First sidecar module: OpenTelemetry (#8013)

* remove opentelemetry from main nginx image

* add opentelemetry sidecar image

* handle extra modules in helm chart

* fix running helm chart

* mount the modules volume in the init container

* merge the mounted folder

* fix the otel image

* fix licence year

* fix cloudbuild image

* use the same nginx version as in the main image

* only retrieve /etc/nginx/modules for now

images/nginx/rootfs/Dockerfile

@@ -33,6 +33,7 @@ ENV LUA_CPATH="/usr/local/lib/lua/?/?.so;/usr/local/lib/lua/?.so;;"
 COPY --from=builder /usr/local /usr/local
 COPY --from=builder /opt /opt
 COPY --from=builder /etc/nginx /etc/nginx
+COPY --from=builder entrypoint.sh /usr/local/entrypoint.sh
 
 RUN apk update \
   && apk upgrade \
@@ -72,4 +73,5 @@ RUN apk update \
 
 EXPOSE 80 443
 
+ENTRYPOINT ["/usr/local/entrypoint.sh"]
 CMD ["nginx", "-g", "daemon off;"]