I have a linux bare-metal server with docker installed.
I work on an asp.net core project on my computer.
My source code is pushed on github.
Each time i commit and push something, github triggers a webhook on my docker hub account.
Docker hub builds me a new image which contains my asp.net core application binaries. (docker hub also run the tests)
This image works fine when i pull it manually on my server.
My question is how can i do this automatically ? Is there a way for my server to "detect" that docker hub contains a new version of the image and run something to pull this image and fire database migrations automatically ?
Thanks
If you have a public ip which external internet such as dockerhub could visit you, then you can use Docker Hub Webhooks:
You can create webhooks like next diagram, set the url which external could visit your service, when image was pushed, it will post some json data to the url you afforded, one example data here, then your own url could receive data and do related things as you like.
And, if you use jenkins, there are lots of plugin help you to do similar things: refer Triggering Docker pipelines with Jenkins, also Polling Docker Registries for Image Changes
If you not have a public ip which dockerhub could visit, then I guess you had to poll dockerhub to see if new image there...
Related
First, I'm noob with Continuous Deployement. I currently have a VPS running 3 docker containers (Flask, MongoDb, Nginx) that I'm pulling from DockerHub with a docker-compose. What I want to do is auto deploy those 3 containers when pushing some code in my github repo. I think It's possible with Ansible but I never used it.
Someone can explain me how to do it ?
Many thx !
Finally I will use Jenkins :)
That implies a webhook, as explained in "How to Integrate Your GitHub Repository to Your Jenkins Project" by Guy Salton
And that means your Jenkins server is accessible through an internet-facing public URL, which is not always obvious when working in a corporate environment.
GitHub Actions "Publishing Docker images" can help publishing the image to DockerHub, but you still need to listen/detect those events in order for your Jenkins to trigger job pulling said ppublished images.
For that, a regular sheduler Jenkins job using regclient/regclient can help checking the latest published SHA2 image ID has or has not changed.
See more with "Container Registry Management with Brandon Mitchell: DevOps and Docker (Ep 108)".
I'm having problems with docker continuous integration.
I setup automated builds in cloud.docker.com for my project, but there is not information at all either in their webs (hub/store) or their api, which shows that my build is not automated.
Docker Cloud looks like this:
But in the registry there is no "builds" section:
I guess that should look like other members projects, something like this:
Also, like I said, using the endpoint: https://registry.hub.docker.com/v2/repositories/{user}/{project}/ shows me "automated build: false"
I just realized that, in some way, there is no link between the Docker Cloud automatic builds and Docker Hub ones.
If you create an automated build in Docker Hub, everything works. I don't understand the logic of this, because if you create a repo either in docker cloud or docker hub, they are syncronized as one, but automated builds created on Docker Cloud don't show correctly in Docker Hub/Store.
Both, the Docker Hub and Docker Store builds will be updated whenever you do a push to your repo or a new build is sent with docker push, but the information about the automatic build only will be showed in Docker Cloud if you did it here.
I am trying to build a jenkins job(trigger builds remotely) on docker image build, build all I am getting on docker hub is following:
HISTORY
ID Status Date & Time
7345... ! ERROR 10/12/17 10:03
Reason (I assume): Docker is not authenticated to post to the jenkins url.
Question: How can I trigger the job automatically when an image gets pushed to docker hub?
Pull and run Watchtower docker image to poll any third-party public Docker image on Docker Hub or Quay that you need (typically as a base image of your own containers). Here's how. "Polling" here does not imply crudely pulling the whole image every 5 minutes or so - we are monitoring periodically for changes in the image, downloading only the checksum (SHA digest) most of the time (when there are no changes in the locally cached image).
Install the Build Token Root Plugin in your Jenkins server and set it up to receive Slack-formatted notifications secured with a token to trigger builds remotely or - safer - locally (those triggers will be coming from Watchtower container, not Slack). Here's how.
Set up Watchtower to post Slack messages to your Jenkins endpoint upon every change in the image(s) (tags) that you want. Here's how.
Optionally, if your scale is so large that you could end up overloading and bringing down the entire Docker Hub with a flood HTTP GET requests (should the time triggers go wrong and turn into a tight loop) make sure to build in some safety checks on top of Watchtower to "watch the watchman".
You can try the following plugin: https://wiki.jenkins.io/display/JENKINS/CloudBees+Docker+Hub+Notification
Which claims to do what you're looking for.
You can configure a WebHook in DockerHub wich will trigger the Jenkins-Build.
Docker Hub webhooks targeting your Jenkings server endpoint require making periodic copies of the image to another repo that you own [see my other answer with Docker Hub -> Watchman -> Jenkins integration through Slack notifications].
More details
You need to set up a cron job with periodic polling (docker pull) of the source repo to [docker] pull its `latest' tag, and if a change is detected, re-tag it as your own and [docker] push to a repo you own (e.g. a "clone" of the source Docker Hub repo) where you have set up a webhook targeting your Jenkings build endpoint.
Then and only then (in a repo you own) will Jenkins plugins such as Docker Hub Notification Trigger work for you.
Polling for Dockerfile / release changes
As a substitute of polling the registry for image changes (which need not generate much network traffic thanks to the local cache of docker images) you can also poll the source Dockerfile on Github using wget. For instance Dockerfiles of the official Docker Hub images are here. In case when the Github repo makes releases, you can get push notifications of them using Github Watch > Releases Only feature and if they have CI docker builds. Docker images will usually be available with a delay after code releases, even with complete automation, so image polling is more reliable.
Other projects
There was also a proposal for a 2019 Google Summer of Code project called Polling Docker Registries for Image Changes that tried to solve this problem for Jenkins users (incl. apparently Google), but sadly it was not taken up by participants.
Run a cron job with a periodic docker search to list all tags in the docker image of interest (here's the script). Note that this script requires the substitution of the jannis/jq image with an existing image (e.g. docker run --rm -i imega/jq).
Save resulting tags list to a file, and monitor it for changes (e.g. with inotifywait).
Fire a POST request using curl to your Jenkins server's endpoint using Generic Webhook Trigger plugin.
Cautions:
for efficiency reasons this tags listing script should be limited to a few (say, 3) top pages or simple repos with a few tags,
image tag monitoring relies on tags being updated correctly (automatically) after each image change, rather than being stuck in the past, like say Ubuntu tags (e.g. trusty-20190515 was updated a few days ago - late November, without the change in its mid-May tag).
What is the right workflow for updating and storing images?
For example:
I download source code from GitHub (project with Docker files, docker-compose.yml)
I run "docker build"
And I push new image to Docker Hub (or AWS ECR)
I make some changes in source code
Push changes to GitHub
And what I should do now to update registry (Docker Hub)?
A) Should I run again "docker build" and then push new image (with new tag) to registry?
B) Should I somehow commit changes to existing image and update existing image on Docker Hub?
This will depend on what for you will use your docker image and what "releasing" policy you adopt.
My recommendation is that you sync the tags you keep on Docker Hub with the release/or tags you have in GitHub and automate as much as you can your production with a continuous integration tools like Jenkins and GitHub webooks.
Then your flow becomes :
You do your code modifications and integrate them in GitHub ideally using a pull request scheme. This means your codes will be merged into your master branch.
Your Jenkins is configured so that when master is changed it will build against your docker file and push it to Docker hub. This will erase your "latest" tag and make sure your latest tag in docker hub is always in sync with your master release on GitHub
If you need to keep additional tags, this will be typical because of different branches or releases of your software. You'll do the same as above with the tag hooked up through Jenkins and GitHub webhooks with a non-master branch. For this, take a look at how the official libraries are organized on GitHub (for example on Postgres or MySQL images).
I have a public docker hub repository, automated build linked to a github repo.
I found I misnamed the tag of my last build.
Is that possible to re-edit the image name manually after building process without influencing the image ?
For the Automated builds, manually pulling, re-tagging and pushing won't work.
First, even if you pull and re-tag your image, you cannot push manually to an Automated Build. You will end up getting Error pushing to registry: Authentication is required.
The true solution would be to go to your Build Details Page, Click on Settings -> Automated Build -> Edit the tag name under Docker Tag Name and hit Save and trigger build. This will create a new tag and triggers the build.
Secondly, you cannot delete the tags (for Automated Builds) on your own. Please contact support#docker.com asking them to delete the tag.
Also, you should refrain from using HTTP DELETE request for Docker Hub. These API Endpoints are only meant for private registry and not for Docker Hub till date. Docker is planning to release the V2 registry Endpoint soon, after which you can safely use the API calls to delete/manipulate tags and images. Until then do not use V1/V2 Endpoints for deleting tags.