Assuming your current working directory is the one where this Readme file is located, the one-liner command which builds and starts the VM configured to run Self Host Blocks’ Nextcloud is:

rm nixos.qcow2; \
  nixos-rebuild build-vm --flake .#basic \
  && QEMU_NET_OPTS="hostfwd=tcp::2222-:2222,hostfwd=tcp::8080-:80" \
     ./result/bin/run-nixos-vm

This will deploy the basic demo. If you want to deploy the ldap or sso demos, use respectively the .#ldap or .#sso flake uris.

You can even test the demos from any directory without cloning this repository by using the GitHub uri like github:ibizaman/selfhostblocks?path=demo/nextcloud

It is very important to remove leftover nixos.qcow2 files, if any.

You can ssh into the VM like this, but this is not required for the demo:

ssh -F ssh_config example

But before that works, you will need to change the permission of the ssh key like so:

chmod 600 sshkey

This is only needed because git mangles with the permissions. You will not even see this change in git status.

If you deploy with Colmena, you must first build the VM and start it:

rm nixos.qcow2; \
  nixos-rebuild build-vm-with-bootloader --fast -I nixos-config=./configuration.nix -I nixpkgs=. ; \
  QEMU_NET_OPTS="hostfwd=tcp::2222-:2222,hostfwd=tcp::8080-:80" ./result/bin/run-nixos-vm

It is very important to remove leftover nixos.qcow2 files, if any.

This last call is blocking, so I advice adding a & at the end of the command otherwise you will need to run the rest of the commands in another terminal.

With the VM started, make the secrets in secrets.yaml decryptable in the VM. This change will appear in git status but you don’t need to commit this.

SOPS_AGE_KEY_FILE=keys.txt \
  nix run --impure nixpkgs#sops -- --config sops.yaml -r -i \
  --add-age $(nix shell nixpkgs#ssh-to-age --command sh -c 'ssh-keyscan -p 2222 -t ed25519 -4 localhost 2>/dev/null | ssh-to-age') \
  secrets.yaml

The nested command, the one in between the parenthesis $(...), is used to print the VM’s public age key, which is then added to the secrets.yaml file in order to make the secrets decryptable by the VM.

If you forget this step, the deploy will seem to go fine but the secrets won’t be populated and Nextcloud will not start.

Make the ssh key private:

chmod 600 sshkey

This is only needed because git mangles with the permissions. You will not even see this change in git status.

You can ssh into the VM like this, but this is not required for the demo:

ssh -F ssh_config example

Assuming you already deployed the basic demo, now you must add the following entry to the /etc/hosts file on the host machine (not the VM):

networking.hosts = {
  "127.0.0.1" = [ "n.example.com" ];
};

Which produces:

$ cat /etc/hosts
127.0.0.1 n.example.com

Go to http://n.example.com:8080 and login with:

This is the admin user of Nextcloud and that’s the end of the basic demo.

Assuming you already deployed the ldap demo, now you must add the following entry to the /etc/hosts file on the host machine (not the VM):

networking.hosts = {
  "127.0.0.1" = [ "n.example.com" "ldap.example.com" ];
};

Which produces:

$ cat /etc/hosts
127.0.0.1 n.example.com ldap.example.com

Go first to http://ldap.example.com:8080 and login with:

Create the group nextcloud_user and a create a user and assign them to that group.

Finally, go to http://n.example.com/login:8080 and login with the user and password you just created above.

Nextcloud doesn’t like being run without SSL protection, which this demo does not setup, so you might see errors loading scripts. See the sso demo for SSL.

This is the end of the ldap demo.

At this point, it is assumed you already deployed the sso demo. There is no host to add to /etc/hosts here. Instead, there is a dnsmasq server running in the VM and you must create a SOCKS proxy to connect to it like so:

ssh -F ssh_config -D 1080 -N example

This is a blocking call but it is not necessary to fork this process in the background by appending & because we will not need to use the terminal for the rest of the demo.

Now, configure your browser to use that SOCKS proxy. When that’s done go to https://ldap.example.com and login with:

Create the group nextcloud_user and a create a user and assign them to that group.

Visit https://auth.example.com and make your browserauthorize the certificate.

Finally, go to https://n.example.com and login with the user and password you just created above. You will see that the login page is actually the one from the SSO provider.

This is the end of the sso demo.

More info about the VM.

We use build-vm-with-bootloader instead of just build-vm as that’s the only way to deploy to the VM.

The VM’s User and password are both nixos, as setup in the configuration.nix file under user.users.nixos.initialPassword.

You can login with ssh -F ssh_config example. You just need to accept the fingerprint.

The VM’s hard drive is a file name nixos.qcow2 in this directory. It is created when you first create the VM and re-used since. You can just remove it when you’re done.

That being said, the VM uses tmpfs to create the writable nix store so if you stumble in a disk space issue, you must increase the virtualisation.vmVariantWithBootLoader.virtualisation.memorySize setting.

More info about the secrets can be found in the Usage manual

To open the secrets.yaml file and optionnally edit it, run:

SOPS_AGE_KEY_FILE=keys.txt nix run --impure nixpkgs#sops -- \
  --config sops.yaml \
  secrets.yaml

You can generate random secrets with:

nix run nixpkgs#openssl -- rand -hex 64

If you choose secrets too small, some services could refuse to start.

The private and public ssh keys were created with:

ssh-keygen -t ed25519 -f sshkey

You don’t need to copy over the ssh public key over to the VM as we set the keyFiles option which copies the public key when the VM gets created. This allows us also to disable ssh password authentication.

For reference, if instead you didn’t copy the key over on VM creating and enabled ssh authentication, here is what you would need to do to copy over the key:

$ nix shell nixpkgs#openssh --command ssh-copy-id -i sshkey -F ssh_config example

If you get a NAR hash mismatch error like hereunder, you need to run nix flake lock --update-input selfhostblocks.

error: NAR hash mismatch in input ...

If you update the Self Host Blocks configuration in flake.nix file, you can just re-deploy.

If you update the configuration.nix file, you will need to rebuild the VM from scratch.

If you update a module in the Self Host Blocks repository, you will need to update the lock file with:

nix flake lock --override-input selfhostblocks ../.. --update-input selfhostblocks