How to pass Prisma database url at build time with docker secrets? - docker

Question

I am trying to dockerize an express app using prisma and supabase, but am unable to get prisma to set the supabase url at build time with docker. Prisma is expecting the url to be in an environment variable named DATABASE_URL. To avoid exposing the url I am passing it as a secret to docker and trying to set it an an environment variable but cannot get it to work. Here are two different approaches I've tried with my Dockerfile:
Dockerfile
# syntax=docker/dockerfile:1.2
FROM node:18.9.0
WORKDIR /app
COPY package*.json .
COPY yarn.lock .
COPY prisma .
RUN --mount=type=secret,id=_env,dst=/etc/secrets/.env \
export $(egrep -v '^#' /etc/secrets/.env | xargs) \
&& yarn install
RUN --mount=type=secret,id=_env,dst=/etc/secrets/.env \
export $(egrep -v '^#' /etc/secrets/.env | xargs) \
&& yarn prisma generate
COPY . .
RUN yarn build
CMD ["yarn", "start:dev"]
Dockerfile2
# syntax=docker/dockerfile:1.2
FROM node:18.9.0
WORKDIR /app
COPY package*.json .
COPY yarn.lock .
COPY prisma .
RUN --mount=type=secret,id=dburl \
DATABASE_URL="$(cat /run/secrets/dburl)" \
&& yarn install
RUN --mount=type=secret,id=dburl \
DATABASE_URL="$(cat /run/secrets/dburl)" \
&& yarn prisma generate
COPY . .
RUN yarn build
CMD ["yarn", "start:dev"]
The build commands for each one are the following respectively:
docker build --progress=plain --no-cache --secret id=_env,src=.env .
docker build --progress=plain --no-cache --secret id=dburl,src=dburl.txt .
Whenever I try this the first call to the prisma client inside the app produces a segmentation fault and crashes the app, whereas it works fine outside of the docker container.
Any help would be greatly appreciated.

Answer 1

Turns out either method actually works. The segmentation fault issue is another problem entirely:
https://github.com/prisma/prisma/issues/10649