Memory Resolver Tutorial

    The basic configuration for the server requires:

    • The operator JWT
    • resolver set to MEMORY
    • resolver_preload set to an object where account public keys are mapped to account JWTs.

    Let’s create the setup:

    Output

    1. Generated operator key - private key stored "~/.nkeys/memory/memory.nk"
    2. Success! - added operator "memory"

    Add an account ‘A’

    1. nsc add account --name A

    Output

    1. Generated account key - private key stored "~/.nkeys/memory/accounts/A/A.nk"
    2. Success! - added account "A"

    Output

    1. ╭──────────────────────────────────────────────────────────────────────────────────────╮
    2. │                                   Account Details                                    │
    3. ├───────────────────────────┬──────────────────────────────────────────────────────────┤
    4. │ Name                      │ A                                                        │
    5. │ Account ID                │ ACSU3Q6LTLBVLGAQUONAGXJHVNWGSKKAUA7IY5TB4Z7PLEKSR5O6JTGR │
    6. │ Issued                    │ 2019-04-30 20:21:34 UTC                                  │
    7. │ Expires                   │                                                          │
    8. ├───────────────────────────┼──────────────────────────────────────────────────────────┤
    10. │ Max Leaf Node Connections │ Unlimited                                                │
    11. │ Max Data                  │ Unlimited                                                │
    12. │ Max Exports               │ Unlimited                                                │
    13. │ Max Imports               │ Unlimited                                                │
    14. │ Max Msg Payload           │ Unlimited                                                │
    15. │ Max Subscriptions         │ Unlimited                                                │
    16. │ Exports Allows Wildcards  │ True                                                     │
    17. ├───────────────────────────┼──────────────────────────────────────────────────────────┤
    18. │ Imports                   │ None                                                     │
    19. │ Exports                   │ None                                                     │
    20. ╰───────────────────────────┴──────────────────────────────────────────────────────────╯

    Create a new user ‘TA’

    1. nsc add user --name TA

    Output

    1. Generated user key - private key stored "~/.nkeys/memory/accounts/A/users/TA.nk"
    2. Success! - added user "TA" to "A"

    The nsc tool can generate a configuration file automatically. You provide a path to the server configuration. The nsc tool will generate the server config for you:

    If you require additional settings, you may want to consider using in your main configuration, to reference the generated files. Otherwise, you can start a server and reference the generated configuration:

    1. nats-server -c /tmp/server.conf

    While generating a configuration file is easy, you may want to craft one by hand to know the details. With the entities created, and a standard location for the .nsc directory. You can reference the operator JWT and the account JWT in a server configuration or the JWT string directly. Remember that your configuration will be in $NSC_HOME/nats/<operator_name>/<operator_name>.jwt for the operator. The account JWT will be in $NSC_HOME/nats/<operator_name>/accounts/<account_name>/<account_name>.jwt

    For the configuration you’ll need:

    • The path to the operator JWT
    • A copy of the contents of the account JWT file

    The format of the file is:

    1. operator: <path to the operator jwt or jwt itself>
    2. resolver: MEMORY
    3. resolver_preload: {
    4.     <public key for an account>: <contents of the account jwt>
    5.     ### add as many accounts as you want
    6.     ...
    7. }

    In this example this translates to:

    1. operator: /Users/synadia/.nsc/nats/memory/memory.jwt
    2. resolver: MEMORY
    3. resolver_preload: {
    4. ACSU3Q6LTLBVLGAQUONAGXJHVNWGSKKAUA7IY5TB4Z7PLEKSR5O6JTGR: eyJ0eXAiOiJqd3QiLCJhbGciOiJlZDI1NTE5In0.eyJqdGkiOiJPRFhJSVI2Wlg1Q1AzMlFJTFczWFBENEtTSDYzUFNNSEZHUkpaT05DR1RLVVBISlRLQ0JBIiwiaWF0IjoxNTU2NjU1Njk0LCJpc3MiOiJPRFdaSjJLQVBGNzZXT1dNUENKRjZCWTRRSVBMVFVJWTRKSUJMVTRLM1lERzNHSElXQlZXQkhVWiIsIm5hbWUiOiJBIiwic3ViIjoiQUNTVTNRNkxUTEJWTEdBUVVPTkFHWEpIVk5XR1NLS0FVQTdJWTVUQjRaN1BMRUtTUjVPNkpUR1IiLCJ0eXBlIjoiYWNjb3VudCIsIm5hdHMiOnsibGltaXRzIjp7InN1YnMiOi0xLCJjb25uIjotMSwibGVhZiI6LTEsImltcG9ydHMiOi0xLCJleHBvcnRzIjotMSwiZGF0YSI6LTEsInBheWxvYWQiOi0xLCJ3aWxkY2FyZHMiOnRydWV9fX0._WW5C1triCh8a4jhyBxEZZP8RJ17pINS8qLzz-01o6zbz1uZfTOJGvwSTS6Yv2_849B9iUXSd-8kp1iMXHdoBA
    5. }

    Save the config at server.conf and start the server:

    To test the configuration, simply use one of the standard tools:

    1. nats pub --creds ~/.nkeys/creds/memory/A/TA.creds hello world