Merge pull request #292 from jalseth/master

Add disk-size argument

README.md

@@ -97,6 +97,27 @@ image was recently merged in nixpkgs):
 NIX_PATH=nixpkgs=../nixpkgs nixos-generate -f do
 ```
 
+## Setting the disk image size
+
+To specify the size of the generated disk image, use the `--disk-size` argument,
+specifying the size in megabytes. This is currently supported by the following
+formats. If this argument is unspecified it defaults to automatic sizing based
+on the generated NixOS build.
+
+- hyperv
+- proxmox
+- qcow
+- raw-efi
+- raw
+- vm
+- vm-nogui
+- vmware
+
+Example (20GB disk):
+```
+nixos-generate -c <your_config.nix> -f <format> --disk-size 20480
+```
+
 ## Cross Compiling
 
 To cross compile nixos images for other architectures you have to configure

formats/hyperv.nix

@@ -1,8 +1,19 @@
-{modulesPath, ...}: {
+{
+  modulesPath,
+  specialArgs,
+  lib,
+  ...
+}: let
+  diskSize = specialArgs.diskSize or "auto";
+in {
   imports = [
     "${toString modulesPath}/virtualisation/hyperv-image.nix"
   ];
 
+  hyperv.baseImageSize =
+    if diskSize == "auto" then "auto"
+    else lib.strings.toIntBase10 diskSize;
+
   formatAttr = "hypervImage";
   fileExtension = ".vhdx";
 }

formats/proxmox.nix

@@ -1,7 +1,14 @@
-{modulesPath, ...}: {
+{
+  modulesPath,
+  specialArgs,
+  ...
+}: {
   imports = [
     "${toString modulesPath}/virtualisation/proxmox-image.nix"
   ];
+
+  proxmox.qemuConf.diskSize = specialArgs.diskSize or "auto";
+
   formatAttr = "VMA";
   fileExtension = ".vma.zst";
 }

formats/qcow.nix

@@ -3,6 +3,7 @@
   lib,
   pkgs,
   modulesPath,
+  specialArgs,
   ...
 }: {
   # for virtio kernel drivers
@@ -29,7 +30,7 @@
 
   system.build.qcow = import "${toString modulesPath}/../lib/make-disk-image.nix" {
     inherit lib config pkgs;
-    diskSize = 8192;
+    diskSize = specialArgs.diskSize or "auto";
     format = "qcow2";
     partitionTableType = "hybrid";
   };

formats/raw-efi.nix

@@ -4,6 +4,7 @@
   options,
   pkgs,
   modulesPath,
+  specialArgs,
   ...
 }: let
   inherit (import ../lib.nix {inherit lib options;}) maybe;
@@ -24,7 +25,7 @@ in {
   system.build.raw = maybe.mkOverride 99 (import "${toString modulesPath}/../lib/make-disk-image.nix" {
     inherit lib config pkgs;
     partitionTableType = "efi";
-    diskSize = "auto";
+    diskSize = specialArgs.diskSize or "auto";
     format = "raw";
   });
 }

formats/raw.nix

@@ -3,6 +3,7 @@
   lib,
   pkgs,
   modulesPath,
+  specialArgs,
   ...
 }: {
   fileSystems."/" = {
@@ -21,7 +22,7 @@
 
   system.build.raw = import "${toString modulesPath}/../lib/make-disk-image.nix" {
     inherit lib config pkgs;
-    diskSize = "auto";
+    diskSize = specialArgs.diskSize or "auto";
     format = "raw";
   };
 

formats/vm.nix

@@ -1,7 +1,18 @@
-{modulesPath, ...}: {
+{
+  modulesPath,
+  specialArgs,
+  lib,
+  ...
+}: let
+  diskSize = specialArgs.diskSize or "auto";
+in {
   imports = [
     "${toString modulesPath}/virtualisation/qemu-vm.nix"
   ];
 
+  virtualisation.diskSize =
+    if diskSize == "auto" then null
+    else lib.strings.toIntBase10 diskSize;
+
   formatAttr = "vm";
 }

formats/vmware.nix

@@ -1,8 +1,19 @@
-{modulesPath, ...}: {
+{
+  modulesPath,
+  specialArgs,
+  lib,
+  ...
+}: let
+  diskSize = specialArgs.diskSize or "auto";
+in {
   imports = [
     "${toString modulesPath}/virtualisation/vmware-image.nix"
   ];
 
+  vmware.baseImageSize =
+    if diskSize == "auto" then "auto"
+    else lib.strings.toIntBase10 diskSize;
+
   formatAttr = "vmwareImage";
   fileExtension = ".vmdk";
 }

nixos-generate

@@ -79,6 +79,10 @@ while [[ $# -gt 0 ]]; do
       cores=$2
       shift
       ;;
+    --disk-size)
+      nix_build_args+=("--argstr" "diskSize" "$2")
+      shift
+      ;;
     --option)
       nix_build_args+=("$1" "$2" "$3")
       shift 2

nixos-generate.nix

@@ -2,6 +2,7 @@
   nixpkgs ? <nixpkgs>,
   configuration ? <nixos-config>,
   system ? builtins.currentSystem,
+  diskSize ? "auto",
   formatConfig,
   flakeUri ? null,
   flakeAttr ? null,
@@ -20,6 +21,9 @@ in
   else
     import "${toString nixpkgs}/nixos/lib/eval-config.nix" {
       inherit system;
+      specialArgs = {
+        diskSize = diskSize;
+      };
       modules = [
         module
         formatConfig