func (p *proxy) lookup(request *http.Request) *route.Pool {
requestPath := request.URL.EscapedPath()
uri := route.Uri(hostWithoutPort(request) + requestPath)
appInstanceHeader := request.Header.Get(router_http.CfAppInstance)
if appInstanceHeader != "" {
appId, appIndex, err := router_http.ValidateCfAppInstance(appInstanceHeader)
if err != nil {
p.logger.Error("invalid-app-instance-header", err)
return nil
} else {
return p.registry.LookupWithInstance(uri, appId, appIndex)
}
}
return p.registry.Lookup(uri)
}
})
})
})
Describe("ValidateCfAppInstance", func() {
var (
appInstanceHeader string
)
Context("when given a complete app instance header", func() {
BeforeEach(func() {
appInstanceHeader = "app-id:1"
})
It("returns the app id and app index", func() {
appID, appIndex, err := commonhttp.ValidateCfAppInstance(appInstanceHeader)
Expect(err).ToNot(HaveOccurred())
Expect(appID).To(Equal("app-id"))
Expect(appIndex).To(Equal("1"))
})
})
Context("when given an incomplete app instance header", func() {
BeforeEach(func() {
appInstanceHeader = "app-id:"
})
It("returns an error", func() {
_, _, err := commonhttp.ValidateCfAppInstance(appInstanceHeader)
Expect(err).To(HaveOccurred())
})