Adds support for pihole update manager (#151)

README.md

@@ -104,6 +104,7 @@ Just run `topgrade`. It will run the following steps:
 * **Linux**: Run [fwupdmgr](https://github.com/hughsie/fwupd) to show firmware upgrade. (View
   only. No upgrades will actually be performed)
 * **Linux**: Run `rpi-update` to update Raspberry Pi Firmware
+* **Linux**: Run [pihole](https://pi-hole.net/) updater
 * Run custom defined commands
 * Final stage
   * **Linux**: Run [needrestart](https://github.com/liske/needrestart)

src/main.rs

@@ -372,6 +372,12 @@ fn run() -> Result<(), Error> {
 
     #[cfg(target_os = "linux")]
     {
+        execute(
+            &mut report,
+            "pihole",
+            || linux::run_pihole_update(sudo.as_ref(), run_type),
+            config.no_retry(),
+        )?;
         execute(
             &mut report,
             "rpi-update",

src/steps/os/linux.rs

@@ -310,6 +310,16 @@ pub fn run_rpi_update(sudo: Option<&PathBuf>, run_type: RunType) -> Result<(), E
     run_type.execute(sudo).arg(rpi_update).check_run()
 }
 
+#[must_use]
+pub fn run_pihole_update(sudo: Option<&PathBuf>, run_type: RunType) -> Result<(), Error> {
+    let sudo = require_option(sudo)?;
+    let pihole = require("pihole")?;
+
+    print_separator("pihole");
+
+    run_type.execute(sudo).arg(pihole).arg("-up").check_run()
+}
+
 #[must_use]
 pub fn run_etc_update(sudo: Option<&PathBuf>, run_type: RunType) -> Result<(), Error> {
     let sudo = require_option(sudo)?;