From 66bfd4f6955beb0d76a6cb2703ab47b60ce6a33e Mon Sep 17 00:00:00 2001
From: S'Bussiso Dube <80188685+Sbussiso@users.noreply.github.com>
Date: Mon, 14 Sep 2026 02:27:09 -0700
Subject: [PATCH] Match pg_dump to the server major, or the nightly backup
 fails
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The Rust port replaced the image's PGDG-sourced postgresql-client-18 with
Debian's default postgresql-client, which is 15. The cluster is 18, and
pg_dump refuses to dump a newer server outright:

  pg_dump: error: aborting because of server version mismatch
  detail: server version: 18.6; pg_dump version: 15.19

So the deploy went green and the backup would have failed at 09:47 UTC —
the same shape as the scale-to-zero break this repo already had once,
where `flyctl ssh console` could not wake a stopped machine.

The Python Dockerfile had solved this deliberately: add the PGDG apt
repo, install postgresql-client-18, purge gnupg afterwards. The port
carried over the *importance* of having pg_dump and dropped the
*solution*. Restored verbatim.

Caught by running the real thing rather than trusting `command -v
pg_dump` — the binary was present and on PATH, and still useless.
Verified in the rebuilt image: pg_dump (PostgreSQL) 18.6.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
---
 Dockerfile | 28 ++++++++++++++++++++++------
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 0146083..749eedf 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -26,17 +26,33 @@ FROM debian:bookworm-slim
 # postgresql-client is NOT optional here, unlike the sync service.
 # .github/workflows/backup.yml runs `flyctl ssh console -C "bash
 # /app/scripts/backup_db.sh"` nightly, and that script needs pg_dump and
-# psql on PATH. Dropping them would leave a green deploy and a backup job
-# that fails at 09:47 UTC — the failure mode this repo has already had
-# once, when scale-to-zero broke the same job.
+# psql on PATH.
+#
+# AND THE MAJOR VERSION MUST MATCH THE SERVER. Debian bookworm ships
+# postgresql-client 15; the cluster is 18. pg_dump refuses to dump a
+# newer server outright:
+#
+#   pg_dump: error: aborting because of server version mismatch
+#   detail: server version: 18.6; pg_dump version: 15.19
+#
+# So this pulls client 18 from PGDG, exactly as the Python image did —
+# that Dockerfile went to the same trouble and the port initially dropped
+# it, which produced a green deploy and a broken backup. gnupg is purged
+# after adding the key so it doesn't linger in the runtime image.
 #
 # ca-certificates for outbound TLS; bash because backup_db.sh is bash,
 # not sh.
 RUN apt-get update \
  && apt-get install -y --no-install-recommends \
-      ca-certificates \
-      postgresql-client \
-      bash \
+      ca-certificates curl gnupg bash \
+ && install -d /usr/share/postgresql-common/pgdg \
+ && curl -fsSL https://www.postgresql.org/media/keys/ACCC4CF8.asc \
+      -o /usr/share/postgresql-common/pgdg/apt.postgresql.org.asc \
+ && echo "deb [signed-by=/usr/share/postgresql-common/pgdg/apt.postgresql.org.asc] https://apt.postgresql.org/pub/repos/apt bookworm-pgdg main" \
+      > /etc/apt/sources.list.d/pgdg.list \
+ && apt-get update \
+ && apt-get install -y --no-install-recommends postgresql-client-18 \
+ && apt-get purge -y gnupg && apt-get autoremove -y \
  && rm -rf /var/lib/apt/lists/*
 
 # Unprivileged. The Python image ran as root; nothing here needs it.