Add things I've learned from building a custom image

Still isn't working quite right, but it's a lot of stuff I'd rather not
lose.

README.md

@@ -9,5 +9,37 @@ Hat tip to [the negation](https://thenegation.com/posts/nixos-do-colmena/) for s
 Build a custom image for Digital Ocean:
 
 ```
-nix-build digitalocean/custom-image.nix
+> nix-build digitalocean/custom-image.nix
+...
+/nix/store/rm84j1a5bskhg2z8gz633m4apjyg848c-digital-ocean-image
+> ls -lh result/
+nixos-image-digital-ocean-25.05pre-git-x86_64-linux.qcow2.gz  nix-support/
 ```
+
+In order to "upload" the image to Digital Ocean you'll need to make the image available via URL. We can use Gleipnir static storage as an example:
+
+```
+rsync result/nixos-image-digital-ocean-25.05pre-git-x86_64-linux.qcow2.gz static.gleipnir.technology:/tmp
+```
+
+Make sure the image is accessible via a public URL.
+Then upload either through the web interface, or using [doctl](https://docs.digitalocean.com/reference/doctl/)
+
+```
+> doctl compute image create "Gleipnir NixOS 25.05" -v --image-description "NixOS 25.05 with ssh keys for eliribble baked in" --image-distribution nixos-25.05 --image-url "https://static.gleipnir.technology/nixos-image-digital-ocean-25.05pre-git-x86_64-linux.qcow2.gz" --region sfo3 --tag-names nixos
+ID           Name                    Type      Distribution    Slug    Public    Min Disk    Created
+192948683    Gleipnir NixOS 25.05    custom    Unknown OS              false     0           2025-07-10T20:22:43Z1G
+```
+
+Then start a droplet using that image:
+
+```
+> doctl compute droplet create "test2.nidus.cloud" --enable-ipv6 --image 192948683 --project-id ce2159e8-02f5-4169-8943-f34ccf812d23 --region sfo3 --size s-1vcpu-1gb --ssh-keys 48777034 --tag-name nixos --wait
+Error: POST https://api.digitalocean.com/v2/droplets: 422 (request "116c778d-8e72-4099-a7c6-c3ad37557c4c") image is not compatible with ipv6
+```
+
+Oh. [Well that sucks](https://docs.digitalocean.com/products/custom-images/details/limits/). Digital Ocean can't do IPv6 on custom images.
+
+## With cloud-init
+Cloud init data:
+curl http://169.254.169.254/metadata/v1.json

digitalocean/create-droplet.sh

@@ -0,0 +1,12 @@
+doctl compute droplet create \
+	"test.nidus.cloud" \
+	--enable-ipv6 \
+	--image debian-12-x64 \
+	--project-id ce2159e8-02f5-4169-8943-f34ccf812d23 \
+	--region sfo3 \
+	--size s-1vcpu-1gb \
+	--ssh-keys 48777034,46710608 \
+	--tag-name nixos \
+	--user-data-file digitalocean/infect-nixos.yaml \
+	--wait
+

digitalocean/custom-image.nix

@@ -1,18 +1,32 @@
 let
-  ## Pin the latest NixOS stable (nixos-25.05) release:
-  nixpkgs = builtins.fetchTarball {
-    url = "https://github.com/NixOS/nixpkgs/archive/refs/tags/25.05.tar.gz";
-    sha256 = "sha256:0q96nxw7jg9l9zlpa3wkma5xzmgkdnnajapwhgb2fk2ll224rgs1";
-  };
+	## Pin the latest NixOS stable (nixos-25.05) release:
+	nixpkgs = builtins.fetchTarball {
+		url = "https://github.com/NixOS/nixpkgs/archive/refs/tags/25.05.tar.gz";
+		sha256 = "sha256:1915r28xc4znrh2vf4rrjnxldw2imysz819gzhk9qlrkqanmfsxd";
+	};
 
-  ## Import nixpkgs:
-  pkgs = import nixpkgs { };
+	## Import nixpkgs:
+	pkgs = import nixpkgs { };
 
-  ## Prepare the NixOS configuration:
-  config = {
-    imports = [
-      "${nixpkgs}/nixos/modules/virtualisation/digital-ocean-image.nix"
-    ];
-  };
+	## Prepare the NixOS configuration:
+	config = {
+		imports = [
+			"${nixpkgs}/nixos/modules/virtualisation/digital-ocean-image.nix"
+		];
+		system.stateVersion = "25.05";
+		users.users.eliribble = {
+			extraGroups = [ "sudo" "wheel" ];
+			initialHashedPassword = "$y$j9T$XYOMZR8RZEiTnpaF8lsxv1$H7YbWDpzbnYXTLN0ZMhvtKOlSMy64P7C/RdLBaeaNf/";
+			isNormalUser = true;
+			openssh.authorizedKeys.keys = [
+				"ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIBvhtF6nRWlA6PVs71Eek7p0p2PxTd3P6ZEGFV2t75MB eliribble@nixos"
+				"ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHL1SpT3KR8XeXtH19muncYVrKxWzWdWtJYNTwoJGTm3 eliribble@Elis-Mac-mini.local"
+			];
+		};
+		users.users.root.openssh.authorizedKeys.keys = [
+			"ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIBvhtF6nRWlA6PVs71Eek7p0p2PxTd3P6ZEGFV2t75MB eliribble@nixos"
+			"ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHL1SpT3KR8XeXtH19muncYVrKxWzWdWtJYNTwoJGTm3 eliribble@Elis-Mac-mini.local"
+		];
+	};
 in
 (pkgs.nixos config).digitalOceanImage

digitalocean/infect-nixos.yaml

@@ -0,0 +1,3 @@
+#cloud-config
+runcmd:
+– curl https://raw.githubusercontent.com/sheran/nixos-infect/master/nixos-infect | PROVIDER=digitalocean NIX_CHANNEL=nixos-23.05 bash 2>&1 | tee /tmp/infect.log