Fix parsing of configuration file argument.

Add a postinstall script.

.goreleaser.yml

@@ -1,3 +1,4 @@
+# yaml-language-server: $schema=https://goreleaser.com/static/schema.json
 before:
   hooks:
     - go mod tidy
@@ -33,7 +34,7 @@ nfpms:
     maintainer: Josh Rich <[email protected]>
     description: A Dynamic DNS client for Cloudflare.
     license: MIT
-    release: 1
+    release: "1"
 
     formats:
       - deb
@@ -57,3 +58,9 @@ nfpms:
       - src: systemd/cf-ddns.service
         dst: /usr/lib/systemd/system/cf-ddns.service
         type: config
+
+    scripts:
+      # preinstall: "scripts/preinstall.sh"
+      postinstall: "scripts/postinstall.sh"
+      # preremove: "scripts/preremove.sh"
+      # postremove: "scripts/postremove.sh"

cmd/root.go

@@ -5,7 +5,7 @@ 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
+	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,
@@ -81,9 +81,9 @@ func init() {
 	// Cobra supports persistent flags, which, if defined here,
 	// will be global for your application.
 
-	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "c", "config file (default is $HOME/.cf-ddns.yaml)")
-	rootCmd.Flags().BoolVarP(&debugFlag, "debug", "d", false, "debug output")
-	rootCmd.Flags().BoolVarP(&profileFlag, "profile", "p", false, "enable profiling")
+	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "/etc/cf-ddns/cf-ddns.yml", "config file (default is /etc/cf-ddns/cf-ddns.yaml)")
+	rootCmd.Flags().BoolVarP(&debugFlag, "debug", "d", false, "debug output (default is false)")
+	rootCmd.Flags().BoolVarP(&profileFlag, "profile", "p", false, "enable profiling (default is false)")
 }
 
 // initConfig reads in config file and ENV variables if set.

scripts/postinstall.sh

@@ -0,0 +1,82 @@
+#!/bin/sh
+
+# Step 1, decide if we should use systemd or init/upstart
+use_systemctl="True"
+systemd_version=0
+if ! command -V systemctl >/dev/null 2>&1; then
+  use_systemctl="False"
+else
+    systemd_version=$(systemctl --version | head -1 | sed 's/systemd //g')
+fi
+
+cleanup() {
+    # This is where you remove files that were not needed on this platform / system
+    if [ "${use_systemctl}" = "False" ]; then
+        rm -f /usr/lib/systemd/system/cf-ddns.service
+    # else
+    #     rm -f /etc/chkconfig/cf-ddns
+    #     rm -f /etc/init.d/cf-ddns
+    fi
+}
+
+cleanInstall() {
+    printf "\033[32m Post Install of an clean install\033[0m\n"
+    # Step 3 (clean install), enable the service in the proper way for this platform
+    if [ "${use_systemctl}" = "False" ]; then
+        # if command -V chkconfig >/dev/null 2>&1; then
+        #   chkconfig --add cf-ddns
+        # fi
+        printf "\033[32m Non-systemd services not supported yet\033[0m\n"
+        # service cf-ddns restart ||:
+    else
+        # rhel/centos7 cannot use ExecStartPre=+ to specify the pre start should be run as root
+        # even if you want your service to run as non root.
+        if [ "${systemd_version}" -lt 231 ]; then
+            printf "\033[31m systemd version %s is less then 231, fixing the service file \033[0m\n" "${systemd_version}"
+            sed -i "s/=+/=/g" /usr/lib/systemd/system/cf-ddns.service
+        fi
+        printf "\033[32m Reload the service unit from disk\033[0m\n"
+        systemctl daemon-reload ||:
+        printf "\033[32m Unmask the service\033[0m\n"
+        systemctl unmask cf-ddns ||:
+        printf "\033[32m Set the preset flag for the service unit\033[0m\n"
+        systemctl preset cf-ddns ||:
+        printf "\033[32m Set the enabled flag for the service unit\033[0m\n"
+        systemctl enable cf-ddns ||:
+        systemctl restart cf-ddns ||:
+    fi
+}
+
+upgrade() {
+    printf "\033[32m Post Install of an upgrade\033[0m\n"
+    # Step 3(upgrade), do what you need
+    # ...
+}
+
+# Step 2, check if this is a clean install or an upgrade
+action="$1"
+if  [ "$1" = "configure" ] && [ -z "$2" ]; then
+  # Alpine linux does not pass args, and deb passes $1=configure
+  action="install"
+elif [ "$1" = "configure" ] && [ -n "$2" ]; then
+    # deb passes $1=configure $2=<current version>
+    action="upgrade"
+fi
+
+case "$action" in
+  "1" | "install")
+    cleanInstall
+    ;;
+  "2" | "upgrade")
+    printf "\033[32m Post Install of an upgrade\033[0m\n"
+    upgrade
+    ;;
+  *)
+    # $1 == version being installed
+    printf "\033[32m Alpine\033[0m"
+    cleanInstall
+    ;;
+esac
+
+# Step 4, clean up unused files, yes you get a warning when you remove the package, but that is ok.
+cleanup

systemd/cf-ddns.service

@@ -6,7 +6,7 @@ After=network-online.target
 
 [Service]
 Type=simple
-ExecStart=/usr/local/bin/cf-ddns -c /etc/cf-ddns/cf-ddns.yml
+ExecStart=/usr/local/bin/cf-ddns
 ProtectSystem=strict
 ProtectHome=yes