Amend README.rst with having a working vagrant in nix-shell now

morph/grid/local/README.rst

 Set up and use a network of local development VMs
 -------------------------------------------------
 
-... using `Vagrant <https://www.vagrantup.com/>`_ to manage VirtualBox VMs [#]_.
-To get started, first install Vagrant and make sure it works.
-One possible way to do it in NixOS:
-
-1. Install Vagrant, by adding the packages:
-
-  - ``vagrant`` (orchestrating virtual machines on the command line)
-     - Only use when version >= 2.2.16 has become available.  Else see below.
-  - Optional: ``packer`` (for creating your own VM images)
-
-2. Add configuration to install and enable VirtualBox:
-
-  - ``virtualisation.virtualbox.host.enable = true;``
-
-3. Add your user to the ``vboxusers`` group, for example:
-
-  - ``users.extraGroups.vboxusers.members = [ "flo" "jp" ];``
-
-
-.. [#] The author of this documentation wasted a lot of time trying to get Vagrant to work with KVM/libvirt.  Issues with networking that looked like guest misconfigurations vanished after changing to the better-tested combination of Vagrant and VirtualBox.
-
-
-Pre-Vagrant 2.2.16: Get Vagrant with the required fixes for NixOS guests
-````````````````````````````````````````````````````````````````````````
-
-The Vagrant nixos-guest template `received a critical update on 2021-03-08 <https://github.com/hashicorp/vagrant/commit/990d94ed9d0b3092e855bc1bb9deeeb7aa7792cf>`_ which came out with Vagrant version 2.2.16.
-
-If you run an older Nixpkgs, retrieve and use the latest Vagrant development version like so::
-
-  NIX_PATH=nixpkgs=https://github.com/NixOS/nixpkgs/archive/refs/heads/master.tar.gz nix-shell -p vagrant
+... using `Vagrant <https://www.vagrantup.com/>`_ to manage VirtualBox VMs.
+(The author of this documentation wasted a lot of time trying to get Vagrant to work with KVM/libvirt.
+Issues with networking that looked like guest misconfigurations vanished after changing to the better-tested combination of Vagrant and VirtualBox.)
 
 
 Use the local development environment
 `````````````````````````````````````
 
-1. Build and start the VMs::
+1. Enter the project's nix-shell::
+
+   nix-shell ../../../shell.nix
+
+2. Build and start the VMs::
 
     VAGRANT_DEFAULT_PROVIDER=virtualbox vagrant up
 
-2. Then, once::
+3. Then, make morph use this ssh config by adding the config to your user's ``~/.ssh/config`` file::
 
-    vagrant ssh-config > ./vagrant-ssh-config
+    install -d ~/.ssh ; vagrant ssh-config >> ~/.ssh/config
 
-3. Edit the output: Add the IPs from ``grid.nix`` to the ``vagrant-ssh-config`` **Host match blocks** so the config reads like::
+4. Edit the generated configuration: Add the ``publicIP`` addresses from ``grid.nix`` to ssh config **Host** match blocks (**not** HostName) so the ``Host`` lines all read like::
 
     Host payments1 192.168.67.21
-      HostName 192.168.67.21
+      HostName 127.0.0.1
       User vagrant
-      Port 22
       [...]
 
-4.  Then, make morph use this ssh config either - with newer morph [#]_ - by pointing it to it::
-
-     export SSH_CONFIG_FILE=./vagrant-ssh-config
+From version 1.5.0 Morph honors the ``SSH_CONFIG_FILE`` environment variable `since 3f90aa88 (March 2020, v 1.5.0) <https://github.com/DBCDK/morph/commit/3f90aa885fac1c29fce9242452fa7c0c505744ef#diff-d155ad793bd62e6ea4c44ba985049ecb13a4f4f32f799791b2bce695a16c0101>`_, so in the future this will get a bit more convenient.
 
-  Or, with older morph, adding the config to your user's ``~/.ssh/config`` file.
+5. Add your SSH key to users.nix so you'll be able to log in after deploying the new configuration::
 
-  .. [#]  Morph honors the ``SSH_CONFIG_FILE`` environment variable `since 3f90aa88 (March 2020, v 1.5.0) <https://github.com/DBCDK/morph/commit/3f90aa885fac1c29fce9242452fa7c0c505744ef#diff-d155ad793bd62e6ea4c44ba985049ecb13a4f4f32f799791b2bce695a16c0101>`_.
+    $EDITOR secrets/users.nix
 
 5. Then, build and deploy our software to the Vagrant VMs::
 
     morph build grid.nix
     morph push grid.nix
+    morph deploy grid.nix boot
+    vagrant halt
+    vagrant up
     morph upload-secrets grid.nix
-    morph deploy grid.nix switch
 
-  You will now be able to log in with the users and keys you set in your ``localdev-users.nix`` file.
+  You should now be able to log in with the users and keys you set in your ``users.nix`` file.