Update Dockerfile

Dockerfile

@@ -4,7 +4,10 @@ ARG BASE_REGISTRY=nexus-docker-secure.levelup-dev.io
 ARG BASE_IMAGE=redhat/ubi/ubi8
 ARG BASE_TAG=8.2
 
-FROM istio/proxyv2:1.5.10 AS base
+# Updated by Renovate
+ARG version=1.5.10
+
+FROM istio/proxyv2:${version} AS base
 
 FROM ${BASE_REGISTRY}/${BASE_IMAGE}:${BASE_TAG}
 
@@ -23,8 +26,9 @@ ARG proxy_version
 ARG istio_version
 
 COPY --from=base /usr/local/bin/envoy /usr/local/bin/envoy
-ENV ISTIO_META_ISTIO_PROXY_SHA=istio-proxy:9b4239dee83dd8894bfc579d412ccd894cff2597
-ENV ISTIO_META_ISTIO_VERSION=1.5.4
+# Iron Bank cannot provide a meaningful SHA here, set it to a placeholder value
+ENV ISTIO_META_ISTIO_PROXY_SHA=isto-proxy:ironbank
+ENV ISTIO_META_ISTIO_VERSION=${version}
 COPY --from=base /usr/local/bin/pilot-agent /usr/local/bin/pilot-agent
 
 COPY --from=base /etc/istio/proxy/envoy_policy.yaml.tmpl /etc/istio/proxy/envoy_policy.yaml.tmpl