Hi there! 
I’m new to using fly.io and I managed very smoothly to launch and deploy my Nuxt 2 application yesterday from my local machine, with only a Dockerfile (with no mentions of my env variables) and fly.toml, where I’ve set my env variables in the [env] section. Everything works perfectly! 
Today I’ve tried to implement a github workflow for deploy (and deploy review app) and now a few hours later I feel like I’m banging my head into a wall. I can’t seem to get the env variables to have it’s values that I’ve set in the fly.toml file.
I’ve tried to also set them via github env variables and secrets, and if I echo them during my build it has the correct values… Although coming in to my nuxt.config.js if I console log for example the process.env.API_ENDPOINT variable it is undefined.
From all I’ve read today it seems that setting my variables in [build.args] instead of [env] in fly.toml could be a solution, and then change my Dockerfile to set the args as env variables. How would that work with secrets then? What do I have to change in the workflow? I’m posting my code below.
If someone out there could help me shine som light on this topic it would be very much appreciated 
I’m confused about why it would make a difference running the build and deploy via workflow when it uses the same fly.toml and Dockerfile…
This is my fly-review.yml where I’ve tried to set the env variables both up and then also pass them as secrets below (for testing)
name: Fly Deploy Review App
on:
# Run this workflow on every PR event. Existing review apps will be updated when the PR is updated.
pull_request:
types: [opened, reopened, synchronize, closed]
env:
FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}
FLY_REGION: lhr
FLY_ORG: personal
API_KEY: ${{ secrets.API_KEY }}
API_ENDPOINT: ${{ vars.API_ENDPOINT }}
AUTH_ENDPOINT: ${{ vars.AUTH_ENDPOINT }}
BASE_URL: ${{ vars.BASE_URL }}
DEFAULT_LOCALE: ${{ vars.DEFAULT_LOCALE }}
FALLBACK_CHANNEL_ID: ${{ vars.FALLBACK_CHANNEL_ID }}
FALLBACK_MARKET_ALIAS: ${{ vars.FALLBACK_MARKET_ALIAS }}
IMAGE_SERVER: ${{ vars.IMAGE_SERVER }}
SIGN_ENDPOINT: ${{ vars.SIGN_ENDPOINT }}
RALPH_ENV: dev
jobs:
review_app:
runs-on: ubuntu-latest
outputs:
url: ${{ steps.deploy.outputs.url }}
# Only run one deployment at a time per PR.
concurrency:
group: pr-${{ github.event.number }}
# Deploying apps with this "review" environment allows the URL for the app to be displayed in the PR UI.
# Feel free to change the name of this environment.
environment:
name: review
# The script in the `deploy` sets the URL output for each review app.
url: ${{ steps.deploy.outputs.url }}
steps:
- name: Get code
uses: actions/checkout@v4
- name: Examine env variables
run: env
- name: Deploy PR app to Fly.io
id: deploy
uses: superfly/fly-pr-review-apps@1.2.0
with:
secrets: API_KEY=${{ secrets.API_KEY }} API_ENDPOINT=${{ vars.API_ENDPOINT }} AUTH_ENDPOINT=${{ vars.AUTH_ENDPOINT }} BASE_URL=${{ vars.BASE_URL }} DEFAULT_LOCALE=${{ vars.DEFAULT_LOCALE }} FALLBACK_CHANNEL_ID=${{ vars.FALLBACK_CHANNEL_ID }} FALLBACK_MARKET_ALIAS=${{ vars.FALLBACK_MARKET_ALIAS }} IMAGE_SERVER=${{ vars.IMAGE_SERVER }} SIGN_ENDPOINT=${{ vars.SIGN_ENDPOINT }} RALPH_ENV=dev
This is my fly.toml file
app = 'name'
primary_region = 'lhr'
[build]
dockerfile = 'Dockerfile.fly'
[env]
API_ENDPOINT = '***'
AUTH_ENDPOINT = '***'
BASE_URL = '***'
DEFAULT_LOCALE = '***'
FALLBACK_CHANNEL_ID = '***'
FALLBACK_MARKET_ALIAS = '***'
IMAGE_SERVER = '***'
RALPH_ENV = '***'
SIGN_ENDPOINT = '***'
[http_service]
internal_port = 3000
force_https = true
auto_stop_machines = true
auto_start_machines = true
min_machines_running = 0
processes = ['app']
[[vm]]
memory = '1gb'
cpu_kind = 'shared'
cpus = 1
and this is my Dockerfile
# syntax = docker/dockerfile:1
ARG NODE_VERSION=16.20.0
FROM node:${NODE_VERSION}-slim as base
LABEL fly_launch_runtime="Nuxt"
# Nuxt app lives here
WORKDIR /app
# Set production environment
ENV NODE_ENV="production"
# Throw-away build stage to reduce size of final image
FROM base as build
# Install packages needed to build node modules
RUN apt-get update -qq && \
apt-get install --no-install-recommends -y build-essential node-gyp pkg-config python
# Install node modules
COPY --link .npmrc package-lock.json package.json ./
RUN npm ci --include=dev
# Copy application code
COPY --link . .
RUN npm install -g node-prune
# Build application
RUN npm run build \
&& node-prune \
&& mkdir output \
&& cp -r package.json nuxt.config.js node_modules .nuxt static scripts config output
# Remove development dependencies
RUN npm prune --omit=dev
# Final stage for app image
FROM base
# Copy built application
COPY --from=build ./app/output ./
# Start the server by default, this can be overwritten at runtime
EXPOSE 3000
ENV HOST=0
ENV NUXT_HOST=0.0.0.0
CMD ["npm", "run", "start"]