Introduction

baetyl-function is a function computing framework on the baetyl framework end side. The function computing framework on the end side consists of the frontend agent and backend function runtime.

The baetyl-function provides the front end agent, which is a function entry. It is called by other services through the exposed HTTP interface and then transmits the request to the back-end function runtime module transparently.

The back end function runtime provides multiple options:

• baetyl-function-python36 provides the Python3.6 function runtime.
• baetyl-function-node10 provides the Node 10 function runtime.
• baetyl-function-sql provides the SQL function runtime, and it is compatible with the SQL92 syntax.

Users can write python, node, and SQL scripts to build their business logic and filter, transform and forward the message, which is very flexible for its use.

The function computing is set based on the event-driven programming model. Users can set the rules using the rule engine baetyl-rule module on the baetyl end side. When a message triggers a certain rule, you can call related functions within this rule. baetyl-rule will request the baetyl-function module in the following format:

https://[baetyl-function-service]/[function-service]/[function]

The baetyl-function-service is the service address of baetyl-function. For example, baetyl-function: 50011,function-service is the service name when the back end function runs, and function represents the function entry. If the `function field is not specified, it will select the first function in its function list by default when the back-end function runs. The function entry represents the executive function. For Python3.6/Node 10 runtime, it consists of function script and handler name. For the SQL runtime, it consists of a function script only. It is the SQL statement written by users in the function script.

For the specific use, refer to the best practice baetyl Edge Rule Engine Practice.

Configuration

The following gives the complete configuration files of baetyl-function and explains the configuration field correspondingly:

server: # Server related settings because the request is proxied to the backend Runtimes module
  address: ":50011" # Listening address
  concurrency: # The number of concurrent connections on the server, if not set, the default value will be used
  disableKeepalive: true # true # Whether to enable keep-alive connections, the default value is false
  tcpKeepalive: false # Whether to actively send keep-alive messages, the default is false
  maxRequestBodySize: # The maximum data volume of Body, the default is 4 * 1024 * 1024 Byte
  readTimeout: 1h # The read timeout time of the server connection, the default value is unlimited
  writeTimeout: 1h # The write timeout time of the server connection, the default value is unlimited
  idleTimeout: 1h # In "keep alive" start condition, the idle timeout during which the server waits for the next message. If the value is 0, the multiplex read timeout time
  ca: example/var/lib/baetyl/testcert/ca.crt # Server's CA certificate path
  key: example/var/lib/baetyl/testcert/server.key # Server's server private key path
  cert: example/var/lib/baetyl/testcert/server.crt # Server's server public key path

client: # Request client related settings of the backend Runtimes module
  grpc: # Grpc client settings
    port: 80 # Backend Runtimes port
    timeout: 5m # Request timeout
    retries: 3 # Request retries

logger: # Log
  level: info # Log level