omyacid: Old Mouse Yells At Cloud-init Daemon

HTTP daemon that interfaces with nzrd to get cloud-init metadata to
instances. The current iteration is completely untested.

Cargo.lock

@@ -108,6 +108,50 @@ version = "1.0.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b3d1d046238990b9cf5bcde22a3fb3584ee5cf65fb2765f454ed428c7a0063da"
 
+[[package]]
+name = "askama"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b79091df18a97caea757e28cd2d5fda49c6cd4bd01ddffd7ff01ace0c0ad2c28"
+dependencies = [
+ "askama_derive",
+ "askama_escape",
+ "humansize",
+ "num-traits",
+ "percent-encoding",
+]
+
+[[package]]
+name = "askama_derive"
+version = "0.12.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "19fe8d6cb13c4714962c072ea496f3392015f0989b1a2847bb4b2d9effd71d83"
+dependencies = [
+ "askama_parser",
+ "basic-toml",
+ "mime",
+ "mime_guess",
+ "proc-macro2",
+ "quote",
+ "serde",
+ "syn 2.0.72",
+]
+
+[[package]]
+name = "askama_escape"
+version = "0.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "619743e34b5ba4e9703bba34deac3427c72507c7159f5fd030aea8cac0cfe341"
+
+[[package]]
+name = "askama_parser"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "acb1161c6b64d1c3d83108213c2a2533a342ac225aabd0bda218278c2ddb00c0"
+dependencies = [
+ "nom",
+]
+
 [[package]]
 name = "async-lock"
 version = "3.4.0"
@@ -121,13 +165,13 @@ dependencies = [
 
 [[package]]
 name = "async-trait"
-version = "0.1.60"
+version = "0.1.81"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "677d1d8ab452a3936018a687b20e6f7cf5363d713b732b8884001317b0e48aa3"
+checksum = "6e0c28dcc82d7c8ead5cb13beb15405b57b8546e93215673ff8ca0349a028107"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 1.0.106",
+ "syn 2.0.72",
 ]
 
 [[package]]
@@ -154,6 +198,61 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
+[[package]]
+name = "axum"
+version = "0.7.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3a6c9af12842a67734c9a2e355436e5d03b22383ed60cf13cd0c18fbfe3dcbcf"
+dependencies = [
+ "async-trait",
+ "axum-core",
+ "bytes",
+ "futures-util",
+ "http",
+ "http-body",
+ "http-body-util",
+ "hyper",
+ "hyper-util",
+ "itoa",
+ "matchit",
+ "memchr",
+ "mime",
+ "percent-encoding",
+ "pin-project-lite",
+ "rustversion",
+ "serde",
+ "serde_json",
+ "serde_path_to_error",
+ "serde_urlencoded",
+ "sync_wrapper 1.0.1",
+ "tokio",
+ "tower",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
+[[package]]
+name = "axum-core"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a15c63fd72d41492dc4f497196f5da1fb04fb7529e631d73630d1b491e47a2e3"
+dependencies = [
+ "async-trait",
+ "bytes",
+ "futures-util",
+ "http",
+ "http-body",
+ "http-body-util",
+ "mime",
+ "pin-project-lite",
+ "rustversion",
+ "sync_wrapper 0.1.2",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
 [[package]]
 name = "backtrace"
 version = "0.3.73"
@@ -187,6 +286,15 @@ version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8c3c1a368f70d6cf7302d78f8f7093da241fb8e8807c05cc9e51a125895a6d5b"
 
+[[package]]
+name = "basic-toml"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "823388e228f614e9558c6804262db37960ec8821856535f5c3f59913140558f8"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "bincode"
 version = "1.3.3"
@@ -548,6 +656,16 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "deranged"
+version = "0.3.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b42b6fa04a440b495c8b04d0e71b707c585f83cb9cb28cf8cd0d976c315e31b4"
+dependencies = [
+ "powerfmt",
+ "serde",
+]
+
 [[package]]
 name = "dhcproto"
 version = "0.12.0"
@@ -1145,12 +1263,101 @@ dependencies = [
  "windows",
 ]
 
+[[package]]
+name = "http"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "21b9ddb458710bc376481b842f5da65cdf31522de232c1ca8146abce2a358258"
+dependencies = [
+ "bytes",
+ "fnv",
+ "itoa",
+]
+
+[[package]]
+name = "http-body"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1efedce1fb8e6913f23e0c92de8e62cd5b772a67e7b3946df930a62566c93184"
+dependencies = [
+ "bytes",
+ "http",
+]
+
+[[package]]
+name = "http-body-util"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "793429d76616a256bcb62c2a2ec2bed781c8307e797e2598c50010f2bee2544f"
+dependencies = [
+ "bytes",
+ "futures-util",
+ "http",
+ "http-body",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "httparse"
+version = "1.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fcc0b4a115bf80b728eb8ea024ad5bd707b615bfed49e0665b6e0f86fd082d9"
+
+[[package]]
+name = "httpdate"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df3b46402a9d5adb4c86a0cf463f42e19994e3ee891101b1841f30a545cb49a9"
+
+[[package]]
+name = "humansize"
+version = "2.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6cb51c9a029ddc91b07a787f1d86b53ccfa49b0e86688c946ebe8d3555685dd7"
+dependencies = [
+ "libm",
+]
+
 [[package]]
 name = "humantime"
 version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
 
+[[package]]
+name = "hyper"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "50dfd22e0e76d0f662d429a5f80fcaf3855009297eab6a0a9f8543834744ba05"
+dependencies = [
+ "bytes",
+ "futures-channel",
+ "futures-util",
+ "http",
+ "http-body",
+ "httparse",
+ "httpdate",
+ "itoa",
+ "pin-project-lite",
+ "smallvec",
+ "tokio",
+]
+
+[[package]]
+name = "hyper-util"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cde7055719c54e36e95e8719f95883f22072a48ede39db7fc17a4e1d5281e9b9"
+dependencies = [
+ "bytes",
+ "futures-util",
+ "http",
+ "http-body",
+ "hyper",
+ "pin-project-lite",
+ "tokio",
+]
+
 [[package]]
 name = "iana-time-zone"
 version = "0.1.53"
@@ -1366,6 +1573,12 @@ version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2532096657941c2fea9c289d370a250971c689d4f143798ff67113ec042024a5"
 
+[[package]]
+name = "matchit"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0e7465ac9959cc2b1404e8e2367b43684a6d13790fe23056cc8c6c5a6b7bcb94"
+
 [[package]]
 name = "md-5"
 version = "0.10.6"
@@ -1403,6 +1616,22 @@ dependencies = [
  "quote",
 ]
 
+[[package]]
+name = "mime"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6877bb514081ee2a7ff5ef9de3281f14a4dd4bceac4c09388074a6b5df8a139a"
+
+[[package]]
+name = "mime_guess"
+version = "2.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7c44f8e672c00fe5308fa235f821cb4198414e1c77935c1ab6948d3fd78550e"
+dependencies = [
+ "mime",
+ "unicase",
+]
+
 [[package]]
 name = "minimal-lexical"
 version = "0.2.1"
@@ -1514,6 +1743,12 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "num-conv"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51d515d32fb182ee37cda2ccdcb92950d6a3c2893aa280e540671c2cd0f3b1d9"
+
 [[package]]
 name = "num-integer"
 version = "0.1.45"
@@ -1646,7 +1881,6 @@ dependencies = [
  "moka",
  "nzr-api",
  "serde",
- "tarpc",
  "tokio",
  "tracing",
  "tracing-subscriber",
@@ -1661,6 +1895,20 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "omyacid"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "askama",
+ "axum",
+ "moka",
+ "nzr-api",
+ "tokio",
+ "tracing",
+ "tracing-subscriber",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.19.0"
@@ -1865,6 +2113,12 @@ version = "0.3.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6ac9a59f73473f1b8d852421e59e64809f025994837ef743615c6d0c5b305160"
 
+[[package]]
+name = "powerfmt"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "439ee305def115ba05938db6eb1644ff94165c5ab5e9420d1c1bcedbba909391"
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.17"
@@ -2098,6 +2352,12 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "rustversion"
+version = "1.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "955d28af4278de8121b7ebeb796b6a45735dc01436d898801014aced2773a3d6"
+
 [[package]]
 name = "ryu"
 version = "1.0.12"
@@ -2162,6 +2422,16 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_path_to_error"
+version = "0.1.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af99884400da37c88f5e9146b7f1fd0fbcae8f6eec4e9da38b67d05486f814a6"
+dependencies = [
+ "itoa",
+ "serde",
+]
+
 [[package]]
 name = "serde_spanned"
 version = "0.6.7"
@@ -2285,9 +2555,9 @@ dependencies = [
 
 [[package]]
 name = "smallvec"
-version = "1.10.0"
+version = "1.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a507befe795404456341dfab10cef66ead4c041f62b8b11bbb92bffe5d0953e0"
+checksum = "3c5e1a9a646d36c3599cd173a41282daf47c44583ad367b8e6837255952e5c67"
 dependencies = [
  "serde",
 ]
@@ -2591,6 +2861,18 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "sync_wrapper"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2047c6ded9c721764247e62cd3b03c09ffc529b2ba5b10ec482ae507a4a70160"
+
+[[package]]
+name = "sync_wrapper"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a7065abeca94b6a8a577f9bd45aa0867a2238b74e8eb67cf10d492bc39351394"
+
 [[package]]
 name = "syslog"
 version = "7.0.0"
@@ -2720,13 +3002,16 @@ dependencies = [
 
 [[package]]
 name = "time"
-version = "0.3.17"
+version = "0.3.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a561bf4617eebd33bca6434b988f39ed798e527f51a1e797d0ee4f61c0a38376"
+checksum = "5dfd88e563464686c916c7e46e623e520ddc6d79fa6641390f2e3fa86e83e885"
 dependencies = [
+ "deranged",
  "itoa",
  "libc",
+ "num-conv",
  "num_threads",
+ "powerfmt",
  "serde",
  "time-core",
  "time-macros",
@@ -2734,16 +3019,17 @@ dependencies = [
 
 [[package]]
 name = "time-core"
-version = "0.1.0"
+version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2e153e1f1acaef8acc537e68b44906d2db6436e2b35ac2c6b42640fff91f00fd"
+checksum = "ef927ca75afb808a4d64dd374f00a2adf8d0fcff8e7b184af886c3c87ec4a3f3"
 
 [[package]]
 name = "time-macros"
-version = "0.2.6"
+version = "0.2.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d967f99f534ca7e495c575c62638eebc2898a8c84c119b89e250477bc4ba16b2"
+checksum = "3f252a68540fde3a3877aeea552b832b40ab9a69e318efd078774a01ddee1ccf"
 dependencies = [
+ "num-conv",
  "time-core",
 ]
 
@@ -2877,6 +3163,34 @@ dependencies = [
  "winnow",
 ]
 
+[[package]]
+name = "tower"
+version = "0.4.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8fa9be0de6cf49e536ce1851f987bd21a43b771b09473c3549a6c853db37c1c"
+dependencies = [
+ "futures-core",
+ "futures-util",
+ "pin-project",
+ "pin-project-lite",
+ "tokio",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
+[[package]]
+name = "tower-layer"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c20c8dbed6283a09604c3e69b4b7eeb54e298b8a600d4d5ecb5ad39de609f1d0"
+
+[[package]]
+name = "tower-service"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6bc1c9ce2b5135ac7f93c72918fc37feb872bdc6a5533a8b85eb4b86bfdae52"
+
 [[package]]
 name = "tracing"
 version = "0.1.40"
@@ -3005,6 +3319,15 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "unicase"
+version = "2.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7d2d4dafb69621809a81864c9c1b864479e1235c0dd4e199924b9742439ed89"
+dependencies = [
+ "version_check",
+]
+
 [[package]]
 name = "unicode-bidi"
 version = "0.3.15"

Cargo.toml

@@ -1,3 +1,3 @@
 [workspace]
-members = ["nzrd", "nzr-api", "client", "nzrdhcp", "nzr-virt"]
+members = ["nzrd", "nzr-api", "client", "nzrdhcp", "nzr-virt", "omyacid"]
 resolver = "2"

nzr-api/src/config.rs

@@ -32,6 +32,7 @@ pub struct SOAConfig {
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct DNSConfig {
     pub listen_addr: String,
+    pub port: u16,
     pub default_zone: Name,
     pub soa: SOAConfig,
 }
@@ -40,6 +41,15 @@ pub struct DNSConfig {
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct DHCPConfig {
     pub listen_addr: String,
+    pub port: u16,
+}
+
+/// Cloud-init configuration, used by omyacid.
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct CloudConfig {
+    pub listen_addr: String,
+    pub port: u16,
+    pub admin_user: String,
 }
 
 /// Server<->Client RPC configuration.
@@ -62,6 +72,7 @@ pub struct Config {
     pub storage: StorageConfig,
     pub dns: DNSConfig,
     pub dhcp: DHCPConfig,
+    pub cloud: CloudConfig,
 }
 
 impl Default for Config {
@@ -84,8 +95,9 @@ impl Default for Config {
                 base_image_pool: "images".to_owned(),
             },
             dns: DNSConfig {
-                listen_addr: "127.0.0.1:5353".to_owned(),
+                listen_addr: "127.0.0.1".to_owned(),
-                default_zone: Name::from_utf8("servers.locaddral").unwrap(),
+                port: 5353,
+                default_zone: Name::from_utf8("servers.local").unwrap(),
                 soa: SOAConfig {
                     nzr_domain: Name::from_utf8("nzr.local").unwrap(),
                     contact: Name::from_utf8("admin.nzr.local").unwrap(),
@@ -96,6 +108,12 @@ impl Default for Config {
             },
             dhcp: DHCPConfig {
                 listen_addr: "127.0.0.1".to_owned(),
+                port: 67,
+            },
+            cloud: CloudConfig {
+                listen_addr: "0.0.0.0".to_owned(),
+                port: 80,
+                admin_user: "admin".to_owned(),
             },
         }
     }

omyacid/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "omyacid"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+nzr-api = { path = "../nzr-api" }
+tokio = { version = "1", features = ["rt-multi-thread", "macros"] }
+axum = "0.7"
+tracing = "0.1"
+tracing-subscriber = "0.3"
+anyhow = "1"
+askama = "0.12"
+moka = { version = "0.12.8", features = ["future"] }

omyacid/src/ctx.rs

@@ -0,0 +1,95 @@
+use std::hash::RandomState;
+use std::net::Ipv4Addr;
+use std::sync::Arc;
+use std::time::Duration;
+
+use anyhow::Context as _;
+use anyhow::Result;
+use moka::future::Cache;
+use nzr_api::config::Config;
+use nzr_api::model::Instance;
+use nzr_api::InstanceQuery;
+use nzr_api::NazrinClient;
+use tokio::net::UnixStream;
+
+#[derive(Clone)]
+struct InstanceMeta {
+    pub inst: Instance,
+    pub userdata: Vec<u8>,
+}
+
+#[derive(Clone)]
+pub struct Context {
+    api_client: NazrinClient,
+    config: Arc<Config>,
+    host_cache: Cache<Ipv4Addr, InstanceMeta, RandomState>,
+}
+
+impl Context {
+    pub async fn new(cfg: Config) -> Result<Self> {
+        let api_client = {
+            let sock = UnixStream::connect(&cfg.rpc.socket_path)
+                .await
+                .context("Connection to nzrd failed")?;
+            nzr_api::new_client(sock)
+        };
+
+        let host_cache = Cache::builder()
+            .time_to_live(Duration::from_secs(15))
+            .max_capacity(5)
+            .build();
+
+        Ok(Self {
+            api_client,
+            host_cache,
+            config: Arc::new(cfg),
+        })
+    }
+
+    // Internal function to hydrate the instance metadata, if needed
+    async fn get_instmeta(&self, addr: Ipv4Addr) -> Result<Option<InstanceMeta>> {
+        if let Some(meta) = self.host_cache.get(&addr).await {
+            tracing::debug!("Cache hit!");
+            Ok(Some(meta))
+        } else {
+            let inst = self
+                .api_client
+                .find_instance(nzr_api::default_ctx(), InstanceQuery::Ipv4Addr(addr))
+                .await
+                .context("RPC error")?
+                .map_err(|e| anyhow::anyhow!("nzrd error: {e}"))?;
+            if let Some(inst) = inst {
+                let userdata = self
+                    .api_client
+                    .get_instance_userdata(nzr_api::default_ctx(), inst.id)
+                    .await
+                    .context("RPC error")?
+                    .map_err(|e| anyhow::anyhow!("nzrd error: {e}"))?;
+
+                let meta = InstanceMeta { inst, userdata };
+
+                self.host_cache.insert(addr, meta.clone()).await;
+
+                Ok(Some(meta))
+            } else {
+                Ok(None)
+            }
+        }
+    }
+
+    pub async fn get_instance(&self, addr: Ipv4Addr) -> Result<Option<Instance>> {
+        self.get_instmeta(addr)
+            .await
+            .map(|opt| opt.map(|im| im.inst))
+    }
+
+    pub async fn get_inst_userdata(&self, addr: Ipv4Addr) -> Result<Option<Vec<u8>>> {
+        self.get_instmeta(addr)
+            .await
+            .map(|opt| opt.map(|im| im.userdata))
+    }
+
+    pub fn cfg(&self) -> &Config {
+        &self.config
+    }
+}

omyacid/src/main.rs

@@ -0,0 +1,120 @@
+mod ctx;
+mod model;
+
+use std::{
+    net::{IpAddr, SocketAddr},
+    process::ExitCode,
+    str::FromStr,
+};
+
+use askama::Template;
+use axum::{
+    extract::{ConnectInfo, State},
+    http::StatusCode,
+    routing::get,
+    Router,
+};
+use model::Metadata;
+use nzr_api::config::Config;
+
+async fn get_meta_data(
+    State(ctx): State<ctx::Context>,
+    ConnectInfo(addr): ConnectInfo<SocketAddr>,
+) -> Result<String, StatusCode> {
+    if let IpAddr::V4(ip) = addr.ip() {
+        match ctx.get_instance(ip).await {
+            Ok(Some(inst)) => {
+                let meta = Metadata {
+                    inst_name: &inst.name,
+                    ssh_pubkeys: Vec::new(), // TODO
+                    username: Some(ctx.cfg().cloud.admin_user.as_ref()),
+                };
+
+                meta.render().map_err(|e| {
+                    tracing::error!("Renderer error: {e}");
+                    StatusCode::INTERNAL_SERVER_ERROR
+                })
+            }
+            Ok(None) => {
+                tracing::warn!("Request from unregistered server {ip}");
+                Err(StatusCode::FORBIDDEN)
+            }
+            Err(err) => {
+                tracing::warn!("{err}");
+                Err(StatusCode::INTERNAL_SERVER_ERROR)
+            }
+        }
+    } else {
+        Err(StatusCode::BAD_REQUEST)
+    }
+}
+
+async fn get_user_data(
+    State(ctx): State<ctx::Context>,
+    ConnectInfo(addr): ConnectInfo<SocketAddr>,
+) -> Result<Vec<u8>, StatusCode> {
+    if let IpAddr::V4(ip) = addr.ip() {
+        match ctx.get_inst_userdata(ip).await {
+            Ok(Some(data)) => Ok(data),
+            Ok(None) => {
+                tracing::warn!("Request from unregistered server {ip}");
+                Err(StatusCode::FORBIDDEN)
+            }
+            Err(err) => {
+                tracing::warn!("{err}");
+                Err(StatusCode::INTERNAL_SERVER_ERROR)
+            }
+        }
+    } else {
+        Err(StatusCode::BAD_REQUEST)
+    }
+}
+
+#[tokio::main]
+async fn main() -> ExitCode {
+    tracing_subscriber::fmt().init();
+    let cfg: Config = match Config::figment().extract() {
+        Ok(cfg) => cfg,
+        Err(err) => {
+            tracing::error!("Unable to get configuration: {err}");
+            return ExitCode::FAILURE;
+        }
+    };
+
+    let http_sock = {
+        let addr = match IpAddr::from_str(&cfg.cloud.listen_addr) {
+            Ok(addr) => addr,
+            Err(err) => {
+                tracing::error!("Invalid listen IP address ({err})");
+                return ExitCode::FAILURE;
+            }
+        };
+        match tokio::net::TcpListener::bind((addr, cfg.cloud.port)).await {
+            Ok(sock) => sock,
+            Err(err) => {
+                tracing::error!("Failed to bind to {addr}:{}: {err}", cfg.cloud.port);
+                return ExitCode::FAILURE;
+            }
+        }
+    };
+
+    let ctx = match ctx::Context::new(cfg).await {
+        Ok(ctx) => ctx,
+        Err(err) => {
+            tracing::error!("{err}");
+            return ExitCode::FAILURE;
+        }
+    };
+
+    let app = Router::new()
+        .route("/meta-data", get(get_meta_data))
+        .route("/user-data", get(get_user_data))
+        .with_state(ctx);
+
+    if let Err(err) = axum::serve(http_sock, app).await {
+        tracing::error!("axum error: {err}");
+        return ExitCode::FAILURE;
+    }
+
+    ExitCode::SUCCESS
+}

omyacid/src/model.rs

@@ -0,0 +1,8 @@
+use askama::Template;
+#[derive(Template)]
+#[template(path = "meta-data.yml")]
+pub struct Metadata<'a> {
+    pub inst_name: &'a str,
+    pub ssh_pubkeys: Vec<&'a String>,
+    pub username: Option<&'a str>,
+}

omyacid/templates/meta-data.yml

@@ -0,0 +1,11 @@
+instance_id: "iid-{{ inst_name }}"
+local_hostname: "{{ inst_name }}"
+{% if !ssh_pubkeys.is_empty() -%}
+public_keys:
+{% for key in ssh_pubkeys -%}
+- "{{ key }}"
+{% endfor %}
+{% endif -%}
+{% if let Some(user) = username -%}
+default_username: "{{ user }}"
+{%- endif %}