From 31dd04b2b99266269e9ebf374860aa912a1ff43e Mon Sep 17 00:00:00 2001
From: Ace Eldeib <aleldeib@microsoft.com>
Date: Sat, 18 Apr 2020 14:19:48 -0700
Subject: [PATCH] :running: allow extra args with tilt

---
 Tiltfile                        | 29 ++++++++++-------------------
 docs/book/src/developer/tilt.md | 23 +++++++++++++++++++++++
 tilt-provider.json              | 18 ++++++++++++++++++
 3 files changed, 51 insertions(+), 19 deletions(-)
 create mode 100644 tilt-provider.json

diff --git a/Tiltfile b/Tiltfile
index 5adafa7ed111..c0047851c749 100644
--- a/Tiltfile
+++ b/Tiltfile
@@ -25,21 +25,6 @@ default_registry(settings.get("default_registry"))
 always_enable_providers = ["core"]
 
 providers = {
-    "core": {
-        "context": ".",
-        "image": "gcr.io/k8s-staging-cluster-api/cluster-api-controller",
-        "live_reload_deps": [
-            "main.go",
-            "go.mod",
-            "go.sum",
-            "api",
-            "cmd",
-            "controllers",
-            "errors",
-            "third_party",
-            "util",
-        ],
-    },
     "kubeadm-bootstrap": {
         "context": "bootstrap/kubeadm",
         "image": "gcr.io/k8s-staging-cluster-api/kubeadm-bootstrap-controller",
@@ -95,7 +80,10 @@ COPY --from=tilt-helper /go/kubernetes/client/bin/kubectl /usr/bin/kubectl
 #     }
 # }
 def load_provider_tiltfiles():
-    provider_repos = settings.get("provider_repos", [])
+    provider_repos = settings.get("provider_repos", ["."])
+    if "." not in provider_repos:
+        provider_repos.append(".")
+
     for repo in provider_repos:
         file = repo + "/tilt-provider.json"
         provider_details = read_json(file, default = {})
@@ -156,14 +144,17 @@ def enable_provider(name):
         additional_docker_build_commands,
     ])
 
-    # Set up an image build for the provider. The live update configuration syncs the output from the local_resource
-    # build into the container.
+    entrypoint = ["sh", "/start.sh", "/manager"]
+    extra_args = p.get("extra_args")
+    if extra_args:
+        entrypoint.extend(extra_args)
+
     docker_build(
         ref = p.get("image"),
         context = context + "/.tiltbuild/",
         dockerfile_contents = dockerfile_contents,
         target = "tilt",
-        entrypoint = ["sh", "/start.sh", "/manager"],
+        entrypoint = entrypoint,
         only = "manager",
         live_update = [
             sync(context + "/.tiltbuild/manager", "/manager"),
diff --git a/docs/book/src/developer/tilt.md b/docs/book/src/developer/tilt.md
index cbb6434486a6..ffb2f54be7c8 100644
--- a/docs/book/src/developer/tilt.md
+++ b/docs/book/src/developer/tilt.md
@@ -192,6 +192,29 @@ COPY --from=tilt-helper /usr/bin/docker /usr/bin/docker
 COPY --from=tilt-helper /go/kubernetes/client/bin/kubectl /usr/bin/kubectl
 ```
 
+
+**extra_args** (Array, default=[]): An array of additional arguments to pass to the main binary configured
+for this provider. Each item in the array will be passed is to the manager. 
+
+Example:
+
+```json
+{
+    "name": "core",
+    "config": {
+        "context": ".",
+        "image": "gcr.io/k8s-staging-cluster-api/cluster-api-controller",
+        "extra_args": ["--feature-gates=MachinePool=true"]
+    }
+}
+```
+
+With this config, the manager will be invoked with:
+
+```bash
+manager --feature-gates=MachinePool=true
+```
+
 ## Customizing Tilt
 
 If you need to customize Tilt's behavior, you can create files in cluster-api's `tilt.d` directory. This file is ignored
diff --git a/tilt-provider.json b/tilt-provider.json
new file mode 100644
index 000000000000..a2ddad17b30e
--- /dev/null
+++ b/tilt-provider.json
@@ -0,0 +1,18 @@
+{
+    "name": "core",
+    "config": {
+        "context": ".",
+        "image": "gcr.io/k8s-staging-cluster-api/cluster-api-controller",
+        "live_reload_deps": [
+            "main.go",
+            "go.mod",
+            "go.sum",
+            "api",
+            "cmd",
+            "controllers",
+            "errors",
+            "third_party",
+            "util"
+        ]
+    }
+}
\ No newline at end of file