如何使用 Ansible 启动 Docker 容器

Question

I am writing a playbook where I want to build and image and start some containers for that image. I was able to build an image but my containers are not getting started. They are being created successfully but not in running state.

Can someone help what am i missing?

- name: Manage Docker instances via Ansible
  hosts: shashank-VM
  connection: local
  become: yes
  become_method: sudo
  tasks:
    - name: Building an image from Dockerfile
      docker_image:
        build:
          path: .
          pull: yes
        name: web
        source: build

    - name: Starting Docker Containers
      docker_container:
        name: my-app-{{ item }}
        image: web:latest
        state: started
      with_sequence: count=4

From the below you can see the containers are created but if i do sudo docker ps I don't see anything.

TASK [Starting Docker Containers] ************************************************************************************************************
/usr/lib/python2.7/dist-packages/requests/__init__.py:80: RequestsDependencyWarning: urllib3 (1.25.9) or chardet (3.0.4) doesn't match a supported version!
  RequestsDependencyWarning)
changed: [shashank-VM] => (item=1)
changed: [shashank-VM] => (item=2)
changed: [shashank-VM] => (item=3)
changed: [shashank-VM] => (item=4)

CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
shashank@shashank-VM:~/docker_project$ sudo docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                     PORTS               NAMES
d5b586266f15        web_new             "/bin/bash"         2 minutes ago       Exited (0) 2 minutes ago                       myvm-app-4
ea45cc1fcf3c        web_new             "/bin/bash"         2 minutes ago       Exited (0) 2 minutes ago                       myvm-app-3
1e685f3d1368        web_new             "/bin/bash"         2 minutes ago       Exited (0) 2 minutes ago                       myvm-app-2
5d03750c3fd2        web_new             "/bin/bash"         2 minutes ago       Exited (0) 2 minutes ago                       myvm-app-1
shashank@shashank-VM:~/docker_project$ sudo docker run -d web_new
6e937d7a8e75c04ea9dc6769fa41b00f5bf455e6f947f002d181d105b94c7265
shashank@shashank-VM:~/docker_project$ sudo docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
shashank@shashank-VM:~/docker_project$ sudo docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                      PORTS               NAMES
6e937d7a8e75        web_new             "/bin/bash"         14 seconds ago      Exited (0) 13 seconds ago                       agitated_bartik

Dockerfile content -

FROM debian:8.5
RUN apt-get update
RUN apt-get install -y nginx
RUN echo 'Default page. Nginx is in your container. ' \
>/usr/share/nginx/html/index.html
EXPOSE 8085

Answer 1

This has nothing to do with Ansible.

Your Docker image is based on debian:8.5 , which when run simply starts a shell. If the shell isn't connected to a terminal, it will exit immediately. Eg, try running:

docker run debian:8.5

If you expect your image to run a persistent service (like nginx ), you need to arrange for nginx to run when you start a container from your image. You do this suing the CMD or ENTRYPOINT directives in your Dockerfile.

For example:

FROM debian:8.5
RUN apt-get update
RUN apt-get install -y nginx
RUN echo 'Default page. Nginx is in your container. ' \
>/usr/share/nginx/html/index.html
EXPOSE 8085
CMD ["nginx", "-g", "daemon off"]