feat: add personal-files slot for mutt configuration

.github/plug-declaration.json

@@ -0,0 +1,3 @@
+{
+    "personal-files": { "allow-installation": true }
+}

README.md

@@ -23,6 +23,14 @@ snap install mutt
 
 <p align="center">Published for <img src="https://raw.githubusercontent.com/anythingcodes/slack-emoji-for-techies/gh-pages/emoji/tux.png" align="top" width="24" /> with :gift_heart: by Snapcrafters</p>
 
+## Snap Configuration
+
+| option          | default | description                                                                                                                                                                                                                 |
+| --------------- | ------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `use-real-home` | `false` | If set to `true`, `mutt` will look for configuration in your home directory in either `$HOME/.muttrc`, `$HOME/.mutt` or `$HOME/.config/mutt`, rather than using configuration stored inside the Snap's user data directory. |
+
+You can change Snap configuration by running `snap set mutt <key>=<value>`. For example, `snap set mutt use-real-home=true`.
+
 ## How to contribute to this snap
 
 Thanks for your interest! Below you find instructions to help you contribute to this snap.

snap/hooks/configure

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# On Fedora $SNAP is under /var and there is some magic to map it to /snap.
+# We need to handle that case and reset $SNAP
+SNAP="${SNAP//\/var\/lib\/snapd/}"
+
+use_real_home="$(snapctl get use-real-home)"
+if [[ -z "$use_real_home" ]]; then
+    snapctl set use-real-home=false
+fi

snap/local/bin/mutt-wrapper

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Run the configure hook which sets defaults for any config options
+"${SNAP}/snap/hooks/configure"
+
+export HOME="$SNAP_USER_COMMON"
+
+use_real_home="$(snapctl get use-real-home)"
+if [[ "${use_real_home}" == "true" ]]; then
+    export HOME="$SNAP_REAL_HOME"
+fi
+
+exec "${SNAP}/usr/local/bin/mutt" "$@"

snap/snapcraft.yaml

@@ -49,12 +49,20 @@ architectures:
 apps:
   mutt:
     environment:
-      HOME: "$SNAP_USER_COMMON"
       TERMINFO_DIRS: $SNAP/lib/terminfo:$SNAP/usr/share/terminfo
-    command: usr/local/bin/mutt
+    command: bin/mutt-wrapper
     plugs:
       - network
       - home
+      - dot-mutt
+
+plugs:
+  dot-mutt:
+    interface: personal-files
+    write:
+      - $HOME/.mutt
+      - $HOME/.muttrc
+      - $HOME/.config/mutt
 
 parts:
   mutt:
@@ -133,3 +141,8 @@ parts:
       tic -xe alacritty,alacritty-direct $CRAFT_PART_SRC/alacritty.info -o .
       mkdir -p $CRAFT_PRIME/lib/terminfo/a/
       cp a/alacritty* $CRAFT_PRIME/lib/terminfo/a/
+
+  local-parts:
+    plugin: dump
+    source: ./snap/local
+    source-type: local