Understanding how Linux containers fit into your workflow—and getting the integration details...

1. Docker Up and Running
Victor S. Recio
Docker Organizer Santo Domingo
@vsrecio / vrecio@nercore.com

2. Agenda
● The Docker Architecture
● Cgroups / Namespaces
● Docker engine/ daemon & API
● Docker Compose
● Networking
● Swarm
● Machine
● Seguridad
● Storage
Demo

3. The Docker Architecture

4. Underlying Technologies
cgroups, which are responsible for
managing resources used by a container (e.
g., CPU and memory usage). They are also
responsible for freezing and unfreezing
containers, as used in the docker pause
functionality.
namespaces are responsible for isolating
containers; making sure that a container’s
filesystem, hostname, users, networking,
and processes are separated from the rest
of the system.

5. Docker Engine
Docker Engine runs on Linux to create the operating environment
for your distributed applications.

6. Docker Remote API
v1.22 API
● List containers
● Create a container
● Inspect a container
● List processes running inside a container
● Get container logs
● Inspect changes on a container’s
filesystem
● Export a container
● Get container stats based on resource usage
● Resize a container TTY
● Start a container
● Stop a container
● Restart a container
● Kill a container
● Update a container
● Rename a container
● Pause a container

7. Docker Compose
version: '2'
services:
db:
image: mysql
web:
build: .
command: python manage.py
runserver 0.0.0.0:8000
volumes:
- .:/code
ports:
- "8000:8000"
depends_on:
- db

8. Networking
$ docker network inspect isolated_nw
[
{
"Name": "CONTAINER",
"Id": "$ID",
"Scope": "local",
"Driver": "bridge",
"IPAM": {
"Driver": "default",
"Config": [
{
"Subnet": "172.21.0.0/16",
"Gateway": "172.21.0.1/16"
}
]
},
"Containers": {},
"Options": {}
}
]
● docker network create
● docker network connect
● docker network ls
● docker network rm
● docker network disconnect
● docker network inspect

9. Docker Swarm overview
Docker Swarm is native clustering for Docker. It turns a pool of Docker
hosts into a single, virtual Docker host.

10. Docker Swarm overview

11. Docker Machine

12. Docker security
Docker containers are, by default, quite secure; especially if you
take care of running your processes inside the containers as non-
privileged users (i.e., non-root).
● Kernel namespaces
● Control groups

13. Manage data in containers
● Volumes are initialized when a container is created.
● Data volumes can be shared and reused among containers.
● Changes to a data volume are made directly.
● Changes to a data volume will not be included when you update an image.
● Data volumes persist even if the container itself is deleted.
Data volumes
A data volume is a specially-designated directory within one or more
containers that bypasses the Union File System.

14. Manage data in containers
Mounts": [
{
"Name": "fac362...80535",
"Source":
"/var/lib/docker/volumes/$ID/_data",
"Destination": "/webapp",
"Driver": "local",
"Mode": "",
"RW": true,
"Propagation": ""
}
]

15. Demo