == 'deposited'
-    deposit_id = deposit['deposit_id']
+    assert set(deposit.keys()) == {
+        "deposit_id",
+        "deposit_status",
+        "deposit_status_detail",
+        "deposit_date",
+    }
+    assert deposit["deposit_status"] == "deposited"
+    deposit_id = deposit["deposit_id"]
 
     for i in range(60):
-        status = json.loads(deposit_host.check_output(
-            'swh deposit status --format json --username test --password test '
-            '--url http://nginx:5080/deposit/1 --deposit-id %s' % deposit_id))
-        if status['deposit_status'] == 'done':
+        status = json.loads(
+            deposit_host.check_output(
+                "swh deposit status --format json --username test --password test "
+                "--url http://nginx:5080/deposit/1 --deposit-id %s" % deposit_id
+            )
+        )
+        if status["deposit_status"] == "done":
             break
         time.sleep(1)
     else:
@@ -43,22 +50,30 @@
 
 def test_create_deposit_with_metadata(deposit_host):
     deposit = deposit_host.check_output(
-        'swh deposit upload --format json --username test --password test '
-        '--url http://nginx:5080/deposit/1 '
-        '--archive /tmp/archive.tgz '
-        '--metadata /tmp/metadata.xml')
+        "swh deposit upload --format json --username test --password test "
+        "--url http://nginx:5080/deposit/1 "
+        "--archive /tmp/archive.tgz "
+        "--metadata /tmp/metadata.xml"
+    )
     deposit = json.loads(deposit)
 
-    assert set(deposit.keys()) == {'deposit_id', 'deposit_status',
-                                   'deposit_status_detail', 'deposit_date'}
-    assert deposit['deposit_status'] == 'deposited'
-    deposit_id = deposit['deposit_id']
+    assert set(deposit.keys()) == {
+        "deposit_id",
+        "deposit_status",
+        "deposit_status_detail",
+        "deposit_date",
+    }
+    assert deposit["deposit_status"] == "deposited"
+    deposit_id = deposit["deposit_id"]
 
     for i in range(60):
-        status = json.loads(deposit_host.check_output(
-            'swh deposit status --format json --username test --password test '
-            '--url http://nginx:5080/deposit/1 --deposit-id %s' % deposit_id))
-        if status['deposit_status'] == 'done':
+        status = json.loads(
+            deposit_host.check_output(
+                "swh deposit status --format json --username test --password test "
+                "--url http://nginx:5080/deposit/1 --deposit-id %s" % deposit_id
+            )
+        )
+        if status["deposit_status"] == "done":
             break
         time.sleep(1)
     else:
@@ -67,32 +82,40 @@
 
 def test_create_deposit_multipart(deposit_host):
     deposit = deposit_host.check_output(
-        'swh deposit upload --format json --username test --password test '
-        '--url http://nginx:5080/deposit/1 '
-        '--archive /tmp/archive.tgz '
-        '--partial')
+        "swh deposit upload --format json --username test --password test "
+        "--url http://nginx:5080/deposit/1 "
+        "--archive /tmp/archive.tgz "
+        "--partial"
+    )
     deposit = json.loads(deposit)
 
-    assert set(deposit.keys()) == {'deposit_id', 'deposit_status',
-                                   'deposit_status_detail', 'deposit_date'}
-    assert deposit['deposit_status'] == 'partial'
-    deposit_id = deposit['deposit_id']
+    assert set(deposit.keys()) == {
+        "deposit_id",
+        "deposit_status",
+        "deposit_status_detail",
+        "deposit_date",
+    }
+    assert deposit["deposit_status"] == "partial"
+    deposit_id = deposit["deposit_id"]
 
     deposit = deposit_host.check_output(
-        'swh deposit upload --format json --username test --password test '
-        '--url http://nginx:5080/deposit/1 '
-        '--metadata /tmp/metadata.xml '
-        '--deposit-id %s'
-        % deposit_id)
+        "swh deposit upload --format json --username test --password test "
+        "--url http://nginx:5080/deposit/1 "
+        "--metadata /tmp/metadata.xml "
+        "--deposit-id %s" % deposit_id
+    )
     deposit = json.loads(deposit)
-    assert deposit['deposit_status'] == 'deposited'
-    assert deposit['deposit_id'] == deposit_id
+    assert deposit["deposit_status"] == "deposited"
+    assert deposit["deposit_id"] == deposit_id
 
     for i in range(60):
-        status = json.loads(deposit_host.check_output(
-            'swh deposit status --format json --username test --password test '
-            '--url http://nginx:5080/deposit/1 --deposit-id %s' % deposit_id))
-        if status['deposit_status'] == 'done':
+        status = json.loads(
+            deposit_host.check_output(
+                "swh deposit status --format json --username test --password test "
+                "--url http://nginx:5080/deposit/1 --deposit-id %s" % deposit_id
+            )
+        )
+        if status["deposit_status"] == "done":
             break
         time.sleep(1)
     else:
diff --git a/docker/tests/test_git_loader.py b/docker/tests/test_git_loader.py
--- a/docker/tests/test_git_loader.py
+++ b/docker/tests/test_git_loader.py
@@ -1,4 +1,4 @@
-# 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
@@ -11,20 +11,20 @@
 def test_git_loader(scheduler_host, git_origin):
     url = git_origin
 
-    print(f'Retrieve references available at {url}')
-    gitrefs = scheduler_host.check_output(f'git ls-remote {url}')
+    print(f"Retrieve references available at {url}")
+    gitrefs = scheduler_host.check_output(f"git ls-remote {url}")
     gitrefs = [x.split() for x in gitrefs.splitlines()]
 
-    print(f'Look for origin {url}')
+    print(f"Look for origin {url}")
     # use quote_plus to prevent urljoin from messing with the 'http://' part of
     # the url
-    origin = apiget(f'origin/{quote_plus(url)}/get')
-    assert origin['url'] == url
+    origin = apiget(f"origin/{quote_plus(url)}/get")
+    assert origin["url"] == url
 
-    visit = apiget(f'origin/{quote_plus(url)}/visit/latest')
-    assert visit['status'] == 'full'
+    visit = apiget(f"origin/{quote_plus(url)}/visit/latest")
+    assert visit["status"] == "full"
 
-    print('Check every identified git ref has been loaded')
+    print("Check every identified git ref has been loaded")
     snapshot = apiget(f'snapshot/{visit["snapshot"]}')
 
     print(f'snapshot has {len(snapshot["branches"])} branches')
@@ -33,17 +33,16 @@
     # check every branch reported by git ls-remote is present in the snapshot
     for rev, branch_name in gitrefs:
         # for tags, only check for final revision id
-        if branch_name.startswith('refs/tags/') \
-           and not branch_name.endswith('^{}'):
+        if branch_name.startswith("refs/tags/") and not branch_name.endswith("^{}"):
             continue
-        rev_desc = apiget(f'revision/{rev}')
-        assert rev_desc['type'] == 'git'
+        rev_desc = apiget(f"revision/{rev}")
+        assert rev_desc["type"] == "git"
 
     tag_revision = {}
     tag_release = {}
     for rev, tag in gitrefs:
-        if tag.startswith('refs/tags/'):
-            if tag.endswith('^{}'):
+        if tag.startswith("refs/tags/"):
+            if tag.endswith("^{}"):
                 tag_revision[tag[:-3]] = rev
             else:
                 tag_release[tag] = rev
@@ -52,11 +51,11 @@
         # check that every release tag listed in the snapshot is known by the
         # archive and consistant
         release_id = tag_release[tag]
-        release = apiget(f'release/{release_id}')
-        assert release['id'] == release_id
-        assert release['target_type'] == 'revision'
-        assert release['target'] == revision
+        release = apiget(f"release/{release_id}")
+        assert release["id"] == release_id
+        assert release["target_type"] == "revision"
+        assert release["target"] == revision
         # and compare this with what git ls-remote reported
         tag_desc = branches[tag]
-        assert tag_desc['target_type'] == 'release'
-        assert tag_desc['target'] == release_id
+        assert tag_desc["target_type"] == "release"
+        assert tag_desc["target"] == release_id
diff --git a/docker/tests/test_vault.py b/docker/tests/test_vault.py
--- a/docker/tests/test_vault.py
+++ b/docker/tests/test_vault.py
@@ -1,4 +1,4 @@
-# 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
@@ -16,23 +16,23 @@
 def test_vault_directory(scheduler_host, git_origin):
     # retrieve the root directory of the master branch of the ingested git
     # repository (by the git_origin fixture)
-    visit = apiget(f'origin/{quote_plus(git_origin)}/visit/latest')
+    visit = apiget(f"origin/{quote_plus(git_origin)}/visit/latest")
     snapshot = apiget(f'snapshot/{visit["snapshot"]}')
     rev_id = snapshot["branches"]["refs/heads/master"]["target"]
-    revision = apiget(f'revision/{rev_id}')
-    dir_id = revision['directory']
+    revision = apiget(f"revision/{rev_id}")
+    dir_id = revision["directory"]
 
     # now cook it
-    cook = apiget(f'vault/directory/{dir_id}/', 'POST')
-    assert cook['obj_type'] == 'directory'
-    assert cook['obj_id'] == dir_id
-    assert cook['fetch_url'].endswith(f'vault/directory/{dir_id}/raw/')
+    cook = apiget(f"vault/directory/{dir_id}/", "POST")
+    assert cook["obj_type"] == "directory"
+    assert cook["obj_id"] == dir_id
+    assert cook["fetch_url"].endswith(f"vault/directory/{dir_id}/raw/")
 
     # while it's cooking, get the directory tree from the archive
     directory = getdirectory(dir_id)
 
     # retrieve the cooked tar file
-    resp = pollapi(f'vault/directory/{dir_id}/raw')
+    resp = pollapi(f"vault/directory/{dir_id}/raw")
     tarf = tarfile.open(fileobj=io.BytesIO(resp.content))
 
     # and check the tarfile seems ok wrt. 'directory'
@@ -42,22 +42,22 @@
     for fname, fdesc in directory:
         tfinfo = tarfiles.get(join(dir_id, fname))
         assert tfinfo, f"Missing path {fname} in retrieved tarfile"
-        if fdesc['type'] == 'file':
-            assert fdesc['length'] == tfinfo.size, \
-                f"File {fname}: length mismatch"
+        if fdesc["type"] == "file":
+            assert fdesc["length"] == tfinfo.size, f"File {fname}: length mismatch"
             fdata = tarf.extractfile(tfinfo).read()
-            for algo in fdesc['checksums']:
+            for algo in fdesc["checksums"]:
                 if algo not in hashlib.algorithms_available:
                     continue
                 hash = hashlib.new(algo, fdata).hexdigest()
-                assert hash == fdesc['checksums'][algo], \
-                    f"File {fname}: {algo} mismatch"
+                assert (
+                    hash == fdesc["checksums"][algo]
+                ), f"File {fname}: {algo} mismatch"
         # XXX what to check for dir? symlink? (other?)
 
     # check that if we ask a second time this directory, it returns the same
     # and does not cook it again
-    recook = apiget(f'vault/directory/{dir_id}/', 'POST')
-    assert recook['obj_type'] == 'directory'
-    assert recook['obj_id'] == dir_id
-    assert recook['id'] == cook['id']
-    assert recook['status'] == 'done'  # no need to wait for this to be true
+    recook = apiget(f"vault/directory/{dir_id}/", "POST")
+    assert recook["obj_type"] == "directory"
+    assert recook["obj_id"] == dir_id
+    assert recook["id"] == cook["id"]
+    assert recook["status"] == "done"  # no need to wait for this to be true