feat(notify): implement executable-based notifier

config/config.go

@@ -298,6 +298,9 @@ func resolveFilepaths(baseDir string, cfg *Config) {
 		for _, cfg := range receiver.RocketchatConfigs {
 			cfg.HTTPConfig.SetDirectory(baseDir)
 		}
+		for _, cfg := range receiver.ExecConfigs {
+			cfg.SetDirectory(baseDir)
+		}
 	}
 }
 
@@ -412,6 +415,14 @@ func (c *Config) UnmarshalYAML(unmarshal func(any) error) error {
 				wh.HTTPConfig = c.Global.HTTPConfig
 			}
 		}
+		for _, ec := range rcv.ExecConfigs {
+			if ec.ExecFile == "" {
+				if c.Global.ExecFile == "" {
+					return errors.New("no global executable file set")
+				}
+				ec.ExecFile = c.Global.ExecFile
+			}
+		}
 		for _, ec := range rcv.EmailConfigs {
 			if ec.TLSConfig == nil {
 				ec.TLSConfig = c.Global.SMTPTLSConfig
@@ -867,6 +878,7 @@ type GlobalConfig struct {
 	RocketchatTokenFile   string               `yaml:"rocketchat_token_file,omitempty" json:"rocketchat_token_file,omitempty"`
 	RocketchatTokenID     *Secret              `yaml:"rocketchat_token_id,omitempty" json:"rocketchat_token_id,omitempty"`
 	RocketchatTokenIDFile string               `yaml:"rocketchat_token_id_file,omitempty" json:"rocketchat_token_id_file,omitempty"`
+	ExecFile              string               `yaml:"exec_file,omitempty" json:"exec_file,omitempty"`
 }
 
 // UnmarshalYAML implements the yaml.Unmarshaler interface for GlobalConfig.
@@ -1010,6 +1022,7 @@ type Receiver struct {
 	PagerdutyConfigs  []*PagerdutyConfig  `yaml:"pagerduty_configs,omitempty" json:"pagerduty_configs,omitempty"`
 	SlackConfigs      []*SlackConfig      `yaml:"slack_configs,omitempty" json:"slack_configs,omitempty"`
 	WebhookConfigs    []*WebhookConfig    `yaml:"webhook_configs,omitempty" json:"webhook_configs,omitempty"`
+	ExecConfigs       []*ExecConfig       `yaml:"exec_configs,omitempty" json:"exec_configs,omitempty"`
 	OpsGenieConfigs   []*OpsGenieConfig   `yaml:"opsgenie_configs,omitempty" json:"opsgenie_configs,omitempty"`
 	WechatConfigs     []*WechatConfig     `yaml:"wechat_configs,omitempty" json:"wechat_configs,omitempty"`
 	PushoverConfigs   []*PushoverConfig   `yaml:"pushover_configs,omitempty" json:"pushover_configs,omitempty"`

config/notifiers.go

@@ -35,6 +35,13 @@ var (
 		},
 	}
 
+	// DefaultExecConfig defines default values for Exec configurations.
+	DefaultExecConfig = ExecConfig{
+		NotifierConfig: NotifierConfig{
+			VSendResolved: true,
+		},
+	}
+
 	// DefaultWebexConfig defines default values for Webex configurations.
 	DefaultWebexConfig = WebexConfig{
 		NotifierConfig: NotifierConfig{
@@ -557,6 +564,51 @@ func (c *WebhookConfig) UnmarshalYAML(unmarshal func(any) error) error {
 	return nil
 }
 
+// ExecConfig configures notifications via a generic exec.
+type ExecConfig struct {
+	NotifierConfig `yaml:",inline" json:",inline"`
+
+	// WorkingDir specifies the working directory of the command.
+	// If Dir is the empty string, the command is run in
+	// the current directory of Alertmanager.
+	WorkingDir string `yaml:"working_dir" json:"working_dir"`
+	// ExecFile is the path of the command to run. Relative values
+	// will be resolved against WorkingDir prior to execution.
+	ExecFile string `yaml:"exec_file" json:"exec_file"`
+	// Arguments is the list of additional command line arguments
+	// to pass to the executable.
+	Arguments []string `yaml:"arguments,omitempty" json:"arguments,omitempty"`
+	// Environment specifies the environment of the process.
+	Environment map[string]string `yaml:"environment,omitempty" json:"environment,omitempty"`
+	// Environment specifies environment variables with values read from files.
+	EnvironmentFiles map[string]string `yaml:"environment_files,omitempty" json:"environment_files,omitempty"`
+
+	// Timeout is the maximum time allowed to invoke the command. Setting this to 0
+	// does not impose a timeout.
+	Timeout time.Duration `yaml:"timeout" json:"timeout"`
+}
+
+// SetDirectory uses [config.JoinDir] to resolver internal
+// path properties to absolute values.
+func (c *ExecConfig) SetDirectory(s string) {
+	c.WorkingDir = commoncfg.JoinDir(s, c.WorkingDir)
+	c.ExecFile = commoncfg.JoinDir(s, c.ExecFile)
+
+	for k, f := range c.EnvironmentFiles {
+		c.EnvironmentFiles[k] = commoncfg.JoinDir(s, f)
+	}
+}
+
+// UnmarshalYAML implements the yaml.Unmarshaler interface.
+func (c *ExecConfig) UnmarshalYAML(unmarshal func(any) error) error {
+	*c = DefaultExecConfig
+	type plain ExecConfig
+	if err := unmarshal((*plain)(c)); err != nil {
+		return err
+	}
+	return nil
+}
+
 // WechatConfig configures notifications via Wechat.
 type WechatConfig struct {
 	NotifierConfig `yaml:",inline" json:",inline"`

config/receiver/receiver.go

@@ -23,6 +23,7 @@ import (
 	"github.com/prometheus/alertmanager/notify"
 	"github.com/prometheus/alertmanager/notify/discord"
 	"github.com/prometheus/alertmanager/notify/email"
+	"github.com/prometheus/alertmanager/notify/exec"
 	"github.com/prometheus/alertmanager/notify/jira"
 	"github.com/prometheus/alertmanager/notify/msteams"
 	"github.com/prometheus/alertmanager/notify/msteamsv2"
@@ -64,6 +65,9 @@ func BuildReceiverIntegrations(nc config.Receiver, tmpl *template.Template, logg
 	for i, c := range nc.WebhookConfigs {
 		add("webhook", i, c, func(l *slog.Logger) (notify.Notifier, error) { return webhook.New(c, tmpl, l, httpOpts...) })
 	}
+	for i, c := range nc.ExecConfigs {
+		add("exec", i, c, func(l *slog.Logger) (notify.Notifier, error) { return exec.New(c, tmpl, l) })
+	}
 	for i, c := range nc.EmailConfigs {
 		add("email", i, c, func(l *slog.Logger) (notify.Notifier, error) { return email.New(c, tmpl, l), nil })
 	}

config/testdata/conf.good.yml

@@ -115,3 +115,11 @@ receivers:
     slack_configs:
       - channel: '#my-channel'
         image_url: 'http://some.img.com/img.png'
+  - name: exec-receiver
+    exec_configs:
+      - exec_file: /bin/cat
+        working_dir: /tmp
+        arguments: [ "-A" ]
+        environment:
+          LANG: C
+        timeout: 5s

docs/configuration.md

@@ -736,6 +736,8 @@ discord_configs:
   [ - <discord_config>, ... ]
 email_configs:
   [ - <email_config>, ... ]
+exec_configs:
+  [ - <exec_config>, ... ]
 msteams_configs:
   [ - <msteams_config>, ... ]
 msteamsv2_configs:
@@ -986,6 +988,51 @@ tls_config:
 [ headers: { <string>: <tmpl_string>, ... } ]
 ```
 
+### `<exec_config>`
+
+The exec receiver allows configuring a generic receiver
+using executables for processing.
+
+```yaml
+# Whether to notify about resolved alerts.
+[ send_resolved: <boolean> | default = true ]
+
+# Directory to change into before running the executable.
+[ working_dir: <filepath> ]
+
+# Script/Binary to invoke for data processing.
+exec_file: <filepath>
+
+# Commandline arguments to pass to the executable.
+arguments:
+  [ - <string> ... ]
+
+# Environment variables to expose to the process in addition to
+# the variables the Alertmanager process already inherited.
+environment:
+  [ <string>: <string> ... ]
+
+# Environment variables to expose to the process in addition to
+# the variables the Alertmanager process already inherited.
+# The actual values are read from the specified files.
+environment_files:
+  [ <string>: <filepath> ... ]
+
+# The maximum time to wait for the call to complete, before interrupting the
+# process and allowing it to be retried. The default value of 0s indicates that
+# no timeout should be applied.
+# NOTE: This will have no effect if set higher than the group_interval.
+[ timeout: <duration> | default = 0s ]
+```
+
+The executable will receive data via STDIN formatted in a similar fashion as the
+[webhook](#webhook_config`. The exit code is used to determine the result of the
+processing:
+
+* Success (0)
+* Error but retryable (3)
+* Unrecoverable error (all other status codes)
+
 ### `<msteams_config>`
 
 Microsoft Teams notifications are sent via the [Incoming Webhooks](https://learn.microsoft.com/en-us/microsoftteams/platform/webhooks-and-connectors/what-are-webhooks-and-connectors) API endpoint.

examples/exec/main.go

@@ -0,0 +1,34 @@
+// Copyright 2018 Prometheus Team
+// 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 main
+
+import (
+	"encoding/json"
+	"log"
+	"os"
+
+	"github.com/prometheus/alertmanager/notify/exec"
+)
+
+func main() {
+	var msg exec.Message
+	err := json.NewDecoder(os.Stdin).Decode(&msg)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	log.Printf("version=%q, group_key=%s\n", msg.Version, msg.GroupKey)
+
+	os.Exit(exec.ExitSuccess)
+}