internal/healthchecks/healthchecks.go

// Copyright 2022 Google LLC
//
// 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 (
	"fmt"
	"log"
	"os"
	"path/filepath"

	"github.com/GoogleCloudPlatform/ops-agent/internal/logs"
)

var healthChecksLogFile = "health-checks.log"

type HealthCheck interface {
	Name() string
	RunCheck(logger logs.StructuredLogger) error
}

type HealthCheckResult struct {
	Name string
	Err  error
}

func singleErrorResultMessage(e error, Name string) string {
	if e != nil {
		if healthError, ok := e.(HealthCheckError); ok {
			if healthError.IsFatal {
				return fmt.Sprintf("[%s] Result: FAIL, Error code: %s, Failure: %s, Solution: %s, Resource: %s",
					Name, healthError.Code, healthError.Message, healthError.Action, healthError.ResourceLink)
			} else {
				return fmt.Sprintf("[%s] Result: WARNING, Error code: %s, Failure: %s, Solution: %s, Resource: %s",
					Name, healthError.Code, healthError.Message, healthError.Action, healthError.ResourceLink)
			}
		}
		return fmt.Sprintf("[%s] Result: ERROR, Detail: %s", Name, e.Error())
	}
	return fmt.Sprintf("[%s] Result: PASS", Name)
}

func (r HealthCheckResult) LogResult(logger logs.StructuredLogger) {
	for _, e := range r.ErrorSlice() {
		if e == nil {
			logger.Infof(singleErrorResultMessage(e, r.Name))
		} else {
			if healthError, ok := e.(HealthCheckError); ok {
				if healthError.IsFatal {
					logger.Errorw(singleErrorResultMessage(e, r.Name), "code", healthError.Code)
				} else {
					logger.Warnw(singleErrorResultMessage(e, r.Name), "code", healthError.Code)
				}
			} else {
				logger.Errorf(singleErrorResultMessage(e, r.Name))
			}
		}
	}
}

func (r HealthCheckResult) ErrorSlice() []error {
	if mwErr, ok := r.Err.(MultiWrappedError); ok {
		return mwErr.Unwrap()
	}
	return []error{r.Err}
}

func LogHealthCheckResults(healthCheckResults []HealthCheckResult, logger logs.StructuredLogger) {
	for _, result := range healthCheckResults {
		result.LogResult(logger)
	}
}

func CreateHealthChecksLogger(logDir string) logs.StructuredLogger {
	path := filepath.Join(logDir, healthChecksLogFile)
	// Make sure the directory exists before writing the file.
	if err := os.MkdirAll(logDir, 0755); err != nil {
		log.Printf("failed to create directory for %q: %v", path, err)
		return logs.Default()
	}
	file, err := os.OpenFile(path, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		log.Printf("failed to open health checks log file %q: %v", path, err)
		return logs.Default()
	}
	file.Close()

	return logs.New(path)
}

type HealthCheckRegistry []HealthCheck

func HealthCheckRegistryFactory() HealthCheckRegistry {
	return HealthCheckRegistry{
		PortsCheck{},
		NetworkCheck{},
		APICheck{},
	}
}

func (r HealthCheckRegistry) RunAllHealthChecks(logger logs.StructuredLogger) []HealthCheckResult {
	var result []HealthCheckResult

	for _, c := range r {
		r := HealthCheckResult{Name: c.Name(), Err: c.RunCheck(logger)}
		r.LogResult(logger)
		result = append(result, r)
	}
	return result
}