Impossible to start a script into my docker container - bash

I am trying to create my own image based on Centos.
I don't understand why when I use CMD command in my docker file to execute a script at startup, it's impossible to start my image (Exited (0) immediatly).
If build without the CMD command and then I connect to the container and I execute "sh /opt/jbossEAP/Mock/scripts/mock_start.sh". I have no issue
I have tryied to use entrypoint command but same result :(
FROM centos:7
ENV container docker
RUN (cd /lib/systemd/system/sysinit.target.wants/; for i in *; do [ $i == \
systemd-tmpfiles-setup.service ] || rm -f $i; done); \
rm -f /lib/systemd/system/multi-user.target.wants/*;\
rm -f /etc/systemd/system/*.wants/*;\
rm -f /lib/systemd/system/local-fs.target.wants/*; \
rm -f /lib/systemd/system/sockets.target.wants/*udev*; \
rm -f /lib/systemd/system/sockets.target.wants/*initctl*; \
rm -f /lib/systemd/system/basic.target.wants/*;\
rm -f /lib/systemd/system/anaconda.target.wants/*;
VOLUME [ "/sys/fs/cgroup" ]
CMD ["/usr/sbin/init"]
RUN yum update -y
RUN mkdir -p /opt/jbossEAP/Mock/scripts/
ADD ./scripts /opt/jbossEAP/Mock/scripts/
RUN chmod +x /opt/jbossEAP/Mock/scripts/mock_start.sh
### START SCRIPT ###
CMD sh /opt/jbossEAP/Mock/scripts/mock_start.sh
mock_start.sh
#!/bin/sh
############################################
echo "hello"

I suspect your CMD or ENTRYPOINT does work, but that the container simply finishes after outputting hello
You can check your docker's output even after it has been stopped with:
docker logs <container-id>
Read https://stackoverflow.com/a/28214133/4486184 for more information on how it works and how to avoid that.
My guesses could be wrong, so please always add to your question:
How you start your docker image
docker ps -a's output
the relevant part of docker logs <container-id>'s output

You're right!!!
I just add and now it's ok.
CMD sh /opt/jbossEAP/Mock/scripts/mock_start.sh && tail -f /dev/null
Thank you very much

Related

Why does my bash script not run properly on every docker container that starts up?

My Dockerfile copies an init.sh script to the container.
# DOCKERFILE
FROM ubuntu:latest
# a bunch of installation commands
COPY init.sh /
ENTRYPOINT bash init.sh
EXPOSE 80
And I have a docker-compose file with 2 services:
Service1: This service is being scaled.
Service2: Database
I have it so that when the Service1 container starts up, this script will run.
#!/bin/bash
# script
# Missing files directory
if [[ ! -e /var/www/drupal/sites/default/files ]]; then
mkdir /var/www/drupal/sites/default/files
chmod a+w /var/www/drupal/sites/default/files
fi
# Missing settings file
cp /var/www/drupal/sites/default/default.settings.php /var/www/drupal/sites/default/settings.php
chmod a+w /var/www/drupal/sites/default/settings.php
# Install Drush & Install Drupal
cd /var/www/drupal && composer require --dev drush/drush
cd /var/www/drupal && vendor/bin/drush site-install standard \
--db-url=mysql://root:random#mariadb:3306/drupaldb -y \
--site-name=ExampleWebsite \
--account-name=random \
--account-pass=random
# Post-Installation Steps
chmod go-w /var/www/drupal/sites/default/settings.php
chmod go-w /var/www/drupal/sites/default
cd /var/www/drupal && vendor/bin/drush cache-rebuild
/usr/sbin/apache2ctl -D FOREGROUND
However, when I run the command to start up the containers along with --scale docker-compose up -d --scale Service1=5, some of the containers run the script properly on start up but some don't. For the ones that don't, I would have to go into the container and manually run the script, then it's fine.
Shouldn't all the containers be the same and would've run the same script properly?
Instead, I would have to manually go into some of the containers and run the script.

How can I set Bash aliases for docker containers in Dockerfile?

I am new to Docker. I found that we can set environment variables using the ENV instruction in the Dockerfile. But how does one set Bash aliases for long commands in Dockerfile?
Basically like you always do, by adding it to the user's .bashrc file:
FROM foo
RUN echo 'alias hi="echo hello"' >> ~/.bashrc
As usual this will only work for interactive shells:
docker build -t test .
docker run -it --rm --entrypoint /bin/bash test hi
/bin/bash: hi: No such file or directory
docker run -it --rm test bash
$ hi
hello
For non-interactive shells you should create a small script and put it in your path, i.e.:
RUN echo -e '#!/bin/bash\necho hello' > /usr/bin/hi && \
chmod +x /usr/bin/hi
If your alias uses parameters (ie. hi Jim -> hello Jim), just add "$#":
RUN echo -e '#!/bin/bash\necho hello "$#"' > /usr/bin/hi && \
chmod +x /usr/bin/hi
To create an alias of an existing command, might also use ln -s:
ln -s $(which <existing_command>) /usr/bin/<my_command>
If you want to use aliases just in Dockerfile, but not inside a container then the shortest way is the ENV declaration:
ENV update='apt-get update -qq'
ENV install='apt-get install -qq'
RUN $update && $install apt-utils \
curl \
gnupg \
python3.6
And for use in a container the way like already described:
RUN printf '#!/bin/bash \n $(which apt-get) install -qq $#' > /usr/bin/install
RUN chmod +x /usr/bin/install
Most of the time I use aliases just in the building stage and do not go inside containers, so the first example is quicker, clearer and simpler for every day use.
I just added this to my app.dockerfile file:
# Set up aliases
ADD ./bashrc_alias.sh /usr/sbin/bashrc_alias.sh
ADD ./initbash_profile.sh /usr/sbin/initbash_profile
RUN chmod +x /usr/sbin/initbash_profile
RUN /bin/bash -C "/usr/sbin/initbash_profile"
And inside the initbash_profile.sh file which just appends my custom aliases and no need to source the .bashrc file:
# Add the Bash aliases
cat /usr/sbin/bashrc_alias.sh >> ~/.bashrc
It worked a treat!
Another option is to just use the "docker exec -it <container-name> command" from outside the container and just use your own .bashrc or the .bash_profile file (what ever you prefer).
E.g.,
docker exec -it docker_app_1 bash
I think the easiest way would be to mount a file into your container containing your aliases, and then specify where Bash should find it:
docker run \
-it \
--rm \
-v ~/.bash_aliases:/tmp/.bash_aliases \
[image] \
/bin/bash --init-file /tmp/.bash_aliases
Sample usage:
echo 'alias what="echo it works"' > my_aliases
docker run -it --rm -v ~/my_aliases:/tmp/my_aliases ubuntu:18.04 /bin/bash --init-file /tmp/my_aliases
alias
Output:
alias what='echo it works'
what
Output:
it works
You can use ENTRYPOINT, but it will not work for aliases, in your Dockerfile:
ADD dev/entrypoint.sh /opt/entrypoint.sh
ENTRYPOINT ["/opt/entrypoint.sh"]
Your entrypoint.sh file:
#!/bin/bash
set -e
function dev_run()
{
}
export -f dev_run
exec "$#"
Here is a Bash function to have your aliases in every container you use interactively.
ducker_it() {
docker cp ~/bin/alias.sh "$1":/tmp
docker exec -it "$1" /bin/bash -c "[[ ! -f /tmp/alias.sh.done ]] \
&& [[ -w /root/.bashrc ]] \
&& cat /tmp/alias.sh >> /root/.bashrc \
&& touch /tmp/alias.sh.done"
docker exec -it "$1" /bin/bash
}
Required step before:
grep ^alias ~/.zshrc > ~/bin/alias.sh
Used some of the previous solutions, but the aliases are not recognised still.
I'm trying to set aliases and use them both within later Dockerfile steps and in the container at runtime.
RUN echo "alias model-downloader='python3 ${MODEL_DL_PATH}/downloader.py'" >> ~/.bash_aliases && \
echo "alias model-converter='python3 ${MODEL_DL_PATH}/converter.py'" >> ~/.bash_aliases && \
source ~/.bash_aliases
# Download the model
RUN model-downloader --name $MODEL_NAME -o $MODEL_DIR --precisions $MODEL_PRECISION;
The solution for me was to use ENV variables that held folder paths and then add the exact executable. I could have use ARG too, but for more of my scenarios I needed the aliases in both the build stage and later in the runtime.
I used the ENV variables in conjunction with a Bash script that runs once dependencies have ponged and sets the Bash source, sets some more env variables, and allows for further commands to pipe through.
#ErikDannenberg's answer did the trick, but in my case, some adjustments were needed.
It didn't work with aliases cause apparently there's an issue with interactive shells.
I reached for his second solution, but it still didn't really work. I checked existing shell scripts in my project and noticed the head comment (first line = #!/usr/bin/env sh) differs a bit from #!/usr/bin/bash. After changing it accordingly it started working for my t and tc "aliases", but I had to use the addendum to his second solution for getting tf to work.
Here's the complete Dockerfile
FROM php:8.1.1-fpm-alpine AS build
RUN apk update && apk add git
RUN curl -sS https://getcomposer.org/installer | php && mv composer.phar /usr/local/bin/composer
RUN apk add --no-cache $PHPIZE_DEPS \
&& pecl install xdebug \
&& docker-php-ext-enable xdebug \
&& touch /usr/local/etc/php/conf.d/99-xdebug.ini \
&& echo "xdebug.mode=coverage" >> /usr/local/etc/php/conf.d/99-xdebug.ini \
&& echo -e '#!/usr/bin/env sh\nphp artisan test' > /usr/bin/t \
&& chmod +x /usr/bin/t \
&& echo -e '#!/usr/bin/env sh\nphp artisan test --coverage' > /usr/bin/tc \
&& chmod +x /usr/bin/tc \
&& echo -e '#!/usr/bin/env sh\nphp artisan test --filter "$#"' > /usr/bin/tf \
&& chmod +x /usr/bin/tf
WORKDIR /var/www

Dockerfile CMD not running at container start

So i've written a Dockerfile for a project, i've defined a CMD to run on starting the container to bootstrap the application.
The Dockerfile looks like
# create our mount folders and volumes
ENV MOUNTED_VOLUME_DIR=sites
RUN mkdir /$MOUNTED_VOLUME_DIR
ENV PATH=$MOUNTED_VOLUME_DIR/sbin:$MOUNTED_VOLUME_DIR/common/bin:$PATH
RUN chown -Rf www-data:www-data /$MOUNTED_VOLUME_DIR
# Mount folders
VOLUME ["/$MOUNTED_VOLUME_DIR/"]
# Expose Ports
EXPOSE 443
# add our environment variables to the server
ADD ./env /env
# Add entry point script
ADD ./start.sh /usr/bin/startContainer
RUN chmod 755 /usr/bin/startContainer
# define entrypoint command
CMD ["/bin/bash", "/usr/bin/startContainer"]
The start.sh script, does some git stuff like cloning the right repo, setting environment vars, as well as starting supervisor.
The start script begins with this
#!/bin/bash
now=$(date +"%T")
echo "Container Start Time : $now" >> /tmp/start.txt
/usr/bin/supervisord -n -c /etc/supervisord.conf
I start my new container like this
docker run -d -p expoPort:contPort -t -i -v /$MOUNTED_VOLUME_DIR/$PROJECT:/$MOUNTED_VOLUME_DIR $CONTAINER_ID /bin/bash
when i login to the container i see that supervisor hasn't been started, and neither has nginx or php5-fpm. the /tmp/start.txt file with a timestamp set from the startContainer script doesn't exist, showing its never ran the CMD in the Dockerfile.
Any hints on to get this fixed would be great
This:
docker run -d -p expoPort:contPort -t -i -v /$MOUNTED_VOLUME_DIR/$PROJECT:/$MOUNTED_VOLUME_DIR $CONTAINER_ID /bin/bash
Says 'run /bin/bash' after instantiating the container. E.g. skip CMD.
Try this:
docker run -d -p expoPort:contPort -t -i -v /$MOUNTED_VOLUME_DIR/$PROJECT:/$MOUNTED_VOLUME_DIR $CONTAINER_ID

How to detect fully interactive shell in bash from docker?

I'm wanting to detect in "docker run" whether -ti has been passed to the entrypoint script.
docker run --help for -t -i
-i, --interactive=false Keep STDIN open even if not attached
-t, --tty=false Allocate a pseudo-TTY
I have tried the following but even when tested locally (not inside docker) it didn't work and printed out "Not interactive" always.
#!/bin/bash
[[ $- == *i* ]] && echo 'Interactive' || echo 'Not interactive'
entrypoint.sh:
#!/bin/bash
set -e
if [ -t 0 ] ; then
echo "(interactive shell)"
else
echo "(not interactive shell)"
fi
/bin/bash -c "$#"
Dockerfile:
FROM debian:7.8
COPY entrypoint.sh /usr/bin/entrypoint.sh
RUN chmod 755 /usr/bin/entrypoint.sh
ENTRYPOINT ["/usr/bin/entrypoint.sh"]
CMD ["/bin/bash"]
build the image:
$ docker build -t is_interactive .
run the image interactively:
$ docker run -ti --rm is_interactive "/bin/bash"
(interactive shell)
root#dd7dd9bf3f4e:/$ echo something
something
root#dd7dd9bf3f4e:/$ echo $HOME
/root
root#dd7dd9bf3f4e:/$ exit
exit
run the image not interactively:
$ docker run --rm is_interactive "echo \$HOME"
(not interactive shell)
/root
$
This stackoverflow answer helped me find [ -t 0 ].

docker run -i -t image /bin/bash - source files first

This works:
# echo 1 and exit:
$ docker run -i -t image /bin/bash -c "echo 1"
1
# exit
# echo 1 and return shell in docker container:
$ docker run -i -t image /bin/bash -c "echo 1; /bin/bash"
1
root#4c064f2554de:/#
Question: How could I source a file into the shell? (this does not work)
$ docker run -i -t image /bin/bash -c "source <(curl -Ls git.io/apeepg) && /bin/bash"
# content from http://git.io/apeepg is sourced and shell is returned
root#4c064f2554de:/#
In my case, I use RUN source command (which will run using /bin/bash) in a Dockerfile to install nvm for node.js
Here is an example.
FROM ubuntu:14.04
RUN rm /bin/sh && ln -s /bin/bash /bin/sh
...
...
RUN source ~/.nvm/nvm.sh && nvm install 0.11.14
I wanted something similar, and expanding a bit on your idea, came up with the following:
docker run -ti --rm ubuntu \
bash -c 'exec /bin/bash --rcfile /dev/fd/1001 \
1002<&0 \
<<<$(echo PS1=it_worked: ) \
1001<&0 \
0<&1002'
--rcfile /dev/fd/1001 will use that file descriptor's contents instead of .bashrc
1002<&0 saves stdin
<<<$(echo PS1=it_worked: ) puts PS1=it_worked: on stdin
1001<&0 moves this stdin to fd 1001, which we use as rcfile
0<&1002 restores the stdin that we saved initially
You can use .bashrc in interactive containers:
RUN curl -O git.io/apeepg.sh && \
echo 'source apeepg.sh' >> ~/.bashrc
Then just run as usual with docker run -it --rm some/image bash.
Note that this will only work with interactive containers.
I don't think you can do this, at least not right now. What you could do is modify your image, and add the file you want to source, like so:
FROM image
ADD my-file /my-file
RUN ["source", "/my-file", "&&", "/bin/bash"]

Resources