Svelte Kit & LiteFS application not reachable by proxy

[alessandrojcm]

Hi there!

First time Fly user here, loving the platform so far but I’m having an issue when trying to deploy Svelte Kit with LiteFS. Svelte Kit only works fine, but when I try to set up LiteFS I get an “Application is not reachable at 0.0.0.0:3000 error”. I followed the official guide and used some other Node.js applications as an example, but no dice.

This is my Fly file:

#
# See https://fly.io/docs/reference/configuration/ for information about how to use this file.
#

app = 'my-app'
primary_region = 'cdg'

[build]

[[mounts]]
  source = 'litefs'
  destination = '/data'

[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

This is my LiteFS configuration file:

# The fuse section describes settings for the FUSE file system. This file system
# is used as a thin layer between the SQLite client in your application and the
# storage on disk. It intercepts disk writes to determine transaction boundaries
# so that those transactions can be saved and shipped to replicas.
fuse:
  dir: "/litefs"

# The data section describes settings for the internal LiteFS storage. We'll
# mount a volume to the data directory so it can be persisted across restarts.
# However, this data should not be accessed directly by the user application.
data:
  dir: "/var/lib/litefs"

# This flag ensure that LiteFS continues to run if there is an issue on starup.
# It makes it easy to ssh in and debug any issues you might be having rather
# than continually restarting on initialization failure.
exit-on-error: false

# This section defines settings for the option HTTP proxy.
# This proxy can handle primary forwarding & replica consistency
# for applications that use a single SQLite database.
proxy:
  addr: ':${INTERNAL_PORT}'
  target: 'localhost:${PORT}'
  db: "db"
  passthrough:
    - "*.ico"
    - "*.png"

# This section defines a list of commands to run after LiteFS has connected
# and sync'd with the cluster. You can run multiple commands but LiteFS expects
# the last command to be long-running (e.g. an application server). When the
# last command exits, LiteFS is shut down.
exec:
  - cmd: "pnpm run:migrate"
    if-candidate: true
  - cmd: "node ./build/index.js --bind 0.0.0.0:3000"

# The lease section specifies how the cluster will be managed. We're using the
# "consul" lease type so that our application can dynamically change the primary.
#
# These environment variables will be available in your Fly.io application.
lease:
  type: "consul"
  advertise-url: "http://${HOSTNAME}.vm.${FLY_APP_NAME}.internal:20202"
  candidate: ${FLY_REGION == PRIMARY_REGION}
  promote: true

  consul:
    url: "${FLY_CONSUL_URL}"
    key: "litefs/${FLY_APP_NAME}"

And this is my Dockerfile:

# syntax = docker/dockerfile:1

# Adjust NODE_VERSION as desired
ARG NODE_VERSION=22.2.0
FROM node:${NODE_VERSION}-slim as base

LABEL fly_launch_runtime="SvelteKit"

# SvelteKit app lives here
WORKDIR /app

# Set production environment
ENV NODE_ENV="production"

# Install pnpm
ARG PNPM_VERSION=9.3.0
RUN npm install -g pnpm@$PNPM_VERSION


# 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 -y && apt-get install -y ca-certificates fuse3 sqlite3
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y build-essential node-gyp pkg-config python-is-python3

# Install node modules
COPY --link .npmrc package.json pnpm-lock.yaml ./
RUN pnpm install --frozen-lockfile --prod=false

# Copy application code
COPY --link . .

# Build application
RUN pnpm run build

# Remove development dependencies
RUN pnpm prune --prod


# Final stage for app image
FROM base

# Copy built application
COPY --from=build /app/build /app/build
COPY --from=build /app/node_modules /app/node_modules
COPY --from=build /app/package.json /app

ADD litefs.yml /etc/litefs.yml
COPY --from=flyio/litefs:0.5 /usr/local/bin/litefs /usr/local/bin/litefs
RUN mkdir -p /data /litefs

# Start the server by default, this can be overwritten at runtime
ENV PORT=3000
ENV HOSTNAME=0.0.0.0
EXPOSE 3000
ENV SQLITE_DATABASE_NAME="file:///litefs/sqlite.db"

CMD [ "litefs", "mount" ]

Also I’m a bit confused here as to which one is the path that my application will use to load the SQLite database, is it the /litefs folder?

Thanks!