vSRX on an Isolated Network – How do I Provision via Cloud-Init?

Background Introduced within the Junos OS Release – 15.1X49-D100 – the vSRX now comes with cloud-init. As per Junipers configuration guide, … the cloud-init package (version 0.7x) comes pre-installed in the vSRX image to help simplify configuring new vSRX instances operating in an OpenStack environment according to a specified user-data file. Cloud-init is performed during … Read more

Troubleshooting Connectivity to the Neutron Metadata Proxy

  Introduction After troubleshooting a recent issue with accessing meta services from a guest instance, and jumping through the various steps within the path, I soon realised – this would make for a great article. Issue So first of all let’s look at the issue. The issue was pretty basic. Quite simply I was unable … Read more

OpenStack Partitioning – Regions, Availability Zones and Host Aggregates

An OpenStack Cloud can be divided into three main hierarchical zones – Regions, Availability Zones and Host Aggregates. Regions A Region is full OpenStack deployment, including its own API endpoints, networks and compute resources[1], excluding the Keystone and Horizon. Each Region shares a single set of Keystone and Horizon services. Host Aggregates Host Aggregates are logical … Read more

How to Build an OpenStack Network using the OpenStack CLI

  Introduction Within this article we will detail the steps required to build a simple Neutron networking topology using the OpenStack CLI. Topology Our topology (Figure 1) will consist of an L3 router, an external network, a tenant network and a range of floating IPs. Our external network will be a VLAN based network and … Read more

The Pros and Cons to Azure’s VNet Peering

Introduction The other day I was asked to design a solution that required VNet peering, after some further digging and research into this feature I thought I’d share some of my findings with you all. Before we dive into the pros and cons, lets take a moment to quickly recap on what VNet peering actually … Read more

A Beginners Guide to AWS Identity and Access Management (IAM)

AWS Identity and Access Management (IAM) is a web service that helps you securely control access to AWS resources for your users. You use IAM to control who can use your AWS resources (authentication) and what resources they can use and in what ways (authorization)[1]. Key features The key IAM features are, Provides centralized control … Read more

A Beginners Guide to Application Services within AWS

AWS provides a suite of application services, such as SQS, SNS, SES and SWF. Each service providing various features and rich toolsets to empower the development and design of your applications. SQS (Simple Queue Service) SQS is a web service that provides access to a distributed message queue. Messages are stored in the queue, these … Read more

The Essential Guide To Moving Docker Containers

Docker provides various commands/methods for moving containers. Within this article we will look at each of the commands, along with examples needed to move your Docker containers between your hosts and repositories. Repo to Repo Lets look at how we get an image from a repository and how we get our local image up to … Read more

Mac OSX Docker shows “Cannot connect to the Docker daemon”

Issue When running Docker you may experience the following error, root# docker images Cannot connect to the Docker daemon. Is the docker daemon running on this host? Solution To start the Docker daemon run the following commands. docker-machine start default eval ‘docker-machine env default’ Below is an example, root# docker-machine start default Starting “default”… (default) … Read more

What is the Difference Between Docker CMD and ENTRYPOINT ?

Within the world of Docker, CMD and ENTRYPOINT are often the cause of confusion. But why, you may ask? This is because both CMD and ENTRYPOINT are used to execute commands at container run time. But do not fear, my fellow Fir3net reader, in this article we will look at the how the 2 differ … Read more

How to Configure Django + Gunicorn inside Docker

Introduction Gunicorn ‘Green Unicorn’ is a Python WSGI HTTP Server for UNIX. It’s a pre-fork worker model ported from Ruby’s Unicornproject[1]. Within this article we will look at the steps on how to configure Gunicorn to serve your Django application inside a Docker container. Entrypoint First of all we create a script[2] and name it entrypoint.sh. … Read more

How to Build a Site to Site VPN Between Azure and a Cisco ASA

Introduction Within this article we will show you how to build a policy based site to site VPN between Microsoft Azure and a Cisco ASA firewall. Details Before we dive into the steps it is worth mentioning the versions and encryption domain used within this tutorial, Versions Azure Deployment Mode ARM (Azure Resource Manager) ASA … Read more

Microsoft Azure – Virtual Networks (VNets) Explained


What is a Virtual Network? A Virtual Network, also known as a VNet is an isolated network within the Microsoft Azure cloud. VNets are synonymous to AWS VPC (Virtual Private Cloud), providing a range of networking features such as the ability to customize DHCP blocks, DNS, routing, inter-VM connectivity, access control and Virtual Private Networks … Read more

AWS – What is Elastic Compute Cloud (EC2) ?

Amazon Elastic Compute Cloud (Amazon EC2) is a web service that provides resizable compute capacity in the cloud.[1] EC2 is divided into various “families” or instance types. EC2 instances are designed to host different workloads, such as database, web or application services. The customer has root access to the instance, which can be spun up … Read more

AWS S3, Storage Gateways and Import/Export

Simple Storage Service (S3) S3 provides secure, durable and highly scalable object storage. The key features to S3 are, Objects are replicated across availability zones for redundancy. Files can be between 1Byte to 5TB in size Provides unlimited storage Files are stored in Buckets, equivalent to a directory S3 is a universal namespace. i.e buckets … Read more

AWS Virtual Private Cloud (VPC)

VPC (Virtual Private Cloud) allows you to create virtual networks within AWS. This allows you to logically separate resources, add additional security, configure networking attributes (such as routing tables etc) along with build VPNs from your remote site into your AWS solution. Each AWS account comes with a default VPC. Within this VPC subnets are … Read more

Docker Command Cheatsheet

Build Command Description docker build -t my_program:v1 . Build an image using the Dockerfile in current directory Execution   Command Description docker run -d -it redis_celery Run container, detached. CMD/Excute in Dockerfile will execute as PID1l docker run -d -it redis_celery ping -c1 Run container. Execute ping command Dockerfile Command Description FROM RUN ENV … Read more

A Beginners Guide to OpenStack Neutron

Introduction Neutron, introduced within the Folsom release, is a cloud networking controller and a networking-as-a-service project within the OpenStack cloud computing initiative. Neutron includes a set of application program interfaces (APIs), plug-ins and authentication/authorization control software that enable interoperability and orchestration of network devices and technologies within infrastructure-as-a-service (IaaS) environments[1]. What is OpenStack ? OpenStack … Read more

How to Build an OpenStack Network using the Neutron CLI


Introduction Within this article we will provide the steps required to build a simple Neutron network. The network will consist of, Provider network (NET_EXTERNAL) Tenant network (NET_INTERNAL) L3 Router (NEUTRON-ROUTER) Floating IPs ( Below is a diagram on how the topology looks, Provider Network First we create the provider network. This is a layer2 network … Read more

OpenStack – NoValidHost: No valid host was found

Issue When creating a new instance within OpenStack you observe the following error, ==> /var/log/nova/nova-conductor.log <== … u”RescheduledException: Build of instance xxx-yyy-zzz was re-scheduled: internal error: no supported architecture for os type ‘hvm’\n”] … NoValidHost: No valid host was found. There are not enough hosts available. Solution This due to running OpenStack within a virtual … Read more

How to Auto Generate an OpenStack RC File

Within this short tutorial we will provide the steps for auto generating the OpenStack RC File. Via Horizon, Within the Project tab click Compute / Access & Security. Choose the API Access tab. Click Download OpenStack RC file.

How to Create an Instance within Nova via the CLI

Within this article we will show you how to create an instance within Nova via the CLI. Available Images First of all we list the images available to Nova. root@openstack-lab:~# nova image-list+————————————–+————————–+——–+——–+| ID | Name | Status | Server |+————————————–+————————–+——–+——–+| 23e82-5d3c-43a2-82b5-457f5e7 | cirros-0.3.2-x86_64-disk | ACTIVE | |+————————————–+————————–+——–+——–+ Flavours Next we check the flavours available. root@openstack-lab:~# … Read more

What is Auto-Scaling?

What is ? Auto-Scaling is a concept within cloud computing that can mean one of two things: Auto-Scaling is a process of virtualization resource automation wherein a cloud service provider will scale the resources of a client’s hosting environment to meet the demand being placed on that environment. In common terms, auto-scaling means a provider … Read more

How do I purge a File from Rackspace`s Cloud File CDN Caches?

Within this article we will show you how to purge a file from Rackspace`s Cloud File CDN Caches. Get Auth Token First all you will need to obtain the Auth Token. This token will be used to perform further actions via the API. For this you will need to obtain your API Key which can … Read more

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