From 709b778904f0d1488f4ac323b42dee7d96f6b098 Mon Sep 17 00:00:00 2001
From: Stas Kelvich <stas.kelvich@gmail.com>
Date: Wed, 19 May 2021 12:32:57 +0300
Subject: [PATCH] Show help in CLI when no arguments provided

---
 pageserver/src/repository.rs |  1 -
 zenith/src/main.rs           | 11 +++++++----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/pageserver/src/repository.rs b/pageserver/src/repository.rs
index b6cdb59770..3e6846def6 100644
--- a/pageserver/src/repository.rs
+++ b/pageserver/src/repository.rs
@@ -353,7 +353,6 @@ mod tests {
     /// "// CORRECT: <correct answer>"
     #[test]
     fn test_relsize() -> Result<()> {
-
         // get_timeline() with non-existent timeline id should fail
         //repo.get_timeline("11223344556677881122334455667788");
 
diff --git a/zenith/src/main.rs b/zenith/src/main.rs
index 1d461e811e..cccc2ffc3b 100644
--- a/zenith/src/main.rs
+++ b/zenith/src/main.rs
@@ -1,6 +1,6 @@
 use anyhow::{anyhow, bail};
 use anyhow::{Context, Result};
-use clap::{App, Arg, ArgMatches, SubCommand};
+use clap::{App, AppSettings, Arg, ArgMatches, SubCommand};
 use control_plane::compute::ComputeControlPlane;
 use control_plane::local_env::{self, LocalEnv};
 use control_plane::storage::PageServerNode;
@@ -27,6 +27,7 @@ fn main() -> Result<()> {
         .required(true);
 
     let matches = App::new("zenith")
+        .setting(AppSettings::ArgRequiredElseHelp)
         .about("Zenith CLI")
         .subcommand(
             SubCommand::with_name("init")
@@ -45,11 +46,12 @@ fn main() -> Result<()> {
                 .arg(Arg::with_name("start-point").required(false).index(2)),
         )
         .subcommand(SubCommand::with_name("status"))
-        .subcommand(SubCommand::with_name("start"))
-        .subcommand(SubCommand::with_name("stop"))
-        .subcommand(SubCommand::with_name("restart"))
+        .subcommand(SubCommand::with_name("start").about("Start local pageserver"))
+        .subcommand(SubCommand::with_name("stop").about("Stop local pageserver"))
+        .subcommand(SubCommand::with_name("restart").about("Restart local pageserver"))
         .subcommand(
             SubCommand::with_name("pg")
+                .setting(AppSettings::ArgRequiredElseHelp)
                 .about("Manage postgres instances")
                 .subcommand(
                     SubCommand::with_name("create")
@@ -65,6 +67,7 @@ fn main() -> Result<()> {
         )
         .subcommand(
             SubCommand::with_name("remote")
+                .setting(AppSettings::ArgRequiredElseHelp)
                 .about("Manage remote pagerservers")
                 .subcommand(
                     SubCommand::with_name("add")