This guide addresses enthusiastic amateurs and professionals with experience with linux, knowlegde on the shell (I used /bin/bash), who want to run a DECENT witness node.

I couldn’t find an easy and understandable step-by-step-guide which explains everything in simple English and also offeres some background – so I gathered all the information, researched, learned and want to share with you now. To make a long story short: I wrote the ultimate guide to setup a DECENT witness node and run it!

Due to the fact that DECENT once forked from bitshares/Graphene it uses a Delegated Proof of Stake (DPoS) consensus mechanism instead of Proof of Work (like for example Bitcoin does). So Mining is not defined in DECENT as a competition of calculations to find a solution for a block hash under changing limitations. Instead DECENT’s DPoS votes single nodes to give them a chance to build blocks. For that, one’s node needs to create a mining object and be voted in for “witnessing” – so to build up blocks with actual transactions and sign them. Of course such a system does not support a “come and go as you want” behaviour, but needs a node to stay online 24/7.

In exchange DPoS is by far faster and scales much better than any PoW-system. In best case it will always extend its limits and can process thousands of transactions per second. So it becomes a system supporting something like real-time processing transactions on a virtual dezentralized machine. If you have already an account from the ICO and a running decentd with wallet_cli compiled, you can go right into action!

Part II: Hardware and environment for your DECENT witness

This was my first stumbling block, setting up DECENT’s witness node.

You need to stay online 24/7 and be reachable under the same ip/domain without restarting decentd (daemon) for a long time.

Basis for everything should be linux (Debian or Ubuntu 16.04), but there are also some hardware requirements, if you want to follow the more complicated way (compiling). I will only touch that topic lightly here, because it easily becomes some “work intensive” and frustrating for both beginner and pros if it does not work. There is a second by far easier to setup version with docker (later more).

For both compiling and the by docker containerized version you need experience with linux and software/hardware which fulfills the following recommended requirements:

• Linux kernel > Version 4
• 4 Cores
• 16 GB RAM
• 500 MB HDD
• reasonable amount of swapspace (let’s say RAM + 100 MB)

A VPS with which is virtalized with openVZ DOES NOT work! The kernel version is too low and usually these offers do not support real swap space and only a 2.6.x kernel, which does not compile the code properly, nor is able to run docker. You can check your kernel version with “uname -r”.

Compiling (build from the scratch)

The sources for the decent network you can find on github. Ich you want to build from the scratch you can also try to follow texxi’s instructions on steemit (little bit outdated). At this point I will only give you a general desciption and common recommendation.

With git you can fork from the source, but for compiling you need special versions of libboost (1.60). So you need to take care to install the needed version of libboost and place it in your #path OR compile libboost for your system in the beginning. Here I see also a hurdle for developer, cause you need to separate your environment from other projects, and you need to take care of versioning. That can become pretty hard, if you have no experience with.

I can only highly recommend to setup your own user for DECENT after preparing the environment for build and make.

BTW: DECENT’s DCore is a complex and far developed project and compiling needs a long time and a high frustration tolerance and eager will to learn for beginners.

Dockerized version – use docker containers

On github a developer led me to a by far easier version. A big thanks at this point to marian-decent-ch for his support the preparation of some test containers and introduction to docker. I guess you are Marian Vanderka on DECENT’s team page. Also thanks to Mark Peter Mansell who is fighting himself through to achieve a proper documentation. I hope my guide for dummies can show where the hurdles for newbie devs are, who are not familiar the the graphene family already.

Also for the use of docker I give you only a common introduction, but I tried this on both docker for windows and linux. Both worked perfectly fine. I recommend a docker gui like portainer or kitematic. It is not really needed, but makes things easier to handle here and there.

What is a docker?

A docker puts everything which is needed to run an app in a container and makes it executetable on different OS or environments. Imagine it like an emulator, but it is more like a virtual machine in a box and this box has connections to its outside world like network, terminal and access to RAM, CPU cores and volumes.

The top source for already prepared docker containers is hub.docker.com where you can find also actual DECENT containers, which seem to be better manintained than some time ago, when I started my research on DECENT. You will need the containers with decentd and the wallet_cli. No need to download them now. docker will do that later automatically and all required dependencies at the first start. Please note that you need a working docker environment on your server. The CE-Version is okay. If you’re on ubuntu 16.04 you can follow these instructions (some complicated) or you can let the docker-script do all the work with:

curl -fsSL get.docker.com -o get-docker.sh

sh get-docker.sh

docker starts the dockerd daemon in the background, which is the entity which catches your docker commands and executes containters. If you only want to give it a quick check, if docker is properly setup to host the DECENT containers, you can open a terminal, respectively two terminals and with

docker run --rm -it --network=host decentnetwork/decentd decentd

and

docker run --rm -it --network=host decentnetwork/cli_wallet cli_wallet

you can start the daemon and the wallet_cli.

Please note that the decentd first needs to sync with the network. Actually there are more than 5 mil blocks, so it needs some time.
Please also note, that the wallet_cli will only connect to the synced daemon.

As a little test this is okay. You can stop the daemon with CTRL+C now. Due to the fact docker started the container with -rm option all the work will be gone anyway after stopping the container.

Please note that I used a root access, but it makes for sure more sense to create a new user, grand sudoer rights, disallow root access, prepare the server to resist against brute force attacks, setup a firewall, also install fail2ban and so on. Please don’t neglect hardening your server! 

Anyway I created a space for decent to store its data. In case you also want to do so you have to add your home dir in the beginning of the path.

mkdir /scratch/decent

(This creates some temporarely space for DECENT’s data. I stole that idea from setting up and using my own lightning wallet.)

Open two terminals. In one you start the daemon. If you don’t use docker you can put it on its own screen. That’s not needed here, I’ll stick to the dockerized version.

docker run -it -v /scratch/decent:/root/.decent --network=host decentnetwork/decentd:latest decentd

That makes docker downloading the latest image and run the daemon in it, but maps the internal folder /root/.decent to the external directory /scratch/decent. That folder we later need access to. About the network you don’t need to care. The container claims and forwards the needed ports itself for the connections to the DECENT network and being reachable for remote procedure calls.

On the terminal you can see the daemon syncing with the network. After a start without the -rm (remove) option and mapping the work directory you can even close the terminal, or stop the daemon with CTRL+C, or stop/start/restart the whole container without to reindex or resync from the beginning. Also the docker container’s ID will stay the same (later more).

Time to startup the wallet_cli container. Please note that you better let the daemon sync first. You can compare block height at explorer.decent.ch. Then in the second terminal you start the second container with

docker run -it -v /scratch/decent:/root/.decent --network=host decentnetwork/cli_wallet:latest cli_wallet

As you see the cli uses the same folder and network. One hit on the RETURN-key and you see a prompt like “NEW >>>” which indicates that the wallet_cli was started for the first time and connected properly to the daemon.

Congratulations – you have a running environment to run a DECENT witness node.

Note, that from here on you can also start/stop the containers with your favorite docker gui (like kitematic or portainer). If you accidently close the shell or terminal you can login again and with

docker ps

you can find a list of running containers.

If you want to take over the STDout of a running container you can do so with

docker attach docker_id

If you want another shell into a running docker container you can do so with

docker exec -i -t docker_id /bin/bash

An now, please follow me into the rabbit hole – we will meet Alice.