Re-implement pushover notifications

This feature was dropped during the rewrite, but I use and like
Pushover.

fixes #107

config/config.go

@@ -389,6 +389,7 @@ type Receiver struct {
 	SlackConfigs     []*SlackConfig     `yaml:"slack_configs,omitempty"`
 	WebhookConfigs   []*WebhookConfig   `yaml:"webhook_configs,omitempty"`
 	OpsGenieConfigs  []*OpsGenieConfig  `yaml:"opsgenie_configs,omitempty"`
+	PushoverConfigs  []*PushoverConfig  `yaml:"pushover_configs,omitempty"`
 
 	// Catches all undefined fields and must be empty after parsing.
 	XXX map[string]interface{} `yaml:",inline"`

config/notifiers.go

@@ -16,6 +16,7 @@ package config
 import (
 	"fmt"
 	"strings"
+	"time"
 )
 
 var (
@@ -89,6 +90,19 @@ var (
 		Source:      `{{ template "opsgenie.default.source" . }}`,
 		// TODO: Add a details field with all the alerts.
 	}
+
+	// DefaultPushoverConfig defines default values for Pushover configurations.
+	DefaultPushoverConfig = PushoverConfig{
+		NotifierConfig: NotifierConfig{
+			VSendResolved: true,
+		},
+		Title:    `{{ template "pushover.default.title" . }}`,
+		Message:  `{{ template "pushover.default.message" . }}`,
+		URL:      `{{ template "pushover.default.url" . }}`,
+		Priority: `{{ if eq .Status "firing" }}2{{ else }}0{{ end }}`, // emergency (firing) or normal
+		Retry:    duration(1 * time.Minute),
+		Expire:   duration(1 * time.Hour),
+	}
 )
 
 // NotifierConfig contains base options common across all notifier configurations.
@@ -283,3 +297,49 @@ func (c *OpsGenieConfig) UnmarshalYAML(unmarshal func(interface{}) error) error
 	}
 	return checkOverflow(c.XXX, "opsgenie config")
 }
+
+type duration time.Duration
+
+func (d *duration) UnmarshalText(text []byte) error {
+	parsed, err := time.ParseDuration(string(text))
+	if err == nil {
+		*d = duration(parsed)
+	}
+	return err
+}
+
+func (d duration) MarshalText() ([]byte, error) {
+	return []byte(time.Duration(d).String()), nil
+}
+
+type PushoverConfig struct {
+	NotifierConfig `yaml:",inline"`
+
+	UserKey  Secret   `yaml:"user_key"`
+	Token    Secret   `yaml:"token"`
+	Title    string   `yaml:"title"`
+	Message  string   `yaml:"message"`
+	URL      string   `yaml:"url"`
+	Priority string   `yaml:"priority"`
+	Retry    duration `yaml:"retry"`
+	Expire   duration `yaml:"expire"`
+
+	// Catches all undefined fields and must be empty after parsing.
+	XXX map[string]interface{} `yaml:",inline"`
+}
+
+// UnmarshalYAML implements the yaml.Unmarshaler interface.
+func (c *PushoverConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	*c = DefaultPushoverConfig
+	type plain PushoverConfig
+	if err := unmarshal((*plain)(c)); err != nil {
+		return err
+	}
+	if c.UserKey == "" {
+		return fmt.Errorf("missing user key in Pushover config")
+	}
+	if c.Token == "" {
+		return fmt.Errorf("missing token in Pushover config")
+	}
+	return checkOverflow(c.XXX, "pushover config")
+}

notify/impl.go

@@ -19,11 +19,13 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"mime"
 	"net"
 	"net/http"
 	"net/mail"
 	"net/smtp"
+	"net/url"
 	"os"
 	"strings"
 	"time"
@@ -134,6 +136,10 @@ func Build(confs []*config.Receiver, tmpl *template.Template) map[string]Fanout
 			n := NewHipchat(c, tmpl)
 			add(i, n, filter(n, c))
 		}
+		for i, c := range nc.PushoverConfigs {
+			n := NewPushover(c, tmpl)
+			add(i, n, filter(n, c))
+		}
 
 		res[nc.Name] = fo
 	}
@@ -682,6 +688,76 @@ func (n *OpsGenie) Notify(ctx context.Context, as ...*types.Alert) error {
 	return nil
 }
 
+// Pushover implements a Notifier for Pushover notifications.
+type Pushover struct {
+	conf *config.PushoverConfig
+	tmpl *template.Template
+}
+
+// NewPushover returns a new Pushover notifier.
+func NewPushover(c *config.PushoverConfig, t *template.Template) *Pushover {
+	return &Pushover{conf: c, tmpl: t}
+}
+
+func (*Pushover) name() string { return "pushover" }
+
+// Notify implements the Notifier interface.
+func (n *Pushover) Notify(ctx context.Context, as ...*types.Alert) error {
+	key, ok := GroupKey(ctx)
+	if !ok {
+		return fmt.Errorf("group key missing")
+	}
+	data := n.tmpl.Data(receiver(ctx), groupLabels(ctx), as...)
+
+	log.With("incident", key).Debugln("notifying Pushover")
+
+	var err error
+	tmpl := tmplText(n.tmpl, data, &err)
+
+	parameters := url.Values{}
+	parameters.Add("token", tmpl(string(n.conf.Token)))
+	parameters.Add("user", tmpl(string(n.conf.UserKey)))
+	title := tmpl(n.conf.Title)
+	message := tmpl(n.conf.Message)
+	parameters.Add("title", title)
+	if len(title)+len(message) > 512 {
+		message = message[:512]
+		log.With("incident", key).Debugf("Truncated message to %q due to Pushover message limit", message)
+	}
+	if message == "" {
+		// Pushover rejects empty messages.
+		message = "(no details)"
+	}
+	parameters.Add("message", message)
+	parameters.Add("url", tmpl(n.conf.URL))
+	parameters.Add("priority", tmpl(n.conf.Priority))
+	parameters.Add("retry", fmt.Sprintf("%d", int64(time.Duration(n.conf.Retry).Seconds())))
+	parameters.Add("expire", fmt.Sprintf("%d", int64(time.Duration(n.conf.Expire).Seconds())))
+
+	apiURL := "https://api.pushover.net/1/messages.json"
+	u, err := url.Parse(apiURL)
+	if err != nil {
+		return err
+	}
+	u.RawQuery = parameters.Encode()
+	log.With("incident", key).Debugf("Pushover URL = %q", u.String())
+
+	resp, err := ctxhttp.Post(ctx, http.DefaultClient, u.String(), "text/plain", nil)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode/100 != 2 {
+		body, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			return err
+		}
+		return fmt.Errorf("unexpected status code %v (body: %s)", resp.StatusCode, string(body))
+	}
+	return nil
+}
+
 func tmplText(tmpl *template.Template, data *template.Data, err *error) func(string) string {
 	return func(name string) (s string) {
 		if *err != nil {

template/default.tmpl

@@ -162,3 +162,8 @@ SOFTWARE.
 </html>
 
 {{ end }}
+
+{{ define "pushover.default.title" }}{{ template "__subject" . }}{{ end }}
+{{ define "pushover.default.message" }}{{ .CommonAnnotations.SortedPairs.Values | join " " }}
+{{ template "__text_alert_list" .Alerts.Firing }}{{ end }}
+{{ define "pushover.default.url" }}{{ template "__alertmanagerURL" . }}{{ end }}