vagrant vm with nameko service to get file from another vagrant machine

[xolosno]

Hi, Does anyone can get any hint for the assignment below?

I have set up 2 VM machines but I fail to understand how to set up microservices that retrieve the files.

Here is what I have done so far:

Vagrant file:

Vagrant.configure("2") do |config|

config.vm.define "backend" do |backend|

backend.vm.box = "bento/ubuntu-16.04"

backend.vm.network :forwarded_port, guest: 80, host: 4568

backend.vm.provider "virtualbox" do |vb|

vb.memory = '512'

end

#backend.vm.network "private_network", type: "dhcp"

backend.vm.network "private_network", ip: '10.1.1.15'

backend.vm.provision "shell", path: "provisioners/install_python_nameko.sh"

end

config.vm.define "frontend" do |frontend|

frontend.vm.box = "bento/ubuntu-16.04"

frontend.vm.network "forwarded_port", guest: 80, host: 4567

frontend.vm.provider "virtualbox" do |vb|

vb.memory = '512'

end

#frontend.vm.network "private_network", type: "dhcp"

frontend.vm.network "private_network", ip: '10.1.1.30'

frontend.vm.provision "shell", path: "provisioners/install_python_nameko.sh"

#frontend.vm.provision "shell", path: "provisioners/install-node.sh"

end

end

Front end server:

import os

import urllib

from nameko.dependency_providers import Config

from nameko.web.handlers import http

from urllib.request import urlopen

import sys

import psutil

class HttpService:

name = "connect_to_client"

config = Config()

# Hello User!

@http('GET', '/')

def get_method0(self, request):

print("\n")

ip = self.config.get('IP')

print("\n")

print("IP: " + str(ip))

print ("Calling Method 1 with python version: ",sys.version_info[:])

print("\n")

sys.stdout.flush()

# Format output for client

msg='''

Hello User!

'''

return msg

# Trailing slash required to avoid 301 redirect which fails. Not resolved.

@http('GET', '/grab/<string:cmd>/')

def get_method1(self, request, cmd):

ip = config.get('IP')

print("\n")

print("IP: " + ip)

print("\n")

cip = "http://"+ip + "/" + cmd

print("\n")

print("IP: " + cip)

print("\n")

with urllib.request.urlopen(cip) as response:

html = response.read()

html = html.decode("utf8")

response.close()

return html

backend server:

import os

import urllib

from nameko.web.handlers import http

from urllib.request import urlopen

import sys

import psutil

class HttpService:

name = "psutils_client"

# Print commands

@http('GET', '/')

def get_method1(self, request):

print("\n")

print ("Calling Method 1 with python version: ",sys.version_info[:])

print("\n")

cmds = '''

COMMANDS:

cpu_times

virtual_memory

swap_memory

net_if_addrs

'''

sys.stdout.flush()

return cmds

@http('GET', '/cpu_times')

def get_cpu_times(self, request):

result = str(psutil.cpu_times()) + '''

'''

return result

@http('GET', '/virtual_memory')

def get_virtual_memory(self, request):

result = str(psutil.virtual_memory()) + '''

'''

return result

@http('GET', '/swap_memory')

def get_swap_memory(self, request):

result = str(psutil.swap_memory()) + '''

'''

return result

@http('GET', '/net_if_addrs')

def get_net_if_addrs(self, request):

result = str(psutil.net_if_addrs()) + '''

'''

return result

I do not know what command should be for the file retrieval.

When I run %nameko run frontend

and then on client curl http://10.1.1.30:80 nothing happen.

Any advice on how to approach it?

Thank you,

Xolosno

The assignment:

Create a simple file retrieval service that consists of two Microservices and a Client. The following depicts the architecture:

Client (Bash shell script) --> FrontEnd Microservice --> BackEnd Microservice

BackEnd Micorservice

The backend, BackEnd, is a simple Python program running in Nameko that has one method:

getFileContents(name-of-file) – return the contents of a file

In a subdirectory named “files”, which resides under the directory where BackEnd.py is, create 4 text files: a.txt, b.txt, c.txt, d.txt

 Put different text into each file.

To get the contents of file a.txt, a caller calls getFileContents(“a.txt”), to get the contents of b.txt, the caller calls getFileContents(“b.txt”), etc.

The BackEnd microservice must run in a Vagrant-based Ubuntu 16.04 VM. So, besides writing the code for the microservice, you must also write the vagrant file and the provisioning code needed to install Python 3, Nameko, and any other dependencies that are needed.

FrontEnd Microservice

The frontend microservice, FrontEnd, is a simple Python-based HTTP object that receives an HTTP request to get a specific file – a.txt, b.txt, c.txt, d.txt. This Python module is integrated into Nameko to receive the HTTP requests.

You only have to handle requests for files that exist. When a request comes in, the FrontEnd code needs to parse the request and call getFileContents in the BackEnd microservice, to get the requested file

When the FrontEnd microservice gets the return from the BackEnd microservice, it returns the file contents (returned by getFileContents) within the HTTP response it sends back to the client.

The FrontEnd microservice must run in a Vagrant-based Ubuntu 16.04 VM. So, besides writing the code for the microservice, you must also write the vagrant file and the provisioning code needed to install Python 3, Nameko, and any other dependencies that are needed.

Client

The Client is a simple bash script that runs in the host machine. It uses wget or curl to get each file.

[Dennis Chang]

My hint to you is:

1. run curl against backend microservice (what do you get?, what should you get?)