diesel-guard: Catch blocking PostgreSQL migrations before they hit production

[ayarotsky]

I built a tool to catch dangerous DB migrations in projects that use Diesel ORM. Operations like CREATE INDEX idx_users_email ON users(email) seem harmless, but block all writes for the entire duration of the index build.

diesel-guard analyzes your migration SQL and shows exactly what's unsafe and how to fix it:

❌ ADD INDEX non-concurrently

Problem:
  Creating an index without CONCURRENTLY acquires a SHARE lock,
  blocking all writes (INSERT, UPDATE, DELETE) during the build.

Safe alternative:
  CREATE INDEX CONCURRENTLY idx_users_email ON users(email);
Installation

cargo install diesel-guard
diesel-guard check migrations/

Current checks

• ADD COLUMN with DEFAULT
• DROP COLUMN
• CREATE INDEX without CONCURRENTLY
• ALTER COLUMN TYPE
• ALTER COLUMN SET NOT NULL
• CREATE EXTENSION
• Unnamed constraints
• RENAME COLUMN
• RENAME TABLE
• ADD SERIAL column to existing tables

Repo: https://github.com/ayarotsky/diesel-guard

[weiznich]

Hi there, that looks really great. Mind submitting a PR adding this as notable community project to the diesel web page here?

[ayarotsky]

Ready sgrif/diesel.rs-website#266

[ayarotsky]

Added Path to v1.