在 docker 容器中找不到文件

Question

I'm doing something extremely simple. Here is my Dockerfile :

FROM alpine:latest

ADD hello.sh /bin/hello
RUN chmod +x /bin/hello

CMD /bin/hello

Then I build the image:

docker build -t hello .

Then I run the image:

docker run hello

And here is the output:

/bin/sh: /bin/hello: not found

Why is this happening? If I run:

docker run hello cat /bin/hello

I can see the content of my script, which makes me even more confused.

Answer 1

The file not found can be from:

• the file actually isn't there, check for typos, make sure you aren't trying to run a quoted command and all the arguments together when you should only be running the command (not this issue, but seen it many times). And make sure you aren't mounting a volume over top of where you expect your command.
• the command at the top of the script doesn't exist. Eg trying to call bash when the container only has sh. This also applies to those that create the script on Windows and have invalid line feeds at the end of the command. I don't believe Alpine includes a bash where other base images do.
• the binary you are trying to run links libraries that do not exist inside the container. This is seen with Alpine with the musl libc version differences.

Answer 2

In my case the problem was that the line-endings for the script were Windows encoded instead of Linux . (Note: This was actually caused by git automatically converting them, which I disabled)

The first line of the script provides the file path to the shell. Because of the extra \\r that is included with Windows EOL the system was trying attaching that hidden character to the filename and that's what caused the Not Found error.

Answer 3

Problem solved by using an ubuntu image instead of an alpine image. Not exactly sure why, but might have to do with the file's user/permission bits getting copied over and not interpreted correctly.

Answer 4

This sounds like you were trying to execute a bash script but alpine by default does not include bash . Instead you need to have your script execute using sh by changing your shebang line to be #!/bin/sh .

In effect, the script is being executed but it's actually saying that /bin/bash does not exist.

Answer 5

I've had similar problem where, no matter how my python app was simple (imagine just hello.py that outputs 'hello world'), when running through docker-compose build && up commands I got error hello.py - not found. It turned out that the issue was that virtualbox did not mount my folder (app) properly. This came as a rescue and resolved my problem in 5 minutes: Docker + Ubuntu + Virtualbox: "volumes" directive in dockerfile not working