EMACS Basic

To run script C-c C-x

C-f Move forward a character

C-b Move backward a character

M-f Move forward a word

M-b Move backward a word

C-n Move to next line

C-p Move to previous line

C-a Move to beginning of line

C-e Move to end of line

M-a Move back to beginning of sentence

M-e Move forward to end of sentence

M-< Go to beginning of file

M-> Go to end of file

QUIT -> C-x C-c

SEARCH -> M-x regex. C-s (C-r for reverse)( Type C-s and then word. Now type C-s agin to step through it)

UNDO -> C-x u

NEW / OPEN FILE -> C-x C-f test.emacs RET

SAVE FILE -> C-x C-s  C-x C-w C-x s

SHOW Line and column number -> M-x line-number-mode   M-x column-number-mode

YANKING

Paste: C-y

Paste the paste M-y

MULTI WINDOWS

C-x 1, C-x 2

DEBUG Emac

emacs —debug-init

M-x goto-char 

 M-x list-packages to list all package in emacs

To get documentation on your current major mode, type C-h m.

Mark a Region

C-Space C-Space

Now use arrow key to block the region and then use command to act on block.

Eg Use C-x TAB to indent

Mail in Emacs

C-x m

Begin composing mail (compose-mail).

C-x 4 m

Likewise, in another window (compose-mail-other-window).

C-x 5 m

Likewise, but in a new frame (compose-mail-other-frame).

C-c C-s

In the mail buffer, send the message (message-send).

C-c C-c

In the mail buffer, send the message and bury the buffer (message-send-and-exit).

Docker Swarm

Docker Swarm creation

docker-machine create --driver virtualbox manager1 ( Driver can be hyperv)

docker-machine create --driver virtualbox manager1

docker-machine create --driver virtualbox worker1

docker-machine create --driver virtualbox worker2

docker-machine create --driver virtualbox worker3

docker-machine create --driver virtualbox worker4

docker-machine create --driver virtualbox worker5

docker-machine ls docker-machine ls 

docker-machine ip manager1

docker-machine ssh manager1

From inside manager1 do init of swarm

docker swarm init --advertise-addr MANAGER_IP

docker node ls

Now get the token for worker joining in manager.

docker swarm join-token worker

docker swarm join-token manager

To join worker1 to manager ssh into worker1 in a new terminal 

docker-machine ssh worker1

docker swarm join --token SWMTKN-1-69hfhzjl83310rnx2b4t07qxmmi1xmgjkg5def1spotpiwki-dg29ra0thuptzmux2jq7brn1g 192.168.99.100:2377   (This is token from docker swarm join-token worker)

Continue with all workers

Now in manager do 

docker info

docker node ls

Create a Service

Now that we have our swarm up and running, it is time to schedule our containers on it. This is the whole beauty of the orchestration layer. We are going to focus on the app and not worry about where the application is going to run.

All we are going to do is tell the manager to run the containers for us and it will take care of scheduling out the containers, sending the commands to the nodes and distributing it.

To start a service, you would need to have the following:

• What is the Docker image that you want to run. In our case, we will run the standard nginx image that is officially available from the Docker hub.
• We will expose our service on port 80.
• We can specify the number of containers (or instances) to launch. This is specified via the replicas parameter.
• We will decide on the name for our service. And keep that handy.

What I am going to do then is to launch 5 replicas of the nginx container. To do that, I am again in the SSH session for my manager1 node. And I give the following docker service create command:

docker service create --replicas 5 -p 80:80 --name web nginx

docker service ls

docker service ps web

docker ps

docker service inspect --pretty web

To scale up the service use below command

docker service scale web=8

Checking:

docker service inspect --pretty web

docker node inspect manager1 --format "{{ .ManagerStatus.Reachability }}"

docker node inspect worker1 --format "{{ .Status.State }}"

Drain:

docker node update --availability drain worker5

docker node update —availability active worker5

To leave (stop) a node go to manager node and issue below command

docker node demote worker5

docker node rm --force worker5  (This has to be done after sometime from previous command)

Before you forcefully remove a manager node, you must first demote it to the worker role. Make sure that you always have an odd number of manager nodes if you demote or remove a manager.

Docker Container commands:

docker container ls

docker container stop

docker container rm

docker container rm image

Get opts in Python

import sys
import os
from java.lang import System

import getopt

def usage():
    print "Usage:"
    print "createJMSModule [-n] -u user -c credential -h host -p port -s serverName -m moduleName [-d subDeploymentName] -j jmsServerName"

try:
    opts, args    = getopt.getopt(sys.argv[1:], "nu:c:h:p:s:m:d:j:",
                                  ["user=", "credential=", "host=", "port=",
                                   "targetServerName=", "moduleName=",
                                   "subDeploymentName=", "jmsServerName="])
except getopt.GetoptError, err:
    print str(err)
    usage()
    sys.exit(2)

reallyDoIt  = true
user        = ''
credential  = ''
host        = ''
port        = ''
targetServerName  = ''
moduleName  = ''
subDeploymentName   = 'DeployToJMSServer'
jmsServerName   = ''

for opt, arg in opts:
    if opt == "-n":
        reallyDoIt  = false
    elif opt == "-u":
        user        = arg
    elif opt == "-c":
        credential  = arg
    elif opt == "-h":
        host        = arg
    elif opt == "-p":
        port        = arg
    elif opt == "-s":
        targetServerName  = arg
    elif opt == "-m":
        moduleName  = arg
    elif opt == "-d":
        subDeploymentName   = arg
    elif opt == "-j":
        jmsServerName   = arg
        
if user == "":
    print "Missing \"-u user\" parameter."
    usage()
    sys.exit(2)
elif credential == "":
    print "Missing \"-c credential\" parameter."
    usage()
    sys.exit(2)
elif host == "":
    print "Missing \"-h host\" parameter."
    usage()
    sys.exit(2)
elif port == "":
    print "Missing \"-p port\" parameter."
    usage()
    sys.exit(2)
elif targetServerName == "":
    print "Missing \"-s serverName\" parameter."
    usage()
    sys.exit(2)
elif moduleName == "":
    print "Missing \"-m moduleName\" parameter."
    usage()
    sys.exit(2)
elif jmsServerName == "":
    print "Missing \"-j jmsServerName\" parameter."
    usage()
    sys.exit(2)

print "Got all the required parameters"