install.sh: install --clone <git-url> [--dir] [--ref]

Clones your own config repository (git@host:owner/repo, https://...,
github:owner/repo) into ~/nix-config or --dir and installs it like
--flake <dir>. An existing clone of the same repository (any URL form) is
reused and, after asking, pulled with --ff-only; another repository, a
non-clone or a different branch is refused. A failed clone hints at SSH
URLs and gh auth login. Uses SteamOS' git, else Nix's.

Checked against local bare repositories through a logging git.

README.md

@@ -91,6 +91,17 @@ with "Restart once": reboot once. Re-running it just switches
 again (`--yes` answers every question). Afterwards edit
 `~/nix-config/home.nix` and switch (see [Usage](#usage)).
 
+Your own config in a git repository: `--clone <git-url>` clones it into
+`~/nix-config` (`--dir <path>`, branch `--ref <branch>`) and installs it like
+`--flake <dir>`; an existing clone of the same repository is reused (after
+asking, `git pull --ff-only`). URLs: `git@github.com:owner/repo`,
+`https://...` or `github:owner/repo`; a private repository needs an SSH URL
+with your key or HTTPS credentials (e.g. `gh auth login`).
+
+```sh
+curl -fsSL https://steam-frame-nix.lhns.de | bash -s -- install --clone git@github.com:owner/my-config
+```
+
 ```sh
 curl -fsSL https://steam-frame-nix.lhns.de | bash -s -- status      # Nix, generation, services
 curl -fsSL https://steam-frame-nix.lhns.de | bash -s -- uninstall   # --keep-nix keeps Nix
@@ -440,8 +451,10 @@ versions left: [docs/cleanup.md](docs/cleanup.md).
   if Nix was already there without flakes;
 - `~/nix-config` (your configuration, a git repository, from the template
   with your user name filled into `flake.nix`) and the link
-  `~/.config/home-manager` to it, unless that exists or `--flake` is given;
-  uninstall removes the link, never the configuration;
+  `~/.config/home-manager` to it, unless that exists or `--flake` is given
+  (with `--flake <dir>` or `--clone`, the link to that directory unless it
+  exists); uninstall removes the link, never the configuration (a clone
+  included);
 - dotfiles in Home Manager's way, renamed to `*.hm-backup-<time>` (kept);
 - `~/.local/state/home-manager`, `~/.local/state/nix` (profiles,
   generations), `~/.nix-profile`, `~/.nix-defexpr`, `~/.nix-channels`,

docs/development.md

@@ -48,7 +48,8 @@ modules/
   session.nix                  switch: outer bus/runtime dir, user services on switch
   cleanup.nix                  switch: `cleanup --orphans`; steam-frame-nix-cleanup on PATH
   cleanup/package.nix          build: install.sh as a command (cleanup, steamvr-debugger-arm, restart-check)
-  cleanup/check.nix            test: install.sh cleanup and restart-check on fake home/runtime dirs
+  cleanup/check.nix            test: install.sh cleanup and restart-check on fake home/runtime dirs,
+                               install --clone against local bare repos
   portal.nix                   Steam session portal config (session.portalFix)
   portal/check.nix             test: KDE FileChooser on by default, absent when disabled
   applications-menu.nix        applications.menu link for KDE apps (session.applicationsMenu)

install.sh

@@ -48,10 +48,17 @@ Nix + Home Manager for SteamOS (Steam Frame, Steam Deck).
 Usage: install.sh <command> [options]
 
 Commands:
-  install [--flake <dir-or-flakeref>] [--yes]
+  install [--flake <dir-or-flakeref> | --clone <git-url> [--dir <path>]
+          [--ref <branch>]] [--yes]
       Install Nix (NixOS nix-installer, steam-deck planner, flakes enabled) if
       it is missing, then activate a Home Manager configuration:
         --flake given        that flake (a directory or a flake reference)
+        --clone given        your config's git repository (git@host:owner/repo,
+                             https://..., github:owner/repo), cloned into
+                             --dir (default ~/nix-config) on branch --ref,
+                             then used like --flake <dir>; an existing clone
+                             of the same repository is reused (and pulled
+                             with --ff-only after asking)
         otherwise            ~/.config/home-manager
         neither exists       a new config in ~/nix-config from the
                              steam-frame-nix template, linked to
@@ -62,7 +69,8 @@ Commands:
   uninstall [--yes] [--keep-nix]
       Stop Home Manager's user services, run 'cleanup --all', uninstall Home
       Manager, uninstall Nix (unless --keep-nix) and remove per-user Nix
-      leftovers. Your configuration directory is never deleted.
+      leftovers. Your configuration directory (also a --clone) is never
+      deleted.
 
   cleanup [--dry-run] [--quiet] (--all | --orphans [--keep <artifact>]...)
       Remove what steam-frame-nix (any version) wrote outside the Nix store,
@@ -309,16 +317,82 @@ create_config() {
   info "linked $HM_CONFIG_LINK -> $dir"
 }
 
+# git, or Nix's when SteamOS has none (only after ensure_nix).
+git_any() {
+  if command -v git >/dev/null 2>&1; then git "$@"
+  else nix run nixpkgs#git -- "$@"; fi
+}
+
+# git URL for --clone: github:owner/repo -> https://github.com/owner/repo.git
+clone_url() {
+  case $1 in
+    github:*)
+      [[ ${1#github:} =~ ^[A-Za-z0-9_.-]+/[A-Za-z0-9_.-]+$ ]] \
+        || die "--clone: expected github:owner/repo, got '$1' (use --ref for a branch)"
+      printf 'https://github.com/%s.git\n' "${1#github:}" ;;
+    *) printf '%s\n' "$1" ;;
+  esac
+}
+
+# host/path of a git URL, to compare SSH and HTTPS forms of one repository.
+repo_id() {
+  local u=$1
+  case $u in
+    *://*) u=${u#*://}; u=${u#*@} ;;
+    *@*:*) u=${u#*@}; u=${u/://} ;;
+  esac
+  u=${u%/}; u=${u%.git}
+  printf '%s\n' "${u,,}"
+}
+
+# Clone the config (--clone), or reuse an existing clone of the same repository.
+clone_config() { # url dir ref
+  local url dir=$2 ref=$3 origin branch
+  url="$(clone_url "$1")"
+  if [[ -e $dir ]] && [[ -n $(ls -A "$dir" 2>/dev/null) ]]; then
+    [[ $(git_any -C "$dir" rev-parse --show-toplevel 2>/dev/null) -ef $dir ]] \
+      && origin="$(git_any -C "$dir" config --get remote.origin.url)" \
+      || die "$dir exists and is not a git clone; move it away or pass --dir <path>"
+    [[ $(repo_id "$origin") == "$(repo_id "$url")" ]] \
+      || die "$dir is a clone of $origin, not $url; move it away or pass --dir <path>"
+    branch="$(git_any -C "$dir" symbolic-ref --short -q HEAD || true)"
+    [[ -z $ref || $branch == "$ref" ]] \
+      || die "$dir is on ${branch:-a detached HEAD}, not $ref; check out $ref there first"
+    step "Using the existing clone in $dir"
+    if confirm "Update it with 'git pull --ff-only'?"; then
+      git_any -C "$dir" pull --ff-only \
+        || warn "git pull failed; using $dir as it is"
+    fi
+    return 0
+  fi
+  step "Cloning $url into $dir"
+  mkdir -p "${dir%/*}"
+  git_any clone ${ref:+--branch "$ref"} -- "$url" "$dir" || die "git clone failed. \
+For a private repository use an SSH URL (git@github.com:owner/repo) with a key \
+your account knows, or HTTPS credentials (e.g. 'gh auth login')."
+}
+
 cmd_install() {
-  local flake='' ref dir=''
+  local flake='' ref dir='' clone='' clone_dir='' clone_ref=''
   while (( $# )); do
     case $1 in
       --flake) [[ $# -ge 2 ]] || die "--flake needs an argument"; flake=$2; shift 2 ;;
+      --clone) [[ $# -ge 2 ]] || die "--clone needs an argument"; clone=$2; shift 2 ;;
+      --dir) [[ $# -ge 2 ]] || die "--dir needs an argument"; clone_dir=$2; shift 2 ;;
+      --ref) [[ $# -ge 2 ]] || die "--ref needs an argument"; clone_ref=$2; shift 2 ;;
       -y|--yes) ASSUME_YES=1; shift ;;
       -h|--help) usage; exit 0 ;;
       *) die "install: unknown option '$1' (see --help)" ;;
     esac
   done
+  if [[ -n $clone ]]; then
+    [[ -z $flake ]] || die "install: --clone and --flake exclude each other"
+    clone_url "$clone" >/dev/null
+    clone_dir=${clone_dir:-$DEFAULT_CONFIG_DIR}
+    [[ $clone_dir == /* ]] || clone_dir=$PWD/$clone_dir
+  elif [[ -n $clone_dir || -n $clone_ref ]]; then
+    die "install: --dir and --ref need --clone"
+  fi
 
   need_not_root
   check_os
@@ -326,6 +400,11 @@ cmd_install() {
 
   ensure_nix
 
+  if [[ -n $clone ]]; then
+    clone_config "$clone" "$clone_dir" "$clone_ref"
+    flake=$clone_dir
+  fi
+
   step "Finding the Home Manager configuration"
   if [[ -n $flake ]]; then
     if [[ -d ${flake%%#*} ]]; then
@@ -1182,7 +1261,7 @@ cmd_uninstall() {
   cat <<EOF
 
 Intentionally left in place:
-  - your configuration (e.g. $DEFAULT_CONFIG_DIR)
+  - your configuration (e.g. $DEFAULT_CONFIG_DIR, also when cloned)
   - files Home Manager renamed to *.hm-backup-<time>
   - app data, e.g. ~/.local/share/docker, Firefox profiles, and Flatpak apps
 Log out or reboot so running sessions drop the removed tweaks.

modules/cleanup/check.nix

@@ -3,11 +3,13 @@
 # aren't ours (left alone), --dry-run changes nothing, a second run changes
 # nothing, SteamVR running defers the debugger key to a runtime drop-in.
 # Also `install.sh restart-check` (what waits for a session/SteamVR restart).
+# Also `install.sh install --clone` (argument parsing and the clone step),
+# against local bare repositories through a logging git, without network.
 { pkgs }:
 let
   cleanup = pkgs.callPackage ./package.nix { };
 in
-pkgs.runCommand "cleanup-check" { nativeBuildInputs = [ cleanup pkgs.jq ]; } ''
+pkgs.runCommand "cleanup-check" { nativeBuildInputs = [ cleanup pkgs.jq pkgs.git ]; } ''
   set -euo pipefail
   fail() { echo "FAIL: $*" >&2; exit 1; }
   export HOME XDG_RUNTIME_DIR STEAM_FRAME_NIX_RUNTIME_DIR STEAM_FRAME_NIX_SYSTEMCTL
@@ -300,5 +302,88 @@ pkgs.runCommand "cleanup-check" { nativeBuildInputs = [ cleanup pkgs.jq ]; } ''
   rm -r $U/gamescope-session.service.d $U/steamvr.service.d; : > $root/proc/net/tcp
   res=$(rc); [ -z "$res" ] || fail "restart-check without the drop-ins: $res"
   echo "F ok"
+
+  # --- G: install --clone ---
+  INSTALL=${../../install.sh}
+  export GIT_AUTHOR_NAME=t GIT_AUTHOR_EMAIL=t@t GIT_COMMITTER_NAME=t GIT_COMMITTER_EMAIL=t@t
+  fresh g
+  R=$root/remotes; mkdir -p $R
+  for repo in config other; do
+    git init -q -b main $R/src-$repo
+    echo "{ outputs = _: { }; }" > $R/src-$repo/flake.nix
+    git -C $R/src-$repo add -A; git -C $R/src-$repo commit -qm init
+    git -C $R/src-$repo branch dev
+    git clone -q --bare $R/src-$repo $R/$repo.git
+  done
+  # The URL forms reach the bare repositories; a git that logs its arguments.
+  export GIT_CONFIG_GLOBAL=$root/gitconfig GITLOG=$root/gitlog
+  git config --global url."file://$R/config.git".insteadOf https://github.com/owner/config.git
+  git config --global --add url."file://$R/config.git".insteadOf git@github.com:owner/config
+  git config --global url."file://$R/other.git".insteadOf https://example.org/other.git
+  mkdir -p $root/bin
+  printf '#!%s\necho "$*" >> "$GITLOG"\nexec %s "$@"\n' ${pkgs.bash}/bin/bash ${pkgs.git}/bin/git > $root/bin/git
+  chmod +x $root/bin/git
+  PATH=$root/bin:$PATH
+  # sourced: run one function with fresh state
+  sfn() { (. $INSTALL; "$@"); }
+  # install with Nix, curl and home-manager stubbed
+  inst() {
+    : > $GITLOG
+    (. $INSTALL; ASSUME_YES=1; ensure_nix() { :; }; curl() { :; }; hm() { echo "hm $*"; }; cmd_install "$@")
+  }
+
+  # parsing
+  res=$(bash $INSTALL install --clone github:owner/config --flake /x 2>&1) && fail "--clone --flake accepted"
+  has "$res" "--clone and --flake exclude each other"
+  res=$(bash $INSTALL install --dir /x 2>&1) && fail "--dir without --clone accepted"
+  has "$res" "--dir and --ref need --clone"
+  res=$(bash $INSTALL install --clone github:owner/config/dev 2>&1) && fail "github:o/r/x accepted"
+  has "$res" "expected github:owner/repo"
+  res=$(bash $INSTALL install --clone 2>&1) && fail "--clone without URL accepted"
+  [ "$(sfn clone_url github:owner/config)" = https://github.com/owner/config.git ] || fail clone_url
+  [ "$(sfn clone_url git@github.com:owner/config)" = git@github.com:owner/config ] || fail clone_url-ssh
+  [ "$(sfn repo_id git@GitHub.com:owner/config.git)" = "$(sfn repo_id https://github.com/owner/config/)" ] || fail repo_id
+  [ "$(sfn repo_id ssh://git@github.com/owner/config)" = github.com/owner/config ] || fail repo_id-ssh
+
+  # each URL form: the git command, the flake dir, the link
+  for url in github:owner/config https://github.com/owner/config.git git@github.com:owner/config; do
+    rm -rf $HOME/nix-config $HOME/.config/home-manager
+    res=$(inst --clone $url)
+    want=$(sfn clone_url $url)
+    grep -qxF -- "clone -- $want $HOME/nix-config" $GITLOG || fail "$url: git: $(cat $GITLOG)"
+    has "$res" "hm switch --flake $HOME/nix-config -b"
+    [ "$(readlink $HOME/.config/home-manager)" = $HOME/nix-config ] || fail "$url: link"
+    [ "$(git -C $HOME/nix-config branch --show-current)" = main ] || fail "$url: branch"
+  done
+
+  # reuse: same repository in another URL form, pulled (--yes)
+  res=$(inst --clone https://github.com/owner/config.git)
+  has "$res" "Using the existing clone in $HOME/nix-config"
+  grep -qxF -- "-C $HOME/nix-config pull --ff-only" $GITLOG || fail "no pull: $(cat $GITLOG)"
+  ! grep -q "^clone" $GITLOG || fail "cloned again"
+  has "$res" "hm switch --flake $HOME/nix-config -b"
+
+  # --dir (relative) and --ref; the existing link stays
+  res=$(cd $HOME && inst --clone github:owner/config --dir cfg --ref dev)
+  grep -qxF -- "clone --branch dev -- https://github.com/owner/config.git $HOME/cfg" $GITLOG || fail "ref: $(cat $GITLOG)"
+  [ "$(git -C $HOME/cfg branch --show-current)" = dev ] || fail "ref branch"
+  has "$res" "hm switch --flake $HOME/cfg -b"
+  [ "$(readlink $HOME/.config/home-manager)" = $HOME/nix-config ] || fail "link replaced"
+  res=$(inst --clone github:owner/config --dir $HOME/cfg --ref main 2>&1) && fail "other branch reused"
+  has "$res" "is on dev, not main"
+
+  # refused: another repository, not a clone, a subdirectory of a clone
+  res=$(inst --clone https://example.org/other.git 2>&1) && fail "other repo reused"
+  has "$res" "is a clone of git@github.com:owner/config, not https://example.org/other.git"
+  mkdir $HOME/plain; echo x > $HOME/plain/x
+  res=$(inst --clone github:owner/config --dir $HOME/plain 2>&1) && fail "plain dir used"
+  has "$res" "is not a git clone"
+  mkdir $HOME/cfg/sub; echo x > $HOME/cfg/sub/x
+  res=$(inst --clone github:owner/config --dir $HOME/cfg/sub 2>&1) && fail "subdir used"
+  has "$res" "is not a git clone"
+  # a failed clone: the hint
+  res=$(inst --clone https://example.org/missing.git --dir $HOME/m 2>&1) && fail "missing repo"
+  has "$res" "gh auth login"
+  echo "G ok"
   touch $out
 ''