Reset

alerting/provider/ntfy/ntfy.go

@@ -0,0 +1,243 @@
+package ntfy
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/TwiN/gatus/v5/alerting/alert"
+	"github.com/TwiN/gatus/v5/client"
+	"github.com/TwiN/gatus/v5/config/endpoint"
+	"gopkg.in/yaml.v3"
+)
+
+const (
+	DefaultURL      = "https://ntfy.sh"
+	DefaultPriority = 3
+	TokenPrefix     = "tk_"
+)
+
+var (
+	ErrInvalidToken           = errors.New("invalid token")
+	ErrTopicNotSet            = errors.New("topic not set")
+	ErrInvalidPriority        = errors.New("priority must between 1 and 5 inclusively")
+	ErrDuplicateGroupOverride = errors.New("duplicate group override")
+)
+
+type Config struct {
+	Topic           string `yaml:"topic"`
+	URL             string `yaml:"url,omitempty"`              // Defaults to DefaultURL
+	Priority        int    `yaml:"priority,omitempty"`         // Defaults to DefaultPriority
+	Token           string `yaml:"token,omitempty"`            // Defaults to ""
+	Email           string `yaml:"email,omitempty"`            // Defaults to ""
+	Click           string `yaml:"click,omitempty"`            // Defaults to ""
+	DisableFirebase bool   `yaml:"disable-firebase,omitempty"` // Defaults to false
+	DisableCache    bool   `yaml:"disable-cache,omitempty"`    // Defaults to false
+}
+
+func (cfg *Config) Validate() error {
+	if len(cfg.URL) == 0 {
+		cfg.URL = DefaultURL
+	}
+	if cfg.Priority == 0 {
+		cfg.Priority = DefaultPriority
+	}
+	if len(cfg.Token) > 0 && !strings.HasPrefix(cfg.Token, TokenPrefix) {
+		return ErrInvalidToken
+	}
+	if len(cfg.Topic) == 0 {
+		return ErrTopicNotSet
+	}
+	if cfg.Priority < 1 || cfg.Priority > 5 {
+		return ErrInvalidPriority
+	}
+	return nil
+}
+
+func (cfg *Config) Merge(override *Config) {
+	if len(override.Topic) > 0 {
+		cfg.Topic = override.Topic
+	}
+	if len(override.URL) > 0 {
+		cfg.URL = override.URL
+	}
+	if override.Priority > 0 {
+		cfg.Priority = override.Priority
+	}
+	if len(override.Token) > 0 {
+		cfg.Token = override.Token
+	}
+	if len(override.Email) > 0 {
+		cfg.Email = override.Email
+	}
+	if len(override.Click) > 0 {
+		cfg.Click = override.Click
+	}
+	if override.DisableFirebase {
+		cfg.DisableFirebase = true
+	}
+	if override.DisableCache {
+		cfg.DisableCache = true
+	}
+}
+
+// AlertProvider is the configuration necessary for sending an alert using Slack
+type AlertProvider struct {
+	DefaultConfig Config `yaml:",inline"`
+
+	// DefaultAlert is the default alert configuration to use for endpoints with an alert of the appropriate type
+	DefaultAlert *alert.Alert `yaml:"default-alert,omitempty"`
+
+	// Overrides is a list of Override that may be prioritized over the default configuration
+	Overrides []Override `yaml:"overrides,omitempty"`
+}
+
+// Override is a case under which the default integration is overridden
+type Override struct {
+	Group  string `yaml:"group"`
+	Config `yaml:",inline"`
+}
+
+// Validate the provider's configuration
+func (provider *AlertProvider) Validate() error {
+	registeredGroups := make(map[string]bool)
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if len(override.Group) == 0 {
+				return ErrDuplicateGroupOverride
+			}
+			if _, ok := registeredGroups[override.Group]; ok {
+				return ErrDuplicateGroupOverride
+			}
+			if len(override.Token) > 0 && !strings.HasPrefix(override.Token, TokenPrefix) {
+				return ErrDuplicateGroupOverride
+			}
+			if override.Priority < 0 || override.Priority >= 6 {
+				return ErrDuplicateGroupOverride
+			}
+			registeredGroups[override.Group] = true
+		}
+	}
+
+	return provider.DefaultConfig.Validate()
+}
+
+// Send an alert using the provider
+func (provider *AlertProvider) Send(ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) error {
+	cfg, err := provider.GetConfig(ep.Group, alert)
+	if err != nil {
+		return err
+	}
+	buffer := bytes.NewBuffer(provider.buildRequestBody(cfg, ep, alert, result, resolved))
+	url := cfg.URL
+	request, err := http.NewRequest(http.MethodPost, url, buffer)
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	if token := cfg.Token; len(token) > 0 {
+		request.Header.Set("Authorization", "Bearer "+token)
+	}
+	if cfg.DisableFirebase {
+		request.Header.Set("Firebase", "no")
+	}
+	if cfg.DisableCache {
+		request.Header.Set("Cache", "no")
+	}
+	response, err := client.GetHTTPClient(nil).Do(request)
+	if err != nil {
+		return err
+	}
+	defer response.Body.Close()
+	if response.StatusCode > 399 {
+		body, _ := io.ReadAll(response.Body)
+		return fmt.Errorf("call to provider alert returned status code %d: %s", response.StatusCode, string(body))
+	}
+	return err
+}
+
+type Body struct {
+	Topic    string   `json:"topic"`
+	Title    string   `json:"title"`
+	Message  string   `json:"message"`
+	Tags     []string `json:"tags"`
+	Priority int      `json:"priority"`
+	Email    string   `json:"email,omitempty"`
+	Click    string   `json:"click,omitempty"`
+}
+
+// buildRequestBody builds the request body for the provider
+func (provider *AlertProvider) buildRequestBody(cfg *Config, ep *endpoint.Endpoint, alert *alert.Alert, result *endpoint.Result, resolved bool) []byte {
+	var message, formattedConditionResults, tag string
+	if resolved {
+		tag = "white_check_mark"
+		message = "An alert has been resolved after passing successfully " + strconv.Itoa(alert.SuccessThreshold) + " time(s) in a row"
+	} else {
+		tag = "rotating_light"
+		message = "An alert has been triggered due to having failed " + strconv.Itoa(alert.FailureThreshold) + " time(s) in a row"
+	}
+	for _, conditionResult := range result.ConditionResults {
+		var prefix string
+		if conditionResult.Success {
+			prefix = "🟢"
+		} else {
+			prefix = "🔴"
+		}
+		formattedConditionResults += fmt.Sprintf("\n%s %s", prefix, conditionResult.Condition)
+	}
+	if len(alert.GetDescription()) > 0 {
+		message += " with the following description: " + alert.GetDescription()
+	}
+	message += formattedConditionResults
+	body, _ := json.Marshal(Body{
+		Topic:    cfg.Topic,
+		Title:    "Gatus: " + ep.DisplayName(),
+		Message:  message,
+		Tags:     []string{tag},
+		Priority: cfg.Priority,
+		Email:    cfg.Email,
+		Click:    cfg.Click,
+	})
+	return body
+}
+
+// GetDefaultAlert returns the provider's default alert configuration
+func (provider *AlertProvider) GetDefaultAlert() *alert.Alert {
+	return provider.DefaultAlert
+}
+
+// GetConfig returns the configuration for the provider with the overrides applied
+func (provider *AlertProvider) GetConfig(group string, alert *alert.Alert) (*Config, error) {
+	cfg := provider.DefaultConfig
+	// Handle group overrides
+	if provider.Overrides != nil {
+		for _, override := range provider.Overrides {
+			if group == override.Group {
+				cfg.Merge(&override.Config)
+				break
+			}
+		}
+	}
+	// Handle alert overrides
+	if len(alert.ProviderOverride) != 0 {
+		overrideConfig := Config{}
+		if err := yaml.Unmarshal(alert.ProviderOverrideAsBytes(), &overrideConfig); err != nil {
+			return nil, err
+		}
+		cfg.Merge(&overrideConfig)
+	}
+	// Validate the configuration
+	err := cfg.Validate()
+	return &cfg, err
+}
+
+// ValidateOverrides validates the alert's provider override and, if present, the group override
+func (provider *AlertProvider) ValidateOverrides(group string, alert *alert.Alert) error {
+	_, err := provider.GetConfig(group, alert)
+	return err
+}