# Hacking on osbuild-composer

## Virtual Machine

*osbuild-composer* cannot be run from the source tree, but has to be installed
onto a system. We recommend doing this by building rpms, with:

    make rpm

This will build rpms from the latest git HEAD (remember to commit changes), for
the current operating system, with a version that contains the commit hash. The
packages end up in `./rpmbuild/RPMS/$arch`.

RPMS are easiest to deal with when they're in a dnf repository. To turn this
directory into a dnf repository and serve it on localhost:8000, run:

    createrepo_c ./rpmbuild/RPMS/x86_64
    python3 -m http.server --directory ./rpmbuild/RPMS/x86_64 8000

To start a ephemeral virtual machine using this repository, run:

    tools/deploy-qemu IMAGE tools/deploy/test

`IMAGE` has to be a path to an cloud-init-enabled image matching the host
operating system, because that's what the packages were built for above.
Note that the Fedora/RHEL cloud images might be too small for some tests
to pass. Run `qemu-img resize IMAGE 10G` to grow them, cloud-init's growpart
module will grow the root partition automatically during boot. 

The second argument points to a directory from which cloud-init user-data is
generated (see `tools/gen-user-data` for details). The one given above tries to
mimic what is run on *osbuild-composer*'s continuous integration
infrastructure, i.e., installing `osbuild-composer-tests` and starting the
service.

The virtual machine uses qemu's [user networking][1], forwarding port 22 to
the host's 2222 and 443 to 4430. You can log into the running machine with

    ssh admin@localhost -p 2222

The password is `foobar`. Stopping the machine loses all data.

For a quick compile and debug cycle, we recommend iterating code using thorough
unit tests before going through the full workflow described above.

[1]: https://wiki.qemu.org/Documentation/Networking#User_Networking_.28SLIRP.29

## Containers

*osbuild-composer* and *osbuild-composer-worker* can be run using Docker
containers. Building and starting containers is generally faster than building
RPMs and installing them in a VM, so this method is more convenient for
developing and testing changes quickly. However, using this method has several
downsides:
- It doesn't build the RPMs so the `.spec` file isn't tested.
- The environment is quite different from production (e.g., installation paths,
  privileges and permissions).
- The setup is not complete for all required services, so some functionality
  isn't available for testing this way (e.g., Koji Hub and all its dependent
  services).

The containers are a good way to quickly test small changes, but before
submitting a Pull Request, it's recommended to run through all the tests using
the [Virtual Machine](#virtual-machine) setup described above.

### Configuration

Each service (*composer* and *worker*) requires a configuration file and a set
of certificates. The storage location for these is shared between the
containers for simplicity. By default it's configured to be at
`./containers/config`, but this can be changed in the
[`./distribution/.env`](./distribution/.env) file by modifying the value of the
`$CONTAINER_CONFIG_DIR` variable (both absolute and relative paths work).

Use the [`tools/gen-certs.sh`](./tools/gen-certs.sh) script to
generate the certificates (using the test OpenSSL config file):

    ./tools/gen-certs.sh ./test/data/x509/openssl.cnf ./containers/config  ./containers/config/ca

Note that the two arguments `./containers/config` and `./containers/config/ca`
should be the same location as the `$CONTAINER_CONFIG_DIR` described above

The services also require a config file each which they expect to be in the
same directory. The following test files can be copied into it:

    cp ./test/data/composer/osbuild-composer.toml ./test/data/composer/osbuild-worker.toml ./containers/config/

The `$CONTAINER_CONFIG_DIR` (default `containers/config`) directory will be mounted inside both containers (see
the [`docker-composer.yml`](./distribution/docker-compose.yml) file).

### Build and run

To build the containers, change into the `distribution/` directory and run:

    docker-compose build

To start the containers, change into the `distribution/` directory and run:

    docker-compose up

You can send requests to the *osbuild-composer* container directly using the
generated certificate and client key. For example, from the project root, run:

    curl -k --cert ./containers/config/client-crt.pem --key ./containers/config/client-key.pem https://172.30.0.10:9196/api/composer-koji/v1/status

To rebuild the containers after a change, add the `--build` flag to the `docker-compose` command:

    docker-compose up --build