68 Matching Annotations
  1. Dec 2019
    1. Combining the upper and lower directories is pretty easy: we can just do it with mount!

      Combining lower and upper directories using mount:

      $ sudo mount -t overlay overlay -o lowerdir=/home/bork/test/lower,upperdir=/home/bork/test/upper,workdir=/home/bork/test/work /home/bork/test/merged

    2. That makes sense, the new file gets created in the upper directory.

      If you add a new file, such as with:

      $ echonew file> merged/new_file

      It will be created in the upper directory

    3. Overlay filesystems, also known as “union filesystems” or “union mounts” let you mount a filesystem using 2 directories: a “lower” directory, and an “upper” directory.

      Docker doesn't make copies of images, but instead uses an overlay.

      Overlay filesystems, let you mount a system using 2 directories:

      • the lower directory (read-only)
      • the upper directory (read and write).

      When a process:

      • reads a file, the overlayfs filesystem driver looks into the upper directory and if it's not present, it looks into the lower one
      • writes a file, overlayfs will just use the upper directory
  2. Nov 2019
  3. Oct 2019
  4. Sep 2019
    1. use the REPOSITORY:TAG combination rather than IMAGE ID

      Error response from daemon: conflict: unable to delete c565603bc87f (cannot be forced) - image has dependent child images

      I really feel like this should be the accepted answer here but it does depend on the root cause of the problem. When you create a tag it creates a dependency and thus you have to delete the tag and the image in that order. If you delete the image by using the tag rather than the id then you are effectively doing just that.

  5. Aug 2019
  6. Jul 2019
    1. Docke

      Docker is a set of coupled software-as-a-service and platform-as-a-service products that use operating-system-level virtualization to develop and deliver software in packages called containers.

    Tags

    Annotators

  7. May 2019
    1. Allan Moraes - Automatizando o Monitoramento de Infraestrutura

      Docker, Grafana e Ansible fazem parte da palestra do Allan e também são tópicos cobertos na prova DevOps Tools do Linux Professional Institute.

      705.1 IT Operations and Monitoring (weight: 4)

    2. Tiago Roberto Lammers - Nossa jornada DevOps na Delivery Much para microserviços e o que aprendemos

      Microservices é um dos temas cobertos pela certificação DevOps Tools do Linux Professional Institute e também é um assunto determinante na escolha de ferramentas do cinto de utilidade de um profissional DevOps. Aproveite para conversar com o Tiago sobre a sua experiência com o uso do Docker, assunto que também cai na prova.

      Tópicos (dentre outros):

      701.1 Modern Software Development (weight: 6) 701.4 Continuous Integration and Continuous Delivery (weight: 5) 702.1 Container Usage (weight: 7)

  8. Apr 2019
    1. 取image的大概过程如下
      1. 从registry获取manifest(image 配置文件)
      2. 读取manifest配置文件的digest,这个就是image id
      3. 根据image id查看本地有无相同id的image
      4. 如果没有,会给registry服务发送请求,获取image的配置文件
      5. 查看本地每一个layer是否存在
      6. 如果不存在,则会去服务器拿相应的layer
      7. 等所有的layer下载完成后,image就下载完成了
    1. If this is a production situation, and security and stability are important, then just "convenience" is likely not the best deciding factor (any more than leaving your house unlocked all the time might be "convenient").

      如果这是生产情况,安全性和稳定性很重要,那么“便利”可能不是最好的决定因素(不仅仅是让你的房子一直解锁可能是“方便的”)

      • 您可以考虑将每个push to registry的版本 - 以某种形式(毕竟,您发布了新版本的代码,并使其他人可以访问)。
      • :latest与Git存储库中的master分支相当。是否每个push to master都考虑准备投入生产?
      • Releases将(通常)通过验证过程(CI/QA /acceptance/etc)。是否应首先验证master中的更改,并且仅在验证(标记并)部署到生产之后?
      • 发行版(Releases)带有版本;这可以是显式版本(标记),也可以是隐式(不可变标记:图像的摘要)

      显式版本 -- image tag<br> 隐式版本 -- 不可变标记 :image digest

    2. This is now a problem, because different instances of the same service now run different versions of the application; this can lead to hard-to-find issues, such as:

      现在这是一个问题,因为同一服务的不同实例现在运行不同版本的应用程序;这可能导致难以发现的问题,例如:

      • 根据访问者最终的节点(或实例),可能会向他们提供不同的内容
      • 对服务进行了安全更新,但某些实例仍然运行旧版本
      • 修复了一个错误,但由于“某些原因”,一些节点仍然暴露了该错误
      • 最新的更新包含一个错误,但它没有引起注意,因为大多数实例仍在运行以前的版本
    3. Doing so would revert to the old behavior, where images are just pulled on each node. This used to cause quite some issues and was intended as a stopgap solution at the time (until pinning by digest was implemented). This section illustrates some of the problems with this approach.

      docker stack deploy中不推荐使用--resolve-image=never<br> 这样做会恢复到原来的行为,即只在每个节点上拉动图像。这曾经引起相当多的问题,并且当时是作为权宜之计的解决方案(直到通过摘要实现固定)。本节说明了此方法的一些问题。

    4. However, there is not a 1:1 relation of digests to tags, so when pulling an image by digest, only the digest is known. If you happen to have an image pulled (manually) with a tag that matches that digest, the tag is shown, but not otherwise

      但是,摘要与标签之间没有1:1的关系,因此在通过摘要pull image时,只知道摘要。如果您碰巧使用与该摘要匹配的标记(手动)拉出图像,则会显示标记,否则不会显示

  9. Mar 2019
    1. Usando Traefik para automatizar o proxy reverso de seus containers docker

      Ainda que esse não seja um assunto cobrado diretamente na prova, essas são ferramentas que devem fazer parte do cinto de utilidades de um bom DevOps. E busca por "container" nos nossos tópicos, nesse link, que tu vais descobrir a importância de conhecer bem sobre o assunto.

    2. Pipeline de CI/CD no Kubernetes usando Jenkins e Spinnaker

      Uau! Muitos assuntos da prova LPI DevOps são explorados nessa palestra. Fica de olho no tópico: 702 Container Management.

  10. Jan 2019
    1. this is in /srv/www/ on the host.

      This site actually gives somewhat clear instructions about which directories from which to run the commands. I think where I went wrong befire was using various directories that in the end did not match the actual installations.

  11. Dec 2018
  12. Jun 2018
  13. May 2018
    1. You can pull the image on a computer that have access to the internet.

      sudo docker pull ubuntu Then you can save this image to a file

      sudo docker save -o ubuntu_image.docker ubuntu Transfer the file on the offline computer (USB/CD/whatever) and load the image from the file:

      sudo docker load ubuntu_image.docker

  14. Apr 2018
  15. Dec 2017
  16. Nov 2017
  17. domino.research.ibm.com domino.research.ibm.com
  18. Sep 2017
    1. NixOS is a Linux distribution with a unique approach to package and configuration management.

      This is another approach to systems management and software as a services. I don't really understand in detail the difference between NixOS and docker, but googling NixOS vs Docker shows that its a topic that is ripe for a bunfight.

    1. Singularity containers can be used to package entire scientific workflows, software and libraries, and even data.

      Very interesting, basically Singularity allows containers to run in HPC environments, so that code running in the container can take advantage of the HPC tools, like massive scale and message passing, while at the same time keeping the stuff in the container safer.

    1. Note: When mapping ports in the HOST:CONTAINER format, you may experience erroneous results when using a container port lower than 60, because YAML will parse numbers in the format xx:yy as sexagesimal (base 60). For this reason, we recommend always explicitly specifying your port mappings as strings.

      Cool feature

  19. Aug 2017
  20. Jun 2017
  21. Mar 2017
    1. Prophet : Facebook에서 오픈 소스로 공개한 시계열 데이터의 예측 도구로 R과 Python으로 작성되었다.

      python statics opensource, also can use R

    2. Docker Swarm을 이용한 쉽고 빠른 분산 서버 관리 : Docker Swarm으로 서버 오케스트레이션 하는 방법을 설명한 글이다. 현재 사용 가능한 오케스트레이션 도구들의 장단점도 정리되어 있고 Swarm이 제공하는 기능을 설명한 후 실제로 따라 해 보면서 테스트해볼 수 있게 글이 작성되어 있어서 오케스트레이션 도구를 검토하고 있다면 찬찬히 읽어봐야 할 글이다. 얼마 전에 Docker Swarm을 보고 간단하면서 기능이 강력해서 꽤 좋은 인상을 받았는데 정리된 글이 나와서 반갑다.(한국어)
  22. Jan 2017
    1. Cannot connect to the Docker daemon

      For Linux/Unix people, it may very well be that you did not add your username to the 'docker' group and as a consequence you cannot communicate with the docker daemon. I had just experienced this (while running Linux Mint 18.1, but the symptoms ought to be similar for Debian/Ubuntu as well).

      To fix it, I ran:

      sudo usermod -aG docker $(whoami)

      Log out and log back in. This ensures your user is running with the correct permissions.

      This will ensure that you do not need to sudo every time, when you interact with docker.

      There are instructions in the below link for Unix (MacOS) users as well.

      Source: http://stackoverflow.com/a/33596140

  23. Dec 2016
  24. Jun 2016
    1. Docker is a type of virtual machine

      How does it compare to the packages installed directly? Could be useful for development, but maybe not practical for HPC applications. Maybe just create a cd iso with all the correct programs and their dependencies.

  25. Apr 2016
    1. In its default configuration, the CJRS web service (either deployed as an executable jar, or a war file in a servlet container) is configured to use the SLURM JobExecutionService, and directly invokes ‘srun’, ‘sbatch’, and ‘salloc’ commands that are available on the host it is running on.A natural consequence of this is that SLURM jobs are submitted using the same user ID as owner of the CJRS web service process. For the purposes of training and demonstration, it is recommended to deploy the application so that it runs as a single, unprivileged user created specifically for the purpose of training. In theory, however, anybody who obtains the executable jar file may run it on a machine they have access to, bound to some random high port exclusive to that user, allowing it to launch SLURM jobs on their behalf via the REST API.

      This will likely not be portable to Docker due to security issues; two separate users will be needed: https://docs.docker.com/engine/security/security/#docker-daemon-attack-surface

  26. Dec 2015
  27. May 2015
  28. Mar 2015
    1. Excellent guide for creating a fresh CoreOS image for AWS using Ext4 and OverlayFS.

      This is the future for CoreOS and should be more stable than btrfs.