I have docker registry from where Mesos pull the containers.My problem is when i destroy the app from Marathon UI and again call the Marathon rest api to deploy the app with same version of app, Mesos is not pulling image from the Master Docker registry It's pulling the image somewhere from local registry or cache. I realized this thing because Mesos completes the task in seconds and if I change the version it takes good time to deploy.
Please let me know If anyone has solution(or confusion related to the question) for this because I read all the documents i didn't get any solution.
Thanks
Try setting the forcePullImage flag to true as mentioned in here. Force pull instructs docker binary to pull the image from the registry even if it is already downloaded on the slave. Please refer to the corresponding documentation for how the docker pull command works.
Related
My overall goal is to install a self-hosted gitlab-runner that is restricted to use prepared docker images from my own docker registry only.
For that I have a system.d configuration that looks like:
/etc/systemd/system/docker.service.d/allow-private-registry-only.conf
BLOCK_REGISTRY='--block-registry=all'
ADD_REGISTRY='--add-registry=my.private.registry:8080'
By this, docker pull is allowed to pull images from my.private.registry/ only.
After I had managed to get this working, I wanted to clean up my local registry and remove old docker images. It was during that process when I stumbled over a docker image named gitlab/gitlab-runner-helper which presumably is some component used by the gitlab-runner itself and presumably has been pulled from docker.io.
Now I'm wondering if it is even possible/advisable to block images from docker.io when using a gitlab-runner?
Any hints are appreciated!
I feel my sovereign duty to extend the accepted answer (it is great btw), because the word 'handle' basically tells us not so much, it is too abstract. Let me explain the whole flow in far more details:
When the build is about to begin, gitlab-runner creates a docker volume (you can observe it with docker volume ls if you want). This volume will server as a storage for caches and artifacts that you are using during the build.
The second thing - You will have at least 2 containers involved in each stage: gitlab-runner-helper, container and the container created from the image you specified (in .gitlab-ci.yml or in config.toml). What gitlab-runner-helper container does it, essentially, just cloning the remote git repository (that you are building) in the aforementioned docker volume along with caches and artifacts.
It can do it becuase within gitlab-runner-helper image itself are 2 important utilities: git (obviously - to clone the repo) and gitlab-runner-helper binary (this utility can pull and push artifacts, caches)
The gitlab-runner-helper container starts before each stage for a couple of seconds, to pull artifacts and caches, and then terminates. After that the container, created from image that you specified will be launched, ant it will also have this volume (from step 1) attached - this is how it receives artifacts btw.
The rest of the details about the registry from where gitlab-runner-helper get pulled are described by #Nicolas pretty well. I append this comment just for someone, who, perhaps, want to know what exactly means this sneaky 'handle' word.
Hope it helps, have a nice day, my friend!
gitlab-runner-helper image is used by GitLab Runner to handle Git, artifacts, and cache operations for docker, docker+machine or kubernetes executors.
As you prefer pulling an image from a private registry, you can override the helper image. Your configuration could be :
[[runners]]
(...)
executor = "docker"
[runners.docker]
(...)
helper_image = "my.private.registry:8080/gitlab/gitlab-runner-helper:tag"
Please ensure the image is present on your registry or your configuration enable proxying docker hub or registry.gitlab.com. For this last, you need to run at least Gitlab runner version 13.7 and having enabled FF_GITLAB_REGISTRY_HELPER_IMAGE feature flag.
I am new to docker container. I met a problem about how to catch changes of my code. Some lines in my local style.css file have been changed. Then I built docker image again, but actually nothing changed when I browsed my app.
Here are some methods I found online and tried, but didn't work.
remove image and build again
--no-cache=true
add a comment in Dockerfile to make it different
docker system prune
--pull
(I also used git pull to get code on my cloud instance, these files were checked to be the latest.)
I know little about docker mechanism, could anyone tell me what the problem is?
Extra info I found:
After stopping container and removing image, I restart my instance, then build image, run container again. Only in this way, can I catch those changes. Does anyone know the problem?
Many thanks!
There appears to be a disconnect on the difference between a container and an image. The container is the running instance of your application. It is based on an image that you have already built. That image has a tag for easier referencing, but the real reference to the image is a sha256 hash and building a new image will change the hash that the tag points to without impacting any of your running containers.
Therefore, the workflow to update your running application in docker is to:
Build a new image
Stop the running container
Start a new container pointing to that image
Cleanup any old images or stopped containers
If you are using docker-compose, it automates the middle two steps with a docker-compose up command, and that even deletes the old container. Most users keep a few copies of older images to allow easy rollback.
I'm setting up a CI/CD workflow for my organization but I'm missing the final piece of the puzzle. Surely this is a solved problem, or do I have to write my own?
The full picture.
I'm running a few EC2 instances on AWS, each running docker in its native swarm mode. A few services are running here which I've started manually via docker service create ....
When a developer commits source code a trigger is sent to jenkins to pull the new code and build a new docker image which is then pushed to my private registry.
All is well and good up to here, but how do I get the new image onto my docker hosts and the running container automatically updated to the new version?
Docker documentation states (here) that the registry can send events to configurable endpoints when a new image gets pushed onto it. This is what I want to automatically react to by having my docker hosts then pull the new image and stop, destroy and restart the service using that new version (with the same env flags, labels, etc etc), but I'm not finding any solution to this that fits my use case.
I've found v2tec/watchtower but it's not swarm-aware nor can it pull from a private registry at the time of writing this question.
Preferably I want a docker image I can deploy on my docker manager which listens to registry events (after pointing the registry config at it) and does the magic I need.
Cost is an issue, but time is less so, so I'm more inclined writing my own solution than I am adopting a fee-based service for this.
One option you have is to SSH to swarm master from Jenkins using SSH plugin and pull the new image and update the service when new image is pushed to the registry.
We have been using locked version of the Minio image (RELEASE.2016-10-07T01-16-39Z), but now it seems to have been removed.
I'm getting this from Docker:
Pulling minio (minio/minio:RELEASE.2016-10-07T01-16-39Z)...
Pulling repository docker.io/minio/minio
ERROR: Tag RELEASE.2016-10-07T01-16-39Z not found in repository docker.io/minio/minio
I'm finding Docker hub hard to navigate. Where can I find a list of available versioned images, or a mirror to my exact image?
You can find the available tags for minio/minio on that repository's tag page.
If you have the image you want already downloaded on any of your systems, you can push it to Docker Hub yourself, then pull it onto your other systems. This has the benefit that you can control whether you delete that image (it's your account, not someone else's).
You can also use a private registry, if you want, which would prevent Docker from deleting the image from Docker Hub against your will for some reason. But that is extra work you may not wish to do (you would have to host the registry yourself, set it up, maintain it...)
We removed the docker version due to incompatibilities, from the recent releases it won't happen.
I got a docker repository that I work on and a bot that constantly pulls it from the repo to keep everything in sync but I need a way to find out if, when I pull, an update was downloaded so I can restart the daemon.
Is there a way with the registry itself or something else I could find out if an update was downloaded or not? I hope I'm making sense :)
As always I seem to find an answer within minutes. For anyone else interested in a solution for this just do a docker inspect __repo__ before running a docker pull __repo__ and save the id or created date in a variable then run inspect again and see if the data does match. If it doesn't you just pulled an update and your bot could issue a restart on the container.