misc: optionally configure simulated omicron.

Add a --nexus-config flag to omicron-dev to allow custom configuration for
local testing.

Author: jmcarp

dev-tools/omicron-dev/src/main.rs

@@ -12,6 +12,8 @@ use nexus_config::NexusConfig;
 use nexus_test_interface::NexusServer;
 use nexus_test_utils::resource_helpers::DiskTest;
 use signal_hook_tokio::Signals;
+use std::fs;
+use std::os;
 
 fn main() -> anyhow::Result<()> {
     oxide_tokio_rt::run(async {
@@ -50,6 +52,9 @@ struct RunAllArgs {
     /// Override the gateway server configuration file.
     #[clap(long, default_value = DEFAULT_SP_SIM_CONFIG)]
     gateway_config: Utf8PathBuf,
+    /// Override the nexus configuration file.
+    #[clap(long, default_value = "./nexus/examples/config.toml")]
+    nexus_config: Utf8PathBuf,
 }
 
 impl RunAllArgs {
@@ -60,9 +65,10 @@ impl RunAllArgs {
         let mut signal_stream = signals.fuse();
 
         // Read configuration.
-        let config_str = include_str!("../../../nexus/examples/config.toml");
-        let mut config: NexusConfig =
-            toml::from_str(config_str).context("parsing example config")?;
+        let config_str = fs::read_to_string(&self.nexus_config)?;
+        let mut config: NexusConfig = toml::from_str(&config_str).context(
+            format!("parsing config: {}", self.nexus_config.as_str()),
+        )?;
         config.pkg.log = dropshot::ConfigLogging::File {
             // See LogContext::new(),
             path: "UNUSED".to_string().into(),

dev-tools/omicron-dev/tests/test-omicron-dev.rs

@@ -139,7 +139,7 @@ async fn test_run_all() {
     let cmd_path = path_to_omicron_dev();
 
     let cmdstr = format!(
-        "( set -o monitor; {} run-all --nexus-listen-port 0 && true )",
+        "( set -o monitor; {} run-all --nexus-listen-port 0 --nexus-config ../../nexus/examples/config.toml && true )",
         cmd_path.display()
     );
     let exec =