hive-c0re: admin socket server + client (stub dispatch)

hive-c0re/src/client.rs

@@ -0,0 +1,27 @@
+use std::path::Path;
+
+use anyhow::{Context, Result, bail};
+use hive_sh4re::{HostRequest, HostResponse};
+use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
+use tokio::net::UnixStream;
+
+pub async fn request(socket: &Path, req: HostRequest) -> Result<HostResponse> {
+    let stream = UnixStream::connect(socket)
+        .await
+        .with_context(|| format!("connect to {}", socket.display()))?;
+    let (read, mut write) = stream.into_split();
+
+    let mut payload = serde_json::to_string(&req)?;
+    payload.push('\n');
+    write.write_all(payload.as_bytes()).await?;
+    write.flush().await?;
+
+    let mut reader = BufReader::new(read);
+    let mut line = String::new();
+    reader.read_line(&mut line).await?;
+    if line.is_empty() {
+        bail!("server closed connection without responding");
+    }
+    let resp: HostResponse = serde_json::from_str(line.trim())?;
+    Ok(resp)
+}

hive-c0re/src/main.rs

@@ -2,10 +2,18 @@ use std::path::PathBuf;
 
 use anyhow::{Result, bail};
 use clap::{Parser, Subcommand};
+use hive_sh4re::{HostRequest, HostResponse};
+
+mod client;
+mod server;
 
 #[derive(Parser)]
 #[command(name = "hive-c0re", about = "hyperhive coordinator daemon and CLI")]
 struct Cli {
+    /// Path to the host admin socket.
+    #[arg(long, global = true, default_value = "/run/hyperhive/host.sock")]
+    socket: PathBuf,
+
     #[command(subcommand)]
     cmd: Cmd,
 }
@@ -17,11 +25,8 @@ enum Cmd {
         /// Flake reference for the agent base template.
         #[arg(long, default_value = "/etc/hyperhive#agent-base")]
         agent_flake: String,
-        /// Path to the host admin socket.
-        #[arg(long, default_value = "/run/hyperhive/host.sock")]
-        socket: PathBuf,
     },
-    /// Spawn a new agent container (creates `hive-agent-<name>`).
+    /// Spawn a new agent container (`hive-agent-<name>`).
     Spawn { name: String },
     /// Stop a managed container (graceful).
     Kill { name: String },
@@ -31,7 +36,8 @@ enum Cmd {
     List,
 }
 
-fn main() -> Result<()> {
+#[tokio::main]
+async fn main() -> Result<()> {
     tracing_subscriber::fmt()
         .with_env_filter(
             tracing_subscriber::EnvFilter::try_from_default_env()
@@ -41,28 +47,20 @@ fn main() -> Result<()> {
 
     let cli = Cli::parse();
     match cli.cmd {
-        Cmd::Serve {
+        Cmd::Serve { agent_flake } => server::serve(&cli.socket, &agent_flake).await,
-            agent_flake,
+        Cmd::Spawn { name } => render(client::request(&cli.socket, HostRequest::Spawn { name }).await?),
-            socket,
+        Cmd::Kill { name } => render(client::request(&cli.socket, HostRequest::Kill { name }).await?),
-        } => {
-            tracing::info!(?socket, %agent_flake, "serve: not yet implemented");
-            bail!("serve not yet implemented");
-        }
-        Cmd::Spawn { name } => {
-            tracing::info!(%name, "spawn: not yet implemented");
-            bail!("spawn not yet implemented");
-        }
-        Cmd::Kill { name } => {
-            tracing::info!(%name, "kill: not yet implemented");
-            bail!("kill not yet implemented");
-        }
         Cmd::Rebuild { name } => {
-            tracing::info!(%name, "rebuild: not yet implemented");
+            render(client::request(&cli.socket, HostRequest::Rebuild { name }).await?)
-            bail!("rebuild not yet implemented");
         }
-        Cmd::List => {
+        Cmd::List => render(client::request(&cli.socket, HostRequest::List).await?),
-            tracing::info!("list: not yet implemented");
-            bail!("list not yet implemented");
     }
 }
+
+fn render(resp: HostResponse) -> Result<()> {
+    println!("{}", serde_json::to_string_pretty(&resp)?);
+    if !resp.ok {
+        bail!(resp.error.unwrap_or_else(|| "request failed".to_owned()));
+    }
+    Ok(())
 }

hive-c0re/src/server.rs

@@ -0,0 +1,70 @@
+use std::path::Path;
+
+use anyhow::{Context, Result};
+use hive_sh4re::{HostRequest, HostResponse};
+use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
+use tokio::net::{UnixListener, UnixStream};
+
+pub async fn serve(socket: &Path, agent_flake: &str) -> Result<()> {
+    if let Some(parent) = socket.parent() {
+        std::fs::create_dir_all(parent)
+            .with_context(|| format!("create socket parent {}", parent.display()))?;
+    }
+    if socket.exists() {
+        std::fs::remove_file(socket).context("remove stale socket")?;
+    }
+
+    let listener = UnixListener::bind(socket)
+        .with_context(|| format!("bind admin socket {}", socket.display()))?;
+    tracing::info!(socket = %socket.display(), %agent_flake, "hive-c0re listening");
+
+    loop {
+        let (stream, _) = listener.accept().await.context("accept connection")?;
+        let agent_flake = agent_flake.to_owned();
+        tokio::spawn(async move {
+            if let Err(e) = handle(stream, &agent_flake).await {
+                tracing::warn!(error = ?e, "connection failed");
+            }
+        });
+    }
+}
+
+async fn handle(stream: UnixStream, agent_flake: &str) -> Result<()> {
+    let (read, mut write) = stream.into_split();
+    let mut reader = BufReader::new(read);
+    let mut line = String::new();
+
+    loop {
+        line.clear();
+        let n = reader.read_line(&mut line).await?;
+        if n == 0 {
+            return Ok(());
+        }
+        let resp = match serde_json::from_str::<HostRequest>(line.trim()) {
+            Ok(req) => dispatch(&req, agent_flake).await,
+            Err(e) => HostResponse::error(format!("parse error: {e}")),
+        };
+        let mut payload = serde_json::to_string(&resp)?;
+        payload.push('\n');
+        write.write_all(payload.as_bytes()).await?;
+        write.flush().await?;
+    }
+}
+
+async fn dispatch(req: &HostRequest, _agent_flake: &str) -> HostResponse {
+    match req {
+        HostRequest::Spawn { name } => {
+            tracing::info!(%name, "spawn (stub)");
+            HostResponse::error("spawn: nixos-container integration pending")
+        }
+        HostRequest::Kill { name } => {
+            tracing::info!(%name, "kill (stub)");
+            HostResponse::error("kill: nixos-container integration pending")
+        }
+        HostRequest::Rebuild { name } => {
+            tracing::info!(%name, "rebuild (stub)");
+            HostResponse::error("rebuild: nixos-container integration pending")
+        }
+        HostRequest::List => HostResponse::list(Vec::new()),
+    }
+}

hive-sh4re/Cargo.toml

@@ -2,3 +2,6 @@
 name = "hive-sh4re"
 edition.workspace = true
 version.workspace = true
+
+[dependencies]
+serde.workspace = true

hive-sh4re/src/lib.rs

@@ -1 +1,54 @@
+//! Wire types shared between `hive-c0re` and the in-container harness.
 
+use serde::{Deserialize, Serialize};
+
+/// Requests on the host admin socket (`/run/hyperhive/host.sock`).
+///
+/// Wire format: one JSON object per line.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "cmd", rename_all = "snake_case")]
+pub enum HostRequest {
+    /// Create and start a sub-agent container `hive-agent-<name>`.
+    Spawn { name: String },
+    /// Stop a managed container (graceful).
+    Kill { name: String },
+    /// Apply pending config to a managed container.
+    Rebuild { name: String },
+    /// List managed containers.
+    List,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct HostResponse {
+    pub ok: bool,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub error: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub agents: Option<Vec<String>>,
+}
+
+impl HostResponse {
+    pub fn success() -> Self {
+        Self {
+            ok: true,
+            error: None,
+            agents: None,
+        }
+    }
+
+    pub fn error(message: impl Into<String>) -> Self {
+        Self {
+            ok: false,
+            error: Some(message.into()),
+            agents: None,
+        }
+    }
+
+    pub fn list(agents: Vec<String>) -> Self {
+        Self {
+            ok: true,
+            error: None,
+            agents: Some(agents),
+        }
+    }
+}