Amazon ECS Notes

ECS Notes

Amazon Elastic Container Servie: Native Doctor Support on AWS

	User Cases:
		Configuration and deployment
		Microservices
			Breaking application into smaller chunks of code
		Batch Processing
		
	Building block service
	Manage cluster state
	Manage containers
	Schedule containers
	Performance at scale
	
	Key Components:
	
		Tasks
		Containers
		Clusters
		Container Instances
		
	Container Instances:
	
		An EC2 instances with Docker daemon running and Amazon ECS Agent
			Agent tracks the state of container instances and make the service aware of the state of container instances
	
	Clusters:
	
		Group of container instances, They are Regional - spans across multiple AZs, They provide resource pool of CPU, Memory and Network etc. 
		You can start empty cluster and dynamically scale it.
		
	Task Definition:
		
		Task Definition : Defines which Docker image to use for containers and how many containers to use in the task, and the resource allocation for each container
		
		Service : A service allows you to run and maintain a specified number (the "desired count") of simultaneous instances of a task definition in an ECS cluster
	
Docker Notes:
=============

Dockerfile:
-----------
FROM amazonlinux

RUN yum install -y nginx
RUN echo "Hello Krishn!" > /usr/share/nginx/html/index.html

EXPOSE 80

CMD ["nginx"]
---------------

Create build:

	docker build -t testimage:0.0.1 .
	docker images
	docker rmi 332af0eb4121
	docker images -a
	
Running build:

docker run --name testcontainer -p 80:80 <imagename>:<tag>
docker ps -a
docker ps
docker rm $(docker ps -aq)


docker run --name samplecontainer -p 80:80 -d 11c206b5e505


[root@ip-10-0-0-211 ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES
0cdaf477b9bd        11c206b5e505        "nginx -g 'daemon ..."   3 minutes ago       Up 3 minutes        0.0.0.0:80->80/tcp   samplecontainer
[root@ip-10-0-0-211 ~]# docker exec -it 0cdaf477b9bd /bin/bash
bash-4.2# ls
bin  boot  dev  etc  home  lib  lib64  local  media  mnt  opt  proc  root  sbin  selinux  srv  sys  tmp  usr  var
bash-4.2# pwd
/
bash-4.2# cd /usr/share/nginx/html/
bash-4.2# ll
bash: ll: command not found
bash-4.2# ls
404.html  50x.html  index.html  nginx-logo.png  poweredby.png
bash-4.2# more index.html
Hello Krishn!
bash-4.2#

bash-4.2# ps -ef
UID        PID  PPID  C STIME TTY          TIME CMD
root         1     0  0 16:28 ?        00:00:00 nginx: master process nginx -g daemon off;
nginx        5     1  0 16:28 ?        00:00:00 nginx: worker process
nginx        6     1  0 16:28 ?        00:00:00 nginx: worker process
root         7     0  0 16:33 pts/0    00:00:00 /bin/bash
root        16     7  0 16:34 pts/0    00:00:00 ps -ef
bash-4.2#

bash-4.2# exit
exit
[root@ip-10-0-0-211 ~]# df -h
Filesystem      Size  Used Avail Use% Mounted on
devtmpfs        3.9G   56K  3.9G   1% /dev
tmpfs           3.9G     0  3.9G   0% /dev/shm
/dev/xvda1       20G  1.4G   19G   8% /
overlay          20G  1.4G   19G   8% /var/lib/docker/overlay2/7c25dab27131c1b780699b66c3c524468a622c3a6edad64c832a60f8d2151a1c/merged
shm              64M     0   64M   0% /var/lib/docker/containers/0cdaf477b9bdc67fe3e1d5d14f12f437f70353e4dcc6dde6b82b237d41f71d45/shm
[root@ip-10-0-0-211 ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES
0cdaf477b9bd        11c206b5e505        "nginx -g 'daemon ..."   6 minutes ago       Up 6 minutes        0.0.0.0:80->80/tcp   samplecontainer
[root@ip-10-0-0-211 ~]# docker stop 0cdaf477b9bd
0cdaf477b9bd
[root@ip-10-0-0-211 ~]# docker rm 0cdaf477b9bd --> to terminate container^C

[root@ip-10-0-0-211 ~]# docker start 0cdaf477b9bd
0cdaf477b9bd
[root@ip-10-0-0-211 ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                NAMES
0cdaf477b9bd        11c206b5e505        "nginx -g 'daemon ..."   10 minutes ago      Up 3 seconds        0.0.0.0:80->80/tcp   samplecontainer
[root@ip-10-0-0-211 ~]# docker stop 0cdaf477b9bd
0cdaf477b9bd


???? how to mount volume in host from existing container