I'm using gitlab-ci for my simple project.
And everything is ok my runner is working on my local machine(ubuntu18-04) and I tested it with simple .gitlab-ci.yml.
Now I try to use the following yml:
image: ubuntu:18.04
build-job:
stage: build
script:
- echo "Hello, $GITLAB_USER_LOGIN!"
- sudo apt-get update
but I get the following error:
/bin/bash: line 110: sudo: command not found
How can I use sudo?
You shouldn't have to worry about updating the Ubuntu image used in a Gitlab CI pipeline job because the docker container is destroyed when the job is finished. Furthermore, the docker images are frequently updated. If you look at ubuntu:18.04's docker hub page, it was just updated 2 days ago: https://hub.docker.com/_/ubuntu?tab=tags&page=1&ordering=last_updated
Since you're doing an update here, I'm going to assume that next you might want to install some packages. It's possible to do so, but not advised since every pipeline that you run will have to install those packages, which can really slow them down. Instead, you can create a custom docker image based on a parent image and customize it that way. Then you can either upload that docker image to docker hub, Gitlab's registry (if using self-hosted Gitlab, it has to be enabled by an admin), or built on all of your gitlab-runners.
Here's a dumb example:
# .../custom_ubuntu:18.04/Dockerfile
FROM ubuntu:18.04
RUN apt-get install git
Next you can build the image: docker build /path/to/directory/that/has/dockerfile, tag it so you can reference it in your pipeline config file: docker tag aaaaafffff59 my_org/custom_ubuntu:18.04. Then if needed you can upload the tagged image docker push my_org/custom_ubuntu:18.04.
In your .gitlab-ci.yml file, reference this custom Ubuntu image:
image: my_org/custom_ubuntu:18.04
build-job:
stage: build
script:
- echo "Hello, $GITLAB_USER_LOGIN!"
- git --version # ensures the package you need is available
You can read more about using custom images in Gitlab CI here: https://docs.gitlab.com/charts/advanced/custom-images/