The program 'docker' is currently not installed.

docker -v

The program 'docker' is currently not installed. You can install it by typing:

sudo apt install docker.io

(my_env) ubuntu@ip-192-31-19-128:/tmp$ sudo apt install docker.io

Reading package lists... Done

Building dependency tree       

Reading state information... Done

The following additional packages will be installed:

  bridge-utils cgroupfs-mount containerd runc ubuntu-fan

Suggested packages:

  mountall aufs-tools debootstrap docker-doc rinse zfs-fuse | zfsutils

The following NEW packages will be installed:

  bridge-utils cgroupfs-mount containerd docker.io runc ubuntu-fan

0 upgraded, 6 newly installed, 0 to remove and 22 not upgraded.

Need to get 16.4 MB of archives.

After this operation, 83.6 MB of additional disk space will be used.

Do you want to continue? [Y/n] Y

Get:1 http://ap-southeast-1.ec2.archive.ubuntu.com/ubuntu xenial/main amd64 bridge-utils amd64 1.5-9ubuntu1 [28.6 kB]

Get:2 http://ap-southeast-1.ec2.archive.ubuntu.com/ubuntu xenial/universe amd64 cgroupfs-mount all 1.2 [4970 B]

Get:3 http://ap-southeast-1.ec2.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 runc amd64 1.0.0~rc2+docker1.12.6-0ubuntu1~16.04.1 [1479 kB]

Get:4 http://ap-southeast-1.ec2.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 containerd amd64 0.2.5-0ubuntu1~16.04.1 [4041 kB]

Get:5 http://ap-southeast-1.ec2.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 docker.io amd64 1.12.6-0ubuntu1~16.04.1 [10.8 MB]

Get:6 http://ap-southeast-1.ec2.archive.ubuntu.com/ubuntu xenial-updates/main amd64 ubuntu-fan all 0.9.2 [30.7 kB]

Fetched 16.4 MB in 1s (12.2 MB/s)

perl: warning: Setting locale failed.

perl: warning: Please check that your locale settings:

LANGUAGE = (unset),

LC_ALL = (unset),

LC_CTYPE = "UTF-8",

LANG = "en_US.UTF-8"

    are supported and installed on your system.

perl: warning: Falling back to a fallback locale ("en_US.UTF-8").

locale: Cannot set LC_CTYPE to default locale: No such file or directory

locale: Cannot set LC_ALL to default locale: No such file or directory

Selecting previously unselected package bridge-utils.

(Reading database ... 62405 files and directories currently installed.)

Preparing to unpack .../bridge-utils_1.5-9ubuntu1_amd64.deb ...

Unpacking bridge-utils (1.5-9ubuntu1) ...

Selecting previously unselected package cgroupfs-mount.

Preparing to unpack .../cgroupfs-mount_1.2_all.deb ...

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Preparing to unpack .../runc_1.0.0~rc2+docker1.12.6-0ubuntu1~16.04.1_amd64.deb ...

Unpacking runc (1.0.0~rc2+docker1.12.6-0ubuntu1~16.04.1) ...

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Preparing to unpack .../containerd_0.2.5-0ubuntu1~16.04.1_amd64.deb ...

Unpacking containerd (0.2.5-0ubuntu1~16.04.1) ...

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Preparing to unpack .../docker.io_1.12.6-0ubuntu1~16.04.1_amd64.deb ...

Unpacking docker.io (1.12.6-0ubuntu1~16.04.1) ...

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Preparing to unpack .../ubuntu-fan_0.9.2_all.deb ...

Unpacking ubuntu-fan (0.9.2) ...

Processing triggers for man-db (2.7.5-1) ...

Processing triggers for ureadahead (0.100.0-19) ...

Processing triggers for systemd (229-4ubuntu19) ...

Setting up bridge-utils (1.5-9ubuntu1) ...

locale: Cannot set LC_CTYPE to default locale: No such file or directory

locale: Cannot set LC_ALL to default locale: No such file or directory

Setting up cgroupfs-mount (1.2) ...

Setting up runc (1.0.0~rc2+docker1.12.6-0ubuntu1~16.04.1) ...

Setting up containerd (0.2.5-0ubuntu1~16.04.1) ...

Setting up docker.io (1.12.6-0ubuntu1~16.04.1) ...

Adding group `docker' (GID 116) ...

Done.

Setting up ubuntu-fan (0.9.2) ...

Processing triggers for systemd (229-4ubuntu19) ...

Processing triggers for ureadahead (0.100.0-19) ...

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conda install traitlets tornado jinja2 sqlalchemy 

conda: command not found

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Permission error- Unable to ssh into Amazon EC2 instance

ssh -i ec2-instance-cert.pem root@publicip or public dns

@@@@@@@@@@@@@@@@@@@@@@@@######@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ ###        WARNING: UNPROTECTED PRIVATE KEY FILE! ###   @
@@@@@@@@@@@@@@@@@@@@@@@@######@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Permissions 0644 for 'test.pem' are too open.

It is required that your private key files are NOT accessible by others.

Solution :
key must not be publicly viewable for SSH to work. Use this command if required

$ chmod 400 ec2-instance-cert.pem

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Mongoose

It is an object modeling tool for nodejs that connects MongoDB.Mongoose take the models and maps them to MongoDB database.

install required dependencies
npm install mongoose

var mongoose = require('mongoose');



/*without callback */
mongoose.connect('localhost','mydatabase');

/* with callback */ create a connection object and bind two callabcks.

var db = mongoose.connection;
db.on('open',function callback(){
//connection success
});
db.on('error',function(msg){
//connection error
});

Schema Creation :

var empSchema = mongoose.Schema({
name: String,
designation : String,
location: String,
Skills: String
});

Model Creation :

var Employee =  mongoose.model('employee',empSchema);

Saving the model :

employee.save(function(err,emp){
if(err){
//error handling
}else{
//success
}
});

Reading the model :

var Employee =  mongoose.model('employee',empSchema);

Employee.find(function(err,emp){
if(err){
//error handling
}else{
//success
}
});

Reading specific model :


Employee.find({name:'SrinivasNidadavolu'},function(err,emp){
if(err){
//error handling
}else{
//success
}
});

output:

[{name:'SrinivasNidadavolu',designation:'software engineer',location:'building number 14,Raheja Mindpsace, Hyderabad',Skills:'Java,C++,AWS,AZURE,Containers,cloud specialist'}]

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Elastic Load Balancing

Elastic Load Balancing automatically distributes the incoming application traffic across multiple was ec2 instances.

Two types of load balancers :
Application Load Balancer
Classic Load Balancer

Elastic Load Balancing :
It is in-region load balancing service and distributed traffic  across multiple availability zones -HTTP/S, TCP/S.
Fully fault tolerant
Buit in health check

Application Load Balancer Features:
• It has Containerized Application Support
• It has Content-Based Routing
• It support for  HTTP/2
• Contains Delete Protection
• Supports WebSockets
• Supports Layer-7 Load Balancing
• Supports Web Application Firewall (WAF)
• Contains Request Tracing

Classic Load Balancer Features:
• Contains Health Checks
• It has High Availability
• Supports Security Features
• Supports Sticky Sessions
• Supports SSL Offloading
• Support for Layer 4 or 7 Load Balancing
• It has Operational Monitoring
• provides Logging
• provides IPv6 Support

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Creating Database MongoDB

MongoDB is document based database.
Creating Database NodeJS - MongoDB

Once mongoDB is up and running,

var mongoDB =  require('mongodb');


var mydbserver =  new mongodb.server('localhost', 27017, {auto_reconnect:true});

/* new mongodb.Db() creates a new database */
/* w:1 sets the write concern */

var database =  new mongodb.Db('eCommerceDb',mydbserver, {w:1});



Collections :

Relational databases uses tables to store data. MongoDB stores data as document format uses collection. It is NoSql type database.

Collections are represented as JSON format.

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Installing MongoDB

Mac Installation :

The easy way to install MongoDB is by using package manager like Homebrew  or MacPorts.

$ sudo brew install mongodb

or 

$ sudo port install mongodb

Setup the data directory

$ sudo mkdir -p /data/db

setup appropriate permissions

$ sudo chown 'id -u' /data/db

Ubuntu Installation :

To authenticate apt-get package, install the public GPG key from MongoDB creators.

$ sudo apt-key adv --keyserver keyserver.ubuntu.com --recv 7F0CEB10

create a file /etc/apt/sources.list.d/10gen.list  and  add the below text

deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen

Install latest stable build of MongoDB

$ sudo apt-get update

$ sudo apt-get install mongodb-10gen

Windows Installation :

Download the latest stable build from https://www.mongodb.com/download-center#community

Make sure appropriate version 64 bit or 32 bit

Install with the installation file.

create the data directory 

mkdir data

mkdir data\db

Running MongoDB

On Mac :

mongod

On Ubuntu :

$ sudo service mongodb start

On Windows :

c:\mongodb\bin\mongod.exe

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