Optional Additional Setup

Profiles can specify 'setup_script' to do additional things.  If additional files/dirs are required, a 'setup_copy' map will copy them to the build instance so that 'setup_script' can use/install them.

TBD: docs.

packer.conf

@@ -69,8 +69,8 @@ builders = [
 provisioners = [
   {
     type        = "file"
-    source      = "../scripts/nvme-ebs-links"
-    destination = "/tmp/nvme-ebs-links"
+    source      = "./profile/{{user `profile`}}/{{user `profile_build`}}/setup-ami.d"
+    destination = "/tmp/setup-ami.d"
   }
   {
     type    = "shell"

scripts/builder.py

@@ -513,16 +513,35 @@ class ConfigBuilder:
             profile = os.path.splitext(os.path.split(file)[-1])[0]
             self.build_profile(profile)
 
+    def rel_symlink(self, src_path, dest_dir, dest):
+        os.symlink(
+            os.path.relpath(src_path, dest_dir),
+            os.path.join(dest_dir, dest))
+
     def build_profile(self, profile):
         build_config = pyhocon.ConfigFactory.parse_file(
             os.path.join(self.config_path, f"{profile}.conf"))
 
         for build, cfg in build_config["BUILDS"].items():
             build_dir = os.path.join(self.out_dir, profile, build)
+            setup_dir = os.path.join(build_dir, "setup-ami.d")
 
             # Always start fresh
             shutil.rmtree(build_dir, ignore_errors=True)
-            os.makedirs(build_dir)
+            os.makedirs(setup_dir)
+
+            # symlink nvme script
+            self.rel_symlink("scripts/nvme-ebs-links", setup_dir, "nvme-ebs-links")
+
+            # symlink additional setup_script
+            if "setup_script" in cfg.keys():
+                self.rel_symlink(cfg["setup_script"], setup_dir, "setup_script")
+                del cfg["setup_script"]
+
+            if "setup_copy" in cfg.keys():
+                for dst, src in cfg["setup_copy"].items():
+                    self.rel_symlink(src, setup_dir, dst)
+                del cfg["setup_copy"]
 
             cfg["profile"] = profile
             cfg["profile_build"] = build

scripts/setup-ami

@@ -154,7 +154,7 @@ install_core_packages() {
 }
 
 setup_mdev() {
-    cp /tmp/nvme-ebs-links "$TARGET/lib/mdev"
+    cp /tmp/setup-ami.d/nvme-ebs-links "$TARGET/lib/mdev"
 
     # insert nvme ebs mdev configs just above "# fallback" comment
     sed -n -i \
@@ -288,6 +288,19 @@ configure_ntp() {
         -i "$TARGET/etc/chrony/chrony.conf"
 }
 
+setup_script() {
+    if [ -f /tmp/setup-ami.d/setup_script ]; then
+        einfo "Executing additional setup script"
+        (
+            cd /tmp/setup-ami.d
+            chmod u+x ./setup_script
+            TARGET="$TARGET" ./setup_script
+        )
+    else
+        einfo "No additional setup script"
+    fi
+}
+
 cleanup() {
     # Sweep cruft out of the image that doesn't need to ship or will be
     # re-generated when the image boots
@@ -344,6 +357,8 @@ main() {
     create_alpine_user
     configure_ntp
 
+    setup_script
+
     einfo "All done, cleaning up"
     cleanup
 }