Updates to text used

Docker_references.md

@@ -7,60 +7,60 @@
 - docker <mngmt commands><sub-commands><options> —>docker command format , older way is - -docker <command><options> ((both works)
 - docker container run --publish 80:80 --detach nginx —> to start container in background
 - docker container ls. —> list of containers(use -a to list all containers)
-- docker container stop {container_id} -> to stop a container
-- docker container logs {containerName} to see the logs
+- docker container stop {container_id} —> to stop a container
+- docker container logs {containerName} —> to see the logs
 - docker container top {container Name) —> list the processes running in docker container
-- docker container rm -f(to forcibly remove a container even if it is running)
-- docker container inspect — details and configuration of a container
-- docker container stats — live performance statistics of a container
+- docker container rm -f —> to forcibly remove a container even if it is running
+- docker container inspect —> details and configuration of a container
+- docker container stats —> live performance statistics of a container
 - docker container update --help —> Update configuration of one or more containers even if they are running
 
 ## Docker shell commands:
 
 - docker container run -it —> start new container interactively
 - docker container run exec -it —> run additional commands inside container (exec runs only inside a cotainer which is already started)
-- docker container run --rm -it --name ununtu ubuntu:14.04 bash(to run bash command at the time of container creation, exec works only on already running/stopped containers)
-- docker container run -it --name nginx nginx bash -> to run bash shell without SSH
+- docker container run --rm -it --name ununtu ubuntu:14.04 bash —> to run bash command at the time of container creation, exec works only on already running/stopped containers
+- docker container run -it --name nginx nginx bash —> to run bash shell without SSH
 - docker container start -ai {containerName} —> to start container in shell mode if it is stopped
-- docker container exec -it {containerId} bash—>Run a command in a running container —> when we exit from this shell, container wont stop bcz exec will start additional process and it wont effect existing one
+- docker container exec -it {containerId} bash —> Run a command in a running container —> when we exit from this shell, container wont stop because exec will start additional process and it wont effect existing one
 
 ## Docker Networking:
 
 - docker container port {container} —> to get the port number on which we are mapping the traffic
 - docker container inspect --format '{{ .NetworkSettings.IPAddress }}' {conainerId} —> to get IP address of a container
-- docker network ls - to get the list of N/W’s
-- docker network inspect {networkName} —> we can see images in this command output id they r mapped
+- docker network ls —> to get the list of N/W’s
+- docker network inspect {networkName} —> we can see images in this command output id they are mapped
 - docker network create {networkName} —> to create a network, which will create with default driver bridge, we can use —driver to specify the driver, otherwise default option it will take(bridge)
-- docker container run -p 81:80 --name nginx2 --network {networkName} -d nginx (to create with specific network}
-- docker network connect {netwrokId} {containerId}, use disconnect in place of connect to disconnect from a network
+- docker container run -p 81:80 --name nginx2 --network {networkName} -d nginx —> to create with specific network
+- docker network connect {netwrokId} {containerId} —> use disconnect in place of connect to disconnect from a network
 
 ## Docker networkd:DNS
 
-- docker exec -it {containerName} ping {anotherContainer}— using this we can ping another a container from other container(prerequistie: they both should be in same network) using built in DNS network
+- docker exec -it {containerName} ping {anotherContainer} —> using this we can ping another a container from other container(prerequistie: they both should be in same network) using built in DNS network
 - docker container run --network-alias search --net test -d elasticsearch:2 —> to create a container with DNS alias(—network-alias) and with network test
 - docker container run --rm --net test alpine nslookup search —> it will search for nslookup DNS entry “search” inside that n/w
 - If we run “docker container run --rm --net test centos curl -s search:9200” it will give different different outputs between two DNS servers
 
 ## Docker Images:
 
-- docker image history {image_name} —> will list the changes in a image..not changes in container, whatver we do a change on a image it will create a new layer
+- docker image history {image_name} —> will list the changes in a image..not changes in container, any changes will create a new layer on top of the base image. 
 - docker image inspect nginx —> returns the metadata of that image
 - docker image tag mongo (new name ex:deekshith:mango} —> to tag an existing image with different name
-- cat ~/.docker/config.json —this file will have all the credentials(In Mac it will store in keychain)
+- cat ~/.docker/config.json —> this file will have all the credentials (In Mac it will store in keychain)
 - docker image push {imageName} —> to push to docker hub after login using “docker login” command
 
-## DockerFIle:
+## DockerFile:
 
 - docker image build -t customnginx .
 
 ## Docker Volumes:
 
 - docker volume prune —> to cleanup unused volumes
-- docker image inspect mysql
+- docker image inspect mysql —> we could look into the displayed properties/config about the container to check if the volume is mounted to the container
 - docker volume ls —> will list the volumes
 - docker volume inspect {volumeName} —> will give info about that volume
-- docker container run -d --name mysql -e MYSQL_ALLOW_EMPTY_PASSWORD=True -v mysql-db:/var/lib/mysql mysql(named volume)
-- docker volume create —> required to do this before “docker run” to use custom drivers and labels
+- docker volume create [OPTIONS] [VOLUME] —> Creates a new volume that containers can consume and store data in. If a name is not specified, Docker generates a random name.
+- docker container run -d --name mysql -e MYSQL_ALLOW_EMPTY_PASSWORD=True -v mysql-db:/var/lib/mysql mysql —> using the named volume created in the above command and bind to the container. -e is used to set the environment variables. 
 
 ## Bind Mount:
 
@@ -77,21 +77,21 @@
 
 ## Docker Swarm:
 
-- “docker info” command output, we can see whether Swarm is acive or not. By default it will be inactive.
+- “docker info”  —> command output, we can see whether Swarm is active or not. By default it will be inactive.
 - docker swarm init —> to initilize docker swarm
-- docker node ls —> it will give the node(manager) which got created
-- docker service —help(service in swarm replaces docker run)
+- docker node ls —> it will list the nodes present in the swarm. Upon initialising, we have only one node. 
+- docker service —help  —>  service in swarm replaces docker run
 - docker service create alpine(image) ping 8.8.8.8 —> to create a service with alpine image and we are using ping in that one to just check the service
 - docker service ls —> to list the services
 - docker service ps {service_name} —> to get more o/p
 - docker service update {serviceName} --replicas 3 —> to run 3 replicas
 - docker service update --help(it will have more options compared to docker container update --help)..using this we can do more things like scaling containers and changing conf etc.
-- docker service rm {serviceName}—> It will also deletes the containers which r started through this service
+- docker service rm {serviceName} —> It will also deletes the containers which r started through this service
 
 ## Swarm with 3 nodes:
 
-- docker-machine(using https://labs.play-with-docker.com/p/bd25oqe08n7000d50rl0#bd25oqe0_bd25p4gabk8g008i6k8g)
-- use “docker swarm init --advertise-addr 192.168.-63” to initlize the swarm where —advertise-ipaddr is the one which is accebile ,ABove command O/P will have the command for joining swarm, copy that and paste it in other nodes to join them,We cant run docker swarm command in the sub nodes, we need to run from manager to promote nodes
+- docker-machine  —> (using https://labs.play-with-docker.com/p/bd25oqe08n7000d50rl0#bd25oqe0_bd25p4gabk8g008i6k8g)
+- docker swarm init --advertise-addr 192.168.-63  —> to initialize the swarm where —advertise-ipaddr is the one which is accebile ,Above command O/P will have the command for joining swarm, copy that and paste it in other nodes to join them, we cant run docker swarm command in the sub nodes, we need to run from manager to promote nodes
 - docker node update --role manager node2 —> to update node2 as a manager an see docker node ls
 - Use “docker swarm join-token manager” to get the manager token and paste that in node command to add as a manager
 - docker service create --replicas 3 alpine ping 8.8.8.8 —> to create with 3 replicas
@@ -101,7 +101,7 @@
 
 Run below commands in 3 node cluster in play-with-docker.com
 
-- add “—driver overlay” at the end of “docker network create” to create a swarm wired bridge network where containers across hosts on same virtual networkwill communicate each other
+- add “—driver overlay” at the end of “docker network create” to create a swarm wired bridge network where containers across hosts on same virtual network will communicate with each other
 - docker service create --name postgres --network mydrupal -e POSTGRES_PASSWORD=mypass postgres(to create a service with custom
 - docker service create --name drupal -p 80:80 --network mydrupal drupal, After running these commands you can access the application in all the nodes
 
@@ -144,7 +144,7 @@ Docker service update:
 
 - docker system df —> will tell you the space used by images,container,local volumes
 - docker system prune —> will remove all the things except the running container and its volumes.
-- docker image prune, docker container prune …we can use this also
-- docker system prune -a —>Remove all unused images not just dangling ones
-- “export DOCKER_STACK_ORCHESTRATOR='swarm' “to switch orchestrator from Kubernetees to swarm mode
+- docker image prune  —> docker container prune …we can use this also
+- docker system prune -a —> Remove all unused images not just dangling ones
+- export DOCKER_STACK_ORCHESTRATOR='swarm'  —> to switch orchestrator from Kubernetes to swarm mode