refactor(guest-agent): isolate simulator into standalone binary

Author: kvinwang

CLAUDE.md

@@ -48,6 +48,7 @@ cargo build --release -p dstack-vmm
 cargo build --release -p dstack-kms
 cargo build --release -p dstack-gateway
 cargo build --release -p dstack-guest-agent
+cargo build --release -p dstack-guest-agent-simulator
 
 # Check code
 cargo check --all-features

Cargo.lock

@@ -24,6 +24,7 @@ members = [
     "iohash",
     "guest-agent",
     "guest-agent/rpc",
+    "guest-agent-simulator",
     "vmm",
     "vmm/rpc",
     "gateway",

Cargo.toml

@@ -0,0 +1,26 @@
+# SPDX-FileCopyrightText: © 2025 Phala Network <dstack@phala.network>
+#
+# SPDX-License-Identifier: Apache-2.0
+
+[package]
+name = "dstack-guest-agent-simulator"
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+
+[[bin]]
+name = "dstack-simulator"
+path = "src/main.rs"
+
+[dependencies]
+anyhow.workspace = true
+clap.workspace = true
+serde.workspace = true
+tracing.workspace = true
+tracing-subscriber.workspace = true
+rocket.workspace = true
+ra-rpc = { workspace = true, features = ["rocket"] }
+ra-tls = { workspace = true, features = ["quote"] }
+dstack-guest-agent = { path = "../guest-agent" }
+dstack-guest-agent-rpc.workspace = true

guest-agent-simulator/Cargo.toml

@@ -0,0 +1,35 @@
+# SPDX-FileCopyrightText: © 2025 Phala Network <dstack@phala.network>
+#
+# SPDX-License-Identifier: Apache-2.0
+
+[default]
+workers = 8
+max_blocking = 64
+ident = "dstack Simulator"
+temp_dir = "/tmp"
+keep_alive = 10
+log_level = "debug"
+
+[default.core]
+keys_file = "appkeys.json"
+compose_file = "app-compose.json"
+sys_config_file = "sys-config.json"
+
+[default.core.simulator]
+attestation_file = "attestation.bin"
+
+[internal-v0]
+address = "unix:./tappd.sock"
+reuse = true
+
+[internal]
+address = "unix:./dstack.sock"
+reuse = true
+
+[external]
+address = "unix:./external.sock"
+reuse = true
+
+[guest-api]
+address = "unix:./guest.sock"
+reuse = true

guest-agent-simulator/dstack.toml

@@ -0,0 +1,128 @@
+// SPDX-FileCopyrightText: © 2025 Phala Network <dstack@phala.network>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+use std::sync::Arc;
+
+use anyhow::{bail, Context, Result};
+use clap::Parser;
+use dstack_guest_agent::{
+    backend::{
+        load_versioned_attestation, simulated_attest_response, simulated_info_attestation,
+        simulated_quote_response, PlatformBackend,
+    },
+    config::{self, Config},
+    AppState, run_server,
+};
+use dstack_guest_agent_rpc::{AttestResponse, GetQuoteResponse};
+use ra_rpc::Attestation;
+use ra_tls::attestation::VersionedAttestation;
+use serde::Deserialize;
+use tracing::warn;
+
+const DEFAULT_CONFIG: &str = include_str!("../dstack.toml");
+
+#[derive(Parser)]
+#[command(author, version, about = "dstack guest agent simulator", long_version = dstack_guest_agent::app_version())]
+struct Args {
+    /// Path to the configuration file
+    #[arg(short, long)]
+    config: Option<String>,
+
+    /// Enable systemd watchdog
+    #[arg(short, long)]
+    watchdog: bool,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+struct SimulatorSettings {
+    attestation_file: String,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+struct SimulatorCoreConfig {
+    #[serde(flatten)]
+    core: Config,
+    simulator: SimulatorSettings,
+}
+
+struct SimulatorPlatform {
+    attestation: VersionedAttestation,
+}
+
+impl SimulatorPlatform {
+    fn new(attestation: VersionedAttestation) -> Self {
+        Self { attestation }
+    }
+}
+
+impl PlatformBackend for SimulatorPlatform {
+    fn attestation_for_info(&self) -> Result<Option<Attestation>> {
+        Ok(Some(simulated_info_attestation(&self.attestation)))
+    }
+
+    fn attestation_override(&self) -> Result<Option<VersionedAttestation>> {
+        Ok(Some(self.attestation.clone()))
+    }
+
+    fn quote_response(&self, report_data: [u8; 64], vm_config: &str) -> Result<GetQuoteResponse> {
+        simulated_quote_response(&self.attestation, report_data, vm_config)
+    }
+
+    fn attest_response(&self, _report_data: [u8; 64]) -> Result<AttestResponse> {
+        Ok(simulated_attest_response(&self.attestation))
+    }
+
+    fn emit_event(&self, event: &str, _payload: &[u8]) -> Result<()> {
+        bail!("runtime event emission is unavailable in simulator mode: {event}")
+    }
+}
+
+#[rocket::main]
+async fn main() -> Result<()> {
+    {
+        use tracing_subscriber::{fmt, EnvFilter};
+        let filter = EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new("info"));
+        fmt().with_env_filter(filter).with_ansi(false).init();
+    }
+    let args = Args::parse();
+    let figment = config::load_config_figment_with_default(DEFAULT_CONFIG, args.config.as_deref());
+    let sim_config: SimulatorCoreConfig = figment
+        .focus("core")
+        .extract()
+        .context("Failed to extract simulator core config")?;
+    warn!(attestation_file = %sim_config.simulator.attestation_file, "starting dstack guest-agent simulator");
+    let attestation = load_versioned_attestation(&sim_config.simulator.attestation_file)?;
+    let state = AppState::new(sim_config.core, Arc::new(SimulatorPlatform::new(attestation)))
+        .await
+        .context("Failed to create simulator app state")?;
+    run_server(state, figment, args.watchdog).await
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn load_fixture_platform() -> SimulatorPlatform {
+        let fixture = load_versioned_attestation(
+            std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../guest-agent/fixtures/attestation.bin"),
+        )
+        .expect("fixture attestation should load");
+        SimulatorPlatform::new(fixture)
+    }
+
+    #[test]
+    fn simulator_rejects_runtime_event_emission() {
+        let platform = load_fixture_platform();
+        let err = platform.emit_event("test.event", b"payload").unwrap_err();
+        assert!(err.to_string().contains("unavailable in simulator mode"));
+    }
+
+    #[test]
+    fn simulator_provides_attestation_override() {
+        let platform = load_fixture_platform();
+        assert!(platform.attestation_override().unwrap().is_some());
+        assert!(platform.attestation_for_info().unwrap().is_some());
+    }
+}

guest-agent-simulator/src/main.rs

@@ -16,9 +16,6 @@ compose_file = "/dstack/.host-shared/app-compose.json"
 sys_config_file = "/dstack/.host-shared/.sys-config.json"
 data_disks = ["/"]
 
-[default.core.simulator]
-enabled = false
-attestation_file = "attestation.bin"
 
 [internal-v0]
 address = "unix:/var/run/dstack/tappd.sock"

guest-agent/dstack.toml

@@ -0,0 +1,99 @@
+// SPDX-FileCopyrightText: © 2024-2025 Phala Network <dstack@phala.network>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+use std::path::Path;
+
+use anyhow::{Context, Result};
+use dstack_attest::emit_runtime_event;
+use dstack_guest_agent_rpc::{AttestResponse, GetQuoteResponse};
+use fs_err as fs;
+use ra_rpc::Attestation;
+use ra_tls::attestation::{VersionedAttestation, TDX_QUOTE_REPORT_DATA_RANGE};
+
+pub trait PlatformBackend: Send + Sync {
+    fn attestation_for_info(&self) -> Result<Option<Attestation>>;
+    fn attestation_override(&self) -> Result<Option<VersionedAttestation>>;
+    fn quote_response(&self, report_data: [u8; 64], vm_config: &str) -> Result<GetQuoteResponse>;
+    fn attest_response(&self, report_data: [u8; 64]) -> Result<AttestResponse>;
+    fn emit_event(&self, event: &str, payload: &[u8]) -> Result<()>;
+}
+
+#[derive(Debug, Default)]
+pub struct RealPlatform;
+
+impl PlatformBackend for RealPlatform {
+    fn attestation_for_info(&self) -> Result<Option<Attestation>> {
+        Ok(Attestation::local().ok())
+    }
+
+    fn attestation_override(&self) -> Result<Option<VersionedAttestation>> {
+        Ok(None)
+    }
+
+    fn quote_response(&self, report_data: [u8; 64], vm_config: &str) -> Result<GetQuoteResponse> {
+        let attestation = Attestation::quote(&report_data).context("Failed to get quote")?;
+        let tdx_quote = attestation.get_tdx_quote_bytes();
+        let tdx_event_log = attestation.get_tdx_event_log_string();
+        Ok(GetQuoteResponse {
+            quote: tdx_quote.unwrap_or_default(),
+            event_log: tdx_event_log.unwrap_or_default(),
+            report_data: report_data.to_vec(),
+            vm_config: vm_config.to_string(),
+        })
+    }
+
+    fn attest_response(&self, report_data: [u8; 64]) -> Result<AttestResponse> {
+        let attestation = Attestation::quote(&report_data).context("Failed to get attestation")?;
+        Ok(AttestResponse {
+            attestation: attestation.into_versioned().to_scale(),
+        })
+    }
+
+    fn emit_event(&self, event: &str, payload: &[u8]) -> Result<()> {
+        emit_runtime_event(event, payload)
+    }
+}
+
+pub fn load_versioned_attestation(path: impl AsRef<Path>) -> Result<VersionedAttestation> {
+    let path = path.as_ref();
+    let attestation_bytes = fs::read(path).with_context(|| {
+        format!(
+            "Failed to read simulator attestation file: {}",
+            path.display()
+        )
+    })?;
+    VersionedAttestation::from_scale(&attestation_bytes)
+        .context("Failed to decode simulator attestation")
+}
+
+pub fn simulated_quote_response(
+    attestation: &VersionedAttestation,
+    report_data: [u8; 64],
+    vm_config: &str,
+) -> Result<GetQuoteResponse> {
+    let VersionedAttestation::V0 { attestation } = attestation.clone();
+    let mut attestation = attestation;
+    let Some(quote) = attestation.tdx_quote_mut() else {
+        return Err(anyhow::anyhow!("Quote not found"));
+    };
+
+    quote.quote[TDX_QUOTE_REPORT_DATA_RANGE].copy_from_slice(&report_data);
+    Ok(GetQuoteResponse {
+        quote: quote.quote.to_vec(),
+        event_log: serde_json::to_string(&quote.event_log)
+            .context("Failed to serialize event log")?,
+        report_data: report_data.to_vec(),
+        vm_config: vm_config.to_string(),
+    })
+}
+
+pub fn simulated_attest_response(attestation: &VersionedAttestation) -> AttestResponse {
+    AttestResponse {
+        attestation: attestation.to_scale(),
+    }
+}
+
+pub fn simulated_info_attestation(attestation: &VersionedAttestation) -> Attestation {
+    attestation.clone().into_inner()
+}

guest-agent/src/backend.rs

@@ -13,7 +13,11 @@ use serde::{de::Error, Deserialize};
 pub const DEFAULT_CONFIG: &str = include_str!("../dstack.toml");
 
 pub fn load_config_figment(config_file: Option<&str>) -> Figment {
-    load_config("dstack", DEFAULT_CONFIG, config_file, true)
+    load_config_figment_with_default(DEFAULT_CONFIG, config_file)
+}
+
+pub fn load_config_figment_with_default(default_config: &str, config_file: Option<&str>) -> Figment {
+    load_config("dstack", default_config, config_file, true)
 }
 
 #[derive(Debug, Clone, Copy, Deserialize)]
@@ -43,8 +47,6 @@ pub struct Config {
     pub sys_config_file: PathBuf,
     #[serde(default)]
     pub pccs_url: Option<String>,
-    pub simulator: Simulator,
-    // List of disks to be shown in the dashboard
     pub data_disks: HashSet<PathBuf>,
 }
 
@@ -67,9 +69,3 @@ where
         raw: content,
     })
 }
-
-#[derive(Debug, Clone, Deserialize)]
-pub struct Simulator {
-    pub enabled: bool,
-    pub attestation_file: String,
-}

guest-agent/src/config.rs

@@ -0,0 +1,22 @@
+// SPDX-FileCopyrightText: © 2024-2025 Phala Network <dstack@phala.network>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+pub const CARGO_PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
+pub const GIT_REV: &str = git_version::git_version!(
+    args = ["--abbrev=20", "--always", "--dirty=-modified"],
+    prefix = "git:",
+    fallback = "unknown"
+);
+
+pub mod backend;
+pub mod config;
+mod guest_api_service;
+mod http_routes;
+mod models;
+pub mod rpc_service;
+mod server;
+mod socket_activation;
+
+pub use rpc_service::AppState;
+pub use server::{app_version, run as run_server};