I am a docker beginner. I have used this SO post to run a shell script with docker run and this works fine. However, what I am trying to do is to apply my shell script to a file that lives in my current working directory, where Dockerfile and script are.
My shell script - given a file as an argument, return its name and the number of lines:
#!/bin/bash
echo $1
wc -l $1
Dockerfile:
FROM ubuntu
COPY ./file.sh /
CMD /bin/bash file.sh
then build and run:
docker build -t test .
docker run -ti test /file.sh text_file
This is what I get:
text_file
wc: text_file: No such file or directory
I'm left clueless why the second line doesn't work, why the file can't be found. I don't want to copy my text_file to the container. Ideally, I'd like to run my script from docker container on any file in my current working directory.
Any help will be much appreciated.
Thanks!!
You're building your Docker image containing the script /file.sh. Still, your Docker container does not contain (or know) about the file text_file which you're passing as an argument.
In order to make it known to your Docker container, you have to mount it when running the container.
docker run --rm -it -v "$PWD"/text_file:/text_file test /file.sh /text_file
In order to check for other files, you just have to swap text_file in both the mount and the argument.
Notes
In addition to Docker volume mounts, I might suggest some more improvements to spice up your image.
In order to run a script, you don't have to use ubuntu as your base image. You might be fine with alpine or even more focused bash. And don't forget to use tags in order to enforce the exact same behavior over time.
You can set your script as an ENTRYPOINT of your Dockerfile. Then, your only specifying the script name (text_file in that case) as your command.
When mounting files, you can change the name of the file in your container. Therefore, you can simplify your script and just mounting the file to test at the exact same place every time you run the container.
FROM alpine:3.10
WORKDIR /tmp
COPY file.sh /usr/local/bin/wordcount
ENTRYPOINT /usr/local/bin/wordcount
CMD file
Then,
docker run --rm -it -v "PWD"/text_file:/tmp/file test
will do the job.
Related
I am trying to copy a folder outside of a container using docker cp, but I am running in an unexpected issue: the command works perfectly outside of a shell script yet fails when running the script.
For example: copy_indices.sh
for x in "${find_container_id_arr[#]}"; do
CONTAINER_NAME="${x}"
CONTAINER_ID=$(docker ps -aqf "name=${x}")
idx_name=$(docker exec -it "$CONTAINER_ID" ls -1 /usr/share/elasticsearch/data/nodes/0/indices)
docker cp "$CONTAINER_ID":/usr/share/elasticsearch/data/nodes/0/indices/"$idx_name" "$ALL_INDICES"/"$idx_name"
done
I determine the container ID using CONTAINER_ID=$(docker ps -aqf "name=${x}"), find the name of folder I need using idx_name=$(docker exec -it "$CONTAINER_ID" ls -1 /usr/share/elasticsearch/data/nodes/0/indices) and then copy it on the host filesystem: docker cp "$CONTAINER_ID":/usr/share/elasticsearch/data/nodes/0/indices/"$idx_name" "$ALL_INDICES"/"$idx_name"
My issue is that every command evaluates and run as expected when not put inside this script. I can run the command docker cp <my_container>:/usr/share/elasticsearch/data/nodes/0/indices/<index_name> ./all_indices/<index_name> and the target folder is indeed found and copied onto the host.
Once these commands are inside a script however, I get an "Error: No such container:path:" error and I can't pinpoint what is going wrong, because the mentionned path indeed exists in the container and the container is correct as I tested it running the "final" command supposed to be executed (the docker cp one).
What could be the reason these commands suddenly stop working when put in a shell script?
I am trying to run a local script with docker bash in windows PowerShell but not working.
My script part is another program, but the finally goal is to process a media file and zip it with the shell script.
The cmd: docker exec -it containername /bin/bash < myscript.sh -f fileone.mp4 -h output
I have an error in ps:
The '<' operator is reserved for future use.
The parameters (and also the files) are changing, if rerun the shell script, and after the script, processing is done it will create a zip file (what I need) with the output name, but random strings will be placed to the zipped filename too.
Anyone tried to use docker in that way in windows?
I figure out a solution for my own question. I just leave it here, if someone needs it.
The docker-compose file:
version: '3.8'
services:
somename:
build:
context: .
dockerfile: Dockerfile
container_name: 'name_if_you_need'
The dockerfile:
FROM debian:latest
# Install and/or config anything what you need
ADD . /newfolder
WORKDIR /newfolder
ENTRYPOINT [ "/newfolder/myscript.sh" ]
To call (with arguments and/or flags if your script need it): docker run --rm -v ${PWD}:/newfolder image_name -flag1 sample.mp4 -flag2 sample (no tty error, not need winpty)
Please note, if your script working with file or files, and you pass it via arguments like me, you need to copy them in your current folder before docker run
With this solution, if your script generates a file or files when/after executing, you will see them automatically in your current folder.
I have a container that is running with no issues. I added a bash script to compliment a couple other scripts already in the container. The docker image copy 2 scripts to /usr/local/bin and they can be accessed with docker exec -c container-name existingscript.
I added my own script to the same directory and when running the same command I get an error that exec cannot run the script: no file or directory,script not located in $PATH. I check path and sure enough, /usr/local/bin is listed. I checked permissions and the script is 755.
I then open an interactive shell with docker exec -it mycontainer bash and run /usr/local/bin/myscript and it runs with no problem.
Why can I not run the script from outside the container like I can the other two (that were included in the image). All three have almost the same functions a day do not use any special programs, one lists files, one adds files, one reads the file.
The base is Ubuntu.
EDIT: Found where I was running into the issue. Provided the answer in case anyone else happens to make the same mistake.
EDIT-2: So the script that came with the docker image to perform a couple common functions calls the image not the container so my adding the scripts to the container had no effect on the script which was why I kept getting the no file or directory error.
The line in the script in question was:
docker run --rm -v "$(pwd)/config":/path/to/file -ti image_name:latest" mynewscript $#
Of course that ran against the image and NOT the container.
Once I noticed that I tried running it with exec instead of run and it ran without error, like so:
docker exec -it container_name mynewscript
The reason is "/usr/local/bin" not in your script's $PATH, you can use /usr/local/bin/myscript explicitly in your script. Or export $PATH first in the script.
While I was adding snippets to help explain the issue I found the problem and the solution.
So I access the scripts inside the container from the host with another script that allows you to do different things based on switch case. The scripts are called against the docker image and not the container so the script I added does not actually exist in the image.
I modified the script to call the container instead of the image and it works as expected.
EDIT: I updated the question with the answer but I am adding it here as well:
So the script that came with the docker image to perform a couple common functions calls the image not the container so my adding the scripts to the container had no effect on the script which was why I kept getting the no file or directory error.
The line in the script in question was:
docker run --rm -v "$(pwd)/config":/path/to/file -ti image_name:latest" mynewscript $#
Of course that ran against the image and NOT the container.
Once I noticed that I tried running it with exec instead of run and it ran without error, like so:
docker exec -it container_name mynewscript
I am very new to docker, and I need help to dockerize a ruby script that takes a a input directory and output directory.
i.e generate_rr_pair.rb BuildRR -n /data/ -o /output
What the script does, is it will take the -n option (input) and check if the directory exists, if it does it uses the files inside as input. The script will then output data to the -o option (output). If the output directory doesn't exist, the script will create the directory and output files there.
How can I create a Dockerfile to handle this? Should I pass these in, as environment variables? Or should I use mounted Volumes? But since the script handles fileIO, I am not sure if I want volumes. The input directory should already exist on the host, and the output directory will get created. Both directories, should remain after docker container stops.
Use the official ruby image in your docker file:
FROM ruby:2.1-onbuild
CMD ["ruby", "generate_rr_pair.rb"]
Building the container as normal
docker build -t myruby .
Which can then be run as follows:
docker run --rm -it -v /data:/data -v /output:/output myruby BuildRR -n /data -o /output
Note that volume mappings are required if you want the ruby script within the container to operate on directories mounted on the host machine.
I am trying to create a shell script for setting up a docker container. My script file looks like:
#!bin/bash
docker run -t -i -p 5902:5902 --name "mycontainer" --privileged myImage:new /bin/bash
Running this script file will run the container in a newly invoked bash.
Now I need to run a script file (test.sh)which is already inside container from the above given shell script.(eg: cd /path/to/test.sh && ./test.sh)
How to do that?
You can run a command in a running container using docker exec [OPTIONS] CONTAINER COMMAND [ARG...]:
docker exec mycontainer /path/to/test.sh
And to run from a bash session:
docker exec -it mycontainer /bin/bash
From there you can run your script.
Assuming that your docker container is up and running, you can run commands as:
docker exec mycontainer /bin/sh -c "cmd1;cmd2;...;cmdn"
I was searching an answer for this same question and found ENTRYPOINT in Dockerfile solution for me.
Dockerfile
...
ENTRYPOINT /my-script.sh ; /my-script2.sh ; /bin/bash
Now the scripts are executed when I start the container and I get the bash prompt after the scripts has been executed.
In case you don't want (or have) a running container, you can call your script directly with the run command.
Remove the iterative tty -i -t arguments and use this:
$ docker run ubuntu:bionic /bin/bash /path/to/script.sh
This will (didn't test) also work for other scripts:
$ docker run ubuntu:bionic /usr/bin/python /path/to/script.py
This command worked for me
cat local_file.sh | docker exec -i container_name bash
You could also mount a local directory into your docker image and source the script in your .bashrc. Don't forget the script has to consist of functions unless you want it to execute on every new shell. (This is outdated see the update notice.)
I'm using this solution to be able to update the script outside of the docker instance. This way I don't have to rerun the image if changes occur, I just open a new shell. (Got rid of reopening a shell - see the update notice)
Here is how you bind your current directory:
docker run -it -v $PWD:/scripts $my_docker_build /bin/bash
Now your current directory is bound to /scripts of your docker instance.
(Outdated)
To save your .bashrc changes commit your working image with this command:
docker commit $container_id $my_docker_build
Update
To solve the issue to open up a new shell for every change I now do the following:
In the dockerfile itself I add RUN echo "/scripts/bashrc" > /root/.bashrc". Inside zshrc I export the scripts directory to the path. The scripts directory now contains multiple files instead of one. Now I can directly call all scripts without having open a sub shell on every change.
BTW you can define the history file outside of your container too. This way it's not necessary to commit on a bash change anymore.
Thomio's answer is helpful but it expects the script to exist inside the image. If you have a one-of script that you want to run/test inside a container (from command-line or to be useful in a script), then you can use
$ docker run ubuntu:bionic /bin/bash -c '
echo "Hello there"
echo "this could be a long script"
'
Have a look at entry points too. You will be able to use multiple CMD
https://docs.docker.com/engine/reference/builder/#/entrypoint
If you want to run the same command on multiple instances you can do this :
for i in c1 dm1 dm2 ds1 ds2 gtm_m gtm_sl; do docker exec -it $i /bin/bash -c "service sshd start"; done
This is old, and I don't have enough reputation points to comment. Still, I guess it is worth sharing how one can generalize Marvin's idea to allow parameters.
docker exec -i mycontainer bash -s arg1 arg2 arg3 < mylocal.sh