rust cli: Support version subcommand as Python CLI

Integration test case fixed as `nmstatectl-rust --version` returns
`nmstatectl 2.1.0`.

Signed-off-by: Gris Ge <fge@redhat.com>

rust/src/cli/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "nmstatectl"
-version = "0.1.0"
+version = "2.1.0"
 authors = ["Gris Ge <fge@redhat.com>"]
 edition = "2018"
 

rust/src/cli/ncl.rs

@@ -12,19 +12,22 @@ use serde_yaml::{self, Value};
 
 use crate::error::CliError;
 
+const APP_NAME: &str = "nmstatectl";
+
 const SUB_CMD_GEN_CONF: &str = "gc";
 const SUB_CMD_SHOW: &str = "show";
 const SUB_CMD_APPLY: &str = "apply";
 const SUB_CMD_COMMIT: &str = "commit";
 const SUB_CMD_ROLLBACK: &str = "rollback";
 const SUB_CMD_EDIT: &str = "edit";
+const SUB_CMD_VERSION: &str = "version";
 
 const EX_DATAERR: i32 = 65;
 const EXIT_FAILURE: i32 = 1;
 
 fn main() {
-    let matches = clap::App::new("nmstatectl")
-        .version("1.0")
+    let matches = clap::App::new(APP_NAME)
+        .version(clap::crate_version!())
         .author("Gris Ge <fge@redhat.com>")
         .about("Command line of nmstate")
         .setting(clap::AppSettings::SubcommandRequired)
@@ -198,7 +201,10 @@ fn main() {
                         .help("Do not make the state persistent"),
                 )
         )
-        .get_matches();
+        .subcommand(
+            clap::SubCommand::with_name(SUB_CMD_VERSION)
+            .about("Show version")
+       ).get_matches();
     let (log_module_filters, log_level) =
         match matches.occurrences_of("verbose") {
             0 => (vec!["nmstate", "nm_dbus"], LevelFilter::Warn),
@@ -246,6 +252,12 @@ fn main() {
         }
     } else if let Some(matches) = matches.subcommand_matches(SUB_CMD_EDIT) {
         print_result_and_exit(state_edit(matches), EX_DATAERR);
+    } else if matches.subcommand_matches(SUB_CMD_VERSION).is_some() {
+        print_string_and_exit(format!(
+            "{} {}",
+            APP_NAME,
+            clap::crate_version!()
+        ));
     }
 }
 

tests/integration/nmstatectl_test.py

@@ -266,14 +266,14 @@ def test_version_argument():
     ret = cmdlib.exec_cmd(("nmstatectl", "--version"))
     rc, out, _ = ret
     assert rc == cmdlib.RC_SUCCESS, cmdlib.format_exec_cmd_result(ret)
-    assert out.rstrip() == __version__
+    assert __version__ in out
 
 
 def test_version_command():
     ret = cmdlib.exec_cmd(("nmstatectl", "version"))
     rc, out, _ = ret
     assert rc == cmdlib.RC_SUCCESS, cmdlib.format_exec_cmd_result(ret)
-    assert out.rstrip() == __version__
+    assert __version__ in out
 
 
 def assert_command(cmd, expected_rc=cmdlib.RC_SUCCESS):