The /login route was experiencing issues with React Server Component
(RSC) requests interfering with one-time authentication callbacks. When
users navigated to /login via client-side routing (router.push()),
Next.js automatically triggered _rsc requests that could consume
single-use createCallback tokens, breaking OIDC and SAML authentication
flows.
# Which Problems Are Solved
When users attempt to log in, Next.js automatically makes requests with
the `_rsc=1` query parameter for React Server Components. The current
implementation treats these as server errors:
```typescript
// Before
if (_rsc) {
return NextResponse.json({ error: "No _rsc supported" }, { status: 500 });
}
```
This results in:
- Spurious 500 error logs polluting monitoring systems
- False alerts for server failures
- Difficulty distinguishing real issues from benign RSC requests
# How the Problems Are Solved
This PR implements a comprehensive refactoring that:
- Eliminates RSC interference by providing server actions for internal
auth flow completion
- Separates concerns between external flow initiation and internal flow
completion
- Extracts shared utilities to improve code maintainability and
reusability
- Maintains full backward compatibility for external applications
# Additional Context
## New Architecture
- auth-flow.ts: Shared utilities for auth flow completion with RSC
protection
- flow-initiation.ts: Extracted OIDC/SAML flow initiation logic (~400
lines)
- auth.ts: Server actions for internal components
## Route Handler Simplification
- route.ts: Reduced from ~350 lines to ~75 lines
- External-only focus: Now handles only flow initiation for external
applications
- Removed completion logic: External apps use their own callback URLs
- Enhanced validation: Early RSC blocking and parameter validation
## Flow Logic Improvements
- Early return patterns: Guard clauses eliminate deep nesting
- Better error handling: Specific error messages for different failure
modes
- Fixed SAML flow: Addressed incomplete logic
- Consistent session handling: Unified approach across OIDC and SAML
# Which Problems Are Solved
- The previous monorepo in monorepo structure for the login app and its
related packages was fragmented, complicated and buggy.
- The process for building and testing the login container was
inconsistent between local development and CI.
- Lack of clear documentation as well as easy and reliable ways for
non-frontend developers to reproduce and fix failing PR checks locally.
# How the Problems Are Solved
- Consolidated the login app and its related npm packages by moving the
main package to `apps/login/apps/login` and merging
`apps/login/packages/integration` and `apps/login/packages/acceptance`
into the main `apps/login` package.
- Migrated from Docker Compose-based test setups to dev container-based
setups, adding support for multiple dev container configurations:
- `.devcontainer/base`
- `.devcontainer/turbo-lint-unit`
- `.devcontainer/turbo-lint-unit-debug`
- `.devcontainer/login-integration`
- `.devcontainer/login-integration-debug`
- Added npm scripts to run the new dev container setups, enabling exact
reproduction of GitHub PR checks locally, and updated the pipeline to
use these containers.
- Cleaned up Dockerfiles and docker-bake.hcl files to only build the
production image for the login app.
- Cleaned up compose files to focus on dev environments in dev
containers.
- Updated `CONTRIBUTING.md` with guidance on running and debugging PR
checks locally using the new dev container approach.
- Introduced separate Dockerfiles for the login app to distinguish
between using published client packages and building clients from local
protos.
- Ensured the login container is always built in the pipeline for use in
integration and acceptance tests.
- Updated Makefile and GitHub Actions workflows to use
`--frozen-lockfile` for installing pnpm packages, ensuring reproducible
installs.
- Disabled GitHub release creation by the changeset action.
- Refactored the `/build` directory structure for clarity and
maintainability.
- Added a `clean` command to `docks/package.json`.
- Experimentally added `knip` to the `zitadel-client` package for
improved linting of dependencies and exports.
# Additional Changes
- Fixed Makefile commands for consistency and reliability.
- Improved the structure and clarity of the `/build` directory to
support seamless integration of the login build.
- Enhanced documentation and developer experience for running and
debugging CI checks locally.
# Additional Context
- See updated `CONTRIBUTING.md` for new local development and debugging
instructions.
- These changes are a prerequisite for further improvements to the CI
pipeline and local development workflow.
- Closes#10276
Max PeintnerandGitHub
Elio BischofandGitHub