add support for providing sudo passwords via environemnt variables

docs/cli.md

@@ -20,7 +20,9 @@ Options:
   print full build logs
 * --env-password
   set a password used by ssh-copy-id, the password should be set by
-  the environment variable SSHPASS
+  the environment variable SSHPASS. Additionally, sudo password can be set
+  via SUDO_PASSWORD environment variable for remote sudo operations
+  (only supported with sudo, not doas)
 * -s, --store-paths <disko-script> <nixos-system>
   set the store paths to the disko-script and nixos-system directly
   if this is given, flake is not needed

docs/quickstart.md

@@ -120,7 +120,9 @@ 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. If providing a
+and add `--env-password` to the `nixos-anywhere` command. Additionally, if your
+target machine requires a sudo password, you can set the `SUDO_PASSWORD`
+environment variable (only supported with sudo, not doas). 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.
 

docs/reference.md

@@ -41,7 +41,9 @@ Options:
   print full build logs
 * --env-password
   set a password used by ssh-copy-id, the password should be set by
-  the environment variable SSHPASS
+  the environment variable SSHPASS. Additionally, sudo password can be set
+  via SUDO_PASSWORD environment variable for remote sudo operations
+  (only supported with sudo, not doas)
 * -s, --store-paths <disko-script> <nixos-system>
   set the store paths to the disko-script and nixos-system directly
   if this is given, flake is not needed

src/get-facts.sh

@@ -16,6 +16,7 @@ hasTar=$(has tar)
 hasCpio=$(has cpio)
 hasSudo=$(has sudo)
 hasDoas=$(has doas)
+hasPasswordlessSudo=$(if [ "$(has sudo)" = "y" ] && sudo -n true >/dev/null 2>&1; then echo "y"; else echo "n"; fi)
 hasWget=$(has wget)
 hasCurl=$(has curl)
 hasSetsid=$(has setsid)