Make DNS configuration optional

pot/src/lib.rs

@@ -16,6 +16,12 @@ use walkdir::WalkDir;
 
 pub type Result<T> = ::std::result::Result<T, error::PotError>;
 
+#[derive(Debug, Clone)]
+pub struct PotDnsConfig {
+    pub pot_name: String,
+    pub ip: IpAddr,
+}
+
 #[derive(Debug, Clone)]
 pub struct PotSystemConfig {
     pub zfs_root: String,
@@ -24,8 +30,7 @@ pub struct PotSystemConfig {
     pub netmask: IpAddr,
     pub gateway: IpAddr,
     pub ext_if: String,
-    pub dns_name: String,
-    pub dns_ip: IpAddr,
+    pub dns: Option<PotDnsConfig>,
 }
 
 impl Default for PotSystemConfig {
@@ -38,8 +43,7 @@ impl Default for PotSystemConfig {
             netmask: IpAddr::V4(Ipv4Addr::new(255, 255, 255, 0)),
             gateway: IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
             ext_if: String::default(),
-            dns_name: String::default(),
-            dns_ip: IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
+            dns: None,
         }
     }
 }
@@ -63,8 +67,10 @@ impl TryFrom<system::PartialSystemConf> for PotSystemConfig {
                 netmask: psc.netmask.unwrap(),
                 gateway: psc.gateway.unwrap(),
                 ext_if: psc.ext_if.unwrap(),
-                dns_name: psc.dns_name.unwrap(),
-                dns_ip: psc.dns_ip.unwrap(),
+                dns: match psc.dns_ip {
+                  Some(ip) => Some(PotDnsConfig{pot_name: psc.dns_name.unwrap(), ip}),
+                  None => None
+                },
             })
         } else {
             Err(error::PotError::IncompleteSystemConf)

pot/src/system.rs

@@ -32,7 +32,16 @@ impl PartialSystemConf {
             Err(_) => return dconf,
         };
         let pconf = PartialSystemConf::from_str(&s).ok().unwrap_or_default();
+        let pconf_has_dns_ip = pconf.dns_ip != None;
         dconf.merge(pconf);
+        // remove dns_ip if it came from default config and is not inside pot network
+        if !pconf_has_dns_ip {
+            if let Some(dns_ip) = &dconf.dns_ip {
+                if !dconf.network.unwrap().contains(dns_ip) {
+                    dconf.dns_ip = None;
+                }
+            }
+        }
         dconf
     }
 
@@ -44,7 +53,7 @@ impl PartialSystemConf {
             && self.gateway.is_some()
             && self.ext_if.is_some()
             && self.dns_name.is_some()
-            && self.dns_ip.is_some()
+            && (self.dns_ip.is_none() || self.dns_name.is_some())
     }
 
     fn merge(&mut self, rhs: PartialSystemConf) {

src/bin/potnet.rs

@@ -303,8 +303,10 @@ fn init_ipdb(conf: &PotSystemConfig, ip_db: &mut BTreeMap<IpAddr, Option<String>
     ip_db.insert(conf.network.broadcast(), None);
     info!("Insert gateway {:?}", conf.gateway);
     ip_db.insert(conf.gateway, Some("default gateway".to_string()));
-    info!("Insert dns {:?}", conf.dns_ip);
-    ip_db.insert(conf.dns_ip, Some(conf.dns_name.clone()));
+    if let Some(dns) = &conf.dns {
+        info!("Insert dns {:?}", dns.ip);
+        ip_db.insert(dns.ip, Some(dns.pot_name.clone()));
+    }
     for v in &get_pot_conf_list(conf.clone()) {
         if v.network_type == NetType::PublicBridge || v.network_type == NetType::PrivateBridge {
             info!("Insert pot {:?}", v.ip_addr.unwrap());
@@ -393,11 +395,13 @@ fn main() -> Result<()> {
                     conf.gateway, conf.network
                 );
             }
-            if !conf.network.contains(&conf.dns_ip) {
-                error!(
-                    "DNS IP ({}) outside the network range ({})",
-                    conf.dns_ip, conf.network
-                );
+            if let Some(dns) = &conf.dns {
+                if !conf.network.contains(&dns.ip) {
+                    error!(
+                        "DNS IP ({}) outside the network range ({})",
+                        dns.ip, conf.network
+                    );
+                }
             }
             if conf.network.netmask() != conf.netmask {
                 error!(