## Installation
### Running docker as non-root user:
	sudo usermod -aG docker $USER

### Dockerfile:
```yml
FROM ubuntu:tag # Sets the image
MAINTAINER Denis Policastro <denis.policastro@gmail.com>
ADD . . # Copy items from host to VM (All from dir to workdir)
COPY /src . # Files or dir
LABEL Description=”Descrição do projeto” # Metadata, D version
ENTRYPOINT [“usr/bin/apache2ctl”, “-D”, “FOREGROUND”] # Main process running on the container, if the process dies the container dies
CMD [“node”, “app.js”] # Params for the entrypoint, example if entrypoint is a bash, ls is a param
ENV TEST=”Test env” # Declare env vars
USER denis # Sets the user, default is root
WORKDIR /srv # Set working dir
VOLUME /host/dir /container/dir
```

### Running Container:
```sh
docker run \
-d | -it \ #Default -d
[--publish | -p] \
[--memory] \
[--cpu-shares] \
[--rm] \
[--env | -e] \
[--network] \
[--net-alias] \
[--name] \
[-v] \
nginx
```

--publish | -p: Specifies the exposed port
HOST_PORT:CONTAINER_PORT

--cpu-shares: Sets the cpu share percent
	512

--memory: # Specifies the max memory consumption for that container
	512m
--rm: # Automatic remove container when exit

--environment | -e: Sets environment variable
	MYSQL_RANDOM_ROOT_PASSWORD=yes

--network: Specifies the network
	NETWORK_NAME

--net-alias: Gives an alias for load balancing the containers inside the container network
	ALIAS

--name: Gives the container a name
	CONTAINER_NAME

-v: Bind a custom volume to the host from the container for persistent data
named_volume:/var/lib/mysql
./mount/to/bind:/var/lib/mysql


##### Using net alias:
	Create two containers:
	docker container run -d --network es_network --net-alias search elasticsearch:2
docker container run -d --network es_network --net-alias search elasticsearch:2
Create another one for querying:
docker container run -it --network es_network centos:7 bash
nslookp search
curl -s search:9200

##### Containers config:
docker container top
docker container inspect --format=’{{ .NetworkSettings }}’ CONTAINER_ID
docker container stats -> CPU, MEM

##### Starting stopped container:
docker start \
# --attach --interactive \
-ai \
CONTAINER_NAME

##### Interacting with running container:
docker exec \
-it \ #(--interactive --tty)
CONTAINER_NAME \
bash | command

##### Change running container configuration:
docker update --help
	Limits CPU, RAM
docker run --memory 512m --cpu-shares 1024 --name nginx1 nginx:lastest
docker run --memory 512m --cpu-shares 512 --name nginx2 nginx:lastest
docker run --memory 512m --cpu-shares 512 --name nginx3 nginx:lastest
docker container -m 256m nginx
--cpu-shares: Percentage of cpus for each container, in this case nginx1 have 50%, nginx2 and nginx3 have 25% each.

##### Networking
docker network ls
docker network inspect NETWORK_NAME
docker network create NETWORK_NAME
docker network connect NETWORK_NAME CONTAINER_NAME
docker network disconnect
Overlay: Used for docker swarm to communicate between containers
Bridge: Used for containers network


Docker-Compose

docker-compose up
docker-compose top
docker-compose down
docker-compose build
docker-compose up --build

Docker Swarm

docker info
Check if swarm is enabled
docker swarm init
Initialize swarm’s master node
docker service create alpine ping 8.8.8.8
Creates a service
docker service ls | docker service ps SERVICE_NAME
Check service status
docker service update SERVICE_NAME --replicas 3
Changes service configuration

##### Creating two services in the same network:

Create the overlay network, for communicating swarm services:
	docker network create --driver overlay mydrupal

Create the services, passing the --network:
docker service create --name drupal --network mydrupal -p 80:80 drupal

docker service create docker service create --name psql --network mydrupal -e POSTGRES_PASSWORD=mypass postgres

##### Changes service configuration:
docker swarm update --help #Changes dynamic

##### Configuring nodes:

docker swarm init --advertise-addr PUBLIC_IP
	This command generates an output, that needs to be executed on worker nodes

docker node update --role manager NODE_NAME
	Changes node role to manager

docker swarm join-token manager
	Generates the output to join the service as a manager