cmd/promtool: add promtool command.

The promtool command should bundle multiple commands that help
in maintaining a running Prometheus server.

cmd/prometheus/main.go

@@ -208,7 +208,7 @@ func reloadConfig(filename string, rls ...Reloadable) bool {
 
 var versionInfoTmpl = `prometheus, version {{.version}} (branch: {{.branch}}, revision: {{.revision}})
   build user:       {{.buildUser}}
-  build date:       {{.builDate}}
+  build date:       {{.buildDate}}
   go version:       {{.goVersion}}
 `
 

cmd/promtool/main.go

@@ -0,0 +1,184 @@
+// Copyright 2015 The Prometheus Authors
+// 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 (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"text/template"
+
+	"gopkg.in/yaml.v2"
+
+	"github.com/prometheus/prometheus/config"
+	"github.com/prometheus/prometheus/promql"
+	"github.com/prometheus/prometheus/util/cli"
+	"github.com/prometheus/prometheus/version"
+)
+
+// CheckConfigCmd validates configuration files.
+func CheckConfigCmd(t cli.Term, args ...string) int {
+	if len(args) == 0 {
+		t.Infof("usage: promtool check-config <files>")
+		return 2
+	}
+	failed := false
+
+	for _, arg := range args {
+		ruleFiles, err := checkConfig(t, arg)
+		if err != nil {
+			t.Errorf("  FAILED: %s", err)
+			failed = true
+		} else {
+			t.Infof("  SUCCESS: %d rule files found", len(ruleFiles))
+		}
+		t.Infof("")
+
+		for _, rf := range ruleFiles {
+			if n, err := checkRules(t, rf); err != nil {
+				t.Errorf("  FAILED: %s", err)
+				failed = true
+			} else {
+				t.Infof("  SUCCESS: %d rules found", n)
+			}
+			t.Infof("")
+		}
+	}
+	if failed {
+		return 1
+	}
+	return 0
+}
+
+func checkConfig(t cli.Term, filename string) ([]string, error) {
+	t.Infof("Checking %s", filename)
+
+	if stat, err := os.Stat(filename); err != nil {
+		return nil, fmt.Errorf("cannot get file info")
+	} else if stat.IsDir() {
+		return nil, fmt.Errorf("is a directory")
+	}
+
+	content, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	var cfg config.Config
+	if err := yaml.Unmarshal(content, &cfg); err != nil {
+		return nil, err
+	}
+	var ruleFiles []string
+	for _, rf := range cfg.RuleFiles {
+		rfs, err := filepath.Glob(rf)
+		if err != nil {
+			return nil, err
+		}
+		// If an explicit file was given, error if it doesn't exist.
+		if !strings.Contains(rf, "*") && len(rfs) == 0 {
+			return nil, fmt.Errorf("%q does not point to an existing file", rf)
+		}
+		ruleFiles = append(ruleFiles, rfs...)
+	}
+
+	return ruleFiles, nil
+}
+
+// CheckRulesCmd validates rule files.
+func CheckRulesCmd(t cli.Term, args ...string) int {
+	if len(args) == 0 {
+		t.Infof("usage: promtool check-rules <files>")
+		return 2
+	}
+	failed := false
+
+	for _, arg := range args {
+		if n, err := checkRules(t, arg); err != nil {
+			t.Errorf("  FAILED: %s", err)
+			failed = true
+		} else {
+			t.Infof("  SUCCESS: %d rules found", n)
+		}
+		t.Infof("")
+	}
+	if failed {
+		return 1
+	}
+	return 0
+}
+
+func checkRules(t cli.Term, filename string) (int, error) {
+	t.Infof("Checking %s", filename)
+
+	if stat, err := os.Stat(filename); err != nil {
+		return 0, fmt.Errorf("cannot get file info")
+	} else if stat.IsDir() {
+		return 0, fmt.Errorf("is a directory")
+	}
+
+	content, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return 0, err
+	}
+
+	rules, err := promql.ParseStmts(string(content))
+	if err != nil {
+		return 0, err
+	}
+	return len(rules), nil
+}
+
+var versionInfoTmpl = `
+prometheus, version {{.version}} (branch: {{.branch}}, revision: {{.revision}})
+  build user:       {{.buildUser}}
+  build date:       {{.builDate}}
+  go version:       {{.goVersion}}
+`
+
+// VersionCmd prints the binaries version information.
+func VersionCmd(t cli.Term, _ ...string) int {
+	tmpl := template.Must(template.New("version").Parse(versionInfoTmpl))
+
+	var buf bytes.Buffer
+	if err := tmpl.ExecuteTemplate(&buf, "version", version.Map); err != nil {
+		panic(err)
+	}
+	t.Out(strings.TrimSpace(buf.String()))
+	return 0
+}
+
+func main() {
+	app := cli.NewApp("promtool")
+
+	app.Register("check-config", &cli.Command{
+		Desc: "validate configuration files for correctness",
+		Run:  CheckConfigCmd,
+	})
+
+	app.Register("check-rules", &cli.Command{
+		Desc: "validate rule files for correctness",
+		Run:  CheckRulesCmd,
+	})
+
+	app.Register("version", &cli.Command{
+		Desc: "print the version of this binary",
+		Run:  VersionCmd,
+	})
+
+	t := cli.BasicTerm(os.Stdout, os.Stderr)
+	os.Exit(app.Run(t, os.Args[1:]...))
+}