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