feat: nat-traversal by detect public_ip from cloud metadata

bin/src/lib.rs

@@ -1,6 +1,10 @@
-use std::{net::SocketAddr, str::FromStr};
+use std::{
+    net::{IpAddr, SocketAddr},
+    str::FromStr,
+};
 
 use atm0s_sdn::{NodeAddr, NodeId};
+use clap::ValueEnum;
 use media_server_protocol::cluster::ZoneId;
 
 mod errors;
@@ -33,3 +37,37 @@ pub async fn fetch_node_addr_from_api(url: &str) -> Result<NodeAddr, String> {
         .ok_or(format!("No data in response from {}", url))?;
     NodeAddr::from_str(&node_addr).map_err(|e| e.to_string())
 }
+
+#[derive(Debug, Clone, ValueEnum)]
+pub enum CloudProvider {
+    Aws,
+    Gcp,
+    Azure,
+    Other,
+}
+
+pub async fn fetch_node_ip_alt_from_cloud(cloud: CloudProvider) -> Result<IpAddr, String> {
+    match cloud {
+        CloudProvider::Aws => {
+            let resp = reqwest::get("http://169.254.169.254/latest/meta-data/local-ipv4").await.map_err(|e| e.to_string())?;
+            let ip = resp.text().await.map_err(|e| e.to_string())?;
+            IpAddr::from_str(&ip).map_err(|e| e.to_string())
+        }
+        CloudProvider::Gcp => {
+            let client = reqwest::Client::new();
+            let resp = client
+                .get("http://metadata/computeMetadata/v1/instance/network-interfaces/0/access-configs/0/external-ip")
+                .header("Metadata-Flavor", "Google")
+                .send()
+                .await
+                .map_err(|e| e.to_string())?;
+            let ip = resp.text().await.map_err(|e| e.to_string())?;
+            IpAddr::from_str(&ip).map_err(|e| e.to_string())
+        }
+        CloudProvider::Azure | CloudProvider::Other => {
+            let resp = reqwest::get("http://ipv4.icanhazip.com").await.map_err(|e| e.to_string())?;
+            let ip = resp.text().await.map_err(|e| e.to_string())?;
+            IpAddr::from_str(&ip).map_err(|e| e.to_string())
+        }
+    }
+}

bin/src/main.rs

@@ -1,6 +1,7 @@
 use std::net::{IpAddr, SocketAddr};
 
 use atm0s_media_server::{fetch_node_addr_from_api, server, NodeConfig};
+use atm0s_media_server::{fetch_node_ip_alt_from_cloud, CloudProvider};
 use atm0s_sdn::NodeAddr;
 use clap::Parser;
 use media_server_protocol::cluster::ZoneId;
@@ -45,6 +46,10 @@ struct Args {
     #[arg(env, long)]
     node_ip_alt: Vec<IpAddr>,
 
+    /// Auto detect node_ip_alt with some common cloud provider metadata.
+    #[arg(env, long)]
+    node_ip_alt_cloud: Option<CloudProvider>,
+
     /// Enable private IP addresses for the node.
     #[arg(env, long)]
     enable_private_ip: bool,
@@ -125,6 +130,11 @@ async fn main() {
         }
     }
 
+    let mut node_ip_alt_cloud = vec![];
+    if let Some(cloud) = args.node_ip_alt_cloud {
+        node_ip_alt_cloud.push(fetch_node_ip_alt_from_cloud(cloud).await.expect("should get node ip alt"));
+    }
+
     let bind_addrs = if let Some(ip) = args.node_ip {
         vec![SocketAddr::new(ip, sdn_port)]
     } else {
@@ -147,7 +157,11 @@ async fn main() {
         seeds: args.seeds,
         bind_addrs,
         zone: ZoneId(args.sdn_zone_id),
-        bind_addrs_alt: args.node_ip_alt.into_iter().map(|ip| SocketAddr::new(ip, sdn_port)).collect::<Vec<_>>(),
+        bind_addrs_alt: node_ip_alt_cloud
+            .into_iter()
+            .chain(args.node_ip_alt.into_iter())
+            .map(|ip| SocketAddr::new(ip, sdn_port))
+            .collect::<Vec<_>>(),
     };
 
     log::info!("Bind addrs {:?}, bind addrs alt {:?}", node.bind_addrs, node.bind_addrs_alt);

docs/getting-started/installation/nat-traversal.md

@@ -0,0 +1,20 @@
+# NAT Traversal
+
+Some cloud providers (like AWS) route all traffic through a NAT gateway, which means that we don't have a public IP address on the VM.
+
+To work around this, we can use the `node_ip_alt` and `node_ip_alt_cloud` options to specify alternative IP addresses for the node.
+
+## Using node_ip_alt
+
+The `node_ip_alt` option takes a list of IP addresses as input, and the node will bind to each of them.
+
+## Using node_ip_alt_cloud
+
+The `node_ip_alt_cloud` option takes a cloud provider as input, and will automatically fetch the alternative IP address for the node.
+
+| Cloud Provider | Fetch URL                                                                                       |
+| -------------- | ----------------------------------------------------------------------------------------------- |
+| AWS            | `http://169.254.169.254/latest/meta-data/local-ipv4`                                            |
+| GCP            | `http://metadata/computeMetadata/v1/instance/network-interfaces/0/access-configs/0/external-ip` |
+| Azure          | `http://ipv4.icanhazip.com`                                                                     |
+| Other          | `http://ipv4.icanhazip.com`                                                                     |