set -euo pipefail no longer works with latest shellcheck-alpine docker image

[monemihir]

For bugs

• SC2039
• koalaman/shellcheck-alpine:latest (released 2 days ago as of writing this issue). The previous version of the container as of writing this issue = v0.6.0
• The rule's wiki page does not already cover this
• I tried on shellcheck.net but it works on the website. Most likely to do only with the docker container
• I searched through https://github.com/koalaman/shellcheck/issues and didn't find anything related

This was working until a few days ago but has suddenly started to give this error. If we go back and try the same script with v0.6.0 it works as expected.

Here's a snippet or screenshot that shows the problem:

#!/usr/bin/env sh
# shellcheck disable=SC2044
set -euo pipefail

rc=0
for filename in $(find . -name '*.sh') ; do
  echo "==> Validating ${filename}"
  shellcheck "${filename}" || exit $?
done

exit $rc

Here's what shellcheck currently says:

In ./tests/scripts/validate_shell_scripts.sh line 3:
--
set -euo pipefail
         ^------^ SC2039: In POSIX sh, set option pipefail is undefined.
 
For more information:
https://www.shellcheck.net/wiki/SC2039 -- In POSIX sh, set option pipefail ...

Here's what I wanted or expected to see:

No issues detected

[Quasic]

I wonder if something happened with #1480

[koalaman]

ShellCheck is correct. pipefail is not a valid shell options for sh scripts. Here's what happens if you try to run your script on Debian based distributions:

$ ./test.sh
./test.sh: 3: set: Illegal option -o pipefail

Your script does not do anything that warrants setting the pipefail option, so you can consider just removing it. If you want to keep it, set the shebang to a shell that supports pipefail such as bash or ksh.

[monemihir]

Can you please tell me the syntax for the shebang for bash? Or what is the path for it in the container?

I have tried the following:

#!/usr/bin/env bash
#!/bin/bash
#!bash

However all of them give on of the following errors:

standard_init_linux.go:190: exec user process caused "no such file or directory"

env: can't execute 'bash': No such file or directory

[koalaman]

Oh, you want to both check and run the scripts inside the alpine-linux container.

Are these scripts intended to ever be runnable outside alpine-linux? If so, the best way may be to install Bash with apk add bash and explicitly depend on that with #!/usr/bin/env bash

If you don't need them to be runnable outside alpine-linux, you can ignore the issue with a comment saying that you already know that sh will be BusyBox's Ash, so it will support pipefail.

Optimally you would just have used #!/usr/bin/env ash, but ShellCheck does not support Ash and will emit warnings saying that, so this is likely not a very pragmatic solution.

[monemihir]

I am using this container like so:

docker-compose run --rm shellcheck sample.sh

The docker-compose file:

---
version: '2.0'
services:
  shellcheck:
    image: koalaman/shellcheck-alpine:latest
    volumes:
      - ".:/build"
    working_dir: /build

Is there anyway I can install bash on the fly and run shellcheck? Unfortunately creating a new container and then using that is not an option for me.

I have tried updating the compose file to override the command but haven't found a working solution.

command: /bin/sh -c "apk add bash" && /bin/shellcheck

command: apk add bash && /bin/shellcheck
entrypoint: /bin/sh -c

command: /bin/sh -c "apk add bash" && /bin/shellcheck
entrypoint: /bin/sh -c

No matter what I do, I keep getting this error:

ERROR: Cannot start service shellcheck: OCI runtime create failed: container_linux.go:348: starting container process caused "exec: \"sample.sh\": executable file not found in $PATH": unknown

[nrxr]

That error is telling you it can't find sample.sh. Did you copy it? It's on the working directory?