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  • 2 min read

How to make VS Code Go extension to work in your cloud folder on different platforms?

I started to play with Go aka Golang. Yeah, leaving the comfort zone, all that buzz. And for quite some time I've been engaged with VS Code whenever/wherever I did dev activities.

VS Code has a solid Go support via its official extension:

Info

This extension adds rich language support for the Go language to VS Code, including:

  • Completion Lists (using gocode)
  • Signature Help (using gogetdoc or godef+godoc)
  • Quick Info (using gogetdoc or godef+godoc)
  • Goto Definition (using gogetdoc or godef+godoc)
  • Find References (using guru)
  • File outline (using go-outline)
  • Workspace symbol search (using go-symbols)
  • Rename (using gorename)
  • Build-on-save (using go build and go test)
  • Lint-on-save (using golint or gometalinter)
  • Format (using goreturns or goimports or gofmt)
  • Generate unit tests skeleton (using gotests)
  • Add Imports (using gopkgs)
  • Add/Remove Tags on struct fields (using gomodifytags)
  • Semantic/Syntactic error reporting as you type (using gotype-live)

Mark that gotools in the brackets, these ones are powering all that extra functionality and got installed into your GOPATH once you install them via VS Code.

And here you might face an issue if you want to use Go + VS Code both on Mac and Linux using the Dropbox folder (or any other syncing service). The issue is that binaries for Mac and Linux will overwrite themselves once you decide to install the extension on your second platform. Indeed, by default VS Code will fetch the source code of the tools and build them, placing binaries in the $GOPATH/bin.

  • 1 min read

How to count lines of code in a Git repo?

Nothing bad in knowing how many lines of code or text out there in your repo. You don't even need your VCS to convey this analytics. All you need is git, grep and wc.

# count lines in .py and .robot files in /nuage-cats dir of the repo
$ git ls-files nuage-cats/ | grep -E ".*(py|robot)" | xargs wc -l
       0 nuage-cats/robot_lib/__init__.py
     817 nuage-cats/robot_lib/lib/NuageQoS.py
     409 nuage-cats/robot_lib/lib/NuageVCIN.py
    1841 nuage-cats/robot_lib/lib/NuageVNS.py
    2964 nuage-cats/robot_lib/lib/NuageVSD.py
    # OMITTED
      26 nuage-cats/test_suites/0910_fail_bridges_kvm_vms/0910_fail_bridges_kvm_vms.robot
   13636 total
  • 11 min read

Building AWS Lambda with Python, S3 and serverless

Cloud-native revolution pointed out the fact that the microservice is the new building block and your best friends now are Containers, AWS, GCE, Openshift, Kubernetes, you-name-it. But suddenly micro became not that granular enough and people started talking about serverless functions!

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When I decided to step in the serverless property I chose AWS Lambda as my instrument of choice. As for experimental subject, I picked up one of my existing projects - a script that tracks new documentation releases for Nokia IP/SDN products (which in the past I aggregated at nokdoc.github.io (now closed)).

Given that not so many posts are going deeper than onboarding a simplest function, I decided to write down the key pieces I needed to uncover to push a real code to the Lambda.

Buckle up, our agenda is fascinating:

  • testing basic Lambda onboarding process powered by Serverless framework
  • accessing files in AWS S3 from within our Lambda with boto3 package and custom AWS IAM role
  • packaging non-standard python modules for our Lambda
  • exploring ways to provision shared code for Lambdas
  • and using path variables to branch out the code in Lambda
  • 2 min read

Destroy and Undefine KVM VMs in a single run

virsh is a goto console utility for managing Qemu/KVM virtual machines. But when it comes to deletion of the VMs you better keep calm - there is no single command to destroy the VM, its definition XML file and disk image.

Probably not a big problem if you have a long-living VMs, but if you in a testing environment it is naturally to spawn and kill VMs quite often. Lets see how xargs can help us with that routine.

  • 21 min read

BGP VPLS deep dive. Nokia SR OS & Juniper

It may very well be that VPLS days are numbered and EVPN is to blame. Nevertheless, it would be naive to expect VPLS extinction in the near future. With all its shortcomings VPLS is still very well standardized, interop-proven and has a huge footprint in MPLS networks of various scale.

In this post I will cover theory and configuration parts for one particular flavor of VPLS signalling - BGP VPLS (aka Kompella VPLS) defined in RFC4761. I'll start with simple single home VPLS scenario while multi-homing techniques and some advanced configurations might appear in a separate post later.

In this topic the following SW releases were used:

  • Nokia (Alcatel-Lucent) VSR 14.0.R4
  • Juniper vMX 14.1R1.10
  • 23 min read

Building Web front end for Python scripts with Flask

Recently I revived my relationship with Python in an effort to tackle the routine tasks appearing here and there. So I started to write some pocket scripts and, luckily, was not the only one on this battlefield - my colleagues also have a bunch of useful scripts. With all those code snippets sent in the emails, cloned from the repos, grabbed on the network shares... I started to wonder how much easier would it be if someone had them all aggregated and presented with a Web UI for a shared access?

Thus, I started to build web front-end to the python scripts we used daily with these goals in mind:

  • allow people with a zero knowledge of Python to use the scripts by interacting with them through a simple Web UI;
  • make script's output more readable by leveraging CSS and HTML formatting;
  • aggregate all the scripts in one a single repo but in a separate sandboxed directories to maintain code manageability.

This short demo should give you some taste of what it is:

Disclaimer: I am nowhere near even a professional python or web developer. And what makes it even worse is that I used (a lot) a very dangerous coding paradigm - SDD - Stack Overflow Driven Development. So, hurt me plenty if you see some awful mistakes.

Project source code

  • 25 min read

Basic L3VPN (BGP/MPLS VPN or VPRN) configuration on Nokia (Alcatel-Lucent) SROS & Juniper MX

The topic of this post is Layer 3 VPN (L3VPN or VPRN as we call it in SROS) configuration, and I decided to kill two birds with one stone by inviting Juniper vMX to our cozy SROS environment.

The BGP/MPLS VPN (RFC 4364) configuration will undergo the following milestones:

  • PE-PE relationship configuration with VPN IPv4 address family introduction
  • PE-CE routing configuration with both BGP and OSPF as routing protocols
  • Export policy configuration for advertising VPN routes on PE routers
  • AS override configuration
  • and many more

We'll wrap it up with the Control Plane/Data Plane evaluation diagrams which help a lot with understanding the whole BGP VPN mechanics. Take your seats, and buckle up!

  • 27 min read

Nokia (Alcatel-Lucent) BGP configuration tutorial. Part 2 - Communities

In the first part of this BGP tutorial we prepared the ground by configuring eBGP/iBGP peering. We did a good job overall, yet the plain BGP peering is not something you would not normally see in production. The power of BGP is in its ability for granular management of multiple routes from multiple sources. And the tools that help BGP to handle this complex task are BGP policies at their full glory.

In this part we will discuss and practice:

  • BGP export/import policies for route advertisement/filtering
  • BGP communities operations
  • BGP routes aggregation: route summarization and the corresponding aggregate and atomic-aggregate path attributes
  • 32 min read

Nokia (Alcatel-Lucent) BGP configuration tutorial. Part 1 - basic eBGP, iBGP

There is no way I would leave you without covering configuration steps for one of the most versatile, scalable and robust internet protocols also known as BGP. And here it is - BGP configuration guide for Nokia (Alcatel-Lucent) Service Routers.

As with the OSPF configuration tutorial I will cover the configuration process for various BGP scenarios along with the verification and troubleshooting steps bundled with colorful figures, detailed code snippets and useful remarks.

BGP is so huge that I had no other option but to write about it in several parts:

Part 1 is dedicated to basic eBGP/iBGP configuration. We will practice with common BGP configuration procedures at first, then learn how to export routes into BGP process and prevent unnecessary route reflection by means of split-horizon over eBGP links.

Next we go over iBGP configuration to spread the eBGP learned routes across the Autonomous Systems. I will explain the necessity of having a full-mesh iBGP topology and the use of the next-hop-self command for iBGP peers.

It's a perfect time to configure some BGP, right?

  • 4 min read

Nokia (Alcatel-Lucent). Configuring Packet (IP) Filters

Packet filters (or in Cisco terminology Access Control Lists, aka ACL) are one of the most used tools in a network engineer's tool set. Blocking telnet/ssh access, restricting specific traffic flows, implementing policy-based routing or NATing - all of these tasks use IP filter's capabilities.

In this example I'll show you how to configure a basic SSH-blocking IP filter on a Nokia (Alcatel-Lucent) SROS running TiMOS-B-12.0.R8.