revert changes on Dockerfiles

docker/DebugDockerfile

@@ -1,14 +1,8 @@
-FROM ubuntu:20.04
+FROM alpine
 LABEL maintainer="Team ACID @ Zalando <team-acid@zalando.de>"
 
 # We need root certificates to deal with teams api over https
-RUN apt-get update \
-    && apt-get install --no-install-recommends -y \
-        curl \
-        ca-certificates \
-        go \
-        git \
-        musl-dev
+RUN apk --no-cache add ca-certificates go git musl-dev
 
 COPY build/* /
 
@@ -22,4 +16,4 @@ RUN chown -R pgo:pgo /dlv
 USER pgo:pgo
 RUN ls -l /
 
-CMD ["/dlv", "--listen=:7777", "--headless=true", "--api-version=2", "exec", "/postgres-operator"]
+CMD ["/dlv", "--listen=:7777", "--headless=true", "--api-version=2", "exec", "/postgres-operator"]

docker/Dockerfile

@@ -9,9 +9,9 @@ RUN apt-get update \
 
 COPY build/* /
 
-RUN addgroup -g 1000 pgo
-RUN adduser -D -u 1000 -G pgo -g 'Postgres Operator' pgo
+RUN addgroup --gid 1000 pgo
+RUN adduser pgo --gecos 'Postgres Operator' --uid 1000 --disabled-password --ingroup pgo
 
 USER 1000:1000
 
-ENTRYPOINT ["/postgres-operator"]
+ENTRYPOINT ["/postgres-operator"]

docker/logical-backup/Dockerfile

@@ -1,8 +1,8 @@
-FROM ubuntu:20.04
+FROM ubuntu:18.04
 LABEL maintainer="Team ACID @ Zalando <team-acid@zalando.de>"
 
 SHELL ["/bin/bash", "-o", "pipefail", "-c"]
-RUN apt-get update \
+RUN apt-get update     \
     && apt-get install --no-install-recommends -y \
         apt-utils \
         ca-certificates \

ui/Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:20.04
+FROM alpine
 LABEL maintainer="Team ACID @ Zalando <team-acid@zalando.de>"
 
 EXPOSE 8081