Implement hot reload (#343)

* Update supported versions in security policy

* Bump github.com/gkampitakis/go-snaps from 0.5.4 to 0.5.7 (#345)

Bumps [github.com/gkampitakis/go-snaps](https://github.com/gkampitakis/go-snaps) from 0.5.4 to 0.5.7.
- [Release notes](https://github.com/gkampitakis/go-snaps/releases)
- [Commits](gkampitakis/go-snaps@v0.5.4...v0.5.7)

---
updated-dependencies:
- dependency-name: github.com/gkampitakis/go-snaps
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Bump golang from 1.22.5-alpine3.19 to 1.22.6-alpine3.19 (#347)

Bumps golang from 1.22.5-alpine3.19 to 1.22.6-alpine3.19.

---
updated-dependencies:
- dependency-name: golang
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Bump golang from 1.22.6-alpine3.19 to 1.23.0-alpine3.19 (#352)

Bumps golang from 1.22.6-alpine3.19 to 1.23.0-alpine3.19.

---
updated-dependencies:
- dependency-name: golang
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Bump github.com/prometheus/client_golang from 1.19.1 to 1.20.0 (#349)

Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.19.1 to 1.20.0.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/v1.20.0/CHANGELOG.md)
- [Commits](prometheus/client_golang@v1.19.1...v1.20.0)

---
updated-dependencies:
- dependency-name: github.com/prometheus/client_golang
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Bump github.com/prometheus/client_golang from 1.20.0 to 1.20.1 (#353)

Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.20.0 to 1.20.1.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/v1.20.1/CHANGELOG.md)
- [Commits](prometheus/client_golang@v1.20.0...v1.20.1)

---
updated-dependencies:
- dependency-name: github.com/prometheus/client_golang
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Bump github.com/prometheus/client_golang from 1.20.1 to 1.20.2 (#354)

Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.20.1 to 1.20.2.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/main/CHANGELOG.md)
- [Commits](prometheus/client_golang@v1.20.1...v1.20.2)

---
updated-dependencies:
- dependency-name: github.com/prometheus/client_golang
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Bump github.com/prometheus/client_golang from 1.20.2 to 1.20.3 (#355)

Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.20.2 to 1.20.3.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/v1.20.3/CHANGELOG.md)
- [Commits](prometheus/client_golang@v1.20.2...v1.20.3)

---
updated-dependencies:
- dependency-name: github.com/prometheus/client_golang
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Bump golang from 1.23.0-alpine3.19 to 1.23.1-alpine3.19 (#356)

Bumps golang from 1.23.0-alpine3.19 to 1.23.1-alpine3.19.

---
updated-dependencies:
- dependency-name: golang
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Bump cosmtrek/air from v1.52.3 to v1.60.0 (#358)

Bumps cosmtrek/air from v1.52.3 to v1.60.0.

---
updated-dependencies:
- dependency-name: cosmtrek/air
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Bump github.com/prometheus/client_golang from 1.20.3 to 1.20.4 (#357)

Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.20.3 to 1.20.4.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/main/CHANGELOG.md)
- [Commits](prometheus/client_golang@v1.20.3...v1.20.4)

---
updated-dependencies:
- dependency-name: github.com/prometheus/client_golang
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Add startup manager

* Refactor startup manager

* Try to get reload working

* Fix prometheus reloading

* Remove comments etc

* Make hot reload functional

* Fix for vim

* Make it optable via hot-reload flag

* Change to small size letters

* Make file watcher react to modification

* Use default nil value for collector

* Make changes according to review

* Small fix

* Check if configs are equal on reloading

* Refactor according to the request

* Change flag name to -watch

---------

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: Jakub Surdej <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.22.5-alpine3.19 as build
+FROM golang:1.23.1-alpine3.19 as build
 
 ARG VERSION \
     GIT_COMMIT \

Dockerfile.dev

@@ -1,7 +1,7 @@
-FROM cosmtrek/air:v1.52.3 as air
+FROM cosmtrek/air:v1.60.0 as air
 
 
-FROM golang:1.22.5-alpine3.19
+FROM golang:1.23.1-alpine3.19
 
 WORKDIR /app
 

SECURITY.md

@@ -5,8 +5,8 @@
 | Version | Supported          |
 | ------- | ------------------ |
 | 2.0.x   | :white_check_mark: |
-| 1.6.x   | :white_check_mark: |
-| < 1.6.0 | :x:                |
+| 1.7.x   | :white_check_mark: |
+| < 1.7.0 | :x:                |
 
 ## Reporting a Vulnerability
 

cmd/exporter/main.go

@@ -1,8 +1,14 @@
 package main
 
-import "github.com/kuskoman/logstash-exporter/internal/startup_manager"
+import (
+	"context"
+
+	"github.com/kuskoman/logstash-exporter/internal/startup_manager"
+)
 
 func main() {
+	ctx := context.Background()
+
 	startupManager := startup_manager.NewStartupManager()
-	startupManager.Initialize()
+	startupManager.Initialize(ctx)
 }

go.mod

@@ -4,28 +4,33 @@ go 1.22.0
 
 require (
 	github.com/joho/godotenv v1.5.1
-	github.com/prometheus/client_golang v1.19.1
+	github.com/prometheus/client_golang v1.20.4
 	gopkg.in/yaml.v2 v2.4.0
 )
 
 require (
+	github.com/fsnotify/fsnotify v1.7.0 // indirect
 	github.com/gkampitakis/ciinfo v0.3.0 // indirect
 	github.com/gkampitakis/go-diff v1.3.2 // indirect
+	github.com/klauspost/compress v1.17.9 // indirect
 	github.com/kr/pretty v0.3.1 // indirect
 	github.com/kr/text v0.2.0 // indirect
 	github.com/maruel/natural v1.1.1 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/oklog/run v1.1.0 // indirect
 	github.com/rogpeppe/go-internal v1.12.0 // indirect
+	github.com/slok/reload v0.1.0 // indirect
 	github.com/tidwall/gjson v1.17.0 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
 	github.com/tidwall/pretty v1.2.1 // indirect
 	github.com/tidwall/sjson v1.2.5 // indirect
+	golang.org/x/sync v0.7.0 // indirect
 )
 
 require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
-	github.com/gkampitakis/go-snaps v0.5.4
+	github.com/gkampitakis/go-snaps v0.5.7
 	github.com/prometheus/client_model v0.6.1
 	github.com/prometheus/common v0.55.0 // indirect
 	github.com/prometheus/procfs v0.15.1 // indirect

go.sum

@@ -3,29 +3,39 @@ github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6r
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
 github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nosvA=
+github.com/fsnotify/fsnotify v1.7.0/go.mod h1:40Bi/Hjc2AVfZrqy+aj+yEI+/bRxZnMJyTJwOpGvigM=
 github.com/gkampitakis/ciinfo v0.3.0 h1:gWZlOC2+RYYttL0hBqcoQhM7h1qNkVqvRCV1fOvpAv8=
 github.com/gkampitakis/ciinfo v0.3.0/go.mod h1:1NIwaOcFChN4fa/B0hEBdAb6npDlFL8Bwx4dfRLRqAo=
 github.com/gkampitakis/go-diff v1.3.2 h1:Qyn0J9XJSDTgnsgHRdz9Zp24RaJeKMUHg2+PDZZdC4M=
 github.com/gkampitakis/go-diff v1.3.2/go.mod h1:LLgOrpqleQe26cte8s36HTWcTmMEur6OPYerdAAS9tk=
-github.com/gkampitakis/go-snaps v0.5.4 h1:GX+dkKmVsRenz7SoTbdIEL4KQARZctkMiZ8ZKprRwT8=
-github.com/gkampitakis/go-snaps v0.5.4/go.mod h1:ZABkO14uCuVxBHAXAfKG+bqNz+aa1bGPAg8jkI0Nk8Y=
+github.com/gkampitakis/go-snaps v0.5.7 h1:uVGjHR4t4pPHU944udMx7VKHpwepZXmvDMF+yDmI0rg=
+github.com/gkampitakis/go-snaps v0.5.7/go.mod h1:ZABkO14uCuVxBHAXAfKG+bqNz+aa1bGPAg8jkI0Nk8Y=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
 github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
+github.com/klauspost/compress v1.17.9 h1:6KIumPrER1LHsvBVuDa0r5xaG0Es51mhhB9BQB2qeMA=
+github.com/klauspost/compress v1.17.9/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
+github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
 github.com/maruel/natural v1.1.1 h1:Hja7XhhmvEFhcByqDoHz9QZbkWey+COd9xWfCfn1ioo=
 github.com/maruel/natural v1.1.1/go.mod h1:v+Rfd79xlw1AgVBjbO0BEQmptqb5HvL/k9GRHB7ZKEg=
 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/oklog/run v1.1.0 h1:GEenZ1cK0+q0+wsJew9qUg/DyD8k3JzYsZAi5gYi2mA=
+github.com/oklog/run v1.1.0/go.mod h1:sVPdnTZT1zYwAJeCMu2Th4T21pA3FPOQRfWjQlk7DVU=
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
-github.com/prometheus/client_golang v1.19.1 h1:wZWJDwK+NameRJuPGDhlnFgx8e8HN3XHQeLaYJFJBOE=
-github.com/prometheus/client_golang v1.19.1/go.mod h1:mP78NwGzrVks5S2H6ab8+ZZGJLZUq1hoULYBAYBw1Ho=
+github.com/prometheus/client_golang v1.20.4 h1:Tgh3Yr67PaOv/uTqloMsCEdeuFTatm5zIq5+qNN23vI=
+github.com/prometheus/client_golang v1.20.4/go.mod h1:PIEt8X02hGcP8JWbeHyeZ53Y/jReSnHgO035n//V5WE=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_model v0.6.1 h1:ZKSh/rekM+n3CeS952MLRAdFwIKqeY8b62p8ais2e9E=
 github.com/prometheus/client_model v0.6.1/go.mod h1:OrxVMOVHjw3lKMa8+x6HeMGkHMQyHDk9E3jmP2AmGiY=
 github.com/prometheus/common v0.55.0 h1:KEi6DK7lXW/m7Ig5i47x0vRzuBsHuvJdi5ee6Y3G1dc=
@@ -35,6 +45,10 @@ github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoG
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/rogpeppe/go-internal v1.12.0 h1:exVL4IDcn6na9z1rAb56Vxr+CgyK3nn3O+epU5NdKM8=
 github.com/rogpeppe/go-internal v1.12.0/go.mod h1:E+RYuTGaKKdloAfM02xzb0FW3Paa99yedzYV+kq4uf4=
+github.com/slok/reload v0.1.0 h1:VEkUHiV+7WCJ5+zKxuWhD41NFpr1G7ACILz43aXuP+8=
+github.com/slok/reload v0.1.0/go.mod h1:rQBFU7T77Rrm9zMyZRtCWexRBcFesEGPWj72KPzra/A=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/tidwall/gjson v1.14.2/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
 github.com/tidwall/gjson v1.17.0 h1:/Jocvlh98kcTfpN2+JzGQWQcqrPQwDrVEMApx/M5ZwM=
 github.com/tidwall/gjson v1.17.0/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
@@ -45,6 +59,9 @@ github.com/tidwall/pretty v1.2.1 h1:qjsOFOWWQl+N3RsoF5/ssm1pHmJJwhjlSbZ51I6wMl4=
 github.com/tidwall/pretty v1.2.1/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
 github.com/tidwall/sjson v1.2.5 h1:kLy8mja+1c9jlljvWTlSazM7cKDRfJuR/bOJhcY5NcY=
 github.com/tidwall/sjson v1.2.5/go.mod h1:Fvgq9kS/6ociJEDnK0Fk1cpYF4FIW6ZF7LAe+6jwd28=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
+golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
 golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
@@ -54,3 +71,4 @@ gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntN
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/startup_manager/flags.go

@@ -10,11 +10,13 @@ import (
 
 type flagsConfig struct {
 	configLocation *string
+	hotReload *bool
 }
 
 func handleFlags() (*flagsConfig, bool) {
 	versionFlag := flag.Bool("version", false, "prints the version and exits")
 	helpFlag := flag.Bool("help", false, "prints the help message and exits")
+	hotReloadFlag := flag.Bool("watch", false, "enable configuration hot reload")
 	configLocationFlag := flag.String("config", config.ExporterConfigLocation, "location of the exporter config file")
 
 	flag.Parse()
@@ -36,6 +38,7 @@ func handleFlags() (*flagsConfig, bool) {
 
 	flagsConfig := &flagsConfig{
 		configLocation: configLocationFlag,
+		hotReload: hotReloadFlag,
 	}
 
 	return flagsConfig, false