I wish to run a legacy application which is compatible with centos6 which no longer has some dependencies maintained and therefore is incompatible with centos7. This application is called pdftk.
I want to (if this is remotely possible) run pdftk within a docker image of centos6 and expose this application to centos7...
The app does a couple of things:
Takes a PDF document as input & form data as input -> fills the PDF with the form data -> outputs the filled in PDF.
The command might look a little like this:
pdftk input.pdf --do-something output.pdf
Would something like this be possible with docker?
So far I have been able to initialise a centos6 image and successfully install pdftk. Any help with the next part (again if possible) would be most appreciated.
Thanks
You can write a Dockerfile with Centos6 as base, then install pdftk and any other dependency. Finally use Dockerfile command ENTRYPOINT to set the pdftk as the command of your image, and pass it the arguments you wish. For example (I haven't tested it, it's only an example):
FROM centos:centos6
RUN yum install pdftk
ENTRYPOINT ["/usr/bin/pdftk"]
Then you can build this image. Supposed you call it 'pdftk', you could run the container as: docker run -it --rm pdftk <arguments> -> docker run -it --rm -v ~/my_pdfs:/pdfs pdftk /pdfs/input.pdf --do-something /pdfs/output.pdf
Related
Like in docker we can enter a container by and have an interactive shell
docker-compose exec containername /bin/bash
Similary in the script in gitlab CI/CD can we enter into it. Like it provides an interactive shell
Eg:
build:
stage: build
script:
- pwd; ls -al
HERE I WANT TO HAVE AN INTERACTIVE SHELL SO THAT I CAN CHECK FEW THINGS
I think we need to do an small detour here and explain how jobs are working in GitLab CI.
Each job is an encapsulated docker container. The container only executes things you like to be executed within the script directive. By default the jobs on shared runners are using a ruby container image.
If you want to check, what you have available within your image, or you want try things out locally. You can do so running a container with this image locally and mounting your project folder into it.
docker run --rm -v "$(pwd):/build/project" -w "/build/project" -it <the job image> /bin/bash # or /bin/sh or whatever shell is available in the image.
# -v mounts the current directory int /build/project in your container
# -w changes the working directory to the mounting point
# /bin/bash starts the shell, it might be that there are others within the image
If you want to use a different docker image, lets say because you are running some other build tool, you can specify this with the image directive like:
build:
image: maven:latest
script:
- echo "some output"
You do have the functionality available within your job, which is provided by the image. As the job will run within a container of that image.
You can even use some tools like https://github.com/firecow/gitlab-ci-local to verify this locally. But in the end those are just docker images, and you can easily recreate the flow on your own.
I am trying to create a docker file to run selenium tests for a java script based project. Below is my docker file so far:
#base image
FROM selenium/standalone-chrome
#access to the project within docker container - Bundle app source
COPY ./seleniumTest/project /app
# Install Node.js
RUN sudo apt-get update
RUN sudo apt-get install --yes curl
RUN curl --silent --location https://deb.nodesource.com/setup_8.x | sudo bash -
#binding
EXPOSE 8080
#Define runtime
ENTRYPOINT /app/login.test.js
while running with $ docker run -p 4000:80 lamgadekamal/dockertest
returns: Unable to find image 'lamkam/dockertest:latest' locally docker: Error response from daemon: manifest for lamkam/dockertest:latest not found. Could not figure out why am I getting this?
I suspect that you need to build your image first, since the image cannot be found.
Run this command from the same directory where your Dockerfile is located. This will build the image.
docker build -t lamgadekamal/dockertest .
You can then verify that the image exists by running docker images
EDIT: After looking at this again, it appears that you are trying to run the wrong image. You are trying to run lamgadekamal/dockertest, but you built the image with the tag lamkam/dockertest? Seems like you have a typo. I would suggest running docker images to see exactly what is there, but in all likelihood, you need to run lamkam/dockertest.
docker run -p 4000:80 lamkam/dockertest
updated: added the missing docker attach.
Hi am trying to run a docker container, with -dti. but I cannot access with a terminal set to dumb. is there a way to change this (it is currently set to xterm, even though my ssh client is dumb)
example:
create the container
docker run -dti --name test -v /my-folder alpine /bin/ash
docker attach test
apk --update add nodejs
cd /my-folder
npm install -g gulp
the last command always contains ascii escape chars to move the cursor.
I have tried "export TERM=dumb" inside the running container, but it does not work.
is there a way to "run" this using the dumb terminal?
I am running this from a script on another computer, via (dumb) ssh.
using the -t which sets this https://docs.docker.com/engine/reference/run/#env-environment-variables, however removing effects the command prompt (the prompt is not shown)
possible solution 1 remove the -t and keep the -i. To see if the command has completed echo out a known token (ENDENDEND). ie
docker run -di --name test -v /my-folder alpine /bin/ash
docker attach test
apk --update add nodejs;echo ENDENDEND
cd /my-folder;echo ENDENDEND
npm install -g gulp;echo ENDENDEND
not pretty, but it works (there is no ascii in the results)
Possible solution 2 use the journal, docker can log out to the linux journal, this can be gathered as commands are executed in the container. (I have yet to fully test this one out. however the log seems to be a nicer output of what happened)
update:
Yep -t is the problem.
However if you want to see the entire process when running a command, maybe this way is better:
docker run -di --name test -v/my-folder alpine /bin/ash
docker exec -it test /bin/ash
finally you need to kill the container after all jobs finished.
docker run -d means "Run container in background and print container ID"
not start the container as a daemon
I was hitting this issue on OSx running docker, i had to do 2 things to stop the terminal/ascii/ansi escape sequences.
remove the "t" option on the docker run command (from docker run -it ... to docker run -i...)
ensure to force bash or sh shells used on osx when running the command from a script file, not the default zsh
Also
the escape sequences were not always visible on the terminal
even so, they still usually caused content corruption, even with SED brought to bear
they always were shown in my editor
I'm creating a Dockerfile to build my docker image. I was wondering what the best way, or if it's even possible, to create a log file of some sort that can show the results of the build and see if there were any errors in the process. For example, right now I have this:
monoVersion="3.8.0"
mkdir ~/mono
curl http://download.mono-project.com/sources/mono/mono-$monoVersion.tar.bz2 | tar xj --strip-components 1 -C ~/mono
cd ~/mono
git apply /src/mono-fix-20131106.patch
./configure --prefix=/usr/local
make -j 2
make install
in a install.sh script. In my Dockerfile I have:
FROM centos
MAINTAINER crystaltwix
ADD . /src
RUN cd /src ; ./install.sh
I'd like a way that I can look at the output after the image is created so every time I grab a different version of Mono, or do something similar when creating a new iamge, I can look after the image is created to see if any errors were generated. Is this possible? Or is that "connection" to the image being built closed once the Dockerfile is completed. Thank you.
One approach that I have been seeing for years (well before docker though docker makes it easier) is to have the script save it's output to a build log with the resulting image so that when you use the image and find a bug you can be sure you know hot this image was created.
RUN cd /src ; ./install.sh | tee buildlog
I am working on creating an automated unit testing system which will utilise docker to test individual student assignments, written in Python, against a single unit test file.
I have created a website where students can upload their assignments but I'm a little but unsure as to how to get the automation with Docker working.
The workflow looks something like this:
A student uploads an assignment for marking
This is copied to a linux host which contains docker
The file sits here while it waits to be tested
So, say I had twenty student uploading there .py files, named as their unique student numbers, could I:
Create a Docker container which runs Ubuntu and Python
Copy the student file and unit test into this container
Run the unit test
Output the results as a text file
Copy this text file back to my webserver to display the results
Could somebody point me in the right direction to get started with this automation? I'm really just after some help of the Docker side of things, not on copying the files from my webserver to the Docker host.
Thanks.
Yes, it is possible to use Docker for that.
The Dockerfile would look like this:
FROM ubuntu
MAINTAINER xxx <user#example.org>
# update ubuntu repository
RUN DEBIAN_FRONTEND=noninteractive apt-get -y update
# install ubuntu packages
RUN DEBIAN_FRONTEND=noninteractive apt-get -y install python python-pip
# install python requirements
RUN pip install ...
# define a mount point
VOLUME /student.py
# define command for this image
CMD ["python","/student.py"]
Now, you have to build this image with docker build -t student_test ..
To start the script and grab the output you can use:
docker run --volume /path/to/s12345.py:/student.py student_test > student_results_12345.txt`.
The --volume parameter is needed, to mount a student script to the defined mount point. Also, you could start multiple containers at once.
All paths are relative to current working directory.
Checkout the following project
https://github.com/CenturyLinkLabs/buildpack-runner
Uses Heroku buildpacks to create a docker image. Crazy but a neat idea if you get it working.