# Basics

Basic configuration revolves around 4 settings:

* The store to read JWTs from
* The HTTP/S configuration
* NATS \(for cases where updates are enabled\)
* Logging

For complete information on please refer to the project's [Github](https://github.com/nats-io/nats-account-server).

## `nsc` Configuration

For a basic usage of the server you can specify the `-nsc` flag, and specify the path to an operator in your environment.

> If you have not yet created an operator or accounts, you'll need to do so before continuing. See [NSC](../nsc/)

You can easily locate the path by running `nsc env` to print your `nsc` settings:

```text
> nsc env
╭──────────────────────────────────────────╮
│             NSC Environment              │
├──────────────────┬─────┬─────────────────┤
│ Setting          │ Set │ Effective Value │
├──────────────────┼─────┼─────────────────┤
│ $NKEYS_PATH      │ No  │ ~/.nkeys        │
│ $NSC_HOME        │ No  │ ~/.nsc          │
│ Config           │     │ ~/.nsc/nsc.json │
├──────────────────┼─────┼─────────────────┤
│ Stores Dir       │     │ ~/.nsc/nats     │
│ Default Operator │     │ Test            │
│ Default Account  │     │ TestAccount     │
│ Default Cluster  │     │                 │
╰──────────────────┴─────┴─────────────────╯
```

The path you are interested in the `Stores Dir`. This is the root of all operators, you'll also need the name of your operator. If your current operator is not listed, you can list all your available operators by doing:

```text
> nsc list operators
```

To start the `nats-account-server` with the operator `Test`:

```text
> nats-account-server -nsc ~/.nsc/nats/Test
2019/05/10 11:22:41.845148 [INF] starting NATS Account server, version 0.0-dev
2019/05/10 11:22:41.845241 [INF] server time is Fri May 10 11:22:41 CDT 2019
2019/05/10 11:22:41.845245 [INF] loading operator from /Users/synadia/.nsc/nats/Test/Test.jwt
2019/05/10 11:22:41.846367 [INF] creating a read-only store for the NSC folder at /Users/synadia/.nsc/nats/Test
2019/05/10 11:22:41.846459 [INF] NATS is not configured, server will not fire notifications on update
2019/05/10 11:22:41.855291 [INF] http listening on port 9090
2019/05/10 11:22:41.855301 [INF] nats-account-server is running
2019/05/10 11:22:41.855303 [INF] configure the nats-server with:
2019/05/10 11:22:41.855306 [INF]   resolver: URL(http://localhost:9090/jwt/v1/accounts/)
```

By default the server will serve JWTs on the localhost at port 9090. The last line in the shown in the printout is important, that is the resolver URL you'll have to provide on your NATS server configuration. You'll also need the matching operator JWT which is on `~/.nsc/nats/Test/Test.jwt` if you are following the example above. On the server configuration you'll need to expand the `~` as necessary. Here's what my NATS server configuration looks like:

```text
operator: /Users/synadia/.nsc/nats/Test/Test.jwt
resolver: URL(http://localhost:9090/jwt/v1/accounts/)
```

Note that servers you create with the `-nsc` option \(or store option\) are read-only. This means that the server will not accept POST requests to update the JWT store.

## Directory Configuration

You can start a server using a plain directory. In this case you'll be responsible for adding any JWT that you want resolved.

> The server looks for account JWTs by using the public key of the account as the file name followed by the extension `.jwt`. The server will not introspect the JWTs, so if you don't name the files correctly, it will fail to find them or serve a JWT that doesn't match the requested account.

```text
> mkdir /tmp/jwts
nats-account-server -dir /tmp/jwts
2019/05/10 11:33:40.501305 [INF] starting NATS Account server, version 0.0-dev
2019/05/10 11:33:40.501383 [INF] server time is Fri May 10 11:33:40 CDT 2019
2019/05/10 11:33:40.501404 [INF] creating a store at /tmp/jwts
2019/05/10 11:33:40.501430 [INF] NATS is not configured, server will not fire notifications on update
2019/05/10 11:33:40.510273 [INF] http listening on port 9090
2019/05/10 11:33:40.510283 [INF] nats-account-server is running
2019/05/10 11:33:40.510285 [INF] configure the nats-server with:
2019/05/10 11:33:40.510291 [INF]   resolver: URL(http://localhost:9090/jwt/v1/accounts/)
```

Configuration for the NATS server is the same as in the previous example:

```text
operator: /Users/synadia/.nsc/nats/Test/Test.jwt
resolver: URL(http://localhost:9090/jwt/v1/accounts/)
```

A step by step tutorial using directory configuration can be found [here](dir_store.md).

## Configuration File

While the `-nsc` and `-dir` store flags are sufficient for some very simple developer setups, any production or non-read-only server will require a configuration file.

Let's take a look at the configuration options:

### Configuration Options

| Option | Description |
| :--- | :--- |
| `http` | An `http` configuration block specifying HTTP options. |
| `logging` | A `logging` configuration block specifying server logging options. |
| `nats` | A `nats` configuration block specifying NATS connection information for the account server to push JWT changes to a NATS server. |
| `operatorjwtpath` | The path to an operator JWT. Required for non-read-only servers. Only JWTs signed by the operator \(or one of it's signing keys\) are accepted. |
| `store` | A `store` configuration block specifying store options. |
| `systemaccountjwtpath` | Path to an Account JWT that should be returned as the system account. |
| `primary` | URL for the primary, `protocol://host:port`. |
| `replicationtimeout` | Timeout, in milliseconds, used by the replica when talking to the primary, defaults to `5000`. |

### `store` Configuration

| Option | Description |
| :--- | :--- |
| `dir` | Configures a directory as a store. |
| `nsc` | Configures an nsc read-only store. The value should be the path to an operator _directory_. Option is mutually exclusive with `dir`. |
| `readonly` | If `true`, the store will not accept POST requests. Note that to receive requests, the store must also have `operatorjwtpath` specified as a root option. |
| `shard` | If `true`, JWTs are shared in the store directory. |

## `logging` Options

| Option | Description |
| :--- | :--- |
| `time` | If `true`, a timestamp is added to log messages. |
| `debug` | If `true`, debug messages are logged. |
| `trace` | If `true`, trace messages are logged. |
| `colors` | If `true`, messages are logged using ANSI color escape sequences. |
| `pid` | If `true`, the process id for the server is added to log messages. |

## `http` Options

| Option | Description |
| :--- | :--- |
| `host` | Interface to listen for requests on. |
| `port` | Port to listen for requests on. |
| `readtimeout` | Max amount of time in milliseconds to wait for a http read operation to complete. |
| `writetimeout` | Max amount of time in milliseconds to wait for a http write operation to complete. |

## `nats` Options

| Option | Description |
| :--- | :--- |
| `servers` | List of NATS servers for the account server to use when connecting to a NATS server to publish updates. |
| `connecttimeout` | Max amount of time in milliseconds to wait for a NATS connection. |
| `reconnecttimewait` | Amount of time in milliseconds to between NATS server reconnect attempts. |
| `tls` | A `tls` configuration block. |
| `usercredentials` | A credentials _creds_ file for connecting to the NATS server. Account must be a member of a system account. |

## `tls` Options

| Option | Description |
| :--- | :--- |
| `root` | filepath to the CA certificate. |
| `cert` | filepath to the certificate. |
| `cert` | filepath to the certificate key. |

## Example Setup

Provided a setup with 4 accounts, one of them a system account, this example shows how to set up the account server by:

* adding the account server to the operator
* configuring the account server
* push the accounts to the account server
* configure a `nats-server` to make use of the account server
* test the setup

```bash
$ export NKEYS_PATH=$(pwd)/nsc/nkeys
$ export NSC_HOME=$(pwd)/nsc/accounts

# Setup script that creates a few sample accounts and a system account
$ curl -sSL https://nats-io.github.io/k8s/setup/nsc-setup.sh | sh

$ nsc list accounts
╭─────────────────────────────────────────────────────────────────╮
│                            Accounts                             │
├──────┬──────────────────────────────────────────────────────────┤
│ Name │ Public Key                                               │
├──────┼──────────────────────────────────────────────────────────┤
│ A    │ AA6LOQIZRKEAC5FUGLMZHAXERZRQFAFQOO7YC6ZMQ325BYUAEPDUEIV5 │
│ B    │ ACPD2M7QFV33HPPY563PI7C664LXG2YVWXQBB6EAHDXZR7EK7L52AWUG │
│ STAN │ ABD4DPO745A5U2JKPWCI7LFGW4UCTN5LPUXDA5BCMXEYWLCU7J346NGU │
│ SYS  │ AB25DCM6BL5SDWYR45F65MSVOVXATN64AZXGI7IGS3IXBPWWDB4FIR2H │
╰──────┴──────────────────────────────────────────────────────────╯

# Add the endpoint for the account server to which accounts can be published
$ nsc edit operator --account-jwt-server-url http://localhost:9090/jwt/v1/ --service-url nats://localhost:4222

# Generate account server config that references the operator jwt
$ echo '
operatorjwtpath: "./nsc/accounts/nats/KO/KO.jwt"

http {
    port: 9090
}
' > nats-account-server.conf

# Start the account server
$ nats-account-server -c nats-account-server.conf &

# Upload the local accounts in the nsc directory structure
$ nsc push -A

# Generate the NATS Server config that points to the account server
$ echo '
operator: "./nsc/accounts/nats/KO/KO.jwt"
resolver: URL(http://localhost:9090/jwt/v1/accounts/)
system_account: AB25DCM6BL5SDWYR45F65MSVOVXATN64AZXGI7IGS3IXBPWWDB4FIR2H
' > nats-server.conf

# Start the NATS Server in trusted operator mode
$ nats-server -c nats-server.conf &

# Try to subscribe on account without permissions, this should fail
$ nats-sub -creds nsc/nkeys/creds/KO/A/test.creds foo
nats: Permissions Violation for Subscription to "foo"

# Subscribe then publish to subject should work on 'test' since enough permissions
$ nats-sub -creds nsc/nkeys/creds/KO/A/test.creds test &
Listening on [test]

# Published message on 'test' subject would be received by started subscriber above
$ nats-pub -creds nsc/nkeys/creds/KO/A/test.creds test foo &
Listening on [test]

# Subscribe using the system account user credentials can receive all system events
$ nats-sub -creds nsc/nkeys/creds/KO/SYS/sys.creds '>'
```