[SOLVED] Docker: Error code 127 when executing shell script

Issue

So I can't seem to figure this out, but I'm getting error code 127 when running a Dockerfile. What causes this error?

My Dockerfile:

FROM composer as comp

FROM php:7.4-fpm-alpine
COPY --from=comp /usr/bin/composer /usr/bin/composer
COPY ./docker/install-deps.sh /tmp/install-deps.sh
RUN echo $(ls /tmp)
RUN /tmp/install-deps.sh
COPY . /var/www
WORKDIR /var/www
RUN composer install -o --no-dev

The results after building the Dockerfile:

Building php
Step 1/9 : FROM composer as comp
 ---> 433420023b60
Step 2/9 : FROM php:7.4-fpm-alpine
 ---> 78e945602ecc
Step 3/9 : COPY --from=comp /usr/bin/composer /usr/bin/composer
 ---> 46117e22b4de
Step 4/9 : COPY ./docker/install-deps.sh /tmp/install-deps.sh
 ---> 7e46a2ee759c
Step 5/9 : RUN echo $(ls /tmp)
 ---> Running in aa1f900032f9
install-deps.sh
Removing intermediate container aa1f900032f9
 ---> eb455e78b7f6
Step 6/9 : RUN /tmp/install-deps.sh
 ---> Running in 6402a15cccb2
/bin/sh: /tmp/install-deps.sh: not found
ERROR: Service 'php' failed to build: The command '/bin/sh -c /tmp/install-deps.sh' returned a non-zero code: 127

The install-deps.sh:

#!/bin/sh

set -e

apk add --update --no-cache \
    postgresql-dev \
    mysql-client \
    yaml-dev \
    git \
    openssl

docker-php-ext-install pcntl pdo_mysql pdo_pgsql

# yaml
apk add --no-cache --virtual .build-deps g++ make autoconf
pecl channel-update pecl.php.net
pecl install yaml
docker-php-ext-enable yaml
apk del --purge .build-deps

Solution

Docker is executing the install-deps.sh script. The issue is with a command inside install-deps.sh that is not recognized when docker attempts to run the script.

As you can see the script returns an error code of 127 meaning that a command within the file does not exist.

For instance - try this:

touch test.sh
echo "not-a-command" >> test.sh
chmod 755 test.sh
/bin/sh -c "./test.sh"

Output:

/root/test.sh: line 1: not-a-command: command not found

Now check the exit code:

echo $?
127

I would suggest running the script inside an interactive environment to identify/install the command that is not found.

Answered By - Sean Ziegler

Answer Checked By - David Marino (WPSolving Volunteer)