Magic DNS and easytier-web improvements (#856)

1. dns add macos system config
2. allow easytier-web serve dashboard and api in same port

easytier/src/instance/dns_server/system_config/darwin.rs

@@ -0,0 +1,135 @@
+use std::{
+    collections::HashSet,
+    fs::{self, OpenOptions},
+    io::{self, Write},
+    os::unix::fs::PermissionsExt,
+    path::Path,
+};
+
+use super::{OSConfig, SystemConfig};
+
+const MAC_RESOLVER_FILE_HEADER: &str = "# Added by easytier\n";
+const ETC_RESOLVER: &str = "/etc/resolver";
+const ETC_RESOLV_CONF: &str = "/etc/resolv.conf";
+
+pub struct DarwinConfigurator {}
+
+impl DarwinConfigurator {
+    pub fn new() -> Self {
+        DarwinConfigurator {}
+    }
+
+    pub fn do_close(&self) -> io::Result<()> {
+        self.remove_resolver_files(|_| true)
+    }
+
+    pub fn supports_split_dns(&self) -> bool {
+        true
+    }
+
+    pub fn do_set_dns(&self, cfg: &OSConfig) -> io::Result<()> {
+        fs::create_dir_all(ETC_RESOLVER)?;
+        let mut keep = HashSet::new();
+
+        // 写 search.easytier 文件
+        if !cfg.search_domains.is_empty() {
+            let search_file = "search.easytier";
+            keep.insert(search_file.to_string());
+            let mut content = String::from(MAC_RESOLVER_FILE_HEADER);
+            content.push_str("search");
+            for domain in &cfg.search_domains {
+                content.push(' ');
+                content.push_str(domain.trim_end_matches('.'));
+            }
+            content.push('\n');
+            Self::write_resolver_file(search_file, &content)?;
+        }
+
+        // 写 match_domains 文件
+        let mut ns_content = String::from(MAC_RESOLVER_FILE_HEADER);
+        for ns in &cfg.nameservers {
+            ns_content.push_str(&format!("nameserver {}\n", ns));
+        }
+        for domain in &cfg.match_domains {
+            let file_base = domain.trim_end_matches('.');
+            keep.insert(file_base.to_string());
+            Self::write_resolver_file(file_base, &ns_content)?;
+        }
+        // 删除未保留的 resolver 文件
+        self.remove_resolver_files(|domain| !keep.contains(domain))?;
+
+        Ok(())
+    }
+
+    fn write_resolver_file(file_name: &str, content: &str) -> io::Result<()> {
+        let path = Path::new(ETC_RESOLVER).join(file_name);
+        let mut file = OpenOptions::new()
+            .create(true)
+            .truncate(true)
+            .write(true)
+            .open(&path)?;
+        file.set_permissions(fs::Permissions::from_mode(0o644))?;
+        file.write_all(content.as_bytes())?;
+        Ok(())
+    }
+
+    fn remove_resolver_files<F>(&self, should_delete: F) -> io::Result<()>
+    where
+        F: Fn(&str) -> bool,
+    {
+        let entries = match fs::read_dir(ETC_RESOLVER) {
+            Ok(e) => e,
+            Err(e) if e.kind() == io::ErrorKind::NotFound => return Ok(()),
+            Err(e) => return Err(e),
+        };
+        for entry in entries {
+            let entry = entry?;
+            let file_type = entry.file_type()?;
+            if !file_type.is_file() {
+                continue;
+            }
+            let name = entry.file_name();
+            let name_str = name.to_string_lossy();
+            if !should_delete(&name_str) {
+                continue;
+            }
+            let full_path = entry.path();
+            let content = fs::read_to_string(&full_path)?;
+            if !content.starts_with(MAC_RESOLVER_FILE_HEADER) {
+                continue;
+            }
+            fs::remove_file(&full_path)?;
+        }
+        Ok(())
+    }
+}
+
+impl SystemConfig for DarwinConfigurator {
+    fn set_dns(&self, cfg: &OSConfig) -> io::Result<()> {
+        self.do_set_dns(cfg)
+    }
+
+    fn close(&self) -> io::Result<()> {
+        self.do_close()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[tokio::test]
+    async fn set_dns_test() -> io::Result<()> {
+        let config = OSConfig {
+            nameservers: vec!["8.8.8.8".into()],
+            search_domains: vec!["example.com".into()],
+            match_domains: vec!["test.local".into()],
+        };
+        let configurator = DarwinConfigurator::new();
+
+        configurator.set_dns(&config)?;
+        configurator.close()?;
+
+        Ok(())
+    }
+}