feat: allow config-specified host prefix instead of 'nid'

coresmd/main.go

@@ -37,6 +37,7 @@ var (
 	cache             *Cache
 	baseURL           *url.URL
 	bootScriptBaseURL *url.URL
+	hostnamePrefix    string
 	leaseDuration     time.Duration
 )
 
@@ -48,8 +49,8 @@ func setup4(args ...string) (handler.Handler4, error) {
 	log.Infof("initializing coresmd/coresmd %s (%s), built %s", version.Version, version.GitCommit, version.BuildTime)
 
 	// Ensure all required args were passed
-	if len(args) != 5 {
-		return nil, errors.New("expected 5 arguments: base URL, boot script base URL, CA certificate path, cache duration, lease duration")
+	if len(args) != 6 {
+		return nil, errors.New("expected 6 arguments: base URL, boot script base URL, CA certificate path, hostname prefix, cache duration, lease duration")
 	}
 
 	// Create new SmdClient using first argument (base URL)
@@ -81,17 +82,25 @@ func setup4(args ...string) (handler.Handler4, error) {
 		log.Infof("CA certificate path was empty, not setting")
 	}
 
+	// Parse hostname prefix
+	hostnamePrefix = strings.Trim(args[3], `"'`)
+	log.Infof("hostname prefix: %s", hostnamePrefix)
+	if hostnamePrefix == "" {
+		log.Info("no hostname prefix set, defaulting to 'nid'")
+		hostnamePrefix = "nid"
+	}
+
 	// Create new Cache using fourth argument (cache validity duration) and new SmdClient
 	// pointer
 	log.Debug("generating new Cache")
-	cache, err = NewCache(args[3], smdClient)
+	cache, err = NewCache(args[4], smdClient)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create new cache: %w", err)
 	}
 
 	// Set lease duration from fifth argument
 	log.Debug("setting lease duration")
-	leaseDuration, err = time.ParseDuration(args[4])
+	leaseDuration, err = time.ParseDuration(args[5])
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse lease duration: %w", err)
 	}
@@ -131,7 +140,7 @@ func Handler4(req, resp *dhcpv4.DHCPv4) (*dhcpv4.DHCPv4, bool) {
 
 	// Set client hostname
 	if ifaceInfo.Type == "Node" {
-		resp.Options.Update(dhcpv4.OptHostName(fmt.Sprintf("nid%04d", ifaceInfo.CompNID)))
+		resp.Options.Update(dhcpv4.OptHostName(fmt.Sprintf("%s%04d", hostnamePrefix, ifaceInfo.CompNID)))
 	}
 
 	// Set root path to this server's IP

resources/config.example.yaml

@@ -43,10 +43,13 @@ server4:
     #      address if name servers are not configured.
     #   3. (OPTIONAL) Path to CA cert used for TLS with the SMD base URL. If
     #      there is already a trusted certificate, this can be blank ("").
-    #   4. Cache validity duration. Coresmd uses a pull-through cache to store
+    #   4. Node hostname prefix. The hostnames given to nodes will be of the
+    #      format "<prefix><nid>". If this argument is blank, "nid" is used as
+    #      the prefix. <nid> is the node ID number, 0-padded to four places.
+    #   5. Cache validity duration. Coresmd uses a pull-through cache to store
     #      network information and this is the duration to refresh that cache.
-    #   5. Lease duration.
-    - coresmd: https://foobar.openchami.cluster http://172.16.0.253:8081 /root_ca/root_ca.crt 30s 1h
+    #   6. Lease duration.
+    - coresmd: https://foobar.openchami.cluster http://172.16.0.253:8081 /root_ca/root_ca.crt '' 30s 1h
 
     # Any requests reaching this point are unknown to SMD and it is up to the
     # administrator to decide how to handle unknown packets.