Go function error handling
If a handler reports a Go function runtime or loading error, the runtime environment automatically captures the error and returns a JSON document with the error type in the response. For more information about the JSON document format, see Calling a function.
The error info is also written to the execution log. You can view the log via the Yandex Cloud CLI or the management console.
Examples of error handling
Case 1: User code goes outside the array boundaries; panic is expected. In fact, the handler captures panic automatically, aggregates information about it, and generates a JSON document stating an error message (errorMessage field), error type (errorType field), and stack trace (stackTrace field).
Function code:
package main
func Handler () (int, error) {
array := []int{1, 2, 3, 4, 5}
return array[15], nil
}
JSON document returned:
{
"errorMessage": "user code execution causes panic: runtime error: index out of range [15] with length 5",
"errorType": "UserCodePanic",
"stackTrace": [
...
]
}
Case 2: User code reports an error by returning it from the function. In this case, the handler detects this error and generates a JSON document stating a custom error message (errorMessage field) and its type (errorType field).
Function code:
package main
import "fmt"
func Handler () (int, error) {
return 0, fmt.Errorf("an error")
}
JSON document returned:
{
"errorMessage": "an error",
"errorType": "UserCodeError"
}