@requestnetwork/request-node

@requestnetwork/request-node is a package part of the Request Network protocol.
This package allows you to run a full Request Node.

Request Nodes are the basic servers used to allow any user to communicate with the Request Network protocol, these servers abstract the complexity of the storage layer for the users. The users can easily create a request or execute an action on a request by sending messages to the Node.

The Request Node runs the two bottom layers of the Request Network protocol:

- Data-access layer: Indexes request transactions and batches them into blocks.
- Storage layers: Persists data from Data-access layer.

Therefore, the Node receives request transactions from users, batches them into blocks and persists them into the storage.

Once received by the Node, other request actors connecting to this Node can directly read the request transaction before it is persisted into the storage layer.

To use Infura to connect to an Ethereum node, get an Infura token on infura.io and
use as provider "NETWORK_YOU_WANT.infura.io/v3/YOUR_INFURA_TOKEN".

Usage

The users can interact with a Request Node either by using the official Client-side Library or by sending manual HTTP requests to the API exposed by the server.

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The API has the following endpoints:

#### persistTransaction

Persists a request transaction and make it available for the other actors of the request.

``
POST /persistTransaction {BODY}
`

##### Body

| Field | Type | Description | Requirement |
| --------------- | -------------- | ------------------------------------------------------------------------------------------- | ------------- |
| transactionData | {data: string} | Data of the request transaction from the transaction layer | Mandatory |
| channelId | string | Channel used to group the transactions, a channel is used to represent a request | Mandatory |
| topics | string[] | Topics to attach to the channel to allows the retrieval of the channel's transactions | Optional |

##### Example

`
curl \
-d '{"channelId": "channelExample", "topics":["topicExample"], "transactionData":{"data": "someData"}}' \
-H "Content-Type: application/json" \
-X POST http://localhost:3000/persistTransaction
`

##### Success 200

| Field | Type | Description |
| ------ | ------ | ------------------------ |
| meta | Object | Metadata of the response |
| result | {} | Empty object |

##### Error

| Code | Description |
| ---- | ------------------------------------------------------ |
| 422 | The input fields of the request are incorrect |
| 500 | The persistTransaction operation from DataAccess fails |

#### getTransactionsByChannelId

Get list of transactions corresponding to a specified channel id.

`
GET /getTransactionsByChannelId?{PARAMETER}
`

##### Parameter

| Field | Type | Description | Requirement |
| ------------------- | -------------------------- | ---------------------------------------------------------------------- | ------------- |
| channelId | string | Channel used to search for transactions | Mandatory |
| timestampBoundaries | {from: number, to: number} | Timestamps to search for transations in a specific temporal boundaries | Optional |

##### Example

`
curl -i "http://localhost:3000/getTransactionsByChannelId?channelId=channelExample"
`

##### Success 200

| Field | Type | Description |
| ------ | ------------------------ | ------------------------ |
| meta | Object | Metadata of the response |
| result | {transactions: string[]} | List of transaction |

##### Error

| Code | Description |
| ---- | -------------------------------------------------------------- |
| 422 | The input fields of the request are incorrect |
| 500 | The getTransactionsByChannelId operation from DataAccess fails |

##### Note

Since the Node doesn't implement a cache yet, all transactions have to be retrieved directly on IPFS.
As a consequence, this request can take a long time if the topic requested indexes many transactions.
This delay will be optimized with the implementation of a cache.

If you experience issues, look into the Graph mode.

#### getChannelsByTopic

Get transactions from channels indexed by a specified topic.

`
GET /getChannelsByTopic?{PARAMETER}
`

##### Parameter

| Field | Type | Description | Requirement |
| -------------- | -------------------------- | ------------------------------------------------------------ | ------------- |
| topic | string | Topic used to search for channels | Mandatory |
| updatedBetween | {from: number, to: number} | Temporal boundaries when the channel has been lately updated | Optional |

##### Example

`
curl -i "http://localhost:3000/getChannelsByTopic?topic=topicExample"
`

##### Success 200

| Field | Type | Description |
| ------ | --------------------------------------- | ------------------------------------------ |
| meta | Object | Metadata of the response |
| result | {transactions: {[channelId]: string[]}} | List of transaction indexed by channel ids |

##### Error

| Code | Description |
| ---- | ------------------------------------------------------ |
| 422 | The input fields of the request are incorrect |
| 500 | The getChannelsByTopic operation from DataAccess fails |

Deployment

A Node can be deployed by anyone. Users interested by running their own node can do it with the following instructions:

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#### Through the npm executable

`bash
npm install -g @requestnetwork/request-node
`

This will allow you to run the node with

`bash
request-node start
`

#### Through the sources

The Request Node source must be downloaded from Github and executed with Node.js.

`bash
git clone https://github.com/RequestNetwork/requestNetwork.git
cd packages/request-node
npm install
npm run build
`

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#### IPFS private network

The Request Node uses IPFS to store and share transactions in a private network.
We use a private network to allow all nodes to connect to each other directly,
instead of having to navigate through the public IPFS network.

To setup your IPFS node to the private network, you can use the request-ipfs docker image. Make sure that docker is installed on your system and then run the following command:

`bash
docker run -p 4001:4001 -p 5001:5001 requestnetwork/request-ipfs
`

This will pull the request-ipfs docker image and run it locally.

#### TheGraph mode

An alternative data access relies on a Graph node, for better indexing & performance.

To enable it, set the GRAPH_NODE_URL environment variable to a Graph node with the Request Storage Subgraph deployed and synced.

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#### Command line

A Request Node can be started locally with the following command:

`bash
npm run start
`

or

`bash
request-node start
`

All command line options are optional.

The options used to run the server are defined as follows:

1. The option is defined in the command line
2. If the option is not defined in the command line, it is defined by the value of its corresponding environment variable
3. If the environment variable is not defined, default value is used

Default values correspond to the basic configuration used to run a server in a test environment.

#### Options:

- --port Port for the server to listen for API requests
- Default value: 3000
- Environment variable name: $PORT
- --networkId Id of the Ethereum network used
- Default value: 0
- Environment variable name: $ETHEREUM_NETWORK_ID
- --providerUrl URL of the web3 provider for Ethereum
- Default value: http://localhost:8545
- Environment variable name: $WEB3_PROVIDER_URL
- --ipfsUrl URL of the IPFS gateway
- Default value: http://localhost:5001
- Environment variable name: $IPFS_URL
- --ipfsTimeout Timeout threshold to connect to the IPFS gateway
- Default value: 10000
- Environment variable name: $IPFS_TIMEOUT
- --blockConfirmations The number of block confirmations to consider a transaction successful
- Default value: 2
- Environment variable name: $BLOCK_CONFIRMATIONS
- --storageConcurrency Maximum number of concurrent calls to Ethereum or IPFS
- Default value: '200'
- Environment variable name: $STORAGE_MAX_CONCURRENCY
- --logLevel The maximum level of messages we will log
- Environment variable name: $LOG_LEVEL
- Available levels: ERROR, WARN, INFO and DEBUG
- --logMode Defines the log format to use
- Environment variable name: $LOG_MODE
- Available modes:
- human is a more human readable log to display during development
- machine is better for parsing on CI or deployments
- --persistTransactionTimeout Defines the delay in seconds to wait before sending a timeout when creating or updating a request
- Default value: 600
- Environment variable name: $PERSIST_TRANSACTION_TIMEOUT
- --externalUrl External url of the node (used to identified where the buffer data are stored before being broadcasted on ethereum)
- Environment variable name: $EXTERNAL_URL
- --graphNodeUrl External url of the Graph node, if any. If specified, this will replace the traditional data access with the Graph implementation. Default is undefined. See TheGraph mode.
- Environment variable name: $GRAPH_NODE_URL

#### Mnemonic

The wallet used to append data into Ethereum blockchain is generated with a mnemonic.

The environment variable $MNEMONIC need to be set to the corresponding mnemonic.

If the environment variable is not set, the default mnemonic is:

`
candy maple cake sugar pudding cream honey rich smooth crumble sweet treat
`

This mnemonic should only be used for testing.

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The Request Node can be deployed with Docker.
The Docker image is available on the DockerHub.
Please refer to the RequestNetwork/docker-images repository
for instructions on how to use this image.

#### Docker for unpublished version

See instructions in Dockerfile.dev.

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To run a Request Node locally for tests, make sure you have the necessary IPFS and Ethereum nodes available.

You can run the following steps to launch a fully local test Request Node:

#### 1. Clone the repository

`bash
git clone https://github.com/RequestNetwork/requestNetwork.git
cd requestNetwork
`

#### 2. Install and build all the dependencies.

`bash
yarn install
yarn build
`

#### 3. On a new terminal, launch a local IPFS node

Make sure the Docker is installed.

`bash
docker run -p 4001:4001 -p 5001:5001 requestnetwork/request-ipfs
`

#### 4. Launch ganache with the default Request Node mnemonic

`bash
ganache-cli -l 90000000 -p 8545 -m \"candy maple cake sugar pudding cream honey rich smooth crumble sweet treat\"
`

#### 5. Deploy the smart contracts on ganache

`bash
cd packages/smart-contracts
yarn deploy
`

#### 6. Run the Request Node

`bash
cd ../packages/request-node
yarn start
``

#### 7. Test

Open a browser and navigate towards: http://localhost:3000/status
You can see the details of your local Request & IPFS nodes.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.
Read the contributing guide

License

MIT