Dockerfile: Use the ubi-minimal image

The new image size is 57% of the old image. UBI image was 284 MB. ubi-minimal
image is 164 MB.

Signed-off-by: Raghavendra Talur <[email protected]>

Author: raghavendra-talur

Dockerfile

@@ -20,7 +20,7 @@ COPY controllers/ controllers/
 # Build
 RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -o manager main.go
 
-FROM registry.access.redhat.com/ubi8/ubi
+FROM registry.access.redhat.com/ubi8/ubi-minimal
 WORKDIR /
 COPY --from=builder /workspace/manager .