# Dev Guide

## No DB mode

When you are working on dex it's convenient to use the "--no-db" flag, which starts up Dex in a mode which uses an in-memory datastore for persistence. It also does not rotate keys, so no overlord is required.

In this mode you provide the binary with paths to files to connectors and users - there are example files you can use inside of `static/fixtures`, named "connectors.json.sample" and "users.json.sample" respectively. If you rename these to the equivalent without the ".sample", the defaults point to this location, making starting dex as simple as:

`./bin/dex-worker  --no-db`

*Do not use this flag in production* - it's not thread safe and data is destroyed when the process dies. In addition, there is no key rotation.

Note: If you want to test out the registration flow, you need to enable that feature by passing `--enable-registration=true` as well.

## Building

To build using the go binary on your host, use the `./build` script.

You can also use a copy of `go` hosted inside a Docker container if you prefix your command with `go-docker`, as in: `./go-docker ./build`

## Docker Build and Push

Once binaries are compiled you can build and push a dex image to quay.io. Before doing this step binaries must be built above using one of the build tools.

```
export DOCKER_USER=<<your user>>
export DOCKER_PASSWORD=<<your password>>
./build-docker-push
```

By default the script pushes to `quay.io/coreos/dex`; if you want to push to a different repository, override the `DOCKER_REGISTRY` and `DOCKER_REPO` environment variables.

## Rebuild API from JSON schema

Go API bindings are generated from a JSON Discovery file.
To regenerate run:

```
./schema/generator
```

For updating generator dependencies see docs in: `schema/generator_import.go`.

## Running Tests

To run all tests (except functional) use the `./test` script; 

If you want to test a single package only, use `PKG=<pkgname> ./test`

The functional tests require a database; create a database (eg. `createdb dex_func_test`) and then pass it as an environment variable to the functional test script, eg.  `DEX_TEST_DSN=postgres://localhost/dex_func_test?sslmode=disable ./test-functional`

To run these tests with Docker is a little trickier; you need to have a container running Postgres, and then you need to link that container to the container running your tests:


```
# Run the Postgres docker container, which creates a db called "postgres"
docker run --name dex_postgres -d postgres

# The host name in the DSN is "postgres"; that works because that is what we
# will alias the link as, which causes Docker to modify /etc/hosts with a "postgres"
# entry.
export DEX_TEST_DSN=postgres://postgres@postgres/postgres?sslmode=disable

# Run the test container, linking it to the Postgres container.
DOCKER_LINKS=dex_postgres:postgres DOCKER_ENV=DEX_TEST_DSN ./go-docker ./test-functional docker

# Remove the container after the tests are run.
rm -f dex_postgres
```