Minor tweaks to the README

Cargo.toml

@@ -4,6 +4,7 @@ version = "0.1.0"
 authors = ["Parity Technologies <admin@parity.io>"]
 edition = "2018"
 license = "GPLv3+"
+default-run = "ledgeracio"
 
 [dependencies]
 substrate-subxt = { git = "https://github.com/paritytech/substrate-subxt.git", branch = "no-sync-required" }

README.md

@@ -2,7 +2,7 @@
 
 # Ledgeracio CLI
 
-Ledgeracio is a command-line tool and Ledger app designed for staking operations
+Ledgeracio is a command-line tool and a Ledger app designed for staking operations
 on Substrate-based networks.
 
 Running `ledgeracio --help` will provide top-level usage instructions.
@@ -24,19 +24,16 @@ necessary support for userspace USB drivers.
 
 ## What is Ledgeracio?
 
-Ledgeracio is a CLI app to perform various tasks common to staking on Kusama and 
+Ledgeracio is a CLI app to perform various tasks common to staking on Kusama and
 Polkadot, aka staking-ops.  Ledgeracio is designed to reduce the risk of user
 error by way of an allowlist of validators that is set up and signed once and
 stored on the Ledger device. Furthermore, Ledgeracio can speed up the workflow
 considerably when compared to alternatives using Parity Signer + Polkadot{.js}.
 
 This repository only contains the CLI.  To submit transactions with Ledgeracio,
-you will also need the companion Ledger app.  Experimental versions are
-available at [Zondax/ledger-polkadot](https://github.com/Zondax/ledger-polkadot)
+you will also need the companion Ledger app that you can install from the Ledger app store for [Polkadot](https://support.ledger.com/hc/en-us/articles/360016289919) and [Kusama](https://support.ledger.com/hc/en-us/articles/360016289979-Kusama-KSM-).  Development versions of the apps are available at [Zondax/ledger-polkadot](https://github.com/Zondax/ledger-polkadot)
 and [Zondax/ledger-kusama](https://github.com/Zondax/ledger-kusama).  Please do
-not use these unaudited versions in production.  In the near future, Ledger will
-approve and sign production versions of these apps, which will be available in
-the Ledger Store.
+not use the unaudited versions in production.  For instruction on how to setup and use your Ledger device with Polkadot/Kusama, see the [Polkadot wiki](https://wiki.polkadot.network/docs/en/learn-ledger).
 
 The Ledgeracio CLI contains two binaries.  The first, simply called
 `ledgeracio`, is used to submit transactions.  The second, called
@@ -48,11 +45,10 @@ can safely be used on virtually any machine on which it will run.
 Some subcommands of `ledgeracio-allowlist`, however, generate and use secret
 keys, which are stored unencrypted on disk.  Therefore, they MUST NOT be used
 except on trusted and secured machines.  Ideally, these subcommands should be
-run on a machine that is reserved for provisioning of Ledgeracio apps, and
-which has no network connectivity.
+run on a machine that is reserved for provisioning of Ledger devices with the Ledgeracio app, and which has no network connectivity.
 
 The allowlist serves to prevent one from accidentally nominating the wrong
-validator, which could result in a slash.  It does not protect against malicious
+validator, which could result in a slash.  It does NOT protect against malicious
 use of the device.  Anyone with both the device and its PIN can uninstall the
 Ledgeracio app and install the standard Polkadot or Kusama app, which uses the
 same derivation path and thus can perform the same transactions.
@@ -117,7 +113,7 @@ binary format.
 ### Device provisioning
 
 `ledgeracio-allowlist` is also used for device provisioning.  To set the
-allowlist, one uses `ledgeracio-allowlist set-key`.  This command will only
+allowlist, use `ledgeracio-allowlist set-key`.  This command will only
 succeed once.  If an allowlist has already been uploaded, it will fail.  The
 only way to change the allowlist signing key is to reinstall the Ledgeracio app,
 which does not result in any funds being lost.
@@ -151,7 +147,7 @@ status.  The first takes an index, while the second takes an address.
 ### Allowlist handling: `ledgeracio-allowlist`
 
 The Ledgeracio app enforces a list of allowed stash accounts.  This is
-managed using the `ledgeracio allowlist` command.
+managed using the `ledgeracio-allowlist` command.
 
 Some subcommands involve the generation or use of secret keys, which are stored
 on disk without encryption.  These subcommands MUST NOT be used on untrusted
@@ -169,7 +165,7 @@ This is to prevent accidental overwrites.
 
 The public key is not sensitive, and is required by anyone who wishes to verify
 signed allowlists and operate on the allowed accounts.  It will be uploaded
-to the Ledger device by `ledgeracio allowlist set-key`.  The secret key allows
+to the Ledger device by `ledgeracio-allowlist set-key`.  The secret key allows
 generating signatures, and therefore must be kept secret.  It should never leave
 the (preferably air gapped) machine it is generated on.
 
@@ -299,8 +295,8 @@ given index.
 #### Announcing an intention to validate: `ledgeracio validator announce <index> [commission]`
 
 This command announces that the controller account at `<index>` intends to
-validate.  An optional commission may also be provided.  If none is supplied, it
-defaults to 100%.
+validate.  An optional commission (as a decimal between 0 and 1 inclusive) may also be provided.  If none is supplied, it
+defaults to 1, or 100%.
 
 #### Cease validation: `ledgeracio validator chill`
 

src/bin/ledgeracio/common.rs

@@ -143,9 +143,36 @@ pub fn pad(mut zeros: u8, value: u128) -> String {
     value
 }
 
+pub fn parse_ppb(data: &str) -> Result<u32, Error> {
+    if data == "1" {
+        Ok(1_000_000_000)
+    } else if data == "0" {
+        Ok(0)
+    } else if !data.starts_with("0.") {
+        Err(
+            "Commission must start with 0. or be equal to 1 (the default) or 0"
+                .to_owned()
+                .into(),
+        )
+    } else if data.len() > 11 {
+        Err("Commission too long.  Check for excess trailing zeroes."
+            .to_owned()
+            .into())
+    } else {
+        let mut len = data.len() - 2;
+        let mut res: u32 = str::parse(&data[2..])?;
+        while len < 9 {
+            res *= 10;
+            len += 1;
+        }
+        Ok(res)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
+
     #[test]
     fn padding_works() {
         assert_eq!(pad(0, 100), "100".to_owned());
@@ -154,4 +181,16 @@ mod tests {
         assert_eq!(pad(3, 10001), "10.001".to_owned());
         assert_eq!(pad(3, 10010), "10.01".to_owned());
     }
+
+    #[test]
+    fn parse_ppb_works() {
+        assert_eq!(parse_ppb("1").unwrap(), 1_000_000_000);
+        assert_eq!(parse_ppb("0").unwrap(), 0);
+        assert!(parse_ppb("0.").is_err());
+        assert_eq!(parse_ppb("0.01").unwrap(), 10_000_000);
+        assert!(parse_ppb("0.0100000000").is_err());
+        assert_eq!(parse_ppb("0.010000000").unwrap(), 10_000_000);
+        assert_eq!(parse_ppb("0.000000000").unwrap(), 0);
+        assert_eq!(parse_ppb("0.999999999").unwrap(), 999_999_999);
+    }
 }

src/bin/ledgeracio/validator.rs

@@ -18,7 +18,8 @@
 //! e.g. rotating session keys, set payment target, announcing
 //! intention to validate etc. Requires a network connection.
 
-use super::{parse_reward_destination, AccountType, AddressSource, Error, LedgeracioPath, StructOpt};
+use super::{common::parse_ppb, parse_reward_destination, AccountType, AddressSource, Error,
+            LedgeracioPath, StructOpt};
 use codec::Decode;
 use core::{future::Future, pin::Pin};
 use ledgeracio::parse_address;
@@ -42,7 +43,11 @@ pub(crate) enum Validator {
     /// specified.
     Show { index: Option<u32> },
     /// Announce intention to validate
-    Announce { index: u32, commission: Option<u32> },
+    Announce {
+        index: u32,
+        #[structopt(parse(try_from_str = parse_ppb))]
+        commission: Option<u32>,
+    },
     /// Chill (announce intention to cease validation)
     Chill { index: u32 },
     /// Replace a session key
@@ -92,8 +97,12 @@ pub(crate) async fn main<T: FnOnce() -> Result<super::HardStore, Error>>(
         }
         Validator::Announce { index, commission } => {
             let path = LedgeracioPath::new(network, AccountType::Validator, index)?;
+            let commission = commission.unwrap_or(1_000_000_000);
+            if commission > 1_000_000_000 {
+                return Err(format!("Commission {} too large (limit is 10⁹)", commission).into())
+            }
             let prefs = ValidatorPrefs {
-                commission: Perbill::from_parts(commission.unwrap_or(u32::max_value())),
+                commission: Perbill::from_parts(commission),
             };
             let signer = keystore()?.signer(path).await?;
             Ok(Some(client.await?.validate(&signer, prefs).await?))