plugeth/swarm
Felix Lange 30cd5c1854
all: new p2p node representation (#17643)
Package p2p/enode provides a generalized representation of p2p nodes
which can contain arbitrary information in key/value pairs. It is also
the new home for the node database. The "v4" identity scheme is also
moved here from p2p/enr to remove the dependency on Ethereum crypto from
that package.

Record signature handling is changed significantly. The identity scheme
registry is removed and acceptable schemes must be passed to any method
that needs identity. This means records must now be validated explicitly
after decoding.

The enode API is designed to make signature handling easy and safe: most
APIs around the codebase work with enode.Node, which is a wrapper around
a valid record. Going from enr.Record to enode.Node requires a valid
signature.

* p2p/discover: port to p2p/enode

This ports the discovery code to the new node representation in
p2p/enode. The wire protocol is unchanged, this can be considered a
refactoring change. The Kademlia table can now deal with nodes using an
arbitrary identity scheme. This requires a few incompatible API changes:

  - Table.Lookup is not available anymore. It used to take a public key
    as argument because v4 protocol requires one. Its replacement is
    LookupRandom.
  - Table.Resolve takes *enode.Node instead of NodeID. This is also for
    v4 protocol compatibility because nodes cannot be looked up by ID
    alone.
  - Types Node and NodeID are gone. Further commits in the series will be
    fixes all over the the codebase to deal with those removals.

* p2p: port to p2p/enode and discovery changes

This adapts package p2p to the changes in p2p/discover. All uses of
discover.Node and discover.NodeID are replaced by their equivalents from
p2p/enode.

New API is added to retrieve the enode.Node instance of a peer. The
behavior of Server.Self with discovery disabled is improved. It now
tries much harder to report a working IP address, falling back to
127.0.0.1 if no suitable address can be determined through other means.
These changes were needed for tests of other packages later in the
series.

* p2p/simulations, p2p/testing: port to p2p/enode

No surprises here, mostly replacements of discover.Node, discover.NodeID
with their new equivalents. The 'interesting' API changes are:

 - testing.ProtocolSession tracks complete nodes, not just their IDs.
 - adapters.NodeConfig has a new method to create a complete node.

These changes were needed to make swarm tests work.

Note that the NodeID change makes the code incompatible with old
simulation snapshots.

* whisper/whisperv5, whisper/whisperv6: port to p2p/enode

This port was easy because whisper uses []byte for node IDs and
URL strings in the API.

* eth: port to p2p/enode

Again, easy to port because eth uses strings for node IDs and doesn't
care about node information in any way.

* les: port to p2p/enode

Apart from replacing discover.NodeID with enode.ID, most changes are in
the server pool code. It now deals with complete nodes instead
of (Pubkey, IP, Port) triples. The database format is unchanged for now,
but we should probably change it to use the node database later.

* node: port to p2p/enode

This change simply replaces discover.Node and discover.NodeID with their
new equivalents.

* swarm/network: port to p2p/enode

Swarm has its own node address representation, BzzAddr, containing both
an overlay address (the hash of a secp256k1 public key) and an underlay
address (enode:// URL).

There are no changes to the BzzAddr format in this commit, but certain
operations such as creating a BzzAddr from a node ID are now impossible
because node IDs aren't public keys anymore.

Most swarm-related changes in the series remove uses of
NewAddrFromNodeID, replacing it with NewAddr which takes a complete node
as argument. ToOverlayAddr is removed because we can just use the node
ID directly.
2018-09-25 00:59:00 +02:00
..
api all: new p2p node representation (#17643) 2018-09-25 00:59:00 +02:00
bmt swarm/network, swarm/storage: validate chunk size (#17397) 2018-08-14 16:03:56 +02:00
chunk swarm/network, swarm/storage: validate chunk size (#17397) 2018-08-14 16:03:56 +02:00
dev swarm: bzz-list, bzz-raw and bzz-immutable schemes (#15667) 2017-12-19 10:49:30 +02:00
fuse swarm: Chunk refactor (#17659) 2018-09-13 11:42:19 +02:00
grafana_dashboards swarm: network rewrite merge 2018-06-21 21:10:31 +02:00
log swarm: network rewrite merge 2018-06-21 21:10:31 +02:00
metrics swarm: ctx propagation; bmt fixes; pss generic notification framework (#17150) 2018-07-09 14:11:49 +02:00
multihash swarm: network rewrite merge 2018-06-21 21:10:31 +02:00
network all: new p2p node representation (#17643) 2018-09-25 00:59:00 +02:00
pot all: fix various comment typos (#17591) 2018-09-19 18:10:40 +02:00
pss all: new p2p node representation (#17643) 2018-09-25 00:59:00 +02:00
sctx cmd/swarm, swarm: added access control functionality (#17404) 2018-08-15 17:41:52 +02:00
services/swap swarm: network rewrite merge 2018-06-21 21:10:31 +02:00
spancontext swarm: integrate OpenTracing; propagate ctx to internal APIs (#17169) 2018-07-13 17:40:28 +02:00
state swarm: network rewrite merge 2018-06-21 21:10:31 +02:00
storage all: new p2p node representation (#17643) 2018-09-25 00:59:00 +02:00
testutil cmd/swarm: added password to ACT (#17598) 2018-09-07 09:56:05 +02:00
tracing swarm: integrate OpenTracing; propagate ctx to internal APIs (#17169) 2018-07-13 17:40:28 +02:00
version params, swarm: begin Geth v1.8.17, Swarm v0.3.5 cycle 2018-09-24 16:02:07 +03:00
AUTHORS swarm: network rewrite merge 2018-06-21 21:10:31 +02:00
network_test.go all: new p2p node representation (#17643) 2018-09-25 00:59:00 +02:00
OWNERS swarm: network rewrite merge 2018-06-21 21:10:31 +02:00
README.md swarm/README: add more sections to easily onboard developers (#17333) 2018-08-07 12:56:01 +02:00
state.go swarm: network rewrite merge 2018-06-21 21:10:31 +02:00
swarm_test.go swarm: Chunk refactor (#17659) 2018-09-13 11:42:19 +02:00
swarm.go all: new p2p node representation (#17643) 2018-09-25 00:59:00 +02:00

Swarm

https://swarm.ethereum.org

Swarm is a distributed storage platform and content distribution service, a native base layer service of the ethereum web3 stack. The primary objective of Swarm is to provide a decentralized and redundant store for dapp code and data as well as block chain and state data. Swarm is also set out to provide various base layer services for web3, including node-to-node messaging, media streaming, decentralised database services and scalable state-channel infrastructure for decentralised service economies.

Travis Gitter

Table of Contents

Building the source

Building Swarm requires Go (version 1.10 or later).

go get -d github.com/ethereum/go-ethereum

go install github.com/ethereum/go-ethereum/cmd/swarm

Running Swarm

Going through all the possible command line flags is out of scope here, but we've enumerated a few common parameter combos to get you up to speed quickly on how you can run your own Swarm node.

To run Swarm you need an Ethereum account. You can create a new account by running the following command:

geth account new

You will be prompted for a password:

Your new account is locked with a password. Please give a password. Do not forget this password.
Passphrase:
Repeat passphrase:

Once you have specified the password, the output will be the Ethereum address representing that account. For example:

Address: {2f1cd699b0bf461dcfbf0098ad8f5587b038f0f1}

Using this account, connect to Swarm with

swarm --bzzaccount <your-account-here>

# in our example

swarm --bzzaccount 2f1cd699b0bf461dcfbf0098ad8f5587b038f0f1

Verifying that your local Swarm node is running

When running, Swarm is accessible through an HTTP API on port 8500.

Confirm that it is up and running by pointing your browser to http://localhost:8500

Ethereum Name Service resolution

The Ethereum Name Service is the Ethereum equivalent of DNS in the classic web. In order to use ENS to resolve names to Swarm content hashes (e.g. bzz://theswarm.eth), swarm has to connect to a geth instance, which is synced with the Ethereum mainnet. This is done using the --ens-api flag.

swarm --bzzaccount <your-account-here> \
      --ens-api '$HOME/.ethereum/geth.ipc'

# in our example

swarm --bzzaccount 2f1cd699b0bf461dcfbf0098ad8f5587b038f0f1 \
      --ens-api '$HOME/.ethereum/geth.ipc'

For more information on usage, features or command line flags, please consult the Documentation.

Documentation

Swarm documentation can be found at https://swarm-guide.readthedocs.io.

Developers Guide

Go Environment

We assume that you have Go v1.10 installed, and GOPATH is set.

You must have your working copy under $GOPATH/src/github.com/ethereum/go-ethereum.

Most likely you will be working from your fork of go-ethereum, let's say from github.com/nirname/go-ethereum. Clone or move your fork into the right place:

git clone git@github.com:nirname/go-ethereum.git $GOPATH/src/github.com/ethereum/go-ethereum

Vendored Dependencies

All dependencies are tracked in the vendor directory. We use govendor to manage them.

If you want to add a new dependency, run govendor fetch <import-path>, then commit the result.

If you want to update all dependencies to their latest upstream version, run govendor fetch +v.

Testing

This section explains how to run unit, integration, and end-to-end tests in your development sandbox.

Testing one library:

go test -v -cpu 4 ./swarm/api

Note: Using options -cpu (number of cores allowed) and -v (logging even if no error) is recommended.

Testing only some methods:

go test -v -cpu 4 ./eth -run TestMethod

Note: here all tests with prefix TestMethod will be run, so if you got TestMethod, TestMethod1, then both!

Running benchmarks:

go test -v -cpu 4 -bench . -run BenchmarkJoin

Profiling Swarm

This section explains how to add Go pprof profiler to Swarm

If swarm is started with the --pprof option, a debugging HTTP server is made available on port 6060.

You can bring up http://localhost:6060/debug/pprof to see the heap, running routines etc.

By clicking full goroutine stack dump (clicking http://localhost:6060/debug/pprof/goroutine?debug=2) you can generate trace that is useful for debugging.

Metrics and Instrumentation in Swarm

This section explains how to visualize and use existing Swarm metrics and how to instrument Swarm with a new metric.

Swarm metrics system is based on the go-metrics library.

The most common types of measurements we use in Swarm are counters and resetting timers. Consult the go-metrics documentation for full reference of available types.

# incrementing a counter
metrics.GetOrRegisterCounter("network.stream.received_chunks", nil).Inc(1)

# measuring latency with a resetting timer
start := time.Now()
t := metrics.GetOrRegisterResettingTimer("http.request.GET.time"), nil)
...
t := UpdateSince(start)

Visualizing metrics

Swarm supports an InfluxDB exporter. Consult the help section to learn about the command line arguments used to configure it:

swarm --help | grep metrics

We use Grafana and InfluxDB to visualise metrics reported by Swarm. We keep our Grafana dashboards under version control at ./swarm/grafana_dashboards. You could use them or design your own.

We have built a tool to help with automatic start of Grafana and InfluxDB and provisioning of dashboards at https://github.com/nonsense/stateth , which requires that you have Docker installed.

Once you have stateth installed, and you have Docker running locally, you have to:

  1. Run stateth and keep it running in the background
stateth --rm --grafana-dashboards-folder $GOPATH/src/github.com/ethereum/go-ethereum/swarm/grafana_dashboards --influxdb-database metrics
  1. Run swarm with at least the following params:
--metrics \
--metrics.influxdb.export \
--metrics.influxdb.endpoint "http://localhost:8086" \
--metrics.influxdb.username "admin" \
--metrics.influxdb.password "admin" \
--metrics.influxdb.database "metrics"
  1. Open Grafana at http://localhost:3000 and view the dashboards to gain insight into Swarm.

Public Gateways

Swarm offers a local HTTP proxy API that Dapps can use to interact with Swarm. The Ethereum Foundation is hosting a public gateway, which allows free access so that people can try Swarm without running their own node.

The Swarm public gateways are temporary and users should not rely on their existence for production services.

The Swarm public gateway can be found at https://swarm-gateways.net and is always running the latest stable Swarm release.

Swarm Dapps

You can find a few reference Swarm decentralised applications at: https://swarm-gateways.net/bzz:/swarmapps.eth

Their source code can be found at: https://github.com/ethersphere/swarm-dapps

Contributing

Thank you for considering to help out with the source code! We welcome contributions from anyone on the internet, and are grateful for even the smallest of fixes!

If you'd like to contribute to Swarm, please fork, fix, commit and send a pull request for the maintainers to review and merge into the main code base. If you wish to submit more complex changes though, please check up with the core devs first on our Swarm gitter channel to ensure those changes are in line with the general philosophy of the project and/or get some early feedback which can make both your efforts much lighter as well as our review and merge procedures quick and simple.

Please make sure your contributions adhere to our coding guidelines:

  • Code must adhere to the official Go formatting guidelines (i.e. uses gofmt).
  • Code must be documented adhering to the official Go commentary guidelines.
  • Pull requests need to be based on and opened against the master branch.
  • Code review guidelines.
  • Commit messages should be prefixed with the package(s) they modify.
    • E.g. "swarm/fuse: ignore default manifest entry"

License

The go-ethereum library (i.e. all code outside of the cmd directory) is licensed under the GNU Lesser General Public License v3.0, also included in our repository in the COPYING.LESSER file.

The go-ethereum binaries (i.e. all code inside of the cmd directory) is licensed under the GNU General Public License v3.0, also included in our repository in the COPYING file.