fixed dockerfile. changed package manager to yarn

.dockerignore

@@ -1 +1,4 @@
-node_modules
+node_modules
+.svelte-kit
+build
+.env

Dockerfile

@@ -1,28 +1,22 @@
-#Dockerfile
-
-# Use this image as the platform to build the app
-FROM node:18-alpine AS external-website
-
-# A small line inside the image to show who made it
-LABEL Developers="Christian Rannes"
-
-# The WORKDIR instruction sets the working directory for everything that will happen next
+FROM node:18-alpine AS builder
+RUN mkdir /app
 WORKDIR /app
 
-# Copy all local files into the image
-COPY . .
+COPY . /app
 
-# Clean install all node modules
-RUN npm ci
+RUN cd /app && yarn install && yarn build
 
-# Build SvelteKit app
-RUN npm run build
+FROM node:18-alpine
 
-# Delete source code files that were used to build the app that are no longer needed
-RUN rm -rf src/ static/ emailTemplates/ docker-compose.yml
+RUN mkdir /app
 
-# The USER instruction sets the user name to use as the default user for the remainder of the current stage
-USER node:node
+COPY --from=builder /app/build /app/build
+COPY --from=builder /app/package.json /app/yarn.lock /app/
 
-# This is the command that will be run inside the image when you tell Docker to start the container
-CMD ["node","build/index.js"]
+RUN cd /app && \
+  yarn install --production &&\
+  yarn cache clean
+
+WORKDIR /app
+
+CMD ["node", "build/index.js"]