feat: Use identity_file as a deployment key

docs/quickstart.md

@@ -113,7 +113,9 @@ example uses a local directory on the source machine.
 If your SSH key is not found, you will be asked for your password. If you are
 using a non-root user, you must have access to sudo without a password. To avoid
 SSH password prompts, set the `SSHPASS` environment variable to your password
-and add `--env-password` to the `nixos-anywhere` command.
+and add `--env-password` to the `nixos-anywhere` command. If providing a
+specific SSH key through `-i` (identity_file), this key will then be used for
+the installation and no temporary SSH key will be created.
 
 ### 7. (Optional) Test your NixOS and Disko configuration
 

src/nixos-anywhere.sh

@@ -367,10 +367,15 @@ runVmTest() {
 }
 
 uploadSshKey() {
-  # we generate a temporary ssh keypair that we can use during nixos-anywhere
   # ssh-copy-id requires this directory
   mkdir -p "$HOME/.ssh/"
-  ssh-keygen -t ed25519 -f "$sshKeyDir"/nixos-anywhere -P "" -C "nixos-anywhere" >/dev/null
+  if [[ -n ${sshPrivateKeyFile} ]]; then
+    cp "$sshPrivateKeyFile" "$sshKeyDir/nixos-anywhere"
+    ssh-keygen -y -f "$sshKeyDir/nixos-anywhere" >"$sshKeyDir/nixos-anywhere.pub"
+  else
+    # we generate a temporary ssh keypair that we can use during nixos-anywhere
+    ssh-keygen -t ed25519 -f "$sshKeyDir"/nixos-anywhere -P "" -C "nixos-anywhere" >/dev/null
+  fi
 
   declare -a sshCopyIdArgs
   if [[ -n ${sshPrivateKeyFile} ]]; then

tests/flake-module.nix

@@ -20,5 +20,6 @@
       from-nixos-with-sudo-stable = import ./from-nixos-with-sudo.nix testInputsStable;
       from-nixos-with-generated-config = import ./from-nixos-generate-config.nix testInputsUnstable;
       from-nixos-build-on-remote = import ./from-nixos-build-on-remote.nix testInputsUnstable;
+      from-nixos-separated-phases = import ./from-nixos-separated-phases.nix testInputsUnstable;
     });
 }

tests/from-nixos-separated-phases.nix

@@ -0,0 +1,52 @@
+(import ./lib/test-base.nix) {
+  name = "from-nixos-separated-phases";
+  nodes = {
+    installer = ./modules/installer.nix;
+    installed = {
+      services.openssh.enable = true;
+      virtualisation.memorySize = 1024;
+
+      users.users.nixos = {
+        isNormalUser = true;
+        openssh.authorizedKeys.keyFiles = [ ./modules/ssh-keys/ssh.pub ];
+        extraGroups = [ "wheel" ];
+      };
+      security.sudo.enable = true;
+      security.sudo.wheelNeedsPassword = false;
+    };
+  };
+  testScript = ''
+    start_all()
+
+    with subtest("Kexec Phase"):
+      installer.succeed("""
+        nixos-anywhere \
+          -i /root/.ssh/install_key \
+          --debug \
+          --kexec /etc/nixos-anywhere/kexec-installer \
+          --phases kexec \
+          --store-paths /etc/nixos-anywhere/disko /etc/nixos-anywhere/system-to-install \
+          nixos@installed >&2
+      """)
+
+    with subtest("Disko Phase"):
+      output = installer.succeed("""
+        nixos-anywhere \
+          -i /root/.ssh/install_key \
+          --debug \
+          --phases disko \
+          --store-paths /etc/nixos-anywhere/disko /etc/nixos-anywhere/system-to-install \
+          installed >&2
+    """)
+
+    with subtest("Install Phase"):
+      installer.succeed("""
+        nixos-anywhere \
+          -i /root/.ssh/install_key \
+          --debug \
+          --phases install \
+          --store-paths /etc/nixos-anywhere/disko /etc/nixos-anywhere/system-to-install \
+          root@installed >&2 
+      """)
+  '';
+}