From fa0b23f30bde82f0922ae7511eda5886203b3bd8 Mon Sep 17 00:00:00 2001
From: Vidya Sagar Reddy Desu <35026133+vidya381@users.noreply.github.com>
Date: Sat, 28 Feb 2026 20:32:05 -0600
Subject: [PATCH 1/4] add DockerDaemonCheck

---
 internal/check/docker.go | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 internal/check/docker.go

diff --git a/internal/check/docker.go b/internal/check/docker.go
new file mode 100644
index 0000000..db81a5c
--- /dev/null
+++ b/internal/check/docker.go
@@ -0,0 +1,29 @@
+package check
+
+import (
+	"context"
+	"os/exec"
+)
+
+type DockerDaemonCheck struct{}
+
+func (c *DockerDaemonCheck) Name() string {
+	return "Docker daemon running"
+}
+
+func (c *DockerDaemonCheck) Run(_ context.Context) Result {
+	err := exec.Command("docker", "info").Run()
+	if err != nil {
+		return Result{
+			Name:    c.Name(),
+			Status:  StatusFail,
+			Message: "Docker daemon is not running",
+			Fix:     "start Docker and try again",
+		}
+	}
+	return Result{
+		Name:    c.Name(),
+		Status:  StatusPass,
+		Message: "Docker daemon is running",
+	}
+}

From b2e72aad1ec9451cb169691881738831ea7176a1 Mon Sep 17 00:00:00 2001
From: Vidya Sagar Reddy Desu <35026133+vidya381@users.noreply.github.com>
Date: Sat, 28 Feb 2026 20:41:18 -0600
Subject: [PATCH 2/4] register docker binary and daemon checks

---
 internal/check/registry.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/internal/check/registry.go b/internal/check/registry.go
index 9faa351..de5f99d 100644
--- a/internal/check/registry.go
+++ b/internal/check/registry.go
@@ -26,7 +26,8 @@ func Build(stack detector.DetectedStack) []Check {
 		}
 	}
 	if stack.Docker {
-		// add Docker checks
+		cs = append(cs, &BinaryCheck{Binary: "docker"})
+		cs = append(cs, &DockerDaemonCheck{})
 	}
 	if stack.Postgres {
 		// add Postgres checks

From 157de4a12606727a50952cfd2ae1771d4cd335bb Mon Sep 17 00:00:00 2001
From: Vidya Sagar Reddy Desu <35026133+vidya381@users.noreply.github.com>
Date: Sat, 28 Feb 2026 20:44:15 -0600
Subject: [PATCH 3/4] make DockerDaemonCheck runner injectable for testing

---
 internal/check/docker.go | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/internal/check/docker.go b/internal/check/docker.go
index db81a5c..0bf4e21 100644
--- a/internal/check/docker.go
+++ b/internal/check/docker.go
@@ -5,15 +5,23 @@ import (
 	"os/exec"
 )
 
-type DockerDaemonCheck struct{}
+type DockerDaemonCheck struct {
+	runner func() error
+}
 
 func (c *DockerDaemonCheck) Name() string {
 	return "Docker daemon running"
 }
 
 func (c *DockerDaemonCheck) Run(_ context.Context) Result {
-	err := exec.Command("docker", "info").Run()
-	if err != nil {
+	run := c.runner
+	if run == nil {
+		run = func() error {
+			return exec.Command("docker", "info").Run()
+		}
+	}
+
+	if err := run(); err != nil {
 		return Result{
 			Name:    c.Name(),
 			Status:  StatusFail,

From 6fff7c28f36a45f005be66640e36f7c2e2f98a40 Mon Sep 17 00:00:00 2001
From: Vidya Sagar Reddy Desu <35026133+vidya381@users.noreply.github.com>
Date: Sat, 28 Feb 2026 20:44:55 -0600
Subject: [PATCH 4/4] add tests for DockerDaemonCheck

---
 internal/check/docker_test.go | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 internal/check/docker_test.go

diff --git a/internal/check/docker_test.go b/internal/check/docker_test.go
new file mode 100644
index 0000000..58ef359
--- /dev/null
+++ b/internal/check/docker_test.go
@@ -0,0 +1,23 @@
+package check
+
+import (
+	"context"
+	"errors"
+	"testing"
+)
+
+func TestDockerDaemonCheck_Pass(t *testing.T) {
+	c := &DockerDaemonCheck{runner: func() error { return nil }}
+	result := c.Run(context.Background())
+	if result.Status != StatusPass {
+		t.Errorf("expected pass, got %v: %s", result.Status, result.Message)
+	}
+}
+
+func TestDockerDaemonCheck_Fail(t *testing.T) {
+	c := &DockerDaemonCheck{runner: func() error { return errors.New("daemon not running") }}
+	result := c.Run(context.Background())
+	if result.Status != StatusFail {
+		t.Errorf("expected fail, got %v", result.Status)
+	}
+}