cli: permit passing alert data via a file

Add a new parameter `--templatefile` for `amtool` so that it would be possible to pass custom alert data. Use an example `template.Data` if none has been passed to permit simple use-cases. Signed-off-by: Giedrius Statkevičius <giedrius.statkevicius@vinted.com>
prometheus · Apr 13, 2021 · 3ae0098 · 3ae0098
1 parent 392b8de
commit 3ae0098
Showing 1 changed file with 75 additions and 57 deletions.
diff --git a/cli/template_render.go b/cli/template_render.go
@@ -15,17 +15,80 @@ package cli
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
+	"io"
+	"os"
 	"time"
 
 	"github.com/prometheus/alertmanager/template"
 	kingpin "gopkg.in/alecthomas/kingpin.v2"
 )
 
+var defaultData = template.Data{
+	Receiver: "receiver",
+	Status:   "alertstatus",
+	Alerts: template.Alerts{
+		template.Alert{
+			Status: "alertstatus",
+			Labels: template.KV{
+				"label1":          "value1",
+				"label2":          "value2",
+				"instance":        "foo.bar:1234",
+				"commonlabelkey1": "commonlabelvalue1",
+				"commonlabelkey2": "commonlabelvalue2",
+			},
+			Annotations: template.KV{
+				"annotation1":          "value1",
+				"annotation2":          "value2",
+				"commonannotationkey1": "commonannotationvalue1",
+				"commonannotationkey2": "commonannotationvalue2",
+			},
+			StartsAt:     time.Now().Add(-5 * time.Minute),
+			EndsAt:       time.Now(),
+			GeneratorURL: "https://generatorurl.com",
+			Fingerprint:  "fingerprint1",
+		},
+		template.Alert{
+			Status: "alertstatus",
+			Labels: template.KV{
+				"foo":             "bar",
+				"baz":             "qux",
+				"commonlabelkey1": "commonlabelvalue1",
+				"commonlabelkey2": "commonlabelvalue2",
+			},
+			Annotations: template.KV{
+				"aaa":                  "bbb",
+				"ccc":                  "ddd",
+				"commonannotationkey1": "commonannotationvalue1",
+				"commonannotationkey2": "commonannotationvalue2",
+			},
+			StartsAt:     time.Now().Add(-10 * time.Minute),
+			EndsAt:       time.Now(),
+			GeneratorURL: "https://generatorurl.com",
+			Fingerprint:  "fingerprint2",
+		},
+	},
+	GroupLabels: template.KV{
+		"grouplabelkey1": "grouplabelvalue1",
+		"grouplabelkey2": "grouplabelvalue2",
+	},
+	CommonLabels: template.KV{
+		"commonlabelkey1": "commonlabelvalue1",
+		"commonlabelkey2": "commonlabelvalue2",
+	},
+	CommonAnnotations: template.KV{
+		"commonannotationkey1": "commonannotationvalue1",
+		"commonannotationkey2": "commonannotationvalue2",
+	},
+	ExternalURL: "https://example.com",
+}
+
 type templateRenderCmd struct {
 	templateFilesGlobs []string
 	templateType       string
 	templateText       string
+	templateFile       *os.File
 }
 
 func configureTemplateRenderCmd(cc *kingpin.CmdClause) {
@@ -37,6 +100,7 @@ func configureTemplateRenderCmd(cc *kingpin.CmdClause) {
 	renderCmd.Flag("templateglob", "Glob of paths that will be expanded and used for rendering").Required().StringsVar(&c.templateFilesGlobs)
 	renderCmd.Flag("templatetext", "The template that will be rendered").Required().StringVar(&c.templateText)
 	renderCmd.Flag("templatetype", "The type of the template. Can be either text (default) or html").EnumVar(&c.templateType, "html", "text")
+	renderCmd.Flag("templatefile", `Full path to a file which contains the data of the alert(-s) with which the --templatetext will be rendered. Must be in JSON. File must be formatted according to the following layout: https://pkg.go.dev/github.com/prometheus/alertmanager/template#Data. If none has been specified then a predefined, simple alert will be used for rendering`).FileVar(&c.templateFile)
 
 	renderCmd.Action(execWithTimeout(c.render))
 }
@@ -52,63 +116,17 @@ func (c *templateRenderCmd) render(ctx context.Context, _ *kingpin.ParseContext)
 		f = tmpl.ExecuteHTMLString
 	}
 
-	data := template.Data{
-		Receiver: "receiver",
-		Status:   "alertstatus",
-		Alerts: template.Alerts{
-			template.Alert{
-				Status: "alertstatus",
-				Labels: template.KV{
-					"label1":          "value1",
-					"label2":          "value2",
-					"instance":        "foo.bar:1234",
-					"commonlabelkey1": "commonlabelvalue1",
-					"commonlabelkey2": "commonlabelvalue2",
-				},
-				Annotations: template.KV{
-					"annotation1":          "value1",
-					"annotation2":          "value2",
-					"commonannotationkey1": "commonannotationvalue1",
-					"commonannotationkey2": "commonannotationvalue2",
-				},
-				StartsAt:     time.Now().Add(-5 * time.Minute),
-				EndsAt:       time.Now(),
-				GeneratorURL: "https://generatorurl.com",
-				Fingerprint:  "fingerprint1",
-			},
-			template.Alert{
-				Status: "alertstatus",
-				Labels: template.KV{
-					"foo":             "bar",
-					"baz":             "qux",
-					"commonlabelkey1": "commonlabelvalue1",
-					"commonlabelkey2": "commonlabelvalue2",
-				},
-				Annotations: template.KV{
-					"aaa":                  "bbb",
-					"ccc":                  "ddd",
-					"commonannotationkey1": "commonannotationvalue1",
-					"commonannotationkey2": "commonannotationvalue2",
-				},
-				StartsAt:     time.Now().Add(-10 * time.Minute),
-				EndsAt:       time.Now(),
-				GeneratorURL: "https://generatorurl.com",
-				Fingerprint:  "fingerprint2",
-			},
-		},
-		GroupLabels: template.KV{
-			"grouplabelkey1": "grouplabelvalue1",
-			"grouplabelkey2": "grouplabelvalue2",
-		},
-		CommonLabels: template.KV{
-			"commonlabelkey1": "commonlabelvalue1",
-			"commonlabelkey2": "commonlabelvalue2",
-		},
-		CommonAnnotations: template.KV{
-			"commonannotationkey1": "commonannotationvalue1",
-			"commonannotationkey2": "commonannotationvalue2",
-		},
-		ExternalURL: "https://example.com",
+	var data template.Data
+	if c.templateFile == nil {
+		data = defaultData
+	} else {
+		content, err := io.ReadAll(c.templateFile)
+		if err != nil {
+			return err
+		}
+		if err := json.Unmarshal(content, &data); err != nil {
+			return err
+		}
 	}
 
 	rendered, err := f(c.templateText, data)