ingress-nginx-helm/controllers/gce/healthchecks/healthchecks.go

/*
Copyright 2015 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package healthchecks

import (
	"net/http"

	"github.com/golang/glog"
	compute "google.golang.org/api/compute/v1"

	"k8s.io/ingress/controllers/gce/utils"
)

// HealthChecks manages health checks.
type HealthChecks struct {
	cloud       SingleHealthCheck
	defaultPath string
	namer       *utils.Namer
	healthCheckGetter
}

// NewHealthChecker creates a new health checker.
// cloud: the cloud object implementing SingleHealthCheck.
// defaultHealthCheckPath: is the HTTP path to use for health checks.
func NewHealthChecker(cloud SingleHealthCheck, defaultHealthCheckPath string, namer *utils.Namer) HealthChecker {
	return &HealthChecks{cloud, defaultHealthCheckPath, namer, nil}
}

// Init initializes the health checker.
func (h *HealthChecks) Init(r healthCheckGetter) {
	h.healthCheckGetter = r
}

// Add adds a healthcheck if one for the same port doesn't already exist.
func (h *HealthChecks) Add(port int64) error {
	wantHC, err := h.healthCheckGetter.HealthCheck(port)
	if err != nil {
		return err
	}
	if wantHC.RequestPath == "" {
		wantHC.RequestPath = h.defaultPath
	}
	name := h.namer.BeName(port)
	wantHC.Name = name
	hc, _ := h.Get(port)
	if hc == nil {
		// TODO: check if the readiness probe has changed and update the
		// health check.
		glog.Infof("Creating health check %v", name)
		if err := h.cloud.CreateHttpHealthCheck(wantHC); err != nil {
			return err
		}
	} else if wantHC.RequestPath != hc.RequestPath {
		// TODO: reconcile health checks, and compare headers interval etc.
		// Currently Ingress doesn't expose all the health check params
		// natively, so some users prefer to hand modify the check.
		glog.Infof("Unexpected request path on health check %v, has %v want %v, NOT reconciling",
			name, hc.RequestPath, wantHC.RequestPath)
	} else {
		glog.Infof("Health check %v already exists and has the expected path %v", hc.Name, hc.RequestPath)
	}
	return nil
}

// Delete deletes the health check by port.
func (h *HealthChecks) Delete(port int64) error {
	name := h.namer.BeName(port)
	glog.Infof("Deleting health check %v", name)
	if err := h.cloud.DeleteHttpHealthCheck(h.namer.BeName(port)); err != nil {
		if !utils.IsHTTPErrorCode(err, http.StatusNotFound) {
			return err
		}
	}
	return nil
}

// Get returns the given health check.
func (h *HealthChecks) Get(port int64) (*compute.HttpHealthCheck, error) {
	return h.cloud.GetHttpHealthCheck(h.namer.BeName(port))
}