diff --git a/swh/core/db/db_utils.py b/swh/core/db/db_utils.py
--- a/swh/core/db/db_utils.py
+++ b/swh/core/db/db_utils.py
@@ -662,3 +662,12 @@
             "Asked for flavor %s, but module does not support database flavors",
             flavor,
         )
+
+    # Grant read-access to guest user on all tables of the schema
+    with connect_to_conninfo(db_or_conninfo) as db:
+        if not db:
+            return None
+
+        with db.cursor() as c:
+            query = "grant select on all tables in schema public to guest"
+            c.execute(query)
diff --git a/swh/core/db/pytest_plugin.py b/swh/core/db/pytest_plugin.py
--- a/swh/core/db/pytest_plugin.py
+++ b/swh/core/db/pytest_plugin.py
@@ -144,6 +144,13 @@
                 else:
                     logger.debug("Create %s from scratch", self.dbname)
                     cur.execute(f'CREATE DATABASE "{self.dbname}";')
+
+                try:
+                    cur.execute("CREATE ROLE guest LOGIN PASSWORD 'guest'")
+                except psycopg2.errors.DuplicateObject:
+                    # We want that role to exist idempotently, if already there fine
+                    pass
+
                 if self.dump_files:
                     logger.warning(
                         "Using dump_files on the postgresql_fact fixture "
diff --git a/swh/core/db/tests/test_cli.py b/swh/core/db/tests/test_cli.py
--- a/swh/core/db/tests/test_cli.py
+++ b/swh/core/db/tests/test_cli.py
@@ -13,6 +13,7 @@
 from swh.core.cli.db import db as swhdb
 from swh.core.db import BaseDb
 from swh.core.db.db_utils import import_swhmodule, swh_db_module, swh_db_version
+from swh.core.db.pytest_plugin import postgresql_fact
 from swh.core.tests.test_cli import assert_section_contains
 
 
@@ -43,6 +44,8 @@
     ),
 )
 
+postgresql = postgresql_fact("postgresql_proc")
+
 
 def test_cli_swh_db_help(swhmain, cli_runner):
     swhmain.add_command(swhdb)