jovian-support-scripts: Init with format scripts

The support scripts are intended to replace vendor scripts for the
little details we can't do the same way.

We're adding the pair of scripts required to format external devices.
Note that the scripts end-up relying on the steamos-manager service,
which in turn already knows how to launch the hw-support scripts.
How convenient.

overlay.nix

@@ -53,6 +53,7 @@ rec {
   jovian-stubs = final.callPackage ./pkgs/jovian-stubs { };
   jovian-greeter = final.callPackage ./pkgs/jovian-greeter { };
   jovian-steam-protocol-handler = final.callPackage ./pkgs/jovian-steam-protocol-handler { };
+  jovian-support-scripts = final.callPackage ./pkgs/jovian-support-scripts { };
 
   jovian-documentation = final.callPackage ./support/docs {
     pagefind = final.callPackage ./pkgs/pagefind { };

pkgs/jovian-support-scripts/default.nix

@@ -0,0 +1,49 @@
+{ stdenv
+, resholve
+
+, bash
+, jq
+, systemd
+, util-linux
+}:
+
+let
+  solution = {
+    scripts = [ "bin/steamos-polkit-helpers/*" ];
+    interpreter = "${bash}/bin/bash";
+    inputs = [
+      jq
+      systemd
+      util-linux
+    ];
+    keep = {
+      "${placeholder "out"}/bin/steamos-polkit-helpers/steamos-format-device" = true;
+    };
+  };
+in
+stdenv.mkDerivation {
+  name = "jovian-support-scripts";
+
+  buildCommand = ''
+    install -D -m 755 ${./steamos-format-sdcard} $out/bin/steamos-format-sdcard
+    install -D -m 755 ${./steamos-format-device} $out/bin/steamos-format-device
+
+    substituteInPlace $out/bin/steamos-format-sdcard \
+      --replace-fail "/usr/bin/steamos-polkit-helpers/steamos-format-device" "$out/bin/steamos-polkit-helpers/steamos-format-device"
+    (
+    cd $out/bin
+
+    mkdir -v steamos-polkit-helpers
+    cd steamos-polkit-helpers
+    ln -v -t . ../steamos-format-*
+    )
+
+    ${resholve.phraseSolution "steamos-format-sdcard" solution}
+    ${resholve.phraseSolution "steamos-format-device" solution}
+  '';
+
+  meta = {
+    # Any script defined here should be prioritized over Steam's own.
+    priority = -10;
+  };
+}

pkgs/jovian-support-scripts/steamos-format-device

@@ -0,0 +1,89 @@
+#!/usr/bin/env bash
+
+set -eu
+
+# [Jovian]
+#
+# Not a polkit helper anymore, this calls the steamos-manager system service
+# to poke through the fhsenv used here.
+#
+# Note that this is uh... quite a hack, but uh... works?
+#
+# The TLDR is:
+#
+#  - We poke the steamos-manager to run the dbus endpoint for formatting
+#  - We `tail` the journal for the output from the script
+#
+# And uh, this fulfills the requirements for Steam (stage=... flags).
+#
+
+cleanup() {
+	 >/dev/null 2>&1 \
+		 kill -9 % || :
+}
+
+trap cleanup EXIT SIGINT SIGTERM
+
+_call() {
+	object="$1"; shift
+	interface="$1"; shift
+	busctl --timeout=99y --expect-reply=yes -j \
+		call \
+		com.steampowered.SteamOSManager1 \
+		"$object" \
+		com.steampowered.SteamOSManager1."${interface}" \
+		"$@" \
+		| jq -r .data[0]
+}
+
+# Only supported flags, from the DBUS interface shape (ssb)
+#  • --skip-validation|--force)
+#  • --device)
+#  • --label)
+
+DEVICE=""
+LABEL="STEAM-$RANDOM"
+VALIDATE="true"
+
+OPTS=$(getopt -l force,skip-validation,device:,label: -n steamos-format-device -- "" "$@")
+
+eval set -- "$OPTS"
+
+while true; do
+	case "$1" in
+		--force)
+			# yes, this is just like --skip-validate in the vendor script
+			VALIDATE="false"
+			shift
+			;;
+		--skip-validation)
+			# yes, this is just like --force in the vendor script
+			VALIDATE="false"
+			shift
+			;;
+		--label)
+			LABEL="$2";
+			shift 2
+			;;
+		--device)
+			DEVICE="$2"
+			shift 2
+			;;
+		--) shift; break ;;
+	esac
+done
+
+if [[ "$DEVICE" == "" ]]; then
+	>&2 printf "Error: --device flag mandatory\n"
+	exit 1
+fi
+
+journalctl --lines=0 --follow \
+	--output cat \
+	--unit steamos-manager.service \
+	SYSLOG_IDENTIFIER=steamos-format-device &
+
+process=$(_call "/com/steampowered/SteamOSManager1" Manager FormatDevice ssb "$DEVICE" "$LABEL" "$VALIDATE")
+res="$(_call "${process}" "SubProcess" Wait)"
+
+exit "$res"

pkgs/jovian-support-scripts/steamos-format-sdcard

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+set -eu
+
+# [Jovian]
+# Not a polkit helper anymore, this calls the `format-device` helper following
+# the same semantics as `usr/lib/hwsupport/format-sdcard.sh`.
+
+exec /usr/bin/steamos-polkit-helpers/steamos-format-device \
+	--device /dev/mmcblk0 "$@"