Container command '/start.sh' not found or does not exist, entrypoint to container is shell script

Project contents:

rob@work:~/git/proj $ ls
lib     node_modules  props.json    start.sh
app.js  Dockerfile    package.json  README.md

start.sh ..

rob@work:~/git/proj $ cat start.sh 
#/bin/bash

# do things
/some/other/stuff

echo "Starting app .."
node app.js

Dockerfile ..

FROM somewhere.com/dependencyProj
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app
COPY . /usr/src/app
COPY props.json /etc/someService.d/props.json
EXPOSE 4101

ENTRYPOINT ["/start.sh"]

Build docker image:

rob@work:~/git/proj $ docker build -t dx/proj:0.0.1 .
Sending build context to Docker daemon 59.99 MB
Step 1 : FROM somewhere.com/dependencyProj
latest: Pulling from dependencyProj
420890c9e918: Already exists 
8ff1af46fe3d: Already exists 
6db3a1c6f4ca: Already exists 
d82a90c4ea1b: Already exists 
f32685681727: Already exists 
797dfb291196: Already exists 
3a713b0b523e: Already exists 
a9c617bff63b: Already exists 
9ab84732ac6e: Already exists 
2a85e0afdd4d: Already exists 
a56b24146ce4: Already exists 
0a91b00da1f7: Already exists 
836b0e7c1105: Already exists 
Digest: sha256:36b7a32bd12b85cbb2fb3203d43807c9b8735d6ceb50d813b76bfe2e5c3ebeb4
Status: Downloaded newer image for somewhere.com/dependencyProj:latest
 ---> 7c52bbbc3feb
Step 2 : RUN mkdir -p /usr/src/app
 ---> Running in aab7cf1f7974
 ---> 250317f63adf
Removing intermediate container aab7cf1f7974
Step 3 : WORKDIR /usr/src/app
 ---> Running in f60088532610
 ---> 60f3d9fe88c4
Removing intermediate container f60088532610
Step 4 : COPY . /usr/src/app
 ---> 004e0a440fb5
Removing intermediate container f247d134d88b
Step 5 : COPY props.json /etc/someService.d/props.json
 ---> 03b48249c94c
Removing intermediate container a3636849765d
Step 6 : EXPOSE 4101
 ---> Running in 0056e5c20264
 ---> 867765176927
Removing intermediate container 0056e5c20264
Step 7 : ENTRYPOINT /start.sh
 ---> Running in 80ae316b0629
 ---> d1e65def77ce
Removing intermediate container 80ae316b0629
Successfully built d1e65def77ce

Run docker image:

rob@work:~/git/proj $ docker run -d dx/proj:0.0.1
0fd1f8087cc5be3e085454cf99b7a3795b9ce15909b0f416ae39380f93feaa44
docker: Error response from daemon: Container command '/start.sh' not found or does not exist..

Solution

You have some issues:

You must use ./start.sh to run the start.sh file from current directory. /start.sh run start.sh in root /, which does not exist.
Your shebang line in start.sh script is wrong, it's must be #!/bin/bash.
You also must set executable permission for start.sh, by running chmod +x start.sh.