I want to run an interactive script inside the docker container. I have created the image which contains the interactive script. I want to run that script when I am launching the image inside the docker container. But its not running.
Can Someone please help me or share a link for that. My need is when I launch the container that script should hit and from the container it should communicate and ask for the input.
Here is a working solution:
First the script which prompts the user: input.sh
#!/bin/sh
echo who are you?
read someone
echo hello $someone
The Dockerfile:
FROM bash:4
COPY ./input.sh input.sh
RUN chmod +x input.sh
CMD ./input.sh
Just build it
docker build -t testinput .
And run it:
docker run -i testinput:latest
The output:
$ docker run -i testinput:latest
who are you?
bob
hello bob
The important part is the -i option that runs the container interactively
Related
Can I execute a local shell script within a docker container using docker run -it ?
Here is what I can do:
$ docker run -it 5ee0b7440be5
bash-4.2# echo "Hello"
Hello
bash-4.2# exit
exit
I have a shell script on my local machine
hello.sh:
echo "Hello"
I would like to execute the local shell script within the container and read the value returned:
$ docker run -it 5e3337440be5 #Some way of passing a reference to hello.sh to the container.
Hello
A specific design goal of Docker is that you can't. A container can't access the host filesystem at all, except to the extent that an administrator explicitly mounts parts of the filesystem into the container. (See #tentative's answer for a way to do this for your use case.)
In most cases this means you need to COPY all of the scripts and support tools into your image. You can create a container running any command you want, and one typical approach is to set the image's CMD to do "the normal thing the container will normally do" (like run a Web server) but to allow running the container with a different command (an admin task, a background worker, ...).
# Dockerfile
FROM alpine
...
COPY hello.sh /usr/local/bin
...
EXPOSE 80
CMD httpd -f -h /var/www
docker build -t my/image .
docker run -d -p 8000:80 --name web my/image
docker run --rm --name hello my/image \
hello.sh
In normal operation you should not need docker exec, though it's really useful for debugging. If you are in a situation where you're really stuck, you need more diagnostic tools to be understand how to reproduce a situation, and you don't have a choice but to look inside the running container, you can also docker cp the script or tool into the container before you docker exec there. If you do this, remember that the image also needs to contain any dependencies for the tool (interpreters like Python or GNU Bash, C shared libraries), and that any docker cpd files will be lost when the container exits.
You can use a bind-mount to mount a local file to the container and execute it. When you do that, however, be aware that you'll need to be providing the container process with write/execute access to the folder or specific script you want to run. Depending on your objective, using Docker for this purpose may not be the best idea.
See #David Maze's answer for reasons why. However, here's how you can do it:
Assuming you're on a Unix based system and the hello.sh script is in your current directory, you can mount that single script to the container with -v $(pwd)/hello.sh:/home/hello.sh.
This command will mount the file to your container, start your shell in the folder where you mounted it, and run a shell:
docker run -it -v $(pwd)/hello.sh:/home/hello.sh --workdir /home ubuntu:20.04 /bin/sh
root#987eb876b:/home ./hello.sh
Hello World!
This command will run that script directly and save the output into the variable output:
output=$(docker run -it -v $(pwd)/hello.sh:/home/test.sh ubuntu:20.04 /home/hello.sh)
echo $output
Hello World!
References for more information:
https://docs.docker.com/storage/bind-mounts/#start-a-container-with-a-bind-mount
https://docs.docker.com/storage/bind-mounts/#use-a-read-only-bind-mount
I have the following Dockerfile
FROM ros:kinetic
COPY . ~/sourceshell.sh
RUN["/bin/bash","-c","source /opt/ros/kinetic/setup.bash"]
when I did this (after building it with docker build -t test
docker run --rm -it test /bin/bash
I had a bash terminal and I could clearly see there was a sourceshell.sh file that I could even execute from the Host
However I modified the docker run like this
docker run --rm -it -w "/root/afolder/" test /bin/bash
and now the file sourceshell.sh is nowhere to be seen.
Where do the files copied in the dockerfile go when the working directory is reasigned with docker run?
Option "-w" is telling your container execute commands and access on/to "/root/afolder" while your are COPYing "sourceshell.sh" to the context of the build, Im not sure, you can check into documentation but i think also "~" is not valid either. In order to see your file exactly where you access you should use your dockerfile like this bellow otherwise you would have to navigate to your file with "cd":
FROM ros:kinetic
WORKDIR /root/afolder
COPY . ./sourceshell.sh
RUN["/bin/bash","-c","source /opt/ros/kinetic/setup.bash"]
Just in case you don't understand the diff of the build and run process:
the code above belongs to the the build context, meaning, first build and image (the one you called it "test"). then the command:
docker run --rm -it -w "/root/afolder/" test /bin/bash
runs a container using "test" image and use WORKDIR "/root/afolder"
I have a Dockerfile in which I have specified an ENTRYPOINT "my_script.sh".In my_script.sh,I am exe.cuting a CURL command.When the docker image with this Dockerfile is built.How should I run it so that output of my_script.sh will be printed on my host.
Dockerfile -
FROM my-company-repo-java-base-image
ADD my_script.sh /root
ENTRYPOINT bash "/root/my_script.sh
my_script.sh
echo "Hello My Script"
curl -x POST "some_api_which_returns_json"
I have built the image using command
docker build
I want to run this image and see output of my_script.sh on my dockerhost.
Given a Docker image whose tag is $DOCKER_IMAGE:
docker container run -it --rm $DOCKER_IMAGE
-i keeps STDIN open
-t allocates a pseudo-TTY
--rm automatically removes the container when it exits
See docker container run for all the options.
Of course you can see the output of shell script. Make sure you delete the old image before building new one when you change the script. Else, your container will keep using the old script over and over. Here's an example
Dockerfile
FROM alpine:3.7
ENTRYPOINT ["/usr/bin/myscript.sh"]
COPY myscript.sh /usr/bin/myscript.sh
myscript.sh
#!/usr/bin/env sh
echo "Hello there"
commands to run:
docker image rm testdocker
docker build --tag testdocker .
docker run testdocker
You should see the line Hello there appears on the terminal
I need to set environment variable in a running docker container. I am already aware of the way of setting environment variable while creating a container. As far I found there is no available straight forward way to do this with docker and docker is planning to add something with new version 1.13.
But I found that some people able to manage it which is not working for me now. I tried following ways but did not work for me-
docker exec -it -u=root test /bin/bash -c "export port=8090"
echo "export port=8090" to /etc/bash.bashrc using a script and then source it
docker exec -it test /bin/bash -c "source /etc/bash.bashrc"
configuring the whole thing in a script and run it from host also did not work. While running script from host all the other command successfully executes except "export port=8090" or "source /etc/bash.bashrc" or "source /root/.bashrc".
Can anyone explain why sourcing file from host does not work in docker container even when I set user("-u=root")? Can anyone help me to solve this? When I source the file from inside the container it works perfectly. But in my case I have to do it from host machine
NOTE:, I am using docker 1.12 and tried the above in ubuntu:16.04 and ubuntu:14.04
If you have a running process in the docker and you are attempting to change the environment variable in the docker so the running process will dynamically change - this will not work. The environment variables of a process are set when it starts. You can see here ways to overcome that, but I don't think that is the right way to go.
I would instead, have a configuration file that the file reads (or listens to) periodically. And when you want to change the configuration change the file.
If this isn't your scenario, please describe your scenario so we can better assist you.
I find a way to provide environment variable to a running container. Fist upgrade your docker-engine. I am using V1.12.5.
create a script with environment variables-
#!/bin/bash
echo "export VAR1=VAL1
export VAR2=VAL2" >> /etc/bash.bashrc
source /etc/bash.bashrc
Now start a container. Here, 'test' is the container name:
docker run -idt --name=test ubuntu
Copy your script to container:
docker cp script.sh test:/
Run the script :
docker exec -it test /bin/bash -c "/script.sh"
Restart your container:
docker restart test
Go to container shell
docker exec -it test /bin/bash
Check the variable
echo $VAR1
How can I debug docker container that I set to always restart.
I have a container that launch nodejs app, with a
CMD ["nodemon", "/usr/src/app/app.js »] that work very well on other container but not on the new one i created it says with docker logs containerName :
Usage: nodemon [nodemon options] [script.js] [args]
See "nodemon --help" for more.
How can I connect to the container to have more informations than logs, for example see some config file or if my nodejs files have been copied.
I didn’t find a way : I would like to use docker exec -it bash and navigate in my docker but because it is always restarting I cannot. How to debug this kind of container ?
EDIT : i use the CMD["bash"] but when i use docker exec -it bash i doesn't work
Because the container keep restarting.
You could make a new image base on your container image, and a different starting script (one which runs the node command for testing, and then opens a bash for instance)
You could need to COPY that script
COPY myscript /usr/local/bin
CMD ["/usr/local/bin/myscript"]
That way, you can test your current image as wrapped in a test image.
You can even only use bash in that new image
CMD["bash"]
And launch the command manually.
For that, you would need to run that image with:
docker run -it --rm myNewImage
That will open an interactive bash session.