Env variable in Dockerfile

Question

I'm trying to dockerize a basic nodejs app. My dockerfile is the follow

FROM node:10

WORKDIR /usr/src/app

COPY package*.json ./

RUN npm install

COPY . .

EXPOSE 80
CMD [ "node", "index.js" ]

After i build the image I'm trying to running it with

docker run -p 3000:3000 imagename -e connectionString=myConnString

But I received always the same error

[eval]:1
connectionString=myConnString

ReferenceError: myConnString is not defined

How can I solve?

The -e connectionString=myConnString should be passed in the docker run i.e. docker run -p 3000:3000 -e connectionString=myConnString imagename - anything passed after the image:tag is passed as [COMMAND] [ARG...] to the ENTRYPOINT (if any) ref. the doc. — masseyb
– masseyb, Commented Aug 31, 2019 at 14:37

masseyb · Accepted Answer · 2019-08-31 14:43:32Z

4

The docker run syntax is docker run [OPTIONS] IMAGE[:TAG|@DIGEST] [COMMAND] [ARG...], anything passed after the IMAGE[:TAG|@DIGEST] is passed as [COMMAND] [ARG...].

The environment variable setting should be passed in the run [OPTIONS] i.e.: docker run -p 3000:3000 -e connectionString=myConnString imagename

answered Aug 31, 2019 at 14:43

masseyb

4,2281 gold badge20 silver badges31 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

mchawre · Accepted Answer · 2019-08-31 14:21:09Z

1

Your docker run command should be:

docker run -p 3000:3000 -e connectionString=myConnString imagename

-e option should be before imagename.

Give it a try.

answered Aug 31, 2019 at 14:21

mchawre

12.5k4 gold badges45 silver badges60 bronze badges

Collectives™ on Stack Overflow

Env variable in Dockerfile

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related