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little_durable_objects/
sandbox.rs

1use std::{collections::HashMap, process::Stdio, time::Duration};
2
3use anyhow::{Context, Result, ensure};
4use async_trait::async_trait;
5use serde::{Deserialize, Serialize};
6use tokio::{io::AsyncWriteExt, process::Command};
7
8use crate::host::HostId;
9
10const PROVIDER_REQUEST_TIMEOUT: Duration = Duration::from_secs(120);
11
12#[derive(Clone, Debug, PartialEq, Eq, Serialize)]
13#[serde(rename_all = "camelCase")]
14pub struct EnsureHostRequest {
15    pub namespace_id: String,
16    pub code_revision: String,
17    pub canonical_region: String,
18    pub host_id: HostId,
19    pub session_id: String,
20    pub host_token: String,
21    pub jwt_public_keys: String,
22    pub control_plane_url: String,
23    pub jwt_issuer: String,
24    pub invocation_jwt_audience: String,
25    pub image_ref: String,
26    pub working_directory: String,
27    pub actor_entrypoint: Option<String>,
28    pub actor_idle_timeout_ms: u64,
29    pub host_idle_timeout_ms: u64,
30}
31
32#[derive(Clone, Debug, PartialEq, Eq, Deserialize)]
33#[serde(rename_all = "camelCase")]
34pub struct ActorHostHandle {
35    pub host_id: HostId,
36    pub route: String,
37    pub canonical_region: String,
38    pub provisioning: Option<ActorHostProvisioning>,
39}
40
41#[derive(Clone, Debug, PartialEq, Eq, Deserialize)]
42#[serde(rename_all = "camelCase")]
43pub struct ActorHostProvisioning {
44    pub provider: String,
45    pub resource_id: String,
46    pub reused: bool,
47    pub resource_lookup_ms: u64,
48    pub existing_lookup_ms: u64,
49    pub create_ms: u64,
50    pub placement_ms: u64,
51    pub tunnel_ms: u64,
52    pub ready_ms: u64,
53    pub metadata_ms: u64,
54    pub total_ms: u64,
55}
56
57#[derive(Clone, Debug, PartialEq, Eq, Serialize)]
58#[serde(rename_all = "camelCase")]
59pub struct WarmImageRequest {
60    pub namespace_id: String,
61    pub code_revision: String,
62    pub canonical_region: String,
63    pub image_ref: String,
64}
65
66#[derive(Clone, Debug, PartialEq, Eq, Deserialize)]
67#[serde(rename_all = "camelCase")]
68pub struct ImageWarmup {
69    pub provider: String,
70    pub resource_id: String,
71    pub total_ms: u64,
72}
73
74#[derive(Clone, Debug, PartialEq, Eq, Serialize)]
75#[serde(rename_all = "camelCase")]
76pub struct TerminateHostsRequest {
77    pub namespace_id: String,
78    pub code_revision: String,
79    pub canonical_regions: Vec<String>,
80}
81
82#[derive(Clone, Debug, PartialEq, Eq, Deserialize)]
83#[serde(rename_all = "camelCase")]
84pub struct HostTermination {
85    pub provider: String,
86    pub resource_ids: Vec<String>,
87}
88
89#[async_trait]
90pub trait SandboxProvider: Send + Sync {
91    async fn ensure_host(&self, request: &EnsureHostRequest) -> Result<ActorHostHandle>;
92    async fn warm_image(&self, request: &WarmImageRequest) -> Result<ImageWarmup>;
93    async fn terminate_hosts(&self, request: &TerminateHostsRequest) -> Result<HostTermination>;
94}
95
96#[derive(Clone)]
97pub struct HostSandboxRuntimeConfig {
98    pub control_plane_url: String,
99    pub jwt_issuer: String,
100    pub invocation_jwt_audience: String,
101    pub actor_idle_timeout_ms: u64,
102    pub host_idle_timeout_ms: u64,
103}
104
105pub struct CommandSandboxProvider {
106    provider_name: String,
107    command: String,
108    environment: HashMap<String, String>,
109}
110
111impl CommandSandboxProvider {
112    pub fn new(
113        provider_name: String,
114        command: String,
115        mut environment: HashMap<String, String>,
116    ) -> Result<Self> {
117        ensure!(
118            !provider_name.is_empty() && provider_name.trim() == provider_name,
119            "sandbox provider name must be non-empty without surrounding whitespace"
120        );
121        ensure!(
122            !command.is_empty() && command.trim() == command,
123            "DURABLE_OBJECT_SANDBOX_COMMAND must be non-empty without surrounding whitespace"
124        );
125        if let Ok(path) = std::env::var("PATH") {
126            environment.entry("PATH".into()).or_insert(path);
127        }
128        Ok(Self {
129            provider_name,
130            command,
131            environment,
132        })
133    }
134}
135
136#[async_trait]
137impl SandboxProvider for CommandSandboxProvider {
138    async fn ensure_host(&self, request: &EnsureHostRequest) -> Result<ActorHostHandle> {
139        let response: ActorHostHandle = self.execute("ensure_host", request).await?;
140        ensure!(
141            response.canonical_region == request.canonical_region,
142            "{} sandbox command returned a host in the wrong canonical region",
143            self.provider_name
144        );
145        ensure!(
146            !response.host_id.as_str().is_empty() && !response.route.is_empty(),
147            "{} sandbox command returned an invalid host",
148            self.provider_name
149        );
150        Ok(response)
151    }
152
153    async fn warm_image(&self, request: &WarmImageRequest) -> Result<ImageWarmup> {
154        self.execute("warm_image", request).await
155    }
156
157    async fn terminate_hosts(&self, request: &TerminateHostsRequest) -> Result<HostTermination> {
158        self.execute("terminate_hosts", request).await
159    }
160}
161
162impl CommandSandboxProvider {
163    async fn execute<Request: Serialize, Reply: for<'de> Deserialize<'de>>(
164        &self,
165        operation: &str,
166        request: &Request,
167    ) -> Result<Reply> {
168        let mut child = Command::new(&self.command)
169            .env_clear()
170            .envs(&self.environment)
171            .stdin(Stdio::piped())
172            .stdout(Stdio::piped())
173            .stderr(Stdio::piped())
174            .kill_on_drop(true)
175            .spawn()
176            .with_context(|| {
177                format!(
178                    "start {} sandbox command {:?}",
179                    self.provider_name, self.command
180                )
181            })?;
182        let document = serde_json::to_vec(&ProviderCommand { operation, request })?;
183        let mut stdin = child
184            .stdin
185            .take()
186            .with_context(|| format!("open {} sandbox command stdin", self.provider_name))?;
187        stdin
188            .write_all(&document)
189            .await
190            .with_context(|| format!("write {} sandbox command request", self.provider_name))?;
191        stdin
192            .shutdown()
193            .await
194            .with_context(|| format!("close {} sandbox command stdin", self.provider_name))?;
195        drop(stdin);
196        let output = tokio::time::timeout(PROVIDER_REQUEST_TIMEOUT, child.wait_with_output())
197            .await
198            .with_context(|| format!("{} sandbox command timed out", self.provider_name))??;
199        ensure!(
200            output.status.success(),
201            "{} sandbox command failed with {}: {}",
202            self.provider_name,
203            output.status,
204            String::from_utf8_lossy(&output.stderr).trim()
205        );
206        serde_json::from_slice(&output.stdout)
207            .with_context(|| format!("decode {} sandbox command response", self.provider_name))
208    }
209}
210
211#[derive(Serialize)]
212struct ProviderCommand<'a, Request> {
213    operation: &'a str,
214    request: &'a Request,
215}
216
217#[cfg(test)]
218mod tests {
219    use super::*;
220
221    #[test]
222    fn decodes_provider_provisioning_timings() {
223        let handle: ActorHostHandle = serde_json::from_value(serde_json::json!({
224            "hostId": "host.v1.namespace.revision.session",
225            "route": "https://host.example.com",
226            "canonicalRegion": "north-america-east",
227            "provisioning": {
228                "provider": "modal",
229                "resourceId": "sb-actor",
230                "reused": false,
231                "resourceLookupMs": 12,
232                "existingLookupMs": 34,
233                "createMs": 56,
234                "placementMs": 78,
235                "tunnelMs": 90,
236                "readyMs": 123,
237                "metadataMs": 4,
238                "totalMs": 397
239            }
240        }))
241        .expect("actor host handle");
242
243        let provisioning = handle.provisioning.expect("provisioning timings");
244        assert_eq!(provisioning.resource_id, "sb-actor");
245        assert_eq!(provisioning.create_ms, 56);
246        assert_eq!(provisioning.total_ms, 397);
247    }
248
249    #[test]
250    fn rejects_ambiguous_command_configuration() {
251        assert!(CommandSandboxProvider::new("".into(), "modal".into(), HashMap::new()).is_err());
252        assert!(CommandSandboxProvider::new("modal".into(), "".into(), HashMap::new()).is_err());
253    }
254}