61 lines
1.8 KiB
Go
61 lines
1.8 KiB
Go
package circuitbreaker
|
|
|
|
import (
|
|
"context"
|
|
"net/http"
|
|
|
|
"github.com/opentracing/opentracing-go/ext"
|
|
"github.com/traefik/traefik/v2/pkg/config/dynamic"
|
|
"github.com/traefik/traefik/v2/pkg/log"
|
|
"github.com/traefik/traefik/v2/pkg/middlewares"
|
|
"github.com/traefik/traefik/v2/pkg/tracing"
|
|
"github.com/vulcand/oxy/cbreaker"
|
|
)
|
|
|
|
const (
|
|
typeName = "CircuitBreaker"
|
|
)
|
|
|
|
type circuitBreaker struct {
|
|
circuitBreaker *cbreaker.CircuitBreaker
|
|
name string
|
|
}
|
|
|
|
// New creates a new circuit breaker middleware.
|
|
func New(ctx context.Context, next http.Handler, confCircuitBreaker dynamic.CircuitBreaker, name string) (http.Handler, error) {
|
|
expression := confCircuitBreaker.Expression
|
|
|
|
logger := log.FromContext(middlewares.GetLoggerCtx(ctx, name, typeName))
|
|
logger.Debug("Creating middleware")
|
|
logger.Debug("Setting up with expression: %s", expression)
|
|
|
|
oxyCircuitBreaker, err := cbreaker.New(next, expression, createCircuitBreakerOptions(expression))
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &circuitBreaker{
|
|
circuitBreaker: oxyCircuitBreaker,
|
|
name: name,
|
|
}, nil
|
|
}
|
|
|
|
// NewCircuitBreakerOptions returns a new CircuitBreakerOption.
|
|
func createCircuitBreakerOptions(expression string) cbreaker.CircuitBreakerOption {
|
|
return cbreaker.Fallback(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
|
|
tracing.SetErrorWithEvent(req, "blocked by circuit-breaker (%q)", expression)
|
|
rw.WriteHeader(http.StatusServiceUnavailable)
|
|
|
|
if _, err := rw.Write([]byte(http.StatusText(http.StatusServiceUnavailable))); err != nil {
|
|
log.FromContext(req.Context()).Error(err)
|
|
}
|
|
}))
|
|
}
|
|
|
|
func (c *circuitBreaker) GetTracingInformation() (string, ext.SpanKindEnum) {
|
|
return c.name, tracing.SpanKindNoneEnum
|
|
}
|
|
|
|
func (c *circuitBreaker) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
|
|
c.circuitBreaker.ServeHTTP(rw, req)
|
|
}
|