Raspberry tutorial review

_kb/nu-raspberry-minting.md

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+---
+title: Mminting on a Raspberry Pi
+nav_heading: Technical Resources
+filename: nu-raspberry-minting.md
+permalink: /nu-raspberry-minting/
+layout: kb
+lang: en
+callouts:
+---
+
+## Introduction
+Holding NuShares comes with a responsibility : it is in your best interest to participate to the network by submitting your votes in each block you mint. 
+
+To maximise the impact of your votes and the reward that comes with staking shares, your Nu client should be minting 24/7.  A cost-efficient solution is delegating the minting to a cheap Raspberry Pi connected to the internet : unlike VPS or cloud service you will keep control over your shares, and you can finally turn off your home computer.  Thanks to  [Nu data-feeds](https://docs.nubits.com/using-a-data-feed/), you can subscribe your raspberry to an external source and control your votes without need to access the pi all the time. 
+
+The Raspberry Pi is a cheap (~40$) and efficient device with enough computational power to let you mint.   
+
+In this minimal tutorial we will see how to setup a minting machine which is different from a [full node](https://bitcoin.org/en/full-node#other-linux-distributions). For security reasons full nodes and minting nodes should be kept separated. 
+
+NOTE : in the examples of this tutorial we used `pico` as text editor, but feel free to use any other editor (nano, vi, etc ...) . 
+
+## What you need
+   - A Raspberry Pi [2 Model B](https://www.raspberrypi.org/products/raspberry-pi-2-model-b/). The  1B and 1B+ can also be used to mint, although R-pi 2 is more efficient, especially when minting with a large number of shares. 
+   - A fresh [SD card](https://www.raspberrypi.org/documentation/installation/sd-cards.md), ideally 8+ GB, class 10 speed  ;
+   - An Ethernet cable or a WiFi dongle ;
+   - Some [NuShares](https://nubits.com/nushares/introduction) (minimum 10k NSR are required for minting) ;
+   - Basic [unix CLI skills](http://linuxcommand.org/) ;
+
+## Prepare the Raspberry Pi
+#### Download and install NOOBS
+Follow the [the official tutorial](https://www.raspberrypi.org/help/noobs-setup/) to install an easy operating system installer which contains Raspbian. Login with your `pi` user, and [connect the raspberry to the internet](https://learn.adafruit.com/downloads/pdf/adafruits-raspberry-pi-lesson-3-network-setup.pdf). 
+
+#### Update all existing software on the Pi 
+ - `$ sudo apt-get update`
+ - `$ sudo apt-get upgrade`
+
+#### Install dependencies required by Nu
+ - `$ sudo apt-get install checkinstall subversion git git-core build-essential`
+ - `$ sudo apt-get install libssl-dev libdb++-dev libminiupnpc-dev`
+ - `$ sudo apt-get install libboost-dev libboost-system-dev libboost-filesystem-dev libboost-program-options-dev libboost-thread-dev libcurl4-openssl-dev`
+
+#### Link libminiupnpc 
+
+ - `$ sudo ln -s /usr/lib/libminiupnpc.so.5 /usr/lib/libminiupnpc.so.10`
+
+###  Optional reccomendations 
+We suggest to follow the optional steps below for additional security : 
+
+####  Setup static ip 
+
+Following one of the many tutorials you can find online, for example [this](http://www.modmypi.com/blog/tutorial-how-to-give-your-raspberry-pi-a-static-ip-address);
+
+#### Enable SSH : 
+Enter `$ sudo raspi-config` in the terminal, then navigate to ssh, hit Enter and select `Enable or disable ssh server`.
+#### Accept passwordless SSH sessions 
+[Follow this tutorial](https://www.raspberrypi.org/documentation/remote-access/ssh/passwordless.md), or if you know what you are doing simply run (on your machines) 
+
+- `$ cat ~/.ssh/id_rsa.pub | ssh pi@<IP-ADDRESS> 'cat >> .ssh/authorized_keys' `
+
+#### Disable SSH password login 
+Edit `/etc/ssh/sshd_config`
+
+- `$ sudo pico /etc/ssh/sshd_config`
+
+and make sure these three parameters are set to `no`
+
+{% highlight text %}
+ChallengeResponseAuthentication no
+PasswordAuthentication no
+UsePAM no
+{% endhighlight %}
+
+Restart SSH with `$ sudo /etc/init.d/ssh restart`
+
+## Download and compile Nu
+
+ - `$ cd ~` #Go to pi user's home directory
+ - `$ git clone https://bitbucket.org/JordanLeePeershares/nubit.git`   #clone NuBits repository locally
+ - `$ cd nubit/src` #Go to source directory 
+ - `$ sudo dd if=/dev/zero of=/swapfile bs=64M count=16` #provide some extra swap partition to speed up compilation time
+ - `$ sudo mkswap /swapfile` 
+ - `$ sudo swapon /swapfile` 
+ - `$ make -f makefile.unix` #Build  nud. This command can take up to 2 hours, will produce an executable file : `nud`
+ - `$ strip nud` #Reduce file size by stripping symbols
+ - `$ sudo mv nud /usr/bin/nud && sudo chmod a+x /usr/bin/nud` #move nud and make it executable
+ - `$ sudo rm -r ~/nubit/` #Remove directory with sources (optional)
+ - `$ sudo swapoff /swapfile`#clean up the previously initiated swap
+ - `$ sudo rm /swapfile`
+
+## Configure Nud
+
+Now that nud is ready, we need to configure it before executing it. 
+
+- `$  mkdir -p ~/.nu`#Create the data folder 
+- `$  touch ~/.nu/nu.conf` #Create an empty configuration file
+- `$  pico ~/.nu/nu.conf`#Edit the nu.conf file
+
+Your nu.conf shuold look like the example below : 
+
+{% highlight text %}
+daemon=1 
+server=1
+rpcuser=<chooseAnUsername>
+rpcpassword=<chooseAPassword>
+port=7890
+{% endhighlight %}
+
+After editing the config, make it read only : 
+ - `$ sudo chmod 400 ~/.nu/nu.conf`
+ 
+The  nu daemon will be listening to RPC messages on the port you specified. We highly suggest *not* to forward that port and leave the pi protected behing the NAT, for local usage only.  
+
+## Start Nud and download the blockchain
+
+Now you will be able to access nud via CLI by typing `nud` followed by the [rpc command](https://docs.nubits.com/rpc-api/) you want to invoke.  
+The first thing you want to do is starting the daemon and let it download the blockchain. This operation can take  several hours - or even days - depending on connectivity.  
+
+- `$  nud -daemon` #will start your nu daemon , startup can take some minutes. 
+
+It is possible that you get an error related to perl and your `locale` settings.  If you get this  error, simply execute the following command that will write an export of your locale to the bash profile your `locale` setting (in the example below being `en_US,` but could also be `en_GB`or something else). 
+- `$ echo export LC_ALL=en_US.UTF-8 >> ~/.profile`
+
+To check how the download of the blockchain is proceeding you can run 
+
+- `$  nud getinfo`
+
+and read the `blocks` number growing while comparing it to the current `height` on [the block explorer](https://blockexplorer.nu/status).   Be patient while the blockchain is being downloaded.
+
+## Configure your minting machine
+
+You can configure nud to automatically run on startup. 
+ - `$ sudo pico /etc/rc.local`
+and add the following line immediately before the last line (`exit 0`) : 
+{% highlight text %}
+.
+.
+.
+nud -daemon
+exit 0
+{% endhighlight %}
+
+Save, exit pico and reboot the pi with
+
+- `$  sudo reboot`
+
+and test if the daemon started automatically : 
+
+- `$  nud getinfo`
+
+### Fund your minting machine. 
+
+You have three options to transfer NuShares to your raspberry : 
+
+1. Send NSR to one of the raspberry receive address (list available receive address with `$ nud listreceivedbyaddress 1 true`
+2. Import an existing private key using `$ nud importprivkey <yourprivkey>`  and clean up bash history right after with `$ cat /dev/null > ~/.bash_history` to delete all traces
+3. Copy an existing walletS.dat file to the raspberry using `scp` . Execute this command from the machine where the existing wallet is hosted :  
+`$ scp local/path/to/walletS.dat pi@<pi.ip.address>:/home/pi/.nu `
+
+Unless you go with the the third option and imported an encrypted wallet, make sure to **encrypt your wallet** with a [sufficiently complex passphrase](https://answers.uchicago.edu/16276) 
+- `$ nud encryptwallet <passphrase>` 
+
+After you have a working node encrypted and funded with NuShares,  you need to **unlock the wallet** using your passphrase to allow minting. 
+To unlock your wallet, type the command below, press enter,  then type your passphrase,  press enter again and finally Control+D:
+
+```
+$ nud walletpassphrase `cat` 999999999 true
+```
+Alternatively, you can use [this bash script](https://gist.github.com/desrever-nu/6e18d037251edeaeb4d6) so you don't have to remember the sequence above everytime. 
+
+### Configure votes
+
+Now you can use data-feeds to configure your vote, so everytime you mint a new block, you will participate to Nu democratic process.  You have also the option to manually configure votes via CLI, but is not reccomended.   
+
+After you [created your own datafeed](https://docs.nubits.com/hosting-a-data-feed/) or chose an [existing datafeed](https://discuss.nubits.com/c/nushares/data-feeds) to delegate your voting power to, [this tutorial](https://docs.nubits.com/using-a-data-feed/#using-data-feeds-from-the-daemon) will teach you how to use data feeds from the daemon.  For example, to subscribe to [Cybnate's data feed](https://discuss.nubits.com/t/cybnates-datafeed-beta/1310) you can use the following command :
+
+- `$  nud setdatafeed https://raw.githubusercontent.com/Cybnate/NuNet-datafeed/master/Cybnate-datafeed.json https://raw.githubusercontent.com/Cybnate/NuNet-datafeed/master/Cybnate-datafeed.txt ShTrp9wbgnhZudk4eYXtBtcMyeBziGzUpc`
+
+Double check if the feed is set correctly by running 
+
+- `$ nud getdatafeed `
+
+Congrats, your minting machine is ready! 
+
+ You can now interact with your node using [rpc commands](https://docs.nubits.com/rpc-api/), and you can also manage the same NSR with a GUI client from your laptop at the same time, just remember to leave the GUI client locked, so it won't mint and interfere with the raspberry.