Enabling System Events with Decentralized Authentication/Authorization
To enable and access system events, you'll have to:
Create an Operator, Account and User
Run a NATS Account Server (or Memory Resolver)
Create an Operator, Account, User
Let's create an operator, system account and system account user:
复制 # Create an operator if you
> nsc add operator -n SAOP
Generated operator key - private key stored "~/.nkeys/SAOP/SAOP.nk"
Success! - added operator "SAOP"
# Add the system account
> nsc add account -n SYS
Generated account key - private key stored "~/.nkeys/SAOP/accounts/SYS/SYS.nk"
Success! - added account "SYS"
# Add a system account user
> nsc add user -n SYSU
Generated user key - private key stored "~/.nkeys/SAOP/accounts/SYS/users/SYSU.nk"
Generated user creds file "~/.nkeys/SAOP/accounts/SYS/users/SYSU.creds"
Success! - added user "SYSU" to "SYS" By default, the operator JWT can be found in ~/.nsc/nats/<operator_name>/<operator.name>.jwt.
NATS-Account-Server
复制 > nats-account-server -nsc ~/.nsc/nats/SAOP The server will by default vend JWT configurations on the an endpoint at: http(s)://<server_url>/jwt/v1/accounts/.
NATS Server Configuration
The server configuration will need:
The operator JWT - (~/.nsc/nats/<operator_name>/<operator.name>.jwt)
The URL where the server can resolve accounts (http://localhost:9090/jwt/v1/accounts/)
The public key of the system_account
The only thing we don't have handy is the public key for the system account. We can get it easy enough:
复制 > nsc list accounts
╭─────────────────────────────────────────────────────────────────╮
│ Accounts │
├──────┬──────────────────────────────────────────────────────────┤
│ Name │ Public Key │
├──────┼──────────────────────────────────────────────────────────┤
│ SYS │ ADWJVSUSEVC2GHL5GRATN2LOEOQOY2E6Z2VXNU3JEIK6BDGPWNIW3AXF │
╰──────┴──────────────────────────────────────────────────────────╯ Because the server has additional resolver implementations, you need to enclose the server url like: URL(<url>).
Let's create server config with the following contents and save it to server.conf:
复制 operator: /Users/synadia/.nsc/nats/SAOP/SAOP.jwt
system_account: ADWJVSUSEVC2GHL5GRATN2LOEOQOY2E6Z2VXNU3JEIK6BDGPWNIW3AXF
resolver: URL(http://localhost:9090/jwt/v1/accounts/) Let's start the nats-server:
复制 > nats-server -c server.conf Inspecting Server Events
Let's add a subscriber for all the events published by the system account:
复制 > nats-sub -creds ~/.nkeys/SAOP/accounts/SYS/users/SYSU.creds ">" Very quickly we'll start seeing messages from the server as they are published by the NATS server. As should be expected, the messages are just JSON, so they can easily be inspected even if just using a simple nats-sub to read them.
To see an an account update:
复制 > nats-pub -creds ~/.nkeys/SAOP/accounts/SYS/users/SYSU.creds foo bar The subscriber will print the connect and disconnect:
复制 "server": {
"host": "0.0.0.0",
"id": "NBTGVY3OKDKEAJPUXRHZLKBCRH3LWCKZ6ZXTAJRS2RMYN3PMDRMUZWPR",
"ver": "2.0.0-RC5",
"seq": 32,
"time": "2019-05-03T14:53:15.455266-05:00"
},
"acc": "ADWJVSUSEVC2GHL5GRATN2LOEOQOY2E6Z2VXNU3JEIK6BDGPWNIW3AXF",
"conns": 1,
"total_conns": 1
}'
"server": {
"host": "0.0.0.0",
"id": "NBTGVY3OKDKEAJPUXRHZLKBCRH3LWCKZ6ZXTAJRS2RMYN3PMDRMUZWPR",
"ver": "2.0.0-RC5",
"seq": 33,
"time": "2019-05-03T14:53:15.455304-05:00"
},
"client": {
"start": "2019-05-03T14:53:15.453824-05:00",
"host": "127.0.0.1",
"id": 6,
"acc": "ADWJVSUSEVC2GHL5GRATN2LOEOQOY2E6Z2VXNU3JEIK6BDGPWNIW3AXF",
"user": "UACPEXCAZEYWZK4O52MEGWGK4BH3OSGYM3P3C3F3LF2NGNZUS24IVG36",
"name": "NATS Sample Publisher",
"lang": "go",
"ver": "1.7.0",
"stop": "2019-05-03T14:53:15.45526-05:00"
},
"sent": {
"msgs": 1,
"bytes": 3
},
"received": {
"msgs": 0,
"bytes": 0
},
"reason": "Client Closed"
}' System Services
$SYS.REQ.SERVER.PING - Discovering Servers
To discover servers in the cluster, and get a small heath summary, publish a request to $SYS.REQ.SERVER.PING. Note that while the example below uses nats-req, only the first answer for the request will be printed. You can easily modify the example to wait until no additional responses are received for a specific amount of time, thus allowing for all responses to be collected.
复制 > nats-req -creds ~/.nkeys/SAOP/accounts/SYS/users/SYSU.creds \$SYS.REQ.SERVER.PING ""
Published [$SYS.REQ.SERVER.PING] : ''
Received [_INBOX.G5mbsf0k7l7nb4eWHa7GTT.omklmvnm] : '{
"server": {
"host": "0.0.0.0",
"id": "NCZQDUX77OSSTGN2ESEOCP4X7GISMARX3H4DBGZBY34VLAI4TQEPK6P6",
"ver": "2.0.0-RC9",
"seq": 47,
"time": "2019-05-02T14:02:46.402166-05:00"
},
"statsz": {
"start": "2019-05-02T13:41:01.113179-05:00",
"mem": 12922880,
"cores": 20,
"cpu": 0,
"connections": 2,
"total_connections": 2,
"active_accounts": 1,
"subscriptions": 10,
"sent": {
"msgs": 7,
"bytes": 2761
},
"received": {
"msgs": 0,
"bytes": 0
},
"slow_consumers": 0
}
}' $SYS.SERVER.<id>.STATSZ - Requesting Server Stats Summary
If you know the server id for a particular server (such as from a response to $SYS.REQ.SERVER.PING), you can query the specific server for its health information:
复制 nats-req -creds ~/.nkeys/SAOP/accounts/SYS/users/SYSU.creds \$SYS.REQ.SERVER.NC7AKPQRC6CIZGWRJOTVFIGVSL7VW7WXTQCTUJFNG7HTCMCKQTGE5PUL.STATSZ ""
Published [$SYS.REQ.SERVER.NC7AKPQRC6CIZGWRJOTVFIGVSL7VW7WXTQCTUJFNG7HTCMCKQTGE5PUL.STATSZ] : ''
Received [_INBOX.DQD44ugVt0O4Ur3pWIOOD1.WQOBevoq] : '{
"server": {
"host": "0.0.0.0",
"id": "NC7AKPQRC6CIZGWRJOTVFIGVSL7VW7WXTQCTUJFNG7HTCMCKQTGE5PUL",
"ver": "2.0.0-RC5",
"seq": 25,
"time": "2019-05-03T14:34:02.066077-05:00"
},
"statsz": {
"start": "2019-05-03T14:32:19.969037-05:00",
"mem": 11874304,
"cores": 20,
"cpu": 0,
"connections": 2,
"total_connections": 4,
"active_accounts": 1,
"subscriptions": 10,
"sent": {
"msgs": 26,
"bytes": 9096
},
"received": {
"msgs": 2,
"bytes": 0
},
"slow_consumers": 0
}
}' 