Create new Dockerfile to run Terminus in isolated environment

- Install base dependencies in Dockerfile
- Add README instructions to utilize standalone Docker container method
- Add notes on using Docker volume for config persistence

Author: erikwebb

Dockerfile

@@ -0,0 +1,39 @@
+# --- Build Layer ---
+FROM php:8.2-cli AS build
+
+# Install dependencies for building PHAR
+RUN apt-get update && apt-get install -y git unzip wget && rm -rf /var/lib/apt/lists/*
+
+# Install Composer
+COPY --from=composer:2 /usr/bin/composer /usr/bin/composer
+
+WORKDIR /app
+
+# Copy source files
+COPY . .
+
+# Install PHP dependencies
+RUN composer install --no-interaction --no-dev --optimize-autoloader
+
+# Install Box for PHAR building
+RUN wget https://github.com/box-project/box/releases/download/4.5.1/box.phar -O /usr/local/bin/box && chmod +x /usr/local/bin/box
+
+# Build PHAR file
+RUN ./scripts/phar_build.sh
+
+# --- Runtime Layer ---
+FROM php:8.2-cli-alpine
+
+WORKDIR /app
+
+# Copy Git
+RUN apk add --no-cache git unzip wget
+
+# Copy Composer from build layer
+COPY --from=build /usr/bin/composer /usr/bin/composer
+
+# Copy built PHAR from build layer
+COPY --from=build /app/terminus.phar /app/terminus.phar
+
+# Set entrypoint to run the PHAR
+ENTRYPOINT ["/app/terminus.phar"]

README.md

@@ -74,3 +74,28 @@ chmod +x terminus
 ./terminus self:update
 sudo ln -s ~/terminus/terminus /usr/local/bin/terminus
 ```
+
+### Standalone Docker container
+
+Terminus can also be built and run as a Docker container, rather than relying on system version of PHP and other dependencies.
+
+```bash
+docker build . -f Dockerfile -t terminus
+```
+
+In order to store configuration and install plugins, Terminus requires a persistent data directory. If you only plan to run Terminus via Docker, please run the following command to create a Docker data volume:
+
+```bash
+docker volume create terminus --ignore
+```
+
+The container can be run of 2 different ways:
+
+- Directly using `docker` (or `podman`, etc.):
+
+        docker run -tv terminus:/root/.terminus terminus:latest art
+
+- Alternatively implement an alias in your local environment:
+
+        alias terminus="docker run -tv ~/.terminus:/root/.terminus terminus:latest"
+        terminus art