NOTE: I'm an embedded programmer, so devops stuff is mildly mysterious to me and I might be using the wrong terms.
When creating my BitBucket self hosted runners, do I HAVE to use docker in docker, or can I take the self-hosted runner container image and add my required tools and licenses to it?
i.e. the docker command it gives me when I create a self-hosted runner has this in it: docker-public.packages.atlassian.com/sox/atlassian/bitbucket-pipelines-runner, can I just create my own Dockerfile image which uses that, and add my software packages, environment variables, etc. and invoke that instead of the original one?
Or do I necessarily need to do docker-in-docker?
As I mentioned in the beginning, a lot of the devops stuff is just what google/stackexchange tells me to do and thus vaguely cargo-cultish. Getting credentials and other stuff from the self-hosted runner image into my docker-in-docker image (without building credentials into the image) seems like its more work to me.
Thanks for any insight
Related
So in my head, Docker is a container management system that allows you to build an application in a unified way so you don't need to worry about version control, client environment configuration and so on.
However, there is some concept that I am clearly missing:
In my head, Docker basically wraps your whole program in a container to be shipped easily to clients and anybody who wants to use your product. And from there I can just tell clients to install so-and-so to set up the whole system in their own system. However, digging into Docker, I don't understand how pulling and pushing images into DockerHub helps that use case as well as not providing an executable to execute DockerImage in a click.
DockerHub images take so many steps to unpack and edit. I was assuming that those templates on DockerHub exists for us to pull and edit the template for our own use cases, but that does not seem to be the case because the steps to unpack an image is much more than I imagined, and the use case seems to be more of "Download and use image, not for editing".
Surely I am missing something about Docker. What is the purpose of pushing and pulling images on DockerHub? How does that fit into the use case of containerizing my software to be executed by clients? Is the function of DockerHub images just to be pulled to be ran and not edited?
It's so hard for me to wrap my head around this because I'm assuming Docker is for containerizing my application to be easily executable by clients who wants to install my system.
To further explain this answer I would even say that docker allows you to have a development environment tied to your application that is the same for all your developers.
You would have your git repo with your app code, and a docker container with all that is needed to run the application.
This way, all your developers are using the same version of software and that docker container(s) should replicate the production environment (you can even deploy with it, that's another use for it) but with this there's no more the "it works on my machine" problem. Because everyone is working on the same environment.
In my case all our projects have a docker-compose structure associated with them so that each project always have their server requirements. And if one developer needs to add a new extension, he can just add it to the docker config files and all developer will receive the same extension once they update to the latest release.
I would say there are two uses to having images on DockerHub.
The first is that some images are extremely useful as-is. Pulling a redis/mariadb image saves you the trouble of setting it and configuring it yourself.
The second is that you can think of a docker image as a layered item: assume your application is a PHP server. You can (and will have to) create an image for your app source code. BUT the container will need PHP to run your source code!
This is why you have a FROM keyword in a Dockerfile, so that you can define a "starting layer". In the case of a PHP server you'd write FROM php:latest, and docker would pull a PHP image for your server to use from DockerHub.
Without using Dockerhub, you'd have make your image from scratch, and therefore to bundle everything in your image, some operating system information, PHP, your code, etc. Having ready-to-use images to start from makes the image you're building much lighter.
I have a nodejs server app and a separate reacts client app.
I have created docker images for both and a docker compose at the top level to build and run both
I'm struggling to understand how I can deploy/host these somewhere?
Do I deploy both separate images to the docker register? Or is this a way of hosting this on it's own as an entire docker container?
If you've already built the docker images on local, you can use DockerHub for hosting the docker images. If you're using Github Actions this gist script can be helpful.
Docker Registry is storage for built images. Think it as location for compiled "binaries" if comparing regular software.
Regularly, you might have some kind of CI for your source code, and when you trigger it for example by committing into 'master' branch, new image is built on the CI. It can push it into registry for long term storing, or push it directly to your hosting server (or registry in your server).
You can configure your docker-compose to pull latest images from private registry, when you just rerun it in your server.
Basically, hosting happens when you just run docker-compose up in some server, if you have done required configurations. It really depends where you are going to host them.
Maybe helpful:
https://www.docker.com/blog/how-to-deploy-on-remote-docker-hosts-with-docker-compose/
https://medium.com/#stoyanov.veseline/pushing-docker-images-to-a-private-registry-with-docker-compose-d2797097751
I think I'm fundamentally missing something. I'm new to CI/CD and trying to set up my first pipeline ever with gitlab.
The project is a pre-existing PHP project.
I don't want to clean it up just yet, at the moment I've pushed the whole thing into a docker container and it's running fine talking to google cloud's mysql databases etc as it should locally and also on a remote google cloud testing VM.
The dream is to be able to push to the development branch, and then merge the dev banch into the test branch which then TRIGGERS automated tests (easy part), and also causes the remote test VM (hosted on google cloud), to PULL the newest changes, rebuild the image from the latest docker file (or pull the latest image from gitlab image register)... and then rebuild the container with the newest image.
I'm playing around with gitlab's runner but I'm not understanding what it's actually for, despite looking through almost all the online content for it.
Do I just install it in the google cloud VM, and then when I push to gitlab from my development machine.. the repo will 'signal' the runner (which is running on the VM, to execute a bunch of scripts (which might include git pull on the newest changes?).
Because I already pre-package my app into a container locally (and push the image to the image registry) do I need to use docker as my executor on the runner? or can i just use shell and shell the commands in?
What am I missing?
TLDR and extra:
Questions:
What is runner actually for,
where is it meant to be installed?
Does it care which directory it is run in?
If it doesn't care which directory it's run,
where does it execute it's script commands? At root?
If I am locally building my own images and uploading them to gitlab's registry,
Do I need to set my executor to docker? Shouldn't I just set it to shell, pull the image, and build it? (Assuming the runner is runing on the remote VM).
What is runner actually for?
You have your project along with a .gitlab-ci.yml file. .gitlab-ci.yml defines what stages your CI/CD pipeline has and what to do in each stage. This typically consists of a build,test,deploy stages. Within each stage you can define multiple job. For example in build stage you may have 3 jobs to build on debian, centos and windows (in GitLab glossary build:debian, build:centos, build:windows). A GitLab runner clones the project read the gitlab-ci.yaml file and do what he is instructed to do. So basically GitLab runner is a Golang process that executes some instructed tasks.
where is it meant to be installed?
You can install a runner in your desired environment listed here. https://docs.gitlab.com/runner/install/
or
you can use a shared runner that is already installed on GitLab's infrastructure.
Does it care which directory it is run in?
Yes. Every task executed by runner is relativly to CI_PROJECT_DIR defined in https://gitlab.com/help/ci/variables/README. But you can alter this behaviour.
where does it execute it's script commands? At root?
Do I need to set my executor to docker? Shouldn't I just set it to shell, pull the image, and build it?
A runner can have mutiple executors such as docker, shell, virtualbox etc but docker being the most common one. If you use docker as the executor you can pull any image from docker hub or your configured registry and you can do loads of stff with docker images. In a docker environment normally you run them as the root user.
https://docs.gitlab.com/runner/executors/README.html
See gitlab access logs , runner is constantly polling the server
What's the differences between the VSTS Build tasks of docker (with preview) and docker without preview?
It's said in the description that 'red' ones can be used with Docker or Azure Container Registry, is this an only difference?
Could they differentiate with docker/compose version or environment (e.g., one for windows, one for linux?)
Based on the source code of them, the difference between them is adding supported for Azure Container Registry, the Docker Registry Connection are the same.
You can setup a private build agent and add these tasks to a build definition and queue build with that build agent, and then these tasks will be downloaded to the _task folder (e.g. _work_task) and you can check it.
Not easy to make good title for this question so if someone have better idea please edit.
That's what I have:
VPS (KVM)
Docker
Nginx-proxy so all docker containers supposed to be exposed are automatically exposed to appropriate domain.
Some apps like Wordpress are just using container with connected volumes which are accesible by FTP so this is not an issue to manage them/update stuff etc.
I have SailsJS app (NodeJS) which I have to dockerize. It will be kept updated quite often.
I will have some apps written in C#(ASP.NET) / Java (Spring) with similar scenario as in point 5.
Both 5 and 6 source code is stored on BitBucket but can be changed if it would be better to have self hosted git server to solve issues.
What I am looking for is to have automated process which will build the docker image when I do commit and make sure that docker will pull the new image and restart container with new content. I do not want to use DockerHub as there is only 1 private repository so it will not work for long term.
I thought I can do it with Jenkins somehow but have no idea how...
You can setup private GitLab server.
It provides THREE necessary things - Git repository (managed as admin by your own), completely private Docker registry (so you can privately store your own docker images) , and own CI - complete and sufficient to do what you request, integrated seamlessly and working with former two.
You would setup GitLab runner so when you do commit image being rebuilt and pushed to component-specific registry, and there are hooks and environments which allow you to set up back connection.