fix bashism

[[ ]] is not available in POSIX sh, and test -o is not well defined
either.

Move the facts-gathering script out so it can be tested with shellcheck.

src/default.nix

@@ -37,13 +37,13 @@ stdenv.mkDerivation {
   src = ./..;
   nativeBuildInputs = [ makeWrapper ];
   installPhase = ''
-    install -D -m 0755 src/nixos-anywhere.sh $out/bin/nixos-anywhere
+    install -D --target-directory=$out/libexec/nixos-anywhere/ -m 0755 src/*.sh
 
     # We prefer the system's openssh over our own, since it might come with features not present in ours:
     # https://github.com/nix-community/nixos-anywhere/issues/62
     #
     # We also prefer system rsync to prevent crashes between rsync and ssh.
-    wrapProgram $out/bin/nixos-anywhere \
+    makeShellWrapper $out/libexec/nixos-anywhere/nixos-anywhere.sh $out/bin/nixos-anywhere \
       --prefix PATH : ${lib.makeBinPath runtimeDeps} --suffix PATH : ${lib.makeBinPath [ openssh ]}
   '';
 

src/get-facts.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+set -efu "${enable_debug:-}"
+has() {
+  command -v "$1" >/dev/null && echo "y" || echo "n"
+}
+is_nixos=$(if test -f /etc/os-release && grep -q ID=nixos /etc/os-release; then echo "y"; else echo "n"; fi)
+cat <<FACTS
+is_os=$(uname)
+is_arch=$(uname -m)
+is_kexec=$(if test -f /etc/is_kexec; then echo "y"; else echo "n"; fi)
+is_nixos=$is_nixos
+is_installer=$(if [ "$is_nixos" = "y" ] && grep -q VARIANT_ID=installer /etc/os-release; then echo "y"; else echo "n"; fi)
+is_container=$(if [ "$(has systemd-detect-virt)" = "y" ]; then systemd-detect-virt --container; else echo "none"; fi)
+has_tar=$(has tar)
+has_sudo=$(has sudo)
+has_doas=$(has doas)
+has_wget=$(has wget)
+has_curl=$(has curl)
+has_setsid=$(has setsid)
+FACTS

src/nixos-anywhere.sh

@@ -62,6 +62,7 @@ step() {
   echo "### $* ###"
 }
 
+here=$(dirname "${BASH_SOURCE[0]}")
 kexec_url=""
 enable_debug=""
 maybe_reboot="sleep 6 && reboot"
@@ -321,29 +322,7 @@ done
 
 import_facts() {
   local facts filtered_facts
-  if ! facts=$(
-    ssh_ -o ConnectTimeout=10 sh -- <<SSH
-set -efu ${enable_debug}
-has(){
-  command -v "\$1" >/dev/null && echo "y" || echo "n"
-}
-is_nixos=\$(if test -f /etc/os-release && grep -q ID=nixos /etc/os-release; then echo "y"; else echo "n"; fi)
-cat <<FACTS
-is_os=\$(uname)
-is_arch=\$(uname -m)
-is_kexec=\$(if test -f /etc/is_kexec; then echo "y"; else echo "n"; fi)
-is_nixos=\$is_nixos
-is_installer=\$(if [[ "\$is_nixos" == "y" ]] && grep -q VARIANT_ID=installer /etc/os-release; then echo "y"; else echo "n"; fi)
-is_container=\$(if [[ "\$(has systemd-detect-virt)" == "y" ]]; then systemd-detect-virt --container; else echo "none"; fi)
-has_tar=\$(has tar)
-has_sudo=\$(has sudo)
-has_doas=\$(has doas)
-has_wget=\$(has wget)
-has_curl=\$(has curl)
-has_setsid=\$(has setsid)
-FACTS
-SSH
-  ); then
+  if ! facts=$(ssh_ -o ConnectTimeout=10 enable_debug=$enable_debug sh -- <"$here"/get-facts.sh); then
     exit 1
   fi
   filtered_facts=$(echo "$facts" | grep -E '^(has|is)_[a-z0-9_]+=\S+')
@@ -510,13 +489,13 @@ export PATH="\$PATH:/run/current-system/sw/bin"
 # needed for installation if initrd-secrets are used
 mkdir -p /mnt/tmp
 chmod 777 /mnt/tmp
-if [[ ${copy_host_keys-n} == "y" ]]; then
+if [ ${copy_host_keys-n} = "y" ]; then
   # NB we copy host keys that are in turn copied by kexec installer.
   mkdir -m 755 -p /mnt/etc/ssh
   for p in /etc/ssh/ssh_host_*; do
     # Skip if the source file does not exist (i.e. glob did not match any files)
     # or the destination already exists (e.g. copied with --extra-files).
-    if [ ! -e "\$p" -o -e "/mnt/\$p" ]; then
+    if [ ! -e "\$p" ] || [ -e "/mnt/\$p" ]; then
       continue
     fi
     cp -a "\$p" "/mnt/\$p"