readme: add disko and nixos-anywhere

README.md

@@ -6,12 +6,13 @@ It is fully reproducible, flakes based, and position-independent, ...
 used flakes:
 
 - image generation: [nixos-generators](https://github.com/nix-community/nixos-generators)
-- disk formatting: [disko](https://github.com/nix-community/disko)
+- disk partitioning: [disko](https://github.com/nix-community/disko)
 - secrets: [sops-nix](https://github.com/Mic92/sops-nix)
 - deployment: [deploy-rs](https://github.com/serokell/deploy-rs), see [usage](#usage)
 - formatting: [pre-commit-hooks](https://github.com/cachix/pre-commit-hooks.nix)
+- install: [nixos-anywhere](https://github.com/numtide/nixos-anywhere/)
 
-## structure
+## Structure
 
 ```text
 .
@@ -23,34 +24,116 @@ used flakes:
 └── profiles     # summarize module collections into single options
 ```
 
-## usage
+## Usage
 
-updating:
+- updating:
 
-```bash
-nix flake update
-```
+    ```bash
+    nix flake update
+    ```
 
-deployment:
+- deployment:
 
-```bash
-deploy .#myHost
-```
+    ```bash
+    deploy .#<flake>
+    ```
 
-secrets:
+- secrets:
 
-```bash
-sops ./machines/myHost/secrets.yaml
-```
+    ```bash
+    sops ./machines/<host>/secrets.yaml
+    ```
 
-images:
+- images:
 
-```bash
-nix build .#install-iso
-nix build .#aarch64-install --system aarch64-linux
-```
+    ```bash
+    nix build .#install-iso
+    nix build .#aarch64-install --system aarch64-linux
+    ```
 
-## inspired by
+- vms:
+
+    ```bash
+    nixos-rebuild build-vm --flake .#<flake>
+    ```
+
+- (re-)install:
+
+    make sure you have ssh-root access to the machine and the ssh-key is used properly.
+    (It does not matter what system is installed before.)
+
+    1. generate config (only needed for new host)
+
+        get `nixos-generate-config` to run via nix and execute
+
+        ```bash
+        nixos-generate-config --no-filesystems --root $(mktemp -d)
+        ```
+
+        reuse the `hardware-configuration.nix` to create a new machine with its flake.
+
+    1. setup secrets
+
+        1. new host
+
+            then prepare the secrets in the following layout:
+
+            ```bash
+            # enter disk encryption key
+            echo "my-super-safe-password" > /tmp/disk.key
+
+            temp=$(mktemp -d)
+            # ssh-host keys
+            install -d -m755 "$temp/etc/ssh"
+            ssh-keygen -o -t rsa -a 100 -N "" -b 4096 -f "$temp/etc/ssh/ssh_host_rsa_key"
+            chmod 600 "$temp/etc/ssh/ssh_host_rsa_key"
+            ssh-keygen -o -t ed25519 -a 100 -N "" -f "$temp/etc/ssh/ssh_host_ed25519_key"
+            chmod 600 "$temp/etc/ssh/ssh_host_ed25519_key"
+            # initrd key
+            install -d -m755 "$temp/etc/secrets/initrd"
+            ssh-keygen -o -t ed25519 -a 100 -N "" -f "$temp/etc/secrets/initrd/ssh_host_ed25519_key"
+            chmod 600 "$temp/etc/secrets/initrd/ssh_host_ed25519_key"
+            ```
+
+        1. existing host
+
+            ```bash
+            echo "my-super-safe-password" > /tmp/disk.key
+            temp=$(mktemp -d)
+            printf '%M %p\n'
+            ```
+
+            should result in something looking like this
+
+            ```text
+            drwx------ $temp
+            drwxr-xr-x $temp/etc
+            drwxr-xr-x $temp/etc/ssh
+            -rw------- $temp/etc/ssh/ssh_host_rsa_key
+            -rw------- $temp/etc/ssh/ssh_host_ed25519_key
+            -rw-r--r-- $temp/etc/ssh/ssh_host_rsa_key.pub
+            -rw-r--r-- $temp/etc/ssh/ssh_host_ed25519_key.pub
+            drwxr-xr-x $temp/etc/secrets
+            drwxr-xr-x $temp/etc/secrets/initrd
+            -rw------- $temp/etc/secrets/initrd/ssh_host_ed25519_key
+            -rw-r--r-- $temp/etc/secrets/initrd/ssh_host_ed25519_key.pub
+            ```
+
+    1. execute install
+
+        now simply install by executing (this will delete all data!):
+
+        ```bash
+        nix run github:numtide/nixos-anywhere -- \
+            --disk-encryption-keys /tmp/disk.key /tmp/disk.key \
+            --extra-files "$temp" \
+            --flake .#<flake> \
+            root@<host>
+        ```
+
+</details>
+
+## Inspired by
 
 - [Nix config by Mic92](https://github.com/Mic92/dotfiles)
 - [Nix config by ambroisie](https://github.com/ambroisie/nix-config)