Cli binary and protocol with dataplane

[Fredi-raspall]

NB: rides on #363

• Adds a cli binary to issue commands to the dataplane process over a unix socket.
• This PR implements the binary and defines the 'protocol' / wire format with the dataplane over the unix socket.
• At the moment, data is returned as strings., but this can be easily changed to json or binary. Deferring this until the complete data model is defined and we can derive those if needed.

Build

just cargo build --package=cli --bin cli  --features=cli

Once in cli

help

... shows the available commands. Many are not implemented.

Give it a try!
The cli can be started to see the syntax of the commands, even if the dataplane does not handle them.
The command completion requires some re-work.

[qmonnet]

I've glanced over the changes, although I haven't looked at each chunk in details. It looks good, no red flags, great work! It's self-contained in its own crate anyway so low risk to break something when we merge it.

Would be great to have more tests, but a number of them will likely require starting the datapath and run some sort of end-to-end test, which we don't really have any infra for, yet, so we can probably keep that for later.

I'll try to build and run this CLI tomorrow to get a better understanding on the features.

[qmonnet]

Suggested change

	//if a node has no name, skip it and adopt
	//its children. This is just to ease the
	//creation of the tree by creating
	//unnamed commands that will not show up
	// If a node has no name, skip it and adopt
	// its children. This is just to ease the
	// creation of the tree by creating
	// unnamed commands that will not show up.

[Fredi-raspall]

I'd leave it as it is. Note that this is not a doc, it's just an internal comment.

[qmonnet]

Doesn't have to be doc comments, we do usually leave a space after the // marker - at least I can't find any other comment instance without that space 🤷. Your call, though.

[qmonnet]

Missing indent

[qmonnet]

I note you added cli to members but not to default-members, which means tests won't be exercised on a simple cargo test from the root of the repository. Is this Probably something we should change?

[Fredi-raspall]

There are not tests at the moment in the CLI

[qmonnet]

Commit suggestion: exiting on CTRL-D or CTRL-C:

diff --git i/cli/src/bin/cli.rs w/cli/src/bin/cli.rs
index 4d471b51782a..ace08396beb6 100644
--- i/cli/src/bin/cli.rs
+++ w/cli/src/bin/cli.rs
@@ -207,7 +207,13 @@ fn main() {
 
     /* infinite loop until user quits */
     while terminal.runs() {
-        let mut input = terminal.prompt();
+        let mut input = match terminal.prompt() {
+            Some(i) => i,
+            None => {
+                terminal.stop();
+                return;
+            }
+        };
         if let Some(node) = cmds.find_best(input.get_tokens()) {
             terminal.add_history_entry(input.get_line().to_owned());
             if let Some(action) = &node.action {
diff --git i/cli/src/terminal.rs w/cli/src/terminal.rs
index dbc2a0d14a4c..2358b423c72e 100644
--- i/cli/src/terminal.rs
+++ w/cli/src/terminal.rs
@@ -5,6 +5,7 @@
 
 use crate::cmdtree::Node;
 use rustyline::config::{ColorMode, CompletionType, Config};
+use rustyline::error::ReadlineError;
 use rustyline::{Cmd, Event, KeyCode, KeyEvent, Modifiers};
 use smallvec::SmallVec;
 use std::collections::VecDeque;
@@ -122,19 +123,34 @@ impl Terminal {
             self.prompt = self.prompt_name.to_owned() + "(✖)# ";
         }
     }
-    pub fn prompt(&mut self) -> TermInput {
+    pub fn prompt(&mut self) -> Option<TermInput> {
         loop {
             let input = self.editor.readline(&self.prompt);
-            if let Ok(line) = input {
-                let line = line.trim();
-                if line.is_empty() {
-                    continue;
+            match (input) {
+                Ok(line) => {
+                    let line = line.trim();
+                    if line.is_empty() {
+                        continue;
+                    }
+                    if let Some(c) = self.proc_line(line) {
+                        return Some(c);
+                    }
                 }
-                if let Some(c) = self.proc_line(line) {
-                    return c;
+                Err(ReadlineError::Interrupted) => {
+                    println!("CTRL-C");
+                    break;
+                },
+                Err(ReadlineError::Eof) => {
+                    println!("CTRL-D");
+                    break;
+                },
+                Err(err) => {
+                    println!("Error: {:?}", err);
+                    break;
                 }
             }
         }
+        None
     }
     pub fn connected(&mut self, value: bool) {
         self.connected = value;

[qmonnet]

Note: Looking at the help output, I'm not entirely clear why some command names appear in blue and bold (in my terminal, at least), and the others with a regular font.

screenshot

[Fredi-raspall]

Note: Looking at the help output, I'm not entirely clear why some command names appear in blue and bold (in my terminal, at least), and the others with a regular font.

screenshot

I wanted to highlight distinct facts in the output, but I believe I did not finish it. Let me redo.

[Fredi-raspall]

Commit suggestion: exiting on CTRL-D or CTRL-C:

diff --git i/cli/src/bin/cli.rs w/cli/src/bin/cli.rs
index 4d471b51782a..ace08396beb6 100644
--- i/cli/src/bin/cli.rs
+++ w/cli/src/bin/cli.rs
@@ -207,7 +207,13 @@ fn main() {
 
     /* infinite loop until user quits */
     while terminal.runs() {
-        let mut input = terminal.prompt();
+        let mut input = match terminal.prompt() {
+            Some(i) => i,
+            None => {
+                terminal.stop();
+                return;
+            }
+        };
         if let Some(node) = cmds.find_best(input.get_tokens()) {
             terminal.add_history_entry(input.get_line().to_owned());
             if let Some(action) = &node.action {
diff --git i/cli/src/terminal.rs w/cli/src/terminal.rs
index dbc2a0d14a4c..2358b423c72e 100644
--- i/cli/src/terminal.rs
+++ w/cli/src/terminal.rs
@@ -5,6 +5,7 @@
 
 use crate::cmdtree::Node;
 use rustyline::config::{ColorMode, CompletionType, Config};
+use rustyline::error::ReadlineError;
 use rustyline::{Cmd, Event, KeyCode, KeyEvent, Modifiers};
 use smallvec::SmallVec;
 use std::collections::VecDeque;
@@ -122,19 +123,34 @@ impl Terminal {
             self.prompt = self.prompt_name.to_owned() + "(✖)# ";
         }
     }
-    pub fn prompt(&mut self) -> TermInput {
+    pub fn prompt(&mut self) -> Option<TermInput> {
         loop {
             let input = self.editor.readline(&self.prompt);
-            if let Ok(line) = input {
-                let line = line.trim();
-                if line.is_empty() {
-                    continue;
+            match (input) {
+                Ok(line) => {
+                    let line = line.trim();
+                    if line.is_empty() {
+                        continue;
+                    }
+                    if let Some(c) = self.proc_line(line) {
+                        return Some(c);
+                    }
                 }
-                if let Some(c) = self.proc_line(line) {
-                    return c;
+                Err(ReadlineError::Interrupted) => {
+                    println!("CTRL-C");
+                    break;
+                },
+                Err(ReadlineError::Eof) => {
+                    println!("CTRL-D");
+                    break;
+                },
+                Err(err) => {
+                    println!("Error: {:?}", err);
+                    break;
                 }
             }
         }
+        None
     }
     pub fn connected(&mut self, value: bool) {
         self.connected = value;

Sorry, I should have mentioned this. There are some "aliases" or shortcuts, that do not show up in the help. If you want to quit, you can type "quit" or "exit" (these are shown), but you can also use "q".

[qmonnet]

There are some "aliases" or shortcuts, that do not show up in the help. If you want to quit, you can type "quit" or "exit" (these are shown), but you can also use "q".

I found quit and exit, and it's OK 🙂. I just find it so much more convenient to exit from a shell session with CTRL+D, as a habit.