env: Enable passing through Hetzner Arch Linux repo to distrobox

Make function easy to run to allow enabling easily in virtual machines
as well.

Signed-off-by: Nathan Chancellor <[email protected]>

fish/functions/add_hetzner_mirror_to_repos.fish

@@ -0,0 +1,41 @@
+#!/usr/bin/env fish
+# SPDX-License-Identifier: MIT
+# Copyright (C) 2024 Nathan Chancellor
+
+function add_hetzner_mirror_to_repos -d "Add Hetzner's internal Arch Linux mirror to /etc/pacman.conf"
+    set program "import arch
+from pathlib import Path
+import sys
+
+# Not using pacman, bail out gracefully
+if not (pacman_conf := Path('/etc/pacman.conf')).exists():
+    sys.exit(0)
+
+orig_pacman_conf_txt = pacman_conf.read_text(encoding='utf-8')
+new_pacman_conf_txt = arch.add_hetzner_mirror_to_repos(orig_pacman_conf_txt)
+
+if orig_pacman_conf_txt != new_pacman_conf_txt:
+    pacman_conf.write_text(new_pacman_conf_txt, encoding='utf-8')"
+
+    if test (count $argv) -eq 0
+        sudo env PYTHONPATH=$PYTHON_FOLDER/setup python -c "$program"
+        return
+    end
+
+    for arg in $argv
+        switch $arg
+            case -p --print-container-routine
+                printf '\n%s\n%s\n%s%s%s\n%s\n' \
+                    '# Import Hetzner mirror from the host configuration if using pacman' \
+                    'if command -v python3 >/dev/null 2>&1; then' \
+                    '    PYTHONPATH=/run/host'$PYTHON_FOLDER'/setup python3 -c "' \
+                    "$program" \
+                    '" || exit' \
+                    'fi'
+
+            case '*'
+                print_error "Unknown argument: $arg"
+                return 1
+        end
+    end
+end

fish/functions/dbxc.fish

@@ -115,6 +115,10 @@ if grep -q host-spawn /etc/fish/conf.d/distrobox_config.fish; then
     sed -i /host-spawn/d /etc/fish/conf.d/distrobox_config.fish
 fi' >$init_hook_sh
 
+    if is_hetzner
+        add_hetzner_mirror_to_repos -p >>$init_hook_sh
+    end
+
     # If we are using docker, we need to explicitly set the container's
     # kvm group to the same group ID as the host's kvm group if it exists
     # so that accelerated VMs work within a container. Do this with an init hook.

fish/functions/is_hetzner.fish

@@ -0,0 +1,10 @@
+#!/usr/bin/env fish
+# SPDX-License-Identifier: MIT
+# Copyright (C) 2024 Nathan Chancellor
+
+function is_hetzner -d "Checks if current running machine is a Hetzner machine"
+    if test $LOCATION = hetzner # duh
+        return 0
+    end
+    PYTHONPATH=$PYTHON_FOLDER/setup python3 -c 'from arch import is_hetzner; import sys; sys.exit(0 if is_hetzner() else 1)'
+end