Remove obsolete Dockerfile.alpine

It hasn't been used for anything for a long time. The comments still
talked about librocksdb, which we also haven't used for a long time.

Dockerfile.alpine

@@ -1,95 +0,0 @@
-#
-# Docker image for console integration testing.
-#
-# We may also reuse it in CI to unify installation process and as a general binaries building
-# tool for production servers.
-#
-# Dynamic linking is used for librocksdb and libstdc++ because librocksdb-sys calls
-# bindgen with "dynamic" feature flag. This also prevents usage of dockerhub alpine-rust
-# images which are statically linked and have guards against any dlopen. I would rather
-# prefer all static binaries so we may change the way librocksdb-sys builds or wait until
-# we will have our own storage and drop rockdb dependency.
-#
-# Cargo-chef is used to separate dependencies building from main binaries building. This
-# way `docker build` will download and install dependencies only of there are changes to
-# out Cargo.toml files.
-#
-
-
-#
-# build postgres separately -- this layer will be rebuilt only if one of
-# mentioned paths will get any changes
-#
-FROM alpine:3.13 as pg-build
-RUN apk add --update clang llvm compiler-rt compiler-rt-static lld musl-dev binutils \
-                     make bison flex readline-dev zlib-dev perl linux-headers libseccomp-dev
-WORKDIR zenith
-COPY ./vendor/postgres vendor/postgres
-COPY ./Makefile Makefile
-# Build using clang and lld
-RUN CC='clang' LD='lld' CFLAGS='-fuse-ld=lld --rtlib=compiler-rt' make postgres -j4
-
-#
-# Calculate cargo dependencies.
-# This will always run, but only generate recipe.json with list of dependencies without
-# installing them.
-#
-FROM alpine:20210212 as cargo-deps-inspect
-RUN apk add --update rust cargo
-RUN cargo install cargo-chef
-WORKDIR zenith
-COPY . .
-RUN cargo chef prepare --recipe-path recipe.json
-
-#
-# Build cargo dependencies.
-# This temp cantainner would be build only if recipe.json was changed.
-#
-FROM alpine:20210212 as deps-build
-RUN apk add --update rust cargo openssl-dev clang build-base
-# rust-rocksdb can be built against system-wide rocksdb -- that saves about
-# 10 minutes during build. Rocksdb apk package is in testing now, but use it
-# anyway. In case of any troubles we can download and build rocksdb here manually
-# (to cache it as a docker layer).
-RUN apk --no-cache --update --repository https://dl-cdn.alpinelinux.org/alpine/edge/testing add rocksdb-dev
-WORKDIR zenith
-COPY --from=pg-build /zenith/tmp_install/include/postgresql/server tmp_install/include/postgresql/server
-COPY --from=cargo-deps-inspect /root/.cargo/bin/cargo-chef /root/.cargo/bin/
-COPY --from=cargo-deps-inspect /zenith/recipe.json recipe.json
-RUN ROCKSDB_LIB_DIR=/usr/lib/ cargo chef cook --release --recipe-path recipe.json
-
-#
-# Build zenith binaries
-#
-FROM alpine:20210212 as build
-RUN apk add --update rust cargo openssl-dev clang build-base
-RUN apk --no-cache --update --repository https://dl-cdn.alpinelinux.org/alpine/edge/testing add rocksdb-dev
-WORKDIR zenith
-COPY . .
-# Copy cached dependencies
-COPY --from=pg-build /zenith/tmp_install/include/postgresql/server tmp_install/include/postgresql/server
-COPY --from=deps-build /zenith/target target
-COPY --from=deps-build /root/.cargo /root/.cargo
-RUN cargo build --release
-
-#
-# Copy binaries to resulting image.
-# build-base hare to provide libstdc++ (it will also bring gcc, but leave it this way until we figure
-# out how to statically link rocksdb or avoid it at all).
-#
-FROM alpine:3.13
-RUN apk add --update openssl build-base libseccomp-dev
-RUN apk --no-cache --update --repository https://dl-cdn.alpinelinux.org/alpine/edge/testing add rocksdb
-COPY --from=build /zenith/target/release/pageserver /usr/local/bin
-COPY --from=build /zenith/target/release/safekeeper /usr/local/bin
-COPY --from=build /zenith/target/release/proxy /usr/local/bin
-COPY --from=pg-build /zenith/tmp_install /usr/local
-COPY docker-entrypoint.sh /docker-entrypoint.sh
-
-RUN addgroup zenith && adduser -h /data -D -G zenith zenith
-VOLUME ["/data"]
-WORKDIR /data
-USER zenith
-EXPOSE 6400
-ENTRYPOINT ["/docker-entrypoint.sh"]
-CMD ["pageserver"]