actions: debootstrap: Use parent-suite name as debootstrap script

Set the script debootstrap uses to the parent suite, falling back to
unstable if the requested suite does not exist.

Signed-off-by: Christopher Obbard <[email protected]>

actions/debootstrap_action.go

@@ -48,7 +48,9 @@ Example:
 - private-key -- provide the client's private key in a file separate from the certificate.
 
 - parent-suite -- release code name which this suite is based on. Useful for downstreams which do
-  not use debian codenames for their suite names (e.g. "stable").
+  not use debian codenames for their suite names (e.g. "stable"). The script debootstrap uses will
+  be set to this property. If the script does not exist, debos will fall back to using the "unstable"
+  debootstrap script.
 */
 package actions
 
@@ -188,6 +190,10 @@ func shouldExcludeUsrIsMerged(suite string) bool {
 	}
 }
 
+func getDebootstrapScriptPath(script string) string {
+	return path.Join("/usr/share/debootstrap/scripts/", script)
+}
+
 func (d *DebootstrapAction) Run(context *debos.DebosContext) error {
 	d.LogStart()
 	cmdline := []string{"debootstrap"}
@@ -242,7 +248,15 @@ func (d *DebootstrapAction) Run(context *debos.DebosContext) error {
 	cmdline = append(cmdline, d.Suite)
 	cmdline = append(cmdline, context.Rootdir)
 	cmdline = append(cmdline, d.Mirror)
-	cmdline = append(cmdline, "/usr/share/debootstrap/scripts/unstable")
+
+	/* Determine debootstrap script to use from d.ParentSuite, falling back to
+	   unstable if a script for the parent suite does not exist. */
+	script := getDebootstrapScriptPath(d.ParentSuite)
+	if _, err := os.Stat(script); err != nil {
+		script = getDebootstrapScriptPath("unstable")
+	}
+	log.Printf("using debootstrap script %s\n", script)
+	cmdline = append(cmdline, script)
 
 	/* Make sure /etc/apt/apt.conf.d exists inside the fakemachine otherwise
 	   debootstrap prints a warning about the path not existing. */