Add OVN BGP Agent image build

Co-Authored-By: Dong Ma <dong.ma@vexxhost.com>
Change-Id: I53a3d4d126a47d875b23a50d3218c41f31bdd053
diff --git a/images/ovn-bgp-agent/Dockerfile b/images/ovn-bgp-agent/Dockerfile
new file mode 100644
index 0000000..afd45a0
--- /dev/null
+++ b/images/ovn-bgp-agent/Dockerfile
@@ -0,0 +1,16 @@
+# SPDX-FileCopyrightText: © 2025 VEXXHOST, Inc.
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Atmosphere-Rebuild-Time: 2024-06-25T22:49:25Z
+
+FROM openstack-venv-builder AS build
+ARG OVN_BGP_AGENT_GIT_REF=704742076a28c13b811ea37e71dae1e4b0aca573
+ADD --keep-git-dir=true https://opendev.org/openstack/ovn-bgp-agent.git#${OVN_BGP_AGENT_GIT_REF} /src/ovn-bgp-agent
+RUN git -C /src/ovn-bgp-agent fetch --unshallow
+RUN --mount=type=cache,target=/root/.cache/uv <<EOF bash -xe
+uv pip install \
+    --constraint /upper-constraints.txt \
+        /src/ovn-bgp-agent
+EOF
+
+FROM openstack-python-runtime
+COPY --from=build --link /var/lib/openstack /var/lib/openstack