I have a simple Dockerfile that copies over a template which I used sed to replace some of the variables. Pretty straight forward. Looks very doable and from what I've seen/read for all intents and purposes, it should do it.
COPY /my-dir/my-textfile.conf /to/my/docker/path.conf
RUN sed -i s:TEXTTOREPLACE:my-new-text:g /to/my/docker/path.conf
I then run docker build.... then docker run ... bash
then I cat my file and TEXTTOREPLACE is still there.
Run the same sed command in the bash and it works no problem.
Any thoughts? What am I doing wrong/not seeing?
Thanks!
EDIT per request: base image is debian:7.11, work station is MAC OSX
Just to recap.
I have the file my-textfile.conf in my working directory. Its content is:
I need to change TEXTTOREPLACE with my-new-text
My test system is Ubuntu Linux 16.04 running Docker version 18.09.0, build
4d60db4.
This is the Dockerfile
FROM debian:7.11
COPY my-textfile.conf /tmp/path.conf
RUN sed -i s:TEXTTOREPLACE:my-new-text:g /tmp/path.conf
I run the following commands:
docker build -t mytestimage .
docker run -ti -d --name mytestcontainer mytestimage
docker exec -ti mytestcontainer /bin/bash
Then, inside the container, I run:
cat /tmp/path.conf
and I get this result:
I need to change my-new-text with my-new-text
So it seems it works as expected.
Related
I present to you the following dilemma I execute my script manually and it works well, see next line for example:
docker exec -ti backup_subversion sh -c "/tmp/my_script.sh"
But when I attempt to schedule the process this line is just skipped.
I have tried to execute just a touch command and it too is ignored.
I have tried to execute as root, same problem.
I have tried to execute in another docker environment: same problem.
My OS is Centos 7.
In this script for example the bug part who will crash :
#!/bin/bash
# Create a container.
docker run -d --name=backup_subversion \
-v /subversion/dump:/var/dump \
--net my_network my_server.domaine.com/subversion/billy:1.9
# I copy a script.
docker cp tools_subversion_dump.sh backup_subversion:/tmp
# This line is ignore since crontab exec.
docker exec -ti backup_subversion sh -c "/tmp/tools_subversion_dump.sh"
Thank you in advance for your answers because it's a mystery to me.
It's probably because you used the -it options that only apply to an interactive shell rather then a pseudo one like the one used in scripts as referenced in the question
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.
Is there a way to check if the docker image has all of the files that the Dockerfile copies over and to understand if the image is built as configured in the Dockerfile? My situation is that the image is built successfully, however when I try running it, docker complains that it cant find some file or other and the container fails to run, so I cant exec on it.
Doing docker inspect is not helping since it does not report on the files in the image. Is there some method?
You can run a shell based on that image:
docker run -it <image-name> bash
Use sh instead if there is no bash available. There you can search for files as any shell.
But maybe you have not bash in the image, so use sh:
docker run -it <image-name> sh
But maybe you have an odd entrypoint, so override it:
docker run -it --entrypoint sh <image-name>
You can see the history of file and check if all the required files are present at the time of image creation
docker image history --no-trunc [image_name] > [file_name]
I'd like to learn the Dockerfile from a very simple start, so here's my Dockfile:
FROM ubuntu
ENTRYPOINT /bin/bash
however, after building the image and run the container, I find that I can't run the bash commands. For example, if I type:
# clear
The container seems to get stuck running in an infinite loop.
So why does that happen? How can I fix it?
How are you running the container? Note that you have to pass the options -i in order to keep STDIN open and the -t to allocate a pseudo-TTY.
Below you can find an example:
docker run -i -t my-image
docker run -it ubuntu
Post this command, you will have a prompt like:
root#26f9e7a42517:/#
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