introduce config file for command arguments

PKGBUILD

@@ -2,7 +2,7 @@
 
 pkgname=prometheus-blackbox-exporter
 pkgver=0.20.0
-pkgrel=1
+pkgrel=2
 pkgdesc="Allows blackbox probing of endpoints over HTTP, HTTPS, DNS, TCP and ICMP"
 arch=('x86_64')
 url="https://github.com/prometheus/blackbox_exporter"
@@ -10,9 +10,13 @@ license=('Apache')
 depends=(glibc)
 makedepends=(go git)
 options=(!lto)
-source=($pkgname-$pkgver.tar.gz::https://github.com/prometheus/blackbox_exporter/archive/v${pkgver}.tar.gz prometheus-blackbox-exporter.service)
+backup=('etc/conf.d/prometheus-blackbox-exporter')
+source=($pkgname-$pkgver.tar.gz::https://github.com/prometheus/blackbox_exporter/archive/v${pkgver}.tar.gz
+        prometheus-blackbox-exporter.service
+        prometheus-blackbox-exporter.conf)
 sha512sums=('62aabcdc7a740521959e9187dcb24be4c8c09c55c60b510efbc9991d37d9a87adf1e11b4577b72c74d14a96c066e09d935a32e4b2ae82d7e2b2ea63b48f31358'
-            'b32d7772cbd8a2fc741d827a7f221d1302ab0c5833c095e5b6dc6befa46a1b12c22e91252fd0e4cf07c9c309d6315c6e1d020508a3baaaa891ab9f7f7d690eae')
+            '72747736e4783e313acb4cb917c3311ed736d69e9b22799132b4aad46b50072f3664c6377c271e720c3e620ab2a6db48110f8d92cc62cf7674cafc32fd1fb2e4'
+            '4cf607e698801396cd7cbde9371b6bc504c7e2ad62e127bccca098222be052e2a312490d93c7ba63304defbb40bc156fc76c79097c6b71bde243d834c02ed2cd')
 
 check() {
   cd blackbox_exporter-$pkgver
@@ -36,6 +40,7 @@ build() {
 }
 
 package() {
+  install -Dm644 prometheus-blackbox-exporter.conf "$pkgdir"/etc/conf.d/prometheus-blackbox-exporter
   install -Dm644 prometheus-blackbox-exporter.service "$pkgdir"/usr/lib/systemd/system/prometheus-blackbox-exporter.service
   cd blackbox_exporter-$pkgver
   install -Dm755 blackbox_exporter "$pkgdir"/usr/bin/prometheus-blackbox-exporter

prometheus-blackbox-exporter.conf

+BLACKBOX_EXPORTER_ARGS="--config.file='/etc/prometheus/blackbox.yml'"

prometheus-blackbox-exporter.service

@@ -3,7 +3,8 @@ Description=Prometheus blackbox Exporter
 After=network.target
 
 [Service]
-ExecStart=/usr/bin/prometheus-blackbox-exporter --config.file="/etc/prometheus/blackbox.yml"
+EnvironmentFile=-/etc/conf.d/prometheus-blackbox-exporter
+ExecStart=/usr/bin/prometheus-blackbox-exporter $BLACKBOX_EXPORTER_ARGS
 ExecReload=/bin/kill -HUP $MAINPID
 DynamicUser=true