chores(examples): Define base image for multi-stage build (#45862)

Just define base docker image for multi-stage build

## Bug

- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have a helpful link attached, see [`contributing.md`](https://github.com/vercel/next.js/blob/canary/contributing.md)

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] [e2e](https://github.com/vercel/next.js/blob/canary/contributing/core/testing.md#writing-tests-for-nextjs) tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have a helpful link attached, see [`contributing.md`](https://github.com/vercel/next.js/blob/canary/contributing.md)

## Documentation / Examples

- [ ] Make sure the linting passes by running `pnpm build && pnpm lint`
- [ ] The "examples guidelines" are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing/examples/adding-examples.md)

examples/with-docker-compose/next-app/prod.Dockerfile

@@ -1,5 +1,7 @@
+FROM node:18-alpine AS base
+
 # Step 1. Rebuild the source code only when needed
-FROM node:18-alpine AS builder
+FROM base AS builder
 
 WORKDIR /app
 
@@ -41,7 +43,7 @@ RUN \
 # Note: It is not necessary to add an intermediate step that does a full copy of `node_modules` here
 
 # Step 2. Production image, copy all the files and run next
-FROM node:18-alpine AS runner
+FROM base AS runner
 
 WORKDIR /app
 
@@ -68,4 +70,4 @@ ENV NEXT_PUBLIC_ENV_VARIABLE=${NEXT_PUBLIC_ENV_VARIABLE}
 
 # Note: Don't expose ports here, Compose will handle that for us
 
-CMD node server.js
+CMD ["node", "server.js"]

examples/with-docker-multi-env/docker/development/Dockerfile

@@ -1,5 +1,7 @@
+FROM node:18-alpine AS base
+
 # 1. Install dependencies only when needed
-FROM node:16-alpine AS deps
+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
 
@@ -15,7 +17,7 @@ RUN \
   fi
 
 # 2. Rebuild the source code only when needed
-FROM node:16-alpine AS builder
+FROM base AS builder
 WORKDIR /app
 COPY --from=deps /app/node_modules ./node_modules
 COPY . .
@@ -24,7 +26,7 @@ COPY .env.development.sample .env.production
 RUN yarn build
 
 # 3. Production image, copy all the files and run next
-FROM node:16-alpine AS runner
+FROM base AS runner
 WORKDIR /app
 
 ENV NODE_ENV=production

examples/with-docker-multi-env/docker/production/Dockerfile

@@ -1,5 +1,7 @@
+FROM node:18-alpine AS base
+
 # 1. Install dependencies only when needed
-FROM node:16-alpine AS deps
+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
 
@@ -16,7 +18,7 @@ RUN \
 
 
 # 2. Rebuild the source code only when needed
-FROM node:16-alpine AS builder
+FROM base AS builder
 WORKDIR /app
 COPY --from=deps /app/node_modules ./node_modules
 COPY . .
@@ -25,7 +27,7 @@ COPY .env.production.sample .env.production
 RUN yarn build
 
 # 3. Production image, copy all the files and run next
-FROM node:16-alpine AS runner
+FROM base AS runner
 WORKDIR /app
 
 ENV NODE_ENV=production

examples/with-docker-multi-env/docker/staging/Dockerfile

@@ -1,5 +1,7 @@
+FROM node:18-alpine AS base
+
 # 1. Install dependencies only when needed
-FROM node:16-alpine AS deps
+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
 
@@ -16,7 +18,7 @@ RUN \
 
 
 # 2. Rebuild the source code only when needed
-FROM node:16-alpine AS builder
+FROM base AS builder
 WORKDIR /app
 COPY --from=deps /app/node_modules ./node_modules
 COPY . .
@@ -25,7 +27,7 @@ COPY .env.staging.sample .env.production
 RUN yarn build
 
 # 3. Production image, copy all the files and run next
-FROM node:16-alpine AS runner
+FROM base AS runner
 WORKDIR /app
 
 ENV NODE_ENV=production