nwaku/waku/v2

Waku v2

This folder contains code related to Waku v2, both as a node and as a protocol.

Introduction

This is an implementation in Nim of Waku v2, which is currently in draft/beta stage.

See spec.

How to Build & Run

Prerequisites

• GNU Make, Bash and the usual POSIX utilities. Git 2.9.4 or newer.

Wakunode

# The first `make` invocation will update all Git submodules.
# You'll run `make update` after each `git pull`, in the future, to keep those submodules up to date.
make wakunode2

# See available command line options
./build/wakunode2 --help

# Connect the client directly with the Status test fleet
# TODO NYI
#./build/wakunode2 --log-level:debug --discovery:off --fleet:test --log-metrics

Note: building wakunode2 requires 2GB of RAM. The build will fail on systems not fulfilling this requirement.

Setting up a wakunode2 on the smallest digital ocean droplet, you can either

• compile on a stronger droplet featuring the same CPU architecture and downgrade after compiling, or
• activate swap on the smallest droplet, or
• use Docker.

Waku v2 Protocol Test Suite

# Run all the Waku v2 tests
make test2

To run a specific test.

# Get a shell with the right environment variables set
./env.sh bash
# Run a specific test
nim c -r ./tests/v2/test_waku_filter.nim

You can also alter compile options. For example, if you want a less verbose output you can do the following. For more, refer to the compiler flags and chronicles documentation.

nim c -r -d:chronicles_log_level=WARN --verbosity=0 --hints=off ./tests/v2/test_waku_filter.nim

You may also want to change the outdir to a folder ignored by git.

nim c -r -d:chronicles_log_level=WARN --verbosity=0 --hints=off --outdir=build ./tests/v2/test_waku_filter.nim

Waku v2 Protocol Example

There is a more basic example, more limited in features and configuration than the wakunode1, located in examples/v2/basic2.nim.

There is also a more full featured example in examples/v2/chat2.nim.

Waku Quick Simulation

NOTE: This section might be slightly out of date as it was written for Waku v1.

One can set up several nodes, get them connected and then instruct them via the JSON-RPC interface. This can be done via e.g. web3.js, nim-web3 (needs to be updated) or simply curl your way out.

The JSON-RPC interface is currently the same as the one of Whisper. The only difference is the addition of broadcasting the topics interest when a filter with a certain set of topics is subcribed.

The quick simulation uses this approach, start_network launches a set of wakunodes, and quicksim instructs the nodes through RPC calls.

Example of how to build and run:

# Build wakunode + quicksim with metrics enabled
make NIMFLAGS="-d:insecure" wakusim2

# Start the simulation nodes, this currently requires multitail to be installed
# TODO Partial support for Waku v2
./build/start_network2 --topology:FullMesh --amount:6 --test-node-peers:2
# In another shell run
./build/quicksim2

The start_network2 tool will also provide a prometheus.yml with targets set to all simulation nodes that are started. This way you can easily start prometheus with this config, e.g.:

cd ./metrics/prometheus
prometheus --config.file=prometheus.yml

A Grafana dashboard containing the example dashboard for each simulation node is also generated and can be imported in case you have Grafana running. This dashboard can be found at ./metrics/waku-sim-all-nodes-grafana-dashboard.json

To read more details about metrics, see next section.

Using Metrics

Metrics are available for valid envelopes and dropped envelopes.

To compile in an HTTP endpoint for accessing the metrics we need to provide the insecure flag:

make NIMFLAGS="-d:insecure" wakunode2
./build/wakunode2 --metrics-server

Ensure your Prometheus config prometheus.yml contains the targets you care about, e.g.:

scrape_configs:
  - job_name: "waku"
    static_configs:
      - targets: ['localhost:8008', 'localhost:8009', 'localhost:8010']

For visualisation, similar steps can be used as is written down for Nimbus here.

There is a similar example dashboard that includes visualisation of the envelopes available at metrics/waku-grafana-dashboard.json.

Spec support

This section last updated November 16, 2020

All Waku v2 specs, except for bridge, are currently in draft.

Docker Image

By default, the target will be a docker image with wakunode, which is the Waku v1 node. You can change this to wakunode2, the Waku v2 node like this:

make docker-image MAKE_TARGET=wakunode2
docker run --rm -it statusteam/nim-waku:latest --help

Generating and configuring a private key

By default a node will generate a new, random key pair each time it boots, resulting in a different public libp2p multiaddrs after each restart.

To maintain consistent addressing across restarts, it is possible to configure the node with a previously generated private key using the --nodekey option.

wakunode2 --nodekey=<64_char_hex>

This option takes a Secp256k1 private key in 64 char hexstring format.

To generate such a key on Linux systems, use the openssl rand command to generate a pseudo-random 32 byte hexstring.

openssl rand -hex 32

Example output:

$ openssl rand -hex 32
6a29e767c96a2a380bb66b9a6ffcd6eb54049e14d796a1d866307b8beb7aee58

where the key 6a29e767c96a2a380bb66b9a6ffcd6eb54049e14d796a1d866307b8beb7aee58 can be used as nodekey.

To create a reusable keyfile on Linux using openssl, use the ecparam command coupled with some standard utilities whenever you want to extract the 32 byte private key in hex format.

# Generate keyfile
openssl ecparam -genkey -name secp256k1 -out my_private_key.pem
# Extract 32 byte private key
openssl ec -in my_private_key.pem -outform DER | tail -c +8 | head -c 32| xxd -p -c 32

Example output:

read EC key
writing EC key
0c687bb8a7984c770b566eae08520c67f53d302f24b8d4e5e47cc479a1e1ce23

where the key 0c687bb8a7984c770b566eae08520c67f53d302f24b8d4e5e47cc479a1e1ce23 can be used as nodekey.

wakunode2 --nodekey=0c687bb8a7984c770b566eae08520c67f53d302f24b8d4e5e47cc479a1e1ce23

Configuring a domain name

It is possible to configure an IPv4 DNS domain name that resolves to the node's public IPv4 address.

wakunode2 --dns4-domain-name=mynode.example.com

This allows for the node's publically announced multiaddrs to use the /dns4 scheme. In addition, nodes with domain name and secure websocket configured, will generate a discoverable ENR containing the /wss multiaddr with /dns4 domain name. This is necessary to verify domain certificates when connecting to this node over secure websocket.

Using DNS discovery to connect to existing nodes

A node can discover other nodes to connect to using DNS-based discovery. The following command line options are available:

--dns-discovery              Enable DNS Discovery
--dns-discovery-url          URL for DNS node list in format 'enrtree://<key>@<fqdn>'
--dns-discovery-name-server  DNS name server IPs to query. Argument may be repeated.

• --dns-discovery is used to enable DNS discovery on the node. Waku DNS discovery is disabled by default.
• --dns-discovery-url is mandatory if DNS discovery is enabled. It contains the URL for the node list. The URL must be in the format enrtree://<key>@<fqdn> where <fqdn> is the fully qualified domain name and <key> is the base32 encoding of the compressed 32-byte public key that signed the list at that location.
• --dns-discovery-name-server is optional and contains the IP(s) of the DNS name servers to query. If left unspecified, the Cloudflare servers 1.1.1.1 and 1.0.0.1 will be used by default.

A node will attempt connection to all discovered nodes.

This can be used, for example, to connect to one of the existing fleets. Current URLs for the published fleet lists:

• production fleet: enrtree://AOGECG2SPND25EEFMAJ5WF3KSGJNSGV356DSTL2YVLLZWIV6SAYBM@prod.waku.nodes.status.im
• test fleet: enrtree://AOGECG2SPND25EEFMAJ5WF3KSGJNSGV356DSTL2YVLLZWIV6SAYBM@test.waku.nodes.status.im

See the separate tutorial for a complete guide to DNS discovery.

Enabling Websocket

Websocket is currently the only Waku transport supported by browser nodes that uses js-waku. Setting up websocket enables your node to directly serve browser peers.

A valid certificate is necessary to serve browser nodes, you can use letsencrypt:

sudo letsencrypt -d <your.domain.name>

You will need the privkey.pem and fullchain.pem files.

To enable secure websocket, pass the generated files to wakunode2: Note, the default port for websocket is 8000.

wakunode2 --websocket-secure-support=true --websocket-secure-key-path="<letsencrypt cert dir>/privkey.pem" --websocket-secure-cert-path="<letsencrypt cert dir>/fullchain.pem"

Self-signed certificates

Self-signed certificates are not recommended for production setups because:

• Browsers do not accept self-signed certificates
• Browsers do not display an error when rejecting a certificate for websocket.

However, they can be used for local testing purposes:

mkdir -p ./ssl_dir/
openssl req -x509 -newkey rsa:4096 -keyout ./ssl_dir/key.pem -out ./ssl_dir/cert.pem -sha256 -nodes
wakunode2 --websocket-secure-support=true --websocket-secure-key-path="./ssl_dir/key.pem" --websocket-secure-cert-path="./ssl_dir/cert.pem"