feat: add copilot-persistence dev container feature

Preserve ~/.copilot folder across container instances using a Docker
volume and symlink, avoiding the need to reconfigure Copilot CLI
after rebuilding the dev container.

Co-authored-by: Copilot <[email protected]>

Author: jsburckhardt

README.md

@@ -30,6 +30,7 @@ This repository contains a _collection_ of Features.
 | Codex-cli | https://github.com/openai/codex | Codex CLI is an experimental project under active development. |
 | ccc | https://github.com/jsburckhardt/co-config | A TUI tool to interactively configure and view GitHub Copilot CLI settings. |
 | Yazi | https://github.com/sxyazi/yazi | Blazing fast terminal file manager written in Rust, based on async I/O. |
+| Copilot Persistence | — | Preserve ~/.copilot folder across container instances (avoids losing Copilot configuration after rebuilding). |
 
 
 
@@ -373,3 +374,21 @@ Running `yazi --version` inside the built container will print the version of ya
 ```bash
 yazi --version
 ```
+
+### `copilot-persistence`
+
+Persists the `~/.copilot` directory across container rebuilds using a Docker volume and symlink, so you don't lose your Copilot configuration when rebuilding your dev container.
+
+```jsonc
+{
+    "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
+    "features": {
+        "ghcr.io/jsburckhardt/devcontainer-features/copilot-persistence:1": {}
+    }
+}
+```
+
+```bash
+# Verify the symlink exists
+test -L "$HOME/.copilot" && echo "copilot-persistence is active"
+```

src/copilot-persistence/devcontainer-feature.json

@@ -0,0 +1,17 @@
+{
+    "name": "Copilot Persistence",
+    "id": "copilot-persistence",
+    "version": "1.0.0",
+    "description": "Preserve ~/.copilot folder across container instances (avoids losing Copilot configuration after rebuilding)",
+    "options": {},
+    "mounts": [
+        {
+            "source": "${devcontainerId}-copilot",
+            "target": "/dc/copilot",
+            "type": "volume"
+        }
+    ],
+    "onCreateCommand": {
+        "copilot-persistence": "/usr/local/share/jsburckhardt-devcontainer-features/copilot-persistence/scripts/oncreate.sh"
+    }
+}

src/copilot-persistence/install.sh

@@ -0,0 +1,49 @@
+#!/bin/sh
+set -e
+
+FEATURE_DIR="/usr/local/share/jsburckhardt-devcontainer-features/copilot-persistence"
+LIFECYCLE_SCRIPTS_DIR="$FEATURE_DIR/scripts"
+LOG_FILE="$FEATURE_DIR/log.txt"
+
+mkdir -p "${FEATURE_DIR}"
+echo "" > "$LOG_FILE"
+
+log() {
+    echo "$1"
+    echo "$1" >> "$LOG_FILE"
+}
+
+log "Activating feature 'copilot-persistence'"
+log "User: ${_REMOTE_USER}     User home: ${_REMOTE_USER_HOME}"
+
+# Skip if already installed
+if [ -f "$FEATURE_DIR/markers/install" ]; then
+    log "Feature 'copilot-persistence' already installed, skipping"
+    exit 0
+fi
+
+# Back up existing .copilot folder if present
+got_old_copilot_folder=false
+if [ -e "$_REMOTE_USER_HOME/.copilot" ]; then
+    log "Moving existing .copilot folder to .copilot-old"
+    mv "$_REMOTE_USER_HOME/.copilot" "$_REMOTE_USER_HOME/.copilot-old"
+    got_old_copilot_folder=true
+else
+    log "No existing .copilot folder found at '$_REMOTE_USER_HOME/.copilot'"
+fi
+
+# Create symlink from ~/.copilot to the mounted volume
+ln -s /dc/copilot/ "$_REMOTE_USER_HOME/.copilot"
+chown -R "${_REMOTE_USER}:${_REMOTE_USER}" "$_REMOTE_USER_HOME/.copilot"
+
+# Copy lifecycle scripts
+if [ -f oncreate.sh ]; then
+    mkdir -p "${LIFECYCLE_SCRIPTS_DIR}"
+    cp oncreate.sh "${LIFECYCLE_SCRIPTS_DIR}/oncreate.sh"
+    chmod +x "${LIFECYCLE_SCRIPTS_DIR}/oncreate.sh"
+fi
+
+# Mark as installed
+log "Adding marker file to indicate persistence is installed"
+mkdir -p "$FEATURE_DIR/markers"
+touch "$FEATURE_DIR/markers/install"

src/copilot-persistence/oncreate.sh

@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+set -e
+
+FEATURE_DIR="/usr/local/share/jsburckhardt-devcontainer-features/copilot-persistence"
+LOG_FILE="$FEATURE_DIR/log.txt"
+
+log() {
+    echo "$1"
+    echo "$1" >> "$LOG_FILE"
+}
+
+# Fix permissions on the log file so the remote user can write to it
+if command -v sudo > /dev/null; then
+    sudo chown -R "$(id -u):$(id -g)" "$LOG_FILE"
+else
+    chown -R "$(id -u):$(id -g)" "$LOG_FILE"
+fi
+
+log "In OnCreate script"
+
+# Skip if oncreate actions already ran
+if [ -f "$FEATURE_DIR/markers/oncreate" ]; then
+    log "Feature 'copilot-persistence' oncreate actions already run, skipping"
+    exit 0
+fi
+
+fix_permissions() {
+    local dir="${1}"
+    if [ ! -w "${dir}" ]; then
+        echo "Fixing permissions of '${dir}'..."
+        sudo chown -R "$(id -u):$(id -g)" "${dir}"
+        echo "Done!"
+    else
+        echo "Permissions of '${dir}' are OK!"
+    fi
+}
+
+fix_permissions "/dc/copilot"
+
+# Mark oncreate as done
+log "Adding marker file to indicate oncreate actions have been run"
+mkdir -p "$FEATURE_DIR/markers"
+if command -v sudo > /dev/null; then
+    sudo touch "$FEATURE_DIR/markers/oncreate"
+else
+    touch "$FEATURE_DIR/markers/oncreate"
+fi
+
+log "Done"

test/_global/scenarios.json

@@ -165,5 +165,11 @@
                 "version": "v26.1.22"
             }
         }
+    },
+    "copilot-persistence": {
+        "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
+        "features": {
+            "copilot-persistence": {}
+        }
     }
 }

test/copilot-persistence/test.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+set -e
+
+source dev-container-features-test-lib
+check "copilot-persistence" test -L "$HOME/.copilot"
+reportResults