sshpass not executing in bash script - bash

Question

I have a dockerfile: (these are the relevent commands)
RUN apk app --update bash openssh sshpass
CMD ["bin/sh", "/home/build/build.sh"]
Which my dockerfile gets ran by this command
docker run --rm -it -v $(pwd):/home <image-name>
and all of the commands within my bash script, that are within the mounted volume execute. These commands range from npm installs to using tar to zip up a file and I want to SFTP that tar.gz file.
I am using sshpass to automate logging in which I know isn't secured, but I'm not worried about that with this application.
sshpass -p <password> sftp -P <port> username#host << EOF
<command>
<command>
EOF
But the sshpass command is never executed. I've tested my docker run command by appending /bin/sh to it and trying it and it also does not run. The SFTP command by itself does.
And when I say it's never executed, I don't receive an error or anything.

Answer 1

Two possible reason
You apk command is wrong, it should be RUN apk add --update bash openssh sshpass, but I assume it typo
Seems like the known host entry is missing, you should check logs `docker logs -f , Also need to add entry in for known-host, check the suggested build script below.
Here is a working example that you can try
Dockerfile
FROM alpine
RUN apk add --update bash openssh sshpass
COPY build.sh /home/build/build.sh
CMD ["bin/sh", "/home/build/build.sh"]
build script
#!/bin/bash
echo "adding host to known host"
mkdir -p ~/.ssh
touch ~/.ssh/known_hosts
ssh-keyscan sftp >> ~/.ssh/known_hosts
echo "run command on remote server"
sshpass -p pass sftp foo#sftp << EOF
ls
pwd
EO
Now build the image, docker build -t ssh-pass .
and finally, the docker-compose for testing the above
version: '3'
services:
sftp-client:
image: ssh-pass
depends_on:
- sftp
sftp:
image: atmoz/sftp
ports:
- "2222:22"
command: foo:pass:1001
so you will able to connect the sftp container using docker-compose up