incorporate suggestions from @benfdking

This commit is contained in:
timothy-spencer 2019-03-25 10:32:29 -07:00
parent 1ff17a3fa1
commit ff4e5588d8
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GPG Key ID: B9DC267D2CB410CD
2 changed files with 56 additions and 1 deletions

24
http.go
View File

@ -24,9 +24,15 @@ func (s *Server) ListenAndServe() {
}
}
// gcpHealthcheck handles healthcheck queries from GCP
// Used with gcpHealthcheck()
const userAgentHeader = "User-Agent"
const googleHealthCheckUserAgent = "GoogleHC/1.0"
const rootPath = "/"
// gcpHealthcheck handles healthcheck queries from GCP.
func gcpHealthcheck(h http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// Check for liveness and readiness: used for Google App Engine
if r.URL.EscapedPath() == "/liveness_check" {
w.WriteHeader(http.StatusOK)
w.Write([]byte("OK"))
@ -37,6 +43,22 @@ func gcpHealthcheck(h http.Handler) http.Handler {
w.Write([]byte("OK"))
return
}
// Check for GKE ingress healthcheck: The ingress requires the root
// path of the target to return a 200 (OK) to indicate the service's good health. This can be quite a challenging demand
// depending on the application's path structure. This middleware filters out the requests from the health check by
//
// 1. checking that the request path is indeed the root path
// 2. ensuring that the User-Agent is "GoogleHC/1.0", the health checker
// 3. ensuring the request method is "GET"
if r.URL.Path == rootPath &&
r.Header.Get(userAgentHeader) == googleHealthCheckUserAgent &&
r.Method == http.MethodGet {
w.WriteHeader(http.StatusOK)
return
}
h.ServeHTTP(w, r)
})
}

View File

@ -54,3 +54,36 @@ func TestGCPHealthcheckNotHealthcheck(t *testing.T) {
assert.Equal(t, "test", rw.Body.String())
}
func TestGCPHealthcheckIngress(t *testing.T) {
handler := func(w http.ResponseWriter, req *http.Request) {
w.Write([]byte("test"))
}
h := gcpHealthcheck(http.HandlerFunc(handler))
rw := httptest.NewRecorder()
r, _ := http.NewRequest("GET", "/", nil)
r.RemoteAddr = "127.0.0.1"
r.Host = "test-server"
r.Header.Set(userAgentHeader, googleHealthCheckUserAgent)
h.ServeHTTP(rw, r)
assert.Equal(t, 200, rw.Code)
assert.Equal(t, "", rw.Body.String())
}
func TestGCPHealthcheckNotIngress(t *testing.T) {
handler := func(w http.ResponseWriter, req *http.Request) {
w.Write([]byte("test"))
}
h := gcpHealthcheck(http.HandlerFunc(handler))
rw := httptest.NewRecorder()
r, _ := http.NewRequest("GET", "/foo", nil)
r.RemoteAddr = "127.0.0.1"
r.Host = "test-server"
r.Header.Set(userAgentHeader, googleHealthCheckUserAgent)
h.ServeHTTP(rw, r)
assert.Equal(t, "test", rw.Body.String())
}