Custom postgres entrypoint to handle major upgrades..

..appropriated from the coop-cloud/outline recipe.

abra.sh

@@ -1,2 +1,3 @@
-export CLICKHOUSE_CONF_VERSION=v1
+export CLICKHOUSE_CONF_VERSION=v2
 export CLICKHOUSE_USER_CONF_VERSION=v2
+export DB_ENTRYPOINT_VERSION=v1

compose.yml

@@ -30,9 +30,15 @@ services:
         - "traefik.http.routers.${STACK_NAME}.tls.certresolver=${LETS_ENCRYPT_ENV}"
         - coop-cloud.${STACK_NAME}.version=1.1.0+1.5.1
   db:
-    image: postgres:13.11-alpine
+    image: postgres:13.11
+    configs:
+      - source: db_entrypoint
+        target: /docker-entrypoint.sh
+        mode: 0555
+    # Custom docker entrypoint to handle major Postgres version upgrades
     volumes:
       - db-data:/var/lib/postgresql/data
+    entrypoint: /docker-entrypoint.sh
     environment:
       - POSTGRES_USER=plausible
       - POSTGRES_PASSWORD=plausible
@@ -68,3 +74,7 @@ configs:
   clickhouse-user-config:
     name: ${STACK_NAME}_clickhouse_user_config_${CLICKHOUSE_USER_CONF_VERSION}
     file: clickhouse-user-config.xml
+  db_entrypoint:
+    name: ${STACK_NAME}_db_entrypoint_${DB_ENTRYPOINT_VERSION}
+    file: entrypoint.postgres.sh.tmpl
+    template_driver: golang

entrypoint.postgres.sh.tmpl

@@ -0,0 +1,44 @@
+#!/bin/bash
+
+set -e
+
+MIGRATION_MARKER=$PGDATA/migration_in_progress
+OLDDATA=$PGDATA/old_data
+NEWDATA=$PGDATA/new_data
+
+if [ -e $MIGRATION_MARKER ]; then
+  echo "FATAL: migration was started but did not complete in a previous run. manual recovery necessary"
+  exit 1
+fi
+
+if [ -f $PGDATA/PG_VERSION ]; then
+  DATA_VERSION=$(cat $PGDATA/PG_VERSION)
+
+  if [ -n "$DATA_VERSION" -a "$PG_MAJOR" != "$DATA_VERSION" ]; then
+    echo "postgres data version $DATA_VERSION found, but need $PG_MAJOR. Starting migration"
+    echo "Installing postgres $DATA_VERSION"
+    sed -i "s/$/ $DATA_VERSION/" /etc/apt/sources.list.d/pgdg.list
+    apt-get update && apt-get install -y --no-install-recommends \
+      postgresql-$DATA_VERSION \
+      && rm -rf /var/lib/apt/lists/*
+    echo "shuffling around"
+    gosu postgres mkdir $OLDDATA $NEWDATA
+    chmod 700 $OLDDATA $NEWDATA
+    mv $PGDATA/* $OLDDATA/ || true
+    touch $MIGRATION_MARKER
+    echo "running initdb"
+    # abuse entrypoint script for initdb by making server error out
+    gosu postgres bash -c "export PGDATA=$NEWDATA ; /usr/local/bin/docker-entrypoint.sh --invalid-arg || true"
+    echo "running pg_upgrade"
+    cd /tmp
+    gosu postgres pg_upgrade --link -b /usr/lib/postgresql/$DATA_VERSION/bin -d $OLDDATA -D $NEWDATA -U $POSTGRES_USER
+    cp $OLDDATA/pg_hba.conf $NEWDATA/
+    mv $NEWDATA/* $PGDATA
+    rm -rf $OLDDATA
+    rmdir $NEWDATA
+    rm $MIGRATION_MARKER
+    echo "migration complete"
+  fi
+fi
+
+/usr/local/bin/docker-entrypoint.sh postgres