Added feature to get password from Vault

To use the feature we need to set the following options in
config section 'client':

use_vault = true
vault_address = http://<IP_ADDRESS:<IP_PORT>
vault_role_id = <ROLE_ID>
vault_secret_id = <SECRET_ID>
vault_secret_path = <deployments/<UNIT>/dev/user/passwords_yml>
vault_secret_mount_path = <secret_v2>
credential_name_in_vault_secret = <prometheus_mysql_exporter_database_password>

#883
Signed-off-by: Mitya_Eremeev <mitossvyaz@mail.ru>

.gitignore

@@ -9,3 +9,5 @@
 .idea
 *.iml
 /vendor
+
+.my.cnf

config/config.go

@@ -23,10 +23,14 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"context"
 
 	"github.com/go-sql-driver/mysql"
 	"github.com/prometheus/client_golang/prometheus"
 
+	"github.com/hashicorp/vault-client-go"
+	"github.com/hashicorp/vault-client-go/schema"
+
 	"gopkg.in/ini.v1"
 )
 
@@ -93,13 +97,9 @@ func (ch *MySqlConfigHandler) ReloadConfig(filename string, mysqldAddress string
 		}
 	}()
 
-	cfg, err := ini.LoadSources(
-		opts,
-		[]byte("[client]\npassword = ${MYSQLD_EXPORTER_PASSWORD}\n"),
-		filename,
-	)
+	cfg, err := PutPasswordInConfig(filename, logger )
 	if err != nil {
-		return fmt.Errorf("failed to load config from %s: %w", filename, err)
+		return fmt.Errorf("failed to put password in config file: %w", err)
 	}
 
 	if host, port, err = net.SplitHostPort(mysqldAddress); err != nil {
@@ -234,3 +234,67 @@ func (m MySqlConfig) CustomizeTLS() error {
 	mysql.RegisterTLSConfig("custom", &tlsCfg)
 	return nil
 }
+
+func PutPasswordInConfig(filename string, logger *slog.Logger) (cfg *ini.File, err error) {
+	cfg, err = ini.LoadSources(opts, filename,)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load config file %s: %w", filename, err)
+	}
+
+	clientSection := cfg.Section("client")
+	if clientSection == nil {
+		logger.Error("msg", "no section 'client' in config", "err", err)
+		return nil, fmt.Errorf("error: %w", err)
+	}
+	useVault, err := clientSection.Key("use_vault").Bool()
+	if err != nil {
+		logger.Error("msg", "failed to get 'use_vault'", "err", err)
+		return nil, fmt.Errorf("error: %w", err)
+		}
+
+	password := "${MYSQLD_EXPORTER_PASSWORD}"
+	if useVault {
+		client, err := vault.New(vault.WithAddress(clientSection.Key("vault_address").String()),)
+		if err != nil {
+			logger.Error("msg", "failed to create vault client", "err", err)
+			return nil, fmt.Errorf("error: %w", err)
+		}
+		ctx := context.Background()
+		resp, err := client.Auth.AppRoleLogin(
+			ctx,
+			schema.AppRoleLoginRequest{
+				RoleId:   clientSection.Key("vault_role_id").String(),
+				SecretId: clientSection.Key("vault_secret_id").String(),
+			},
+		)
+		if err != nil {
+			logger.Error("msg", "failed to login to vault", "err", err)
+			return nil, fmt.Errorf("error: %w", err)
+		}
+		if err := client.SetToken(resp.Auth.ClientToken); err != nil {
+			logger.Error("msg", "failed to set vault token", "err", err)
+			return nil, fmt.Errorf("error: %w", err)
+		}
+		data, err := client.Secrets.KvV2Read(
+			ctx,
+			clientSection.Key("vault_secret_path").String(),
+			vault.WithMountPath(clientSection.Key("vault_secret_mount_path").String()),
+		)
+		if err != nil {
+			logger.Error("msg", "failed to get data", "err", err)
+			return nil, fmt.Errorf("error: %w", err)
+		}
+
+		password = data.Data.Data[clientSection.Key("credential_name_in_vault_secret").String()].(string)
+	}
+
+	cfg, err = ini.LoadSources(
+		opts,
+		[]byte("[client]\npassword = " + password + "\n"),
+		filename,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load %s: %w", filename, err)
+	}
+	return cfg, nil
+}

go.mod

@@ -24,14 +24,21 @@ require (
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/coreos/go-systemd/v22 v22.5.0 // indirect
 	github.com/gopherjs/gopherjs v1.17.2 // indirect
+	github.com/hashicorp/go-cleanhttp v0.5.2 // indirect
+	github.com/hashicorp/go-retryablehttp v0.7.1 // indirect
+	github.com/hashicorp/go-rootcerts v1.0.2 // indirect
+	github.com/hashicorp/go-secure-stdlib/strutil v0.1.2 // indirect
+	github.com/hashicorp/vault-client-go v0.4.3 // indirect
 	github.com/jpillora/backoff v1.0.0 // indirect
 	github.com/jtolds/gls v4.20.0+incompatible // indirect
 	github.com/klauspost/compress v1.17.9 // indirect
 	github.com/mdlayher/socket v0.4.1 // indirect
 	github.com/mdlayher/vsock v1.2.1 // indirect
+	github.com/mitchellh/go-homedir v1.1.0 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f // indirect
 	github.com/prometheus/procfs v0.15.1 // indirect
+	github.com/ryanuber/go-glob v1.0.0 // indirect
 	github.com/smarty/assertions v1.15.0 // indirect
 	github.com/xhit/go-str2duration/v2 v2.1.0 // indirect
 	golang.org/x/crypto v0.27.0 // indirect
@@ -40,6 +47,7 @@ require (
 	golang.org/x/sync v0.8.0 // indirect
 	golang.org/x/sys v0.25.0 // indirect
 	golang.org/x/text v0.18.0 // indirect
+	golang.org/x/time v0.0.0-20220922220347-f3bd1da661af // indirect
 	google.golang.org/protobuf v1.34.2 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 )

go.sum

@@ -26,6 +26,18 @@ github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gopherjs/gopherjs v1.17.2 h1:fQnZVsXk8uxXIStYb0N4bGk7jeyTalG/wsZjQ25dO0g=
 github.com/gopherjs/gopherjs v1.17.2/go.mod h1:pRRIvn/QzFLrKfvEz3qUuEhtE/zLCWfreZ6J5gM2i+k=
+github.com/hashicorp/go-cleanhttp v0.5.1/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtngrth3wmdIIUrZ80=
+github.com/hashicorp/go-cleanhttp v0.5.2 h1:035FKYIWjmULyFRBKPs8TBQoi0x6d9G4xc9neXJWAZQ=
+github.com/hashicorp/go-cleanhttp v0.5.2/go.mod h1:kO/YDlP8L1346E6Sodw+PrpBSV4/SoxCXGY6BqNFT48=
+github.com/hashicorp/go-hclog v0.9.2/go.mod h1:5CU+agLiy3J7N7QjHK5d05KxGsuXiQLrjA0H7acj2lQ=
+github.com/hashicorp/go-retryablehttp v0.7.1 h1:sUiuQAnLlbvmExtFQs72iFW/HXeUn8Z1aJLQ4LJJbTQ=
+github.com/hashicorp/go-retryablehttp v0.7.1/go.mod h1:vAew36LZh98gCBJNLH42IQ1ER/9wtLZZ8meHqQvEYWY=
+github.com/hashicorp/go-rootcerts v1.0.2 h1:jzhAVGtqPKbwpyCPELlgNWhE1znq+qwJtW5Oi2viEzc=
+github.com/hashicorp/go-rootcerts v1.0.2/go.mod h1:pqUvnprVnM5bf7AOirdbb01K4ccR319Vf4pU3K5EGc8=
+github.com/hashicorp/go-secure-stdlib/strutil v0.1.2 h1:kes8mmyCpxJsI7FTwtzRqEy9CdjCtrXrXGuOpxEA7Ts=
+github.com/hashicorp/go-secure-stdlib/strutil v0.1.2/go.mod h1:Gou2R9+il93BqX25LAKCLuM+y9U2T4hlwvT1yprcna4=
+github.com/hashicorp/vault-client-go v0.4.3 h1:zG7STGVgn/VK6rnZc0k8PGbfv2x/sJExRKHSUg3ljWc=
+github.com/hashicorp/vault-client-go v0.4.3/go.mod h1:4tDw7Uhq5XOxS1fO+oMtotHL7j4sB9cp0T7U6m4FzDY=
 github.com/jpillora/backoff v1.0.0 h1:uvFg412JmmHBHw7iwprIxkPMI+sGQ4kzOWsMeHnm2EA=
 github.com/jpillora/backoff v1.0.0/go.mod h1:J/6gKK9jxlEcS3zixgDgUAsiuZ7yrSoa/FX5e0EB2j4=
 github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
@@ -43,6 +55,8 @@ github.com/mdlayher/socket v0.4.1 h1:eM9y2/jlbs1M615oshPQOHZzj6R6wMT7bX5NPiQvn2U
 github.com/mdlayher/socket v0.4.1/go.mod h1:cAqeGjoufqdxWkD7DkpyS+wcefOtmu5OQ8KuoJGIReA=
 github.com/mdlayher/vsock v1.2.1 h1:pC1mTJTvjo1r9n9fbm7S1j04rCgCzhCOS5DY0zqHlnQ=
 github.com/mdlayher/vsock v1.2.1/go.mod h1:NRfCibel++DgeMD8z/hP+PPTjlNJsdPOmxcnENvE+SE=
+github.com/mitchellh/go-homedir v1.1.0 h1:lukF9ziXFxDFPkA1vsr5zpc1XuPDn/wFntq5mG+4E0Y=
+github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
 github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f h1:KUppIJq7/+SVif2QVs3tOP0zanoHgBEVAwHxUSIzRqU=
@@ -61,11 +75,14 @@ github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0leargg
 github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
+github.com/ryanuber/go-glob v1.0.0 h1:iQh3xXAumdQ+4Ufa5b25cRpC5TYKlno6hsv6Cb3pkBk=
+github.com/ryanuber/go-glob v1.0.0/go.mod h1:807d1WSdnB0XRJzKNil9Om6lcp/3a0v4qIHxIXzX/Yc=
 github.com/smarty/assertions v1.15.0 h1:cR//PqUBUiQRakZWqBiFFQ9wb8emQGDb0HeGdqGByCY=
 github.com/smarty/assertions v1.15.0/go.mod h1:yABtdzeQs6l1brC900WlRNwj6ZR55d7B+E8C6HtKdec=
 github.com/smartystreets/goconvey v1.8.1 h1:qGjIddxOk4grTu9JPOU31tVfq3cNdBlNa5sSznIX1xY=
 github.com/smartystreets/goconvey v1.8.1/go.mod h1:+/u4qLyY6x1jReYOp7GOM2FSt8aP9CzCZL03bI28W60=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
@@ -83,6 +100,8 @@ golang.org/x/sys v0.25.0 h1:r+8e+loiHxRqhXVl6ML1nO3l1+oFoWbnlu2Ehimmi34=
 golang.org/x/sys v0.25.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.18.0 h1:XvMDiNzPAl0jr17s6W9lcaIhGUfUORdGCNsuLmPG224=
 golang.org/x/text v0.18.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
+golang.org/x/time v0.0.0-20220922220347-f3bd1da661af h1:Yx9k8YCG3dvF87UAn2tu2HQLf2dt/eR1bXxpLMWeH+Y=
+golang.org/x/time v0.0.0-20220922220347-f3bd1da661af/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
 google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=