Jekyll2026-01-25T23:08:51+01:00https://nextnet.top/feed.xmlNicolas Herbaut, Associate ProfessorResearch at the LaBRI, Teaching in Université de Bordeaux (IUT INFO)Nicolas HerbautSemantic matchmaking for a data-driver marketplace demo2021-06-14T00:00:00+02:002021-06-14T00:00:00+02:00https://nextnet.top/content/blog-postextract from our recently published paper in DEEP-BDB-2021, for which we publish a Demo.

A client’s request contains requested asset specifications for data, algorithms and infrastructure on the blockchain system for service composition. Since we aim to build a use case-agnostic system, we must support a wide and dynamic range of application domains. To this end, we rely on an ontology-based resource retrieval and allocation system, which have already been proposed in the literature for cloud services provisioning \cite{ma2011ontology} or dataset \cite{kushiro2013method} discovery.

With a common ontology used to describe both client requirements and providers assets, matchmaking can be done on-chain, through the emission of a specific event targeted at providers that can fulfill client requests or off-chain, through the continuous monitoring of new clients’ requests publicly available on the blockchain. Based on the asset ontology, each provider can analyze the asset specifications published by the client and know if it owns a matching asset, in which case it will take part in the auction phase through asset bids

]]>Nicolas Herbautusing gandi livedns as a Dynamic DNS server2018-02-02T00:00:00+01:002018-02-02T00:00:00+01:00https://nextnet.top/content/blog-postThat’s still working in 2021

To experiment with widely distributed systems, I administrate some rasberry pi zeros W scattered in France in residential homes. These systems are attached to residential gateways through Wifi with dynamic IP addresses and I needed a way to reliably connect to them to launch experiments.

In the nineties, I used a service called Dyndns, which offered a free service for updating subdomains with dynamic IPs. This free service no longer exists, so I started looking for an alternatives. Most of them were costly and required the installation of closed-sources update clients. Opensource alternatives such as hopper.pw required complicated installations and also a dedicated domain name.

Hopefully, I’ve been a loyal customer of Gandi for some years now, and thanks to the introduction their livedns API, it can be used to update my main dns zone through a REST API.

prerequisites: curl jq (apt-get install curl jq)

# retreive current external IP address from Akamai server
MY_IP=$(curl -s http://whatismyip.akamai.com/)  

# Gandi livedn API KEY
APIKEY="................."

# Static Domain hosted at Gandi
DOMAIN="nextnet.top"

# Dynamic Subdomain
SUBDOMAIN="pi3gre"

#Get the current Zone for the provided domain
CURRENT_ZONE_HREF=$(curl -s -H "X-Api-Key: $APIKEY" https://dns.api.gandi.net/api/v5/domains/$DOMAIN | jq -r '.zone_records_href')

# Update the A reccord of the Dynamic Subdomain by PUTing on the current zone
curl -D- -X PUT -H "Content-Type: application/json" \
        -H "X-Api-Key: $APIKEY" \
        -d "{\"rrset_name\": \"$SUBDOMAIN\",
             \"rrset_type\": \"A\",
             \"rrset_ttl\": 1200,
             \"rrset_values\": [\"$MY_IP\"]}" \
        $CURRENT_ZONE_HREF/$SUBDOMAIN/A
]]>Nicolas Herbaut