Dockerfile-multigres

# syntax=docker/dockerfile:1.4
# 1.4: minimum version for heredoc support in RUN (used for nix config below); also covers COPY --chmod (1.2+)
# Multigres PostgreSQL image — layered on top of the supabase base image.
#
# Put all ARGs up top for better discoverability.
# Use non-versioned `ARG THE_ARG` in the stage that uses it to get the ref to this one.
#
# The supabase image must be built first:
#   docker build -f Dockerfile-supabase -t supabase-postgres:17 .
#   docker build -f Dockerfile-multigres -t multigres:17 .
#
# Override the base image at build time:
#   docker build -f Dockerfile-multigres \
#       --build-arg SUPABASE_IMAGE=registry.example.com/supabase-postgres:17 \
#       -t multigres:17 .

ARG ALPINE_VERSION=3.23
ARG GOLANG_VERSION=1.26
ARG PGCTLD_REV=b713432298450dd0095498193e86d9f9a9f2c348
ARG SUPABASE_IMAGE=supabase-postgres:17

####################
# Stage 1: pgBackRest nix builder
####################
FROM alpine:${ALPINE_VERSION} AS pgbackrest-builder

RUN apk add --no-cache \
    bash \
    coreutils \
    curl \
    shadow \
    sudo \
    xz

RUN cat >/tmp/extra-nix.conf <<EOF
extra-experimental-features = nix-command flakes
extra-substituters = https://nix-postgres-artifacts.s3.amazonaws.com
extra-trusted-public-keys = nix-postgres-artifacts:dGZlQOvKcNEjvT7QEAJbcV6b6uk7VF/hWMjhYleiaLI=
EOF
RUN curl -L https://releases.nixos.org/nix/nix-2.34.6/install | sh -s -- --daemon --no-channel-add --yes --nix-extra-conf-file /tmp/extra-nix.conf
ENV PATH="${PATH}:/nix/var/nix/profiles/default/bin"

WORKDIR /nixpg
COPY flake.nix flake.lock ./
COPY nix/ ./nix/

RUN nix profile add path:.#pg-backrest && \
    nix store gc && \
    readlink -f /nix/var/nix/profiles/default/bin/pgbackrest > /pgbackrest-store-path

####################
# Stage 2: pgctld builder
####################

FROM golang:${GOLANG_VERSION}-alpine AS pgctld-builder

ARG PGCTLD_REV

RUN apk add --no-cache git

RUN git clone https://github.com/multigres/multigres.git /multigres && \
    cd /multigres && \
    git checkout ${PGCTLD_REV} && \
    # Copy pico CSS assets before build (mirrors pgctld.nix preBuild step)
    cp external/pico/pico.* go/common/web/templates/css/ 2>/dev/null || true && \
    CGO_ENABLED=0 go build -ldflags="-s -w" -o /usr/local/bin/pgctld ./go/cmd/pgctld

####################
# Stage 3: Multigres image
####################
# SUPABASE_IMAGE is set by the release workflow via --build-arg, derived from
# PG_VERSION and the release matrix in ansible/vars.yml.
FROM ${SUPABASE_IMAGE} AS production

# Merge pgBackRest nix store closure into the inherited /nix/store, then symlink the binary.
# We copy only the store (not the profile) to avoid clobbering the supabase image's profile.
COPY --from=pgbackrest-builder /nix/store /nix/store
COPY --from=pgbackrest-builder /pgbackrest-store-path /pgbackrest-store-path
RUN ln -sf "$(cat /pgbackrest-store-path)" /usr/local/bin/pgbackrest && \
    rm /pgbackrest-store-path

# Copy pgctld binary; keep it separate so the wrapper script can reference it cleanly
COPY --from=pgctld-builder /usr/local/bin/pgctld /usr/local/bin/pgctld-bin

# pgctld config template — /etc/pgctld is a mount point in k8s so use a custom dir
COPY docker/pgctld/postgresql.conf.tmpl /etc/pgctld-custom/postgresql.conf.tmpl
# Pre-init SQL: creates the postgres superuser before supabase init scripts run.
# docker-entrypoint.sh does this automatically; pgctld init does not.
COPY docker/pgctld/pre-init/ /etc/pgctld-custom/pre-init/

# Multigres-specific migration fixups: equivalents of Ansible after-create hooks
# (extension ownership, not run automatically in Docker).
# Filename sorts after 00-extension.sql so pg_stat_statements exists first.
COPY docker/pgctld/multigres-migrations/ /docker-entrypoint-initdb.d/migrations/

# Wrapper: injects --postgres-config-template on every pgctld call so unmodified
# k8s manifests and local provisioner commands work without extra flags
COPY --chmod=0755 docker/pgctld/pgctld-layered.sh /usr/local/bin/pgctld

# The supabase base config /etc/postgresql/postgresql.conf IS loaded in Multigres:
# the operator's --pg-initdb-extra-conf appends `include = '/etc/postgresql/postgresql.conf'`
# onto pgctld's generated config. It therefore must not carry settings that assume the
# base image's `postgres -D /etc/postgresql` layout, so we neutralize two here:
#
#   - data_directory = '/var/lib/postgresql/data' would override pgctld's -D/PGDATA and
#     redirect PostgreSQL off the freshly-initdb'd <pooler-dir>/pg_data to the base image's
#     empty dir, which fails startup ("data directory ... has invalid permissions") and
#     leaves the pooler stuck retrying the first backup forever. pgctld pins the data dir
#     via -D, so comment it out (matching the pre-layered image, which shipped it disabled).
#   - the wal-g include is dangling (wal-g is unused in Multigres; pgbackrest handles
#     backups), so delete it and its now-orphaned files.
RUN sed -i \
        -e "s|^data_directory = '/var/lib/postgresql/data'|#data_directory = '/var/lib/postgresql/data'|" \
        -e "/^include = '\/etc\/postgresql-custom\/wal-g.conf'/d" \
        /etc/postgresql/postgresql.conf && \
    rm -f /etc/postgresql-custom/wal-g.conf /home/postgres/wal_fetch.sh /root/wal_change_ownership.sh

# pgctld uses pooler-dir for pgBackRest config, unix sockets, and state files.
RUN mkdir -p /var/lib/pgctld && chown postgres:postgres /var/lib/pgctld

# No HEALTHCHECK defined here: inherits the probe from the supabase base image.
# Kubernetes ignores Docker HEALTHCHECK entirely — use readinessProbe in the Pod spec.
# STOPSIGNAL inherited from supabase base image (SIGINT — smart shutdown).
USER postgres

# pgctld is the cluster lifecycle manager for Multigres: it handles initdb,
# config templating, replication setup, and coordinated restarts. Running it
# as PID 1 ensures it receives stop signals directly and can shut down
# PostgreSQL cleanly before the container exits.
ENTRYPOINT ["/usr/local/bin/pgctld"]
# "server" is pgctld's daemon mode: auto-inits PGDATA if empty, starts PostgreSQL,
# and runs as a gRPC lifecycle server. The wrapper injects --postgres-config-template
# and --pg-initdb-sql-dirs; the CMD provides the subcommand and pooler-dir.
CMD ["server", "--pooler-dir", "/var/lib/pgctld"]