Add central postgres database

stacks/postgres/init/create-service-dbs.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+set -euo pipefail
+
+until pg_isready -U "$POSTGRES_USER" -q; do sleep 1; done
+
+for secret_file in /run/secrets/*_postgres_password; do
+  [ -f "$secret_file" ] || continue
+  [ "$secret_file" = "/run/secrets/postgres_password" ] && continue
+
+  service="$(basename "$secret_file" _postgres_password)"
+  password="$(cat "$secret_file")"
+
+  echo "Ensuring database and user for '$service'..."
+
+  psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" <<-SQL
+    DO \$\$
+    BEGIN
+      IF NOT EXISTS (SELECT FROM pg_roles WHERE rolname = '$service') THEN
+        CREATE ROLE "$service" WITH LOGIN PASSWORD '$password';
+      ELSE
+        ALTER ROLE "$service" WITH PASSWORD '$password';
+      END IF;
+    END
+    \$\$;
+
+    SELECT 'CREATE DATABASE "$service" OWNER "$service"'
+    WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = '$service')\gexec
+SQL
+done
+
+touch /tmp/init_complete

stacks/postgres/init/entrypoint.sh

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+#!/bin/bash
+set -euo pipefail
+
+/init/create-service-dbs.sh &
+
+exec docker-entrypoint.sh postgres