nats.docs/nats-tools/nas/nas_conf.md

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, please refer to the project's Github.

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.

> 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:

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.

Configuration File

While the -dir store flag is 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.
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 will be stored in multiple sub directories of 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

$ 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 '>'