Attempt to implement and test setting static ips from instance metadata

rust/Cargo.lock

@@ -187,7 +187,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
 [[package]]
-name = "hetzner-ipv6"
+name = "hetzner-static-ip"
 version = "1.0.0"
 dependencies = [
  "anyhow",

rust/default.nix

@@ -26,7 +26,7 @@ let
       fileset = lib.fileset.unions [
         ./Cargo.lock
         ./Cargo.toml
-        (craneLib.fileset.commonCargoSources ./lib/common)
+        (craneLib.fileset.commonCargoSources ./lib)
         (craneLib.fileset.commonCargoSources ./program/${crate})
       ];
     };
@@ -40,6 +40,19 @@ in
         pname = crateName;
         cargoExtraArgs = "-p ${crateName}";
         src = fileSetForCrate crateName;
+        nativeBuildInputs = [ pkgs.makeWrapper ];
+        postFixup = ''
+          wrapProgram $out/bin/${crateName} --set PATH "${
+            lib.makeBinPath [
+              pkgs.curl
+              pkgs.uutils-coreutils-noprefix
+              pkgs.iproute2
+            ]
+          }"
+        '';
+        meta = {
+          mainProgram = crateName;
+        };
       }
     );
   checks = {

rust/lib/common/src/yaml.rs

@@ -8,3 +8,53 @@ pub fn string(str: &str) -> String {
 pub fn to_string<T: ?Sized + Serialize>(value: &T) -> anyhow::Result<String> {
     serde_yml::to_string(value).context("Could not serialize to yaml")
 }
+
+pub fn from_str<D: for<'de> serde::Deserialize<'de>>(s: &str) -> anyhow::Result<D> {
+    serde_yml::from_str(s).map_err(|e| anyhow::format_err!("{e}:\n{}", extract_context(&e, s)))
+}
+
+fn extract_context(serde_error: &serde_yml::Error, s: &str) -> String {
+    let Some(location) = serde_error.location() else {
+        return String::from("Error provided no location information, could not extract context");
+    };
+    let lines: Vec<_> = s.lines().collect();
+    if lines.len() == 1 {
+        let (col_begin, highlight) = if location.column() > 30 {
+            (location.column() - 30, 30)
+        } else {
+            (1, location.column())
+        };
+        let col_end = if lines[0].len() + 31 < location.column() {
+            lines[0].len() + 1
+        } else {
+            location.column() + 30
+        };
+        let mut line: String = lines[0]
+            .chars()
+            .skip(col_begin - 1)
+            .take(col_end - col_begin)
+            .collect();
+        line.push('\n');
+        line.extend(std::iter::repeat_n(' ', highlight - 1));
+        line.push('^');
+        line
+    } else {
+        let error_line = location.line();
+        let mut result = String::new();
+        if error_line > 1 {
+            result.push_str(&format!("{}: {}\n", error_line - 1, lines[error_line - 2]));
+        }
+        result.push_str(&format!("{}: {}\n", error_line, lines[error_line - 1]));
+        result.push_str(&format!(
+            "{}  {}\n",
+            " ".repeat(error_line.to_string().len()),
+            std::iter::repeat_n(' ', location.column() - 1)
+                .chain(['^'].into_iter())
+                .collect::<String>(),
+        ));
+        if lines.len() > error_line {
+            result.push_str(&format!("{}: {}\n", error_line + 1, lines[error_line]));
+        }
+        result
+    }
+}

rust/program/hetzner-ipv6/src/main.rs

@@ -1,28 +0,0 @@
-use clap::{Parser, Subcommand};
-fn main() {
-    common::entrypoint(program);
-}
-
-#[derive(Parser, Debug)]
-#[command(version, about, long_about = None)]
-pub struct Args {
-    #[command(subcommand)]
-    pub command: Commands,
-}
-
-#[derive(Debug, Subcommand)]
-pub enum Commands {
-    /// Configures the ipv6 address using instance metadata and iproute2
-    Configure,
-}
-
-fn program() -> anyhow::Result<()> {
-    let args = Args::parse();
-    match args.command {
-        Commands::Configure => configure(),
-    }
-}
-
-fn configure() -> anyhow::Result<()> {
-    Ok(())
-}

rust/program/hetzner-static-ip/Cargo.toml

@@ -1,8 +1,8 @@
 [package]
-name = "hetzner-ipv6"
+name = "hetzner-static-ip"
 edition = "2024"
 version = "1.0.0"
-metadata.crane.name = "hetzner-ipv6"
+metadata.crane.name = "hetzner-static-ip"
 
 [dependencies]
 anyhow = { workspace = true }

rust/program/hetzner-static-ip/src/main.rs

@@ -0,0 +1,71 @@
+use anyhow::Context as _;
+use clap::{Parser, Subcommand};
+
+use crate::metadata::Instance;
+
+mod metadata;
+
+fn main() {
+    common::entrypoint(program);
+}
+
+#[derive(Parser, Debug)]
+#[command(version, about, long_about = None)]
+pub struct Args {
+    #[command(subcommand)]
+    pub command: Commands,
+}
+
+#[derive(Debug, Subcommand)]
+pub enum Commands {
+    /// Configures the ipv6 address using instance metadata and iproute2
+    Configure,
+}
+
+fn program() -> anyhow::Result<()> {
+    let args = Args::parse();
+    match args.command {
+        Commands::Configure => configure(),
+    }
+}
+
+fn configure() -> anyhow::Result<()> {
+    let metadata_api = common::env::read_env("INSTANCE_API_URI")
+        .unwrap_or(String::from("http://169.254.169.254/hetzner/v1/metadata"));
+    let metadata = common::curl::read_text_as_string(&metadata_api)?;
+    let metadata: Instance = common::yaml::from_str(&metadata)
+        .context("Could not parse instance metadata into expected format")?;
+    for m in metadata.network_config.config {
+        for subnet in m.subnets {
+            match subnet {
+                metadata::InstanceNetworkConfigConfigSubnet::Static {
+                    ipv6,
+                    ipv4,
+                    address,
+                    gateway,
+                } => {
+                    let mut cmd = common::proc::Command::new("ip");
+                    if ipv6.is_some_and(|v| v) {
+                        cmd.arg("-6");
+                    }
+                    if ipv4.is_some_and(|v| v) {
+                        cmd.arg("-4");
+                    }
+                    cmd.args(["addr", "add", &address, "dev", &m.name]);
+                    cmd.try_spawn_to_string()?;
+                    let mut cmd = common::proc::Command::new("ip");
+                    if ipv6.is_some_and(|v| v) {
+                        cmd.arg("-6");
+                    }
+                    if ipv4.is_some_and(|v| v) {
+                        cmd.arg("-4");
+                    }
+                    cmd.args(["route", "add", "default", "via", &gateway, "dev", &m.name]);
+                    cmd.try_spawn_to_string()?;
+                }
+                metadata::InstanceNetworkConfigConfigSubnet::Dhcp {} => continue,
+            }
+        }
+    }
+    Ok(())
+}

rust/program/hetzner-static-ip/src/metadata.rs

@@ -0,0 +1,32 @@
+use serde::Deserialize;
+
+#[derive(Debug, Deserialize)]
+pub struct Instance {
+    #[serde(rename = "network-config")]
+    pub network_config: InstanceNetworkConfig,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct InstanceNetworkConfig {
+    pub config: Vec<InstanceNetworkConfigConfig>,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct InstanceNetworkConfigConfig {
+    pub name: String,
+    pub subnets: Vec<InstanceNetworkConfigConfigSubnet>,
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(tag = "type")]
+pub enum InstanceNetworkConfigConfigSubnet {
+    #[serde(rename = "static")]
+    Static {
+        ipv6: Option<bool>,
+        ipv4: Option<bool>,
+        address: String,
+        gateway: String,
+    },
+    #[serde(rename = "dhcp")]
+    Dhcp {},
+}

rust/rust-toolchain.toml

@@ -1,4 +1,4 @@
 [toolchain]
 channel = "1.88.0"
-components = ["rustfmt", "clippy", "cargo"]
+components = ["rustfmt", "clippy", "cargo", "rust-src"]
 profile = "minimal"