nim-codex/README.md

# Codex Decentralized Durability Engine

> The Codex project aims to create a decentralized durability engine that allows persisting data in p2p networks. In other words, it allows storing files and data with predictable durability guarantees for later retrieval.

> WARNING: This project is under active development and is considered pre-alpha.

[![License: Apache](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)
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[![Stability: experimental](https://img.shields.io/badge/stability-experimental-orange.svg)](#stability)
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## Build and Run

For detailed instructions on preparing to build nim-codex see [*Building Codex*](BUILDING.md).

To build the project, clone it and run:

```bash
make update && make
```

The executable will be placed under the `build` directory under the project root.

Run the client with:

```bash
build/codex
```
## Configuration

It is possible to configure a Codex node in several ways:
 1. CLI options
 2. Env. variable
 3. Config

The order of priority is the same as above: Cli arguments > Env variables > Config file values.

### Environment variables

In order to set a configuration option using environment variables, first find the desired CLI option
and then transform it in the following way:

 1. prepend it with `CODEX_`
 2. make it uppercase
 3. replace `-` with `_`

For example, to configure `--log-level`, use `CODEX_LOG_LEVEL` as the environment variable name.

### Configuration file

A [TOML](https://toml.io/en/) configuration file can also be used to set configuration values. Configuration option names and corresponding values are placed in the file, separated by `=`. Configuration option names can be obtained from the `codex --help` command, and should not include the `--` prefix. For example, a node's log level (`--log-level`) can be configured using TOML as follows:

```toml
log-level = "trace"
```

The Codex node can then read the configuration from this file using the `--config-file` CLI parameter, like `codex --config-file=/path/to/your/config.toml`.

### CLI Options

```
build/codex --help
Usage:

codex [OPTIONS]... command

The following options are available:

     --config-file          Loads the configuration from a TOML file [=none].
     --log-level            Sets the log level [=info].
     --metrics              Enable the metrics server [=false].
     --metrics-address      Listening address of the metrics server [=127.0.0.1].
     --metrics-port         Listening HTTP port of the metrics server [=8008].
 -d, --data-dir             The directory where codex will store configuration and data..
 -i, --listen-addrs         Multi Addresses to listen on [=/ip4/0.0.0.0/tcp/0].
 -a, --nat                  IP Addresses to announce behind a NAT [=127.0.0.1].
 -e, --disc-ip              Discovery listen address [=0.0.0.0].
 -u, --disc-port            Discovery (UDP) port [=8090].
     --net-privkey          Source of network (secp256k1) private key file path or name [=key].
 -b, --bootstrap-node       Specifies one or more bootstrap nodes to use when connecting to the network..
     --max-peers            The maximum number of peers to connect to [=160].
     --agent-string         Node agent string which is used as identifier in network [=Codex].
     --api-bindaddr         The REST API bind address [=127.0.0.1].
 -p, --api-port             The REST Api port [=8080].
     --repo-kind            backend for main repo store (fs, sqlite) [=fs].
 -q, --storage-quota        The size of the total storage quota dedicated to the node [=8589934592].
 -t, --block-ttl            Default block timeout in seconds - 0 disables the ttl [=$DefaultBlockTtl].
     --block-mi             Time interval in seconds - determines frequency of block maintenance cycle: how
                            often blocks are checked for expiration and cleanup.
                            [=$DefaultBlockMaintenanceInterval].
     --block-mn             Number of blocks to check every maintenance cycle. [=1000].
 -c, --cache-size           The size in MiB of the block cache, 0 disables the cache - might help on slow
                            hardrives [=0].
     --persistence          Enables persistence mechanism, requires an Ethereum node [=false].
     --eth-provider         The URL of the JSON-RPC API of the Ethereum node [=ws://localhost:8545].
     --eth-account          The Ethereum account that is used for storage contracts [=EthAddress.none].
     --eth-deployment       The json file describing the contract deployment [=string.none].
     --validator            Enables validator, requires an Ethereum node [=false].
     --validator-max-slots  Maximum number of slots that the validator monitors [=1000].

Available sub-commands:

codex initNode
```

#### Logging

Codex uses [Chronicles](https://github.com/status-im/nim-chronicles) logging library, which allows great flexibility in working with logs.
Chronicles has the concept of topics, which categorize log entries into semantic groups.

Using the `log-level` parameter, you can set the top-level log level like `--log-level="trace"`, but more importantly,
you can set log levels for specific topics like `--log-level="info; trace: marketplace,node; error: blockexchange"`,
which sets the top-level log level to `info` and then for topics `marketplace` and `node` sets the level to `trace` and so on.

### Example: running two Codex clients

To get acquainted with Codex, consider running the manual two-client test described [HERE](docs/TWOCLIENTTEST.md).

## API

The client exposes a REST API that can be used to interact with the clients. Overview of the API can be found on [api.codex.storage](https://api.codex.storage).