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electric-postgres-security

security
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Pre-deploy security checklist for Postgres with Electric. Checks REPLICATION role, SELECT grants, CREATE on database, table ownership, REPLICA IDENTITY FULL on all synced tables, publication management (auto vs manual with ELECTRIC_MANUAL_TABLE_PUBLISHING), connection pooler exclusion for DATABASE_URL (use direct connection), and ELECTRIC_POOLED_DATABASE_URL for pooled queries. Load before deploying Electric to production or when diagnosing Postgres permission errors.

This skill builds on electric-proxy-auth. Read it first for proxy security patterns.

Electric — Postgres Security Checklist

Run through each section before deploying Electric to production.

User Permission Checks

Check: Electric user has REPLICATION role

Expected:

sql
SELECT rolreplication FROM pg_roles WHERE rolname = 'electric_user';
-- Should return: true

Fail condition: rolreplication = false or user does not exist. Fix: ALTER ROLE electric_user WITH REPLICATION;

Check: Electric user has SELECT on synced tables

Expected:

sql
SELECT has_table_privilege('electric_user', 'todos', 'SELECT');
-- Should return: true

Fail condition: Returns false. Fix: GRANT SELECT ON todos TO electric_user; or GRANT SELECT ON ALL TABLES IN SCHEMA public TO electric_user;

Check: Electric user has CREATE on database

Expected:

sql
SELECT has_database_privilege('electric_user', current_database(), 'CREATE');
-- Should return: true (unless using manual publishing mode)

Fail condition: Returns false and not using ELECTRIC_MANUAL_TABLE_PUBLISHING=true. Fix: GRANT CREATE ON DATABASE mydb TO electric_user;

Table Configuration Checks

Check: REPLICA IDENTITY FULL on all synced tables

Expected:

sql
SELECT relname, relreplident
FROM pg_class
WHERE relname IN ('todos', 'users')
  AND relreplident = 'f';  -- 'f' = FULL

Fail condition: relreplident is 'd' (default) or 'n' (nothing). Fix: ALTER TABLE todos REPLICA IDENTITY FULL;

Check: Tables are in the Electric publication

Expected:

sql
SELECT tablename FROM pg_publication_tables
WHERE pubname = 'electric_publication_default';

Fail condition: Synced tables missing from the list. Fix (manual mode): ALTER PUBLICATION electric_publication_default ADD TABLE todos;

Connection Checks

Check: DATABASE_URL uses direct connection (not pooler)

Expected:

DATABASE_URL=postgres://user:pass@db-host:5432/mydb

Fail condition: URL points to a connection pooler (e.g., PgBouncer on port 6432, Supabase pooler). Fix: Use direct Postgres connection for DATABASE_URL. Set ELECTRIC_POOLED_DATABASE_URL separately for pooled queries.

Check: wal_level is set to logical

Expected:

sql
SHOW wal_level;
-- Should return: logical

Fail condition: Returns replica or minimal. Fix: Set wal_level = logical in postgresql.conf and restart Postgres.

Common Security Mistakes

CRITICAL Using connection pooler for DATABASE_URL

Wrong:

sh
DATABASE_URL=postgres://user:pass@pooler.example.com:6432/mydb

Correct:

sh
DATABASE_URL=postgres://user:pass@db.example.com:5432/mydb
ELECTRIC_POOLED_DATABASE_URL=postgres://user:pass@pooler.example.com:6432/mydb

Connection poolers (except PgBouncer 1.23+) do not support logical replication. Electric must connect directly to Postgres for its replication slot.

Source: website/docs/guides/deployment.md:91

HIGH Missing REPLICA IDENTITY FULL on tables

Wrong:

sql
CREATE TABLE todos (id UUID PRIMARY KEY, text TEXT);
-- Replica identity defaults to 'default' (PK only)

Correct:

sql
CREATE TABLE todos (id UUID PRIMARY KEY, text TEXT);
ALTER TABLE todos REPLICA IDENTITY FULL;

Without REPLICA IDENTITY FULL, Electric cannot stream the full row on updates and deletes. Updates may be missing non-PK columns.

Source: website/docs/guides/troubleshooting.md:373

HIGH Electric user without REPLICATION role

Wrong:

sql
CREATE USER electric_user WITH PASSWORD 'secret';

Correct:

sql
CREATE USER electric_user WITH PASSWORD 'secret' REPLICATION;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO electric_user;

Electric uses logical replication and requires the REPLICATION role on the database user.

Source: website/docs/guides/postgres-permissions.md

Pre-Deploy Summary

  • Electric user has REPLICATION role
  • Electric user has SELECT on all synced tables
  • Electric user has CREATE on database (or manual publishing configured)
  • All synced tables have REPLICA IDENTITY FULL
  • All synced tables are in the Electric publication
  • DATABASE_URL uses direct Postgres connection (not pooler)
  • wal_level = logical in Postgres config
  • ELECTRIC_SECRET is set (not using ELECTRIC_INSECURE=true)
  • Secrets are injected server-side only (never in client bundle)

See also: electric-proxy-auth/SKILL.md — Proxy injects secrets that Postgres security enforces. See also: electric-deployment/SKILL.md — Deployment requires correct Postgres configuration.

Version

Targets Electric sync service v1.x.