Wire up CLI to FML command lines

components/support/nimbus-cli/src/cli.rs

@@ -2,7 +2,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
-use std::path::PathBuf;
+use std::{ffi::OsString, path::PathBuf};
 
 use chrono::Utc;
 use clap::{Args, Parser, Subcommand};
@@ -176,6 +176,13 @@ pub(crate) enum CliCommand {
         list: ExperimentListArgs,
     },
 
+    /// Execute a nimbus-fml command. See
+    ///
+    /// nimbus-cli fml -- --help
+    ///
+    /// for more.
+    Fml { args: Vec<OsString> },
+
     /// Displays information about an experiment
     Info {
         #[command(flatten)]

components/support/nimbus-cli/src/cmd.rs

@@ -5,7 +5,7 @@
 #[cfg(feature = "server")]
 use crate::output::server;
 use crate::{
-    output::deeplink,
+    output::{deeplink, fml_cli},
     protocol::StartAppProtocol,
     sources::ManifestSource,
     value_utils::{
@@ -73,6 +73,7 @@ pub(crate) fn process_cmd(cmd: &AppCommand) -> Result<bool> {
         )?,
 
         AppCommand::FetchList { list, file } => list.fetch_list(file.as_ref())?,
+        AppCommand::FmlPassthrough { args, cwd } => fml_cli(args, cwd)?,
         AppCommand::Info { experiment, output } => experiment.print_info(output.as_ref())?,
         AppCommand::Kill { app } => app.kill_app()?,
         AppCommand::List { list, .. } => list.print_list()?,

components/support/nimbus-cli/src/main.rs

@@ -166,6 +166,11 @@ enum AppCommand {
         file: Option<PathBuf>,
     },
 
+    FmlPassthrough {
+        args: Vec<OsString>,
+        cwd: PathBuf,
+    },
+
     Info {
         experiment: ExperimentSource,
         output: Option<PathBuf>,
@@ -348,6 +353,10 @@ impl TryFrom<&Cli> for AppCommand {
 
                 AppCommand::FetchList { list, file: output }
             }
+            CliCommand::Fml { args } => {
+                let cwd = std::env::current_dir().expect("Current Working Directory is not set");
+                AppCommand::FmlPassthrough { args, cwd }
+            }
             CliCommand::Info { experiment, output } => AppCommand::Info {
                 experiment: ExperimentSource::try_from(&experiment)?,
                 output,

components/support/nimbus-cli/src/output/fml_cli.rs

@@ -0,0 +1,30 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+use std::{
+    ffi::{OsStr, OsString},
+    path::Path,
+    vec,
+};
+
+use anyhow::Result;
+use nimbus_fml::command_line::do_main;
+
+pub(crate) fn fml_cli(args: &Vec<OsString>, cwd: &Path) -> Result<bool> {
+    // We prepend the string `nimbus-cli fml` to the args to pass to FML
+    // because the clap uses the 0th argument for help messages.
+    let first = OsStr::new("nimbus-cli fml").to_os_string();
+    let mut cli_args = vec![&first];
+
+    // To make this a little more ergonomic, if the user has just typed
+    // `nimbus-cli fml`, then we can help them a little bit.
+    let help = OsStr::new("--help").to_os_string();
+    if args.is_empty() {
+        cli_args.push(&help);
+    } else {
+        cli_args.extend(args);
+    }
+    do_main(cli_args, cwd)?;
+    Ok(true)
+}

components/support/nimbus-cli/src/output/mod.rs

@@ -5,6 +5,9 @@
 pub(crate) mod deeplink;
 mod features;
 mod fetch;
+mod fml_cli;
 pub(crate) mod info;
 #[cfg(feature = "server")]
 pub(crate) mod server;
+
+pub(crate) use fml_cli::fml_cli;