distribution/health/health_test.go
Aaron Lehmann b9b9cafa8f Expose a Registry type in health package, so unit tests can stay isolated from each other
Update docs.

Change health_test.go tests to create their own registries and register
the checks there. The tests now call CheckStatus directly instead of
polling the HTTP handler, which returns results from the default
registry.

Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
2015-08-20 15:07:54 -07:00

107 lines
2.9 KiB
Go

package health
import (
"errors"
"fmt"
"net/http"
"net/http/httptest"
"testing"
)
// TestReturns200IfThereAreNoChecks ensures that the result code of the health
// endpoint is 200 if there are not currently registered checks.
func TestReturns200IfThereAreNoChecks(t *testing.T) {
recorder := httptest.NewRecorder()
req, err := http.NewRequest("GET", "https://fakeurl.com/debug/health", nil)
if err != nil {
t.Errorf("Failed to create request.")
}
StatusHandler(recorder, req)
if recorder.Code != 200 {
t.Errorf("Did not get a 200.")
}
}
// TestReturns500IfThereAreErrorChecks ensures that the result code of the
// health endpoint is 500 if there are health checks with errors
func TestReturns503IfThereAreErrorChecks(t *testing.T) {
recorder := httptest.NewRecorder()
req, err := http.NewRequest("GET", "https://fakeurl.com/debug/health", nil)
if err != nil {
t.Errorf("Failed to create request.")
}
// Create a manual error
Register("some_check", CheckFunc(func() error {
return errors.New("This Check did not succeed")
}))
StatusHandler(recorder, req)
if recorder.Code != 503 {
t.Errorf("Did not get a 503.")
}
}
// TestHealthHandler ensures that our handler implementation correct protects
// the web application when things aren't so healthy.
func TestHealthHandler(t *testing.T) {
// clear out existing checks.
DefaultRegistry = NewRegistry()
// protect an http server
handler := http.Handler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusNoContent)
}))
// wrap it in our health handler
handler = Handler(handler)
// use this swap check status
updater := NewStatusUpdater()
Register("test_check", updater)
// now, create a test server
server := httptest.NewServer(handler)
checkUp := func(t *testing.T, message string) {
resp, err := http.Get(server.URL)
if err != nil {
t.Fatalf("error getting success status: %v", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusNoContent {
t.Fatalf("unexpected response code from server when %s: %d != %d", message, resp.StatusCode, http.StatusNoContent)
}
// NOTE(stevvooe): we really don't care about the body -- the format is
// not standardized or supported, yet.
}
checkDown := func(t *testing.T, message string) {
resp, err := http.Get(server.URL)
if err != nil {
t.Fatalf("error getting down status: %v", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusServiceUnavailable {
t.Fatalf("unexpected response code from server when %s: %d != %d", message, resp.StatusCode, http.StatusServiceUnavailable)
}
}
// server should be up
checkUp(t, "initial health check")
// now, we fail the health check
updater.Update(fmt.Errorf("the server is now out of commission"))
checkDown(t, "server should be down") // should be down
// bring server back up
updater.Update(nil)
checkUp(t, "when server is back up") // now we should be back up.
}