Introduction to IPFS

What is IPFS?

The best reference is its home page. IPFS stands for Inter Planetary File System.

Its goal is replace HTTP and build a better web, how it works? To understand it, we need to remove from our heads the idea of centralized servers hosting files to the internet nodes and imagine the whole internet of nodes as a huge storage unit.

• Each file and all of the blocks within it are given a unique fingerprint called a cryptographic hash.

• IPFS removes duplications across the network and tracks version history for every file.

• Each network node stores only content it is interested in, and some indexing information that helps figure out who is storing what.

• When looking up files, you're asking the network to find nodes storing the content behind a unique hash.

• Every file can be found by human-readable names using a decentralized naming system called IPNS.

For the reader interested in the particulars, here is The IPFS white paper

All we need to be part of the IPFS is running a version of the IPFS daemon, or having access to a remote IPFS node. INFURA provides an IPFS node for developers.

Installation of the daemon in local computer

Just install the executable and run it. Is that simple.

Check the one according to your OS, to test it, enter

> ipfs help
USAGE:

    ipfs - Global p2p merkle-dag filesystem.

We review the basic operation of the IPFS daemon in this guide

Using the Docker Image

Docker presents a number of benefits. Among them, that you can get encapsulated images of an applications, with their libraries, in a way analog to downloading an App. Although IPFS has its docker image, we will use the modified ConsenSys' one, as it has some small modifications, namely, the inclusion of CORS support.

You just need to have docker installed in your machine and prepare two directories

mkdir -p $HOME/ipfs/staging
mkdir -p $HOME/ipfs/data

chmod -R 777 $HOME/ipfs

Once the preparations are done, run the following command

docker run -ti \
    --rm \
    --name ipfs \
    -v $HOME/ipfs/staging:/export \
    -v $HOME/ipfs/data:/ipfs/data \
    -p 4001:4001 \
    -p 5001:5001 \
    -p 8080:8080 \
    consensysllc/go-ipfs:v0.4.4-custom-start

This command does these steps:

• Pulls, if there is not already there, the image consensysllc/go-ipfs:v0.4.4-custom-start.
• Mounts both two directories prepared above into the image. So we don't start from scratch everytime.
• Maps three ports from the host (your machine) into the image: 4001, 5001 and 8080.

If you are curious, this is the Dockerfile we are using in our machine

FROM ipfs/go-ipfs:v0.4.4
MAINTAINER Herman Junge <[email protected]>

COPY start_ipfs.sh /usr/local/bin/start_ipfs
ENTRYPOINT ["/usr/local/bin/start_ipfs"]

and the start script

#!/bin/sh

user=$(whoami)
repo="$IPFS_PATH"

# Test whether the mounted directory is writable for us
if [ ! -w "$repo" 2>/dev/null ]; then
  echo "error: $repo is not writable for user $user (uid=$(id -u $user))"
  exit 1
fi

ipfs version

if [ -e "$repo/config" ]; then
  echo "Found IPFS fs-repo at $repo"
else
  ipfs init
  ipfs config Addresses.API /ip4/0.0.0.0/tcp/5001
  ipfs config Addresses.Gateway /ip4/0.0.0.0/tcp/8080
  ipfs config --json API.HTTPHeaders.Access-Control-Allow-Origin '["*"]'
  ipfs config --json API.HTTPHeaders.Access-Control-Allow-Methods '["PUT", "GET", "POST"]'
fi

# For the love of Krishna, do not use `--debug`!
# You can modify them later, けど. See
# https://ipfs.io/docs/commands/#ipfs-log-level
exec env IPFS_LOGGING=info ipfs daemon --enable-gc

And that'd be!

If you want to run the console tutorial using this very image, you need to add a single flag into docker.

# Add this flag just before the name of the image
--entrypoint /bin/bash

So you override the start of IPFS daemon, and run /bin/bash.

Using the IPFS node of INFURA

Now, there may be a number of reasons where you don't want to run a local IPFS node, neither installed nor a docker. Enter INFURA.

INFURA maintains a remote IPFS node at the address https://ipfs.infura.io/.

• Gateway: https://ipfs.infura.io
• RPC: https://ipfs.infura.io:5001