Use centos stream to build and create repo

extensions/Dockerfile

@@ -1,25 +1,23 @@
-## Builds the webserver for the repo service.
-FROM golang as gobuild
-ADD repo-server/main.go .
-RUN mkdir /build
-RUN go build -o /build/webserver main.go
-
 ## Downloads the extensions given the extensions.yaml
 ARG RHCOS_VERSION=latest
 FROM registry.ci.openshift.org/rhcos-devel/rhel-coreos:${RHCOS_VERSION} as os
 #Expects repos from redhat-coreos, like when building rhcos locally.
 RUN rpm-ostree compose extensions --rootfs=/ --output-dir=/usr/share/rpm-ostree/extensions/ {manifest,extensions}.yaml
 
 ## Creates the repo metadata for the extensions
-FROM quay.io/centos/centos:stream8 as repo
+FROM quay.io/centos/centos:stream8 as builder
 COPY --from=os /usr/share/rpm-ostree/extensions/ /usr/share/rpm-ostree/extensions/
-RUN dnf install -y createrepo_c
+RUN dnf install -y createrepo_c golang
+ADD repo-server/main.go .
+RUN mkdir /build
+RUN go build -o /build/webserver main.go
+
 RUN createrepo_c /usr/share/rpm-ostree/extensions/
 
 ## Final container that has the extensions and webserver
 FROM registry.access.redhat.com/ubi8/ubi:latest
-COPY --from=gobuild /build/webserver /usr/bin/webserver
-COPY --from=repo /usr/share/rpm-ostree/extensions/ /usr/share/rpm-ostree/extensions/
+COPY --from=builder /build/webserver /usr/bin/webserver
+COPY --from=builder /usr/share/rpm-ostree/extensions/ /usr/share/rpm-ostree/extensions/
 
 CMD ["./usr/bin/webserver"]
 EXPOSE 9666/tcp