From f217a2f54d0428c4abf2701863e26cd00f6c8b2b Mon Sep 17 00:00:00 2001
From: dawn <dawn@tangled.org>
Date: Fri, 17 Jul 2026 09:28:39 +0000
Subject: [PATCH] spindle/engines/nixery: make engine fully lazy

Signed-off-by: dawn <dawn@tangled.org>
---
 spindle/engines/nixery/engine.go | 33 ++++++++++++++++++++++++---------
 spindle/engines/nixery/engine_test.go | 25 +++++++++++++++++++++++++
 2 file(s) changed, 49 insertion(s)(+), 9 deletion(s)(-)

diff --git a/spindle/engines/nixery/engine.go b/spindle/engines/nixery/engine.go
--- a/spindle/engines/nixery/engine.go
+++ b/spindle/engines/nixery/engine.go
@@ -35,9 +35,10 @@
 type cleanupFunc func(context.Context) error
 
 type Engine struct {
-	docker client.APIClient
-	l      *slog.Logger
-	cfg    *config.Config
+	dockerMu sync.Mutex
+	docker   client.APIClient
+	l        *slog.Logger
+	cfg      *config.Config
 
 	slotter engine.WorkflowSlotter
 
@@ -164,15 +165,9 @@ return path.Join(nixery, dependencies)
 }
 
 func New(ctx context.Context, cfg *config.Config) (*Engine, error) {
-	dcli, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
-	if err != nil {
-		return nil, err
-	}
-
 	l := log.FromContext(ctx).With("component", "spindle")
 
 	e := &Engine{
-		docker:  dcli,
 		l:       l,
 		cfg:     cfg,
 		slotter: engine.NewSemaphoreSlotter(cfg.NixeryPipelines.MaxConcurrentWorkflows),
@@ -181,6 +176,22 @@
 	e.cleanup = make(map[string][]cleanupFunc)
 
 	return e, nil
+}
+
+func (e *Engine) ensureDocker() (client.APIClient, error) {
+	e.dockerMu.Lock()
+	defer e.dockerMu.Unlock()
+
+	if e.docker != nil {
+		return e.docker, nil
+	}
+
+	dcli, err := client.NewClientWithOpts(client.FromEnv, client.WithAPIVersionNegotiation())
+	if err != nil {
+		return nil, err
+	}
+	e.docker = dcli
+	return dcli, nil
 }
 
 func (e *Engine) AcquireWorkflowSlot(
@@ -214,6 +225,10 @@ if err != nil {
 			err = fmt.Errorf("Failed to setup container:\n%w", err)
 		}
 	}()
+
+	if _, err := e.ensureDocker(); err != nil {
+		return err
+	}
 
 	/// -------------------------NETWORK CREATION---------------------------------------
 	_, err = e.docker.NetworkCreate(ctx, networkName(wid), network.CreateOptions{
diff --git a/spindle/engines/nixery/engine_test.go b/spindle/engines/nixery/engine_test.go
new file mode 100644
--- /dev/null
+++ b/spindle/engines/nixery/engine_test.go
@@ -0,0 +1,25 @@
+package nixery
+
+import (
+	"context"
+	"testing"
+
+	"tangled.org/core/spindle/config"
+)
+
+func TestNewDefersDockerClientUntilWorkflowSetup(t *testing.T) {
+	t.Setenv("DOCKER_HOST", "tcp://127.0.0.1:2376")
+	t.Setenv("DOCKER_TLS_VERIFY", "1")
+	t.Setenv("DOCKER_CERT_PATH", t.TempDir())
+
+	e, err := New(context.Background(), &config.Config{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if e.docker != nil {
+		t.Fatal("docker client initialized during engine initialization")
+	}
+	if _, err := e.ensureDocker(); err == nil {
+		t.Fatal("expected incomplete Docker TLS configuration to fail when first used")
+	}
+}

--
tangled.sh