I am trying to run below the demo using the `docker file`.

<https://github.com/OpusCapita/fsm-workflow>

my `docker file`

```
# Docker context should be "<repo-root>"

FROM node:8-alpine
LABEL maintainer="OpusCapita"

ENV HOST 0.0.0.0
ENV PORT 3020

COPY ./ /demo

WORKDIR /demo

RUN npm i --unsafe-perm && \
  cd ./packages/examples/complete-demo && \
  npm run demo:build

WORKDIR /demo/packages/examples/complete-demo

CMD ["npm", "run", "demo:start"]

EXPOSE $PORT
© 2019 GitHub, Inc.

```

getting this error when I am deploying.

```
sh: lerna: not found

npm ERR! file sh

```

**logs**

```
Building image...
Step 1/10 : FROM node:8-alpine

 ---> e8b2a6e1bbd7

Step 2/10 : LABEL maintainer="OpusCapita"

 ---> Using cache

 ---> 2ee8a0ffc36f

Step 3/10 : ENV HOST 0.0.0.0

 ---> Using cache

 ---> 3980c8fcd99c

Step 4/10 : ENV PORT 3020

 ---> Using cache

 ---> 04cd54009ba2

Step 5/10 : COPY ./ /demo

 ---> b321c3cc1ac5

Step 6/10 : WORKDIR /demo

 ---> Running in fbf59913ad9b

Removing intermediate container fbf59913ad9b

 ---> 1cd94112afd1

Step 7/10 : RUN npm i --unsafe-perm && npm install -g rimraf && npm install --g lerna &&   cd ./packages/examples/complete-demo &&   npm run demo:build

 ---> Running in 35dceefe2cb8

> @opuscapita/fsm-workflow@ postinstall /demo
> npm run bootstrap

> @opuscapita/fsm-workflow@ bootstrap /demo
> lerna bootstrap

sh: lerna: not found

npm ERR! file sh

npm ERR!
 code ELIFECYCLE
npm ERR! errno ENOENT
npm ERR! syscall spawn

npm ERR!
 @opuscapita/fsm-workflow@ bootstrap: `lerna bootstrap`
npm ERR! spawn ENOENT
npm ERR! 
npm ERR! Failed at the @opuscapita/fsm-workflow@ bootstrap script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

```