I am looking to pass an environment variable which should get a random id.
Something like below.
ENV SERVICE_TAG= $uuid
In short, every time I run the container, I should get a random id for this environment variable inside the container.
Can anyone please suggest the way forward?
Thanks and regards,
Prasanth.
Add uuidgen package to the image. In case you are using alpine add
RUN apk add --no-cache util-linux
to the Dockerfile
Then in the entrypoint of your Dockerfile add
Below is a sample Dockerfile
FROM alpine:latest
RUN apk add --no-cache util-linux
ENTRYPOINT export UUID=`uuidgen` && echo $UUIDFROM alpine:latest
You should pass the environment variable from a docker run -env parameter generated uuid or guid from your shell, eg:
bash:
docker run --env SERVICE_TAG=$(uuidgen) yourimage
See more details at the official docker docs:
https://docs.docker.com/engine/reference/commandline/run/#set-environment-variables--e---env---env-file
Related
My Dockerfile looks like the following:
from httpd:${bamboo.test.tag}
COPY index.html /usr/local/apache2/htdocs/
In Bamboo I have a task with the following script:
docker build --no-cache -t myproj/my .
When running the job, I get the following error:
build 26-Sep-2022 10:42:26 Step 1/2 : from httpd:${bamboo.test.tag}
error 26-Sep-2022 10:42:26 failed to process "httpd:${bamboo.test.tag}": missing ':' in substitution
How can I substitute the tag?
This is actually a problem with how you are using the dockerfile.
Docker will not expand environment variables inside your Dockerfile. You need to pass the environment value as a build argument in the docker build command then use the ARG keyword inside the Dockerfile.
Your Dockerfile would look like this:
ARG IMAGE_TAG
from httpd:${IMAGE_TAG}
COPY index.html /usr/local/apache2/htdocs/
And you would need to change you docker build command to:
docker build --no-cache --build-arg IMAGE_TAG=${bamboo.test.tag} -t myproj/my .
Check a more detailed explanation here
Like in docker we can enter a container by and have an interactive shell
docker-compose exec containername /bin/bash
Similary in the script in gitlab CI/CD can we enter into it. Like it provides an interactive shell
Eg:
build:
stage: build
script:
- pwd; ls -al
HERE I WANT TO HAVE AN INTERACTIVE SHELL SO THAT I CAN CHECK FEW THINGS
I think we need to do an small detour here and explain how jobs are working in GitLab CI.
Each job is an encapsulated docker container. The container only executes things you like to be executed within the script directive. By default the jobs on shared runners are using a ruby container image.
If you want to check, what you have available within your image, or you want try things out locally. You can do so running a container with this image locally and mounting your project folder into it.
docker run --rm -v "$(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
I am making a test file. I need to have a docker image and run it like this:
docker run www.google.com
Everytime that url changes, I need to pass it into a file inside the docker. Is that possible?
Sure. You need a custom docker image but this is definitely possible.
Let's say you want to execute the command "ping -c 3" and pass it the parameter you send in the command line.
You can build a custom image with the following Dockerfile:
FROM alpine:latest
COPY entrypoint.sh /entrypoint.sh
RUN chmod +x /entrypoint.sh
ENTRYPOINT /entrypoint.sh
The entrypoint.sh file contains the following:
#!/bin/sh
ping -c 3 "$WEBSITE"
Then, you have to build you image by running:
docker build -t pinger .
Now, you can run your image with this command:
docker run --rm -e WEBSITE=www.google.com pinger
By changing the value of the WEBSITE env variable in the latest step you can get what you requested.
I just solved it by adding this:
--env="url=test"
to the docker run, but I guess your way of doing it, is better.
Thank you
I've set an environment variable (NPM_TOKEN) for my repo in Docker Cloud to use when building my Dockerfile. However, the variable is always empty...
Tried both of these in Dockerfile:
RUN echo ${NPM_TOKEN}
and:
ARG NPM_TOKEN
RUN echo ${NPM_TOKEN}
Am I wrong in assuming that Docker Clouds environment variables for build does the same thing as --build-arg?
It took me along time, but you can use build hooks to set variables for automated builds!
https://docs.docker.com/docker-cloud/builds/advanced/#build-hook-examples