When user linux docker image no issues, but windows docker image fails - docker

I get the following error when using windows docker golang image...
Job failed: Error response from daemon: manifest for
golang:latest-windowsservercore-1803 not found
line from .gitlab-ciyml file...
image: golang:latest-windowsservercore
However, when I use the default golang image which is based on linux i think, it works fine with no errors.
the below works...
image: golang:latest
I need the build phase to build windows executable;le hence the change. I have tried lots of different permutations take from...
https://hub.docker.com/_/golang
but nothing works is there something I am doing wrong?

This image is based on Windows Server Core
(microsoft/windowsservercore). As such, it only works in places which
that image does, such as Windows 10 Professional/Enterprise
(Anniversary Edition) or Windows Server 2016.
golang-dockerhub
So if you using gitlib then there is also some limitation and combination of the container.
The Docker executor
GitLab Runner can use Docker to run jobs on user provided images. This
is possible with the use of Docker executor.
The Docker executor when used with GitLab CI, connects to Docker
Engine and runs each build in a separate and isolated container using
the predefined image that is set up in .gitlab-ci.yml and in
accordance in config.toml.
The following table lists what combinations of containers, executors, and OS are supported.
docker executor
You can check also window container limitation here

Related

is it ok to build docker image with docker:18 and load image with different docker:19?

I am using circleci to build images and export them as tar.gz using docker version 18.
But now I have docker 19 on all of my swarm manager and worker.
I have done the following steps to deploy services in swarm.
Load docker images using docker load command
Run docker stack deploy servername to deploy
I have tested it, and it works fine but I want to know is it the right thing to do?
It works for sure.
Here is a link with the breaking changes and incompatibilities of docker :
Documentation
When you build a public image, you cannot know the versions of docker which will pulling it, the compatibility is an important thing for the ecosystem of docker.

Docker in Docker, Building docker agents in a docker contained Jenkins Server

I am currently running a Jenkins with Docker. When trying to build docker apps, i am facing some doubt on if i should use Docker in Docker (Dind) by binding the /var/run/docker.sock file or by installing another instance of docker in my Jenkins Docker. I actually saw that previously, it was discouraged to use something else than the docker.sock.
I don't actually understand why we should use something else than the docker daemon from the host apart from not polluting it.
sources : https://itnext.io/docker-in-docker-521958d34efd
Best solution for "jenkins in docker container needs docker" case is to add your host as a node(slave) in jenkins. This will make every build step (literally everything) run in your host machine. It took me a month to find perfect setup.
Mount docker socket in jenkins container: You will lose context. The files you want to COPY inside image is located inside workspace in jenkins container and your docker is running at host. COPY fails for sure.
Install docker client in jenkins container: You have to alter official jenkins image. Adds complexity. And you will lose context too.
Add your host as jenkins node: Perfect. You have the contex. No altering the official image.
Without completely understanding why you would need to use Docker in Docker - I suspect you need to meet some special requirements considering the environment in which you build the actual image, may I suggest you multistage building of docker images? You might find it useful as it enables you to first build the building environment and then build the actual image (hence the name 'multistage-building). Check it out here: https://docs.docker.com/develop/develop-images/multistage-build/

Best practice using docker inside Jenkins?

Hi I'm learning how to use Jenkins integrated with Docker and I don't understand what should I do to communicate them.
I'm running Jenkins inside a Docker container and I want to build an image in a pipeline. So I need to execute some docker commands inside the Jenkins container.
So the thing here is where docker come from. I understand that we need to bind mount the docker host daemon (socket) to the Jenkins container but this container still needs the binaries to execute Docker.
I have seen some approaches to achieve this and I'm confused what should I do. I have seen:
bind mount the docker binary (/usr/local/bin/docker:/usr/bin/docker)
installing docker in the image
if I'm not wrong the blue ocean image comes with Docker pre-installed (I have not found any documentation of this)
Also I don't understand what Docker plugins for Jenkins can do for me.
Thanks!
Docker has a client server architecture. The server is the docker deamon and the client is basically the command line interface that allows you to execute docker ... from the command line.
Thus when running Jenkins inside Docker you will need access to connect to the deamon. This is acheieved by binding the /var/run/docker.sock into the container.
At this point you need something to communicate with the Deamon which is the server. You can either do that by providing access to docker binaries. This can be achived by either mounting the docker binaries, or installing the
client binaries inside the Jenkins container.
Alternatively, you can communicate with the deamon using the Docker Rest API without having the docker client binaries inside the Jenkins container. You can for instance build an image using the API.
Also I don't understand what Docker plugins for Jenkins can do for me
The Docker plugin for Jenkins isn't useful for the use case that you described. This plugin allows you to provision Jenkins slaves using Docker. You can for instance run a compilation inside a Docker container that gets automatically provisioned by Jenkins
It is not best practice to use Docker with Jenkins. It is also not a bad practice. The relationship between Jenkins and Docker is not determined in such a manner that having Docker is good or bad.
Jenkins is a Continuous Integration Server, which is a fancy way of saying "a service that builds stuff at various times, according to predefined rules"
If your end result is a docker image to be distributed, you have Jenkins call your docker build command, collect the output, and report on the success / failure of the docker build command.
If your end result is not a docker image, you have Jenkins call your non-docker build command, collect the output, and report on the success / failure of the non-docker build.
How you have the build launched depends on how you would build the product. Makefiles are launched with make, Apache Ant with ant, Apache Maven with mvn package, docker with docker build and so on. From Jenkin's perspective, it doesn't matter, provided you provide a complete set of rules to launch the build, collect the output, and report the success or failure.
Now, for the 'Docker plugin for Jenkins'. As #yamenk stated, Jenkins uses build slaves to perform the build. That plugin will launch the build slave within a Docker container. The thing built within that container may or may not be a docker image.
Finally, running Jenkins inside a docker container just means you need to bind your Docker-ized Jenkins to the external world, as #yamenk indicates, or you'll have trouble launching builds.
Bind mounting the docker binary into the jenkins image only works if the jenkins images is "close enough" - it has to contain the required shared libraries!
So when sing a standard jenkins/jenkins:2.150.1 within an ubuntu 18.04 this is not working unfortunately. (it looked so nice and slim ;)
So the the requirement is to build or find a docker image which contains a compatible docker client for the host docker service is.
Many people seem to install docker in their jenkins image....

Docker - is it necessary to push images to remote server?

I have successfully built some Docker images:
Now I would like to start my microservices by docker-compose, unfortunatelly I am unable to pull those images i.e. repository callista/discovery-server not found: does not exist or no pull access I solved this error by logging into my DockerHub account and pushining those images to remote server. But it seems to me like a little overkill to send such larges images (which are likely to change pretty soon) over the Internet over and over again twice (push&pull).
Is it possible to configure Docker to install those images locally and not to pull from remote server?
I use Docker 1.8 and work on Windows 10.
Do you need to run this images in a server different from the one you build then?
If you need you have some alternatives:
As #engineer-dollery said, you can run a registry into your network, than you would not need to send it over the internet, only in your network. Docs: https://docs.docker.com/registry/deploying/
You could use the docker save and docker import to move then around too. Docs: https://docs.docker.com/engine/reference/commandline/save/
But if the server you run the images is the same you build then...
...than you could just add the tag image to your docker-compose services, and do a docker-compose build, as #lauri said, but with the image docker-compose will create a image with that name after the build, and then you could do docker run using than. Or do a docker-compose up --build so it will always build than again if something changes into the Dockerfile
If you define build option in docker-compose.yml, you should be able to build images locally with Docker Compose and then it uses those images without pulling. By default Docker Compose builds images if they are not found locally. If you want to rebuild images just add --build option docker-compose up command docker-compose up --build
Docker Compose build reference:
https://docs.docker.com/compose/compose-file/#build

How I use a local container in a swarm cluster

A colleague find out Docker and want to use it for our project. I start to use Docker for test. After reading an article about Docker swarm I want to test it.
I have installed 3 VM (ubuntu server 14.04) with docker and swarm. I followed some How To ( http://blog.remmelt.com/2014/12/07/docker-swarm-setup/ and http://devopscube.com/docker-tutorial-getting-started-with-docker-swarm/). My cluster work. I can launch for exemple a basic apache container (the image was pull in the Docker hub) but I want to use my own image (an apache server with my web site).
I tested to load an image (after save it in a .tar) but this option isn't supported by the clustering mode, same thing with the import option.
So my question is : Can I use my own image without to push it in the Docker hub and how I do this ?
If your own image is based on a Dockerfile that you build you can execute the build command on your project while targeting the swarm.
However if the image wasn't built, but created manually you need to have a registry in between that you can push to, either docker hub or some other registry solution like https://github.com/docker/docker-registry

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