main: Support generating the shoelaces mapping file.

Containerfile

@@ -33,6 +33,7 @@ RUN apk add git && \
 
 FROM base as shoelaces
 WORKDIR /
+ENV SHOELACES_MAPFILE=/var/lib/shoelaces/mappings.yaml
 COPY --from=shoelaces_build /shoelaces/shoelaces /usr/local/bin/shoelaces
 COPY --from=shoelaces_build /shoelaces/web /usr/share/shoelaces/web
 COPY runit/shoelaces /etc/service/shoelaces

README.md

@@ -19,9 +19,15 @@ in the environment:
   * `DNSMASQ_TEMPLATE` - A go template expression for the dhcp-hosts
     file.  Defaults to a suitable configuration for IPv4.  The default
     template is `{{JoinStrings .HWAddr ","}},{{.Addr}}`.
+  * `SHOELACES_MAPFILE` - A file to write out shoelaces mappings too.
+    Must be named `mappings.yaml` and at the path expected by
+    shoelaces.  Only relevant in images that contain shoelaces.
+  * `SHOELACES_TAG_PREFIX` - A prefix that if found on a tag will be
+    used to form the mapping for shoelaces to supply the correct boot
+    files to the machine without human interaction.
 
 The search through netbox by default pulls hosts that have the
-`pxe-enable` tag set.  Hosts are then filtered to ensure they hae a
+$NETBOX_TAG tag set.  Hosts are then filtered to ensure they have a
 primary IPv4 address and at least one interface that has a MAC address
 set.  Hosts that have the correct tag but do not have at least one MAC
 address associated with a non-management-only interface and a primary
@@ -37,7 +43,6 @@ install time, it is more likely that only one interface will be
 brought up, but it is still prefered that the machine get its final
 address.
 
-
 ## Configuring dnsmasq
 
 You will need to supply a suitable dnsmasq config file that points to
@@ -71,3 +76,22 @@ In this example the server hosting the PXE services is located at
 dnsmasq not to provide services to hosts that do not have a
 pre-existing reservation, which can be useful if your network does not
 use DHCP except for machine installation.
+
+## Using with Shoelaces
+
+Shoelaces is a powerful ipxe mapping tool that can mux different boot
+images to different machines by hand or by address.  Each build of the
+containers from this repo comes in a non-shoelaces flavor and a
+shoelaces flavor.  Using shoelaces will provide a web interface on
+port 8081 that allows you to manually select ipxe scripts.  Shoelaces
+expects to find your template scripts in `/var/lib/shoelaces/ipxe` and
+can serve static assets for you from `/var/lib/shoelaces/static`.
+
+Shoelaces is also capable of directly mapping a machine to its boot
+scripts based on tags in netbox.  To use this behavior configure the
+value of `SHOELACES_TAG_PREFIX` to the prefix used by the tags you
+have set in Netbox.  For example, if you wanted machines that posess
+the tags `pxe-zerotouch-deb11` to boot with the ipxe script
+`deb11.ipxe`, you would configure the tag to be `pxe-zerotouch-`. Only
+the first tag found will be mapped, so its a good idea to carefully
+plan the tag structure in use for these tags to be unique.

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"encoding/json"
 	"io"
 	"log"
 	"os"
@@ -19,6 +20,25 @@ type DHCPHost struct {
 	Addr     string
 }
 
+// ShoelacesHost is a host that can be mapped without user input in
+// shoelaces.
+type ShoelacesHost struct {
+	Network string     `json:"network"`
+	Script  ShoeScript `json:"script"`
+}
+
+// ShoeScript is the nested script type for shoelaces.  It is only
+// supported to specify by name.
+type ShoeScript struct {
+	Name string `json:"name"`
+}
+
+// ShoelacesNetworkMap matches the structure that shoelaces expects to
+// be able to read in.
+type ShoelacesNetworkMap struct {
+	NetworkMaps []ShoelacesHost `json:"networkMaps"`
+}
+
 func main() {
 	if _, verbose := os.LookupEnv("VERBOSE"); !verbose {
 		log.SetOutput(io.Discard)
@@ -56,13 +76,15 @@ func main() {
 
 	site := os.Getenv("NETBOX_SITE")
 	tag := os.Getenv("NETBOX_TAG")
+	shoetag := os.Getenv("SHOELACES_TAG_PREFIX")
 	devices, err := nb.ListDevices(site, tag)
 	if err != nil {
 		log.Println("Error listing devices:", err)
 		os.Exit(1)
 	}
 
 	hosts := make(map[int64]*DHCPHost, len(devices))
+	shoenets := []ShoelacesHost{}
 	for _, dev := range devices {
 		ipaddr := strings.SplitN(dev.PrimaryIPv4.Address, "/", 2)[0]
 
@@ -91,11 +113,41 @@ func main() {
 			Addr:     ipaddr,
 			HWAddr:   hwaddrs,
 		}
+
+		// Construct the shoelaces mapping if enabled.
+		if shoetag != "" {
+			for _, tag := range dev.Tags {
+				if strings.HasPrefix(tag.Slug, shoetag) {
+					// Map this script for this host's IPs
+					shoehost := ShoelacesHost{
+						Network: ipaddr + "/32",
+						Script: ShoeScript{
+							Name: strings.TrimPrefix(tag.Slug, shoetag) + ".ipxe",
+						},
+					}
+					shoenets = append(shoenets, shoehost)
+					break
+				}
+			}
+		}
 	}
 
 	for _, host := range hosts {
 		if err := hostTmpl.Execute(os.Stdout, host); err != nil {
 			log.Println("Error executing template", err)
 		}
 	}
+
+	if os.Getenv("SHOELACES_MAPFILE") != "" {
+		bytes, err := json.Marshal(ShoelacesNetworkMap{NetworkMaps: shoenets})
+		if err != nil {
+			log.Println("Error marshalling shoelaces mappings", err)
+			os.Exit(1)
+		}
+
+		if err := os.WriteFile(os.Getenv("SHOELACES_MAPFILE"), bytes, 0644); err != nil {
+			log.Println("Error writing shoelaces mappings", err)
+			os.Exit(1)
+		}
+	}
 }

netbox/type.go

@@ -6,13 +6,22 @@ type Address struct {
 	Address string
 }
 
+// Tag is a small associated label that is used to group machines.
+// This is used by the shoelaces mapper to determine what target
+// should be mapped for the particular machine.
+type Tag struct {
+	Name string
+	Slug string
+}
+
 // Device represents the minimum information we wish to retreive from
 // the netbox devices API as opposed to using the full fat OpenAPI
 // client.
 type Device struct {
 	ID          int64
 	Name        string  `json:"name"`
 	PrimaryIPv4 Address `json:"primary_ip4"`
+	Tags        []Tag   `json:"tags"`
 }
 
 // Interface represents the minimum informatino we wish to retreive

runit/netbox-dnsmasq-dhcp/run

@@ -1,6 +1,17 @@
 #!/bin/sh
 
 while true ; do
-    /usr/local/bin/netbox-dhcp-hosts > /run/dhcp-hosts && pkill -SIGHUP dnsmasq
+    if /usr/local/bin/netbox-dhcp-hosts | sort > /run/dhcp-hosts.next ; then
+        if ! diff /run/dhcp-hosts /run/dhcp-hosts.next ; then
+            echo "Updated host mappings, reloading services"
+            mv /run/dhcp-hosts.next /run/dhcp-hosts
+
+            pkill -SIGHUP dnsmasq
+
+            if [ -n "$SHOELACES_TAG_PREFIX" ] ; then
+                sv restart shoelaces
+            fi
+        fi
+    fi
     sleep 600
 done