Add dockerfile and remove immediate redirect upon closing collab editor

Author: bensohh

apps/signalling-service/Dockerfile

@@ -0,0 +1,21 @@
+FROM node:18-alpine AS base
+
+# Install dependencies only when needed
+FROM base AS deps
+# Check https://github.com/nodejs/docker-node/tree/b4117f9333da4138b03a546ec926ef50a31506c3#nodealpine to understand why libc6-compat might be needed.
+RUN apk add --no-cache libc6-compat
+WORKDIR /app
+
+COPY package*.json pnpm-lock.yaml* ./
+RUN \
+    if [ -f pnpm-lock.yaml ]; then corepack enable pnpm && pnpm i --frozen-lockfile; \
+    else echo "Lockfile not found." && exit 1; \
+    fi
+
+COPY . .
+
+# Expose port 3001 so it can be mapped by Docker daemon.
+EXPOSE 4444
+
+# Define the command to run your app using CMD which defines your runtime.
+CMD [ "node", "server.js" ]