Allow to override default IMDS endpoint

README.md

@@ -105,6 +105,21 @@ Alternatively, you can add `tinycloud=cloud=<cloud>` (preferred) or `ds=<cloud>`
 `/sys/class/dmi/id/product_serial` (QEMU hack) is another way to explicitly
 choose a cloud provider.
 
+### Custom Metadata Service Endpoint
+
+For custom or non-standard metadata services, you can
+override the default IMDS endpoint by setting `IMDS_ENDPOINT` in
+`/etc/tiny-cloud.conf`:
+
+```sh
+# For Tinkerbell or other custom metadata services
+IMDS_ENDPOINT=192.0.2.1:50061
+```
+
+The default endpoint is `169.254.169.254` for most cloud providers. This
+setting allows you to specify a custom IP address and optional port for the
+metadata service.
+
 ## Operation
 
 The first time an instance boots -- either freshly instantiated from an image,

bin/imds

@@ -52,7 +52,8 @@ unset -f \
 ### default variables/functions
 
 # Common to many clouds
-IMDS_ENDPOINT="169.254.169.254"
+# Can be overridden in /etc/tiny-cloud.conf
+: "${IMDS_ENDPOINT:=169.254.169.254}"
 
 # Common to AWS and NoCloud(ish)
 IMDS_HOSTNAME="meta-data/hostname"

lib/tiny-cloud/tiny-cloud.conf

@@ -8,6 +8,11 @@
 # User account where instance SSH keys are installed
 #CLOUD_USER=alpine
 
+# IMDS endpoint override (IP:PORT or IP)
+# Defaults to 169.254.169.254 for most clouds
+# Useful for custom metadata services
+#IMDS_ENDPOINT=169.254.169.254
+
 # IMDS token validity, in seconds (AWS only)
 #IMDS_TOKEN_TTL=5