From 2273b198a162bdbb602ffbc158748ad063ecc145 Mon Sep 17 00:00:00 2001
From: Brandon Kimbrough <53441835+bkimbrough88@users.noreply.github.com>
Date: Thu, 11 Mar 2021 18:44:49 -0500
Subject: [PATCH] Add ability to set the MTU size of the docker in docker
 container (#385)

* adding abilitiy to set docker in docker MTU size

* safeguards to only set MTU env var if it is set
---
 api/v1alpha1/runner_types.go                   |  2 ++
 api/v1alpha1/zz_generated.deepcopy.go          |  5 +++++
 ...tions.summerwind.dev_runnerdeployments.yaml |  3 +++
 ...tions.summerwind.dev_runnerreplicasets.yaml |  3 +++
 .../crds/actions.summerwind.dev_runners.yaml   |  3 +++
 ...tions.summerwind.dev_runnerdeployments.yaml |  3 +++
 ...tions.summerwind.dev_runnerreplicasets.yaml |  3 +++
 .../bases/actions.summerwind.dev_runners.yaml  |  3 +++
 controllers/runner_controller.go               | 18 ++++++++++++++++++
 runner/startup.sh                              |  4 ++++
 10 files changed, 47 insertions(+)

diff --git a/api/v1alpha1/runner_types.go b/api/v1alpha1/runner_types.go
index 614d734d..9a1d06aa 100644
--- a/api/v1alpha1/runner_types.go
+++ b/api/v1alpha1/runner_types.go
@@ -92,6 +92,8 @@ type RunnerSpec struct {
 	DockerdWithinRunnerContainer *bool `json:"dockerdWithinRunnerContainer,omitempty"`
 	// +optional
 	DockerEnabled *bool `json:"dockerEnabled,omitempty"`
+	// +optional
+	DockerMTU *int64 `json:"dockerMTU,omitempty"`
 }
 
 // ValidateRepository validates repository field.
diff --git a/api/v1alpha1/zz_generated.deepcopy.go b/api/v1alpha1/zz_generated.deepcopy.go
index f5752e73..b2c5ea52 100644
--- a/api/v1alpha1/zz_generated.deepcopy.go
+++ b/api/v1alpha1/zz_generated.deepcopy.go
@@ -689,6 +689,11 @@ func (in *RunnerSpec) DeepCopyInto(out *RunnerSpec) {
 		*out = new(bool)
 		**out = **in
 	}
+	if in.DockerMTU != nil {
+		in, out := &in.DockerMTU, &out.DockerMTU
+		*out = new(int64)
+		**out = **in
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new RunnerSpec.
diff --git a/charts/actions-runner-controller/crds/actions.summerwind.dev_runnerdeployments.yaml b/charts/actions-runner-controller/crds/actions.summerwind.dev_runnerdeployments.yaml
index 17c05808..9c2cba09 100644
--- a/charts/actions-runner-controller/crds/actions.summerwind.dev_runnerdeployments.yaml
+++ b/charts/actions-runner-controller/crds/actions.summerwind.dev_runnerdeployments.yaml
@@ -433,6 +433,9 @@ spec:
                       type: array
                     dockerEnabled:
                       type: boolean
+                    dockerMTU:
+                      format: int64
+                      type: integer
                     dockerdContainerResources:
                       description: ResourceRequirements describes the compute resource requirements.
                       properties:
diff --git a/charts/actions-runner-controller/crds/actions.summerwind.dev_runnerreplicasets.yaml b/charts/actions-runner-controller/crds/actions.summerwind.dev_runnerreplicasets.yaml
index c23bfe9a..d3580df5 100644
--- a/charts/actions-runner-controller/crds/actions.summerwind.dev_runnerreplicasets.yaml
+++ b/charts/actions-runner-controller/crds/actions.summerwind.dev_runnerreplicasets.yaml
@@ -433,6 +433,9 @@ spec:
                       type: array
                     dockerEnabled:
                       type: boolean
+                    dockerMTU:
+                      format: int64
+                      type: integer
                     dockerdContainerResources:
                       description: ResourceRequirements describes the compute resource requirements.
                       properties:
diff --git a/charts/actions-runner-controller/crds/actions.summerwind.dev_runners.yaml b/charts/actions-runner-controller/crds/actions.summerwind.dev_runners.yaml
index 4e5e947b..090f1af6 100644
--- a/charts/actions-runner-controller/crds/actions.summerwind.dev_runners.yaml
+++ b/charts/actions-runner-controller/crds/actions.summerwind.dev_runners.yaml
@@ -398,6 +398,9 @@ spec:
               type: array
             dockerEnabled:
               type: boolean
+            dockerMTU:
+              format: int64
+              type: integer
             dockerdContainerResources:
               description: ResourceRequirements describes the compute resource requirements.
               properties:
diff --git a/config/crd/bases/actions.summerwind.dev_runnerdeployments.yaml b/config/crd/bases/actions.summerwind.dev_runnerdeployments.yaml
index 17c05808..9c2cba09 100644
--- a/config/crd/bases/actions.summerwind.dev_runnerdeployments.yaml
+++ b/config/crd/bases/actions.summerwind.dev_runnerdeployments.yaml
@@ -433,6 +433,9 @@ spec:
                       type: array
                     dockerEnabled:
                       type: boolean
+                    dockerMTU:
+                      format: int64
+                      type: integer
                     dockerdContainerResources:
                       description: ResourceRequirements describes the compute resource requirements.
                       properties:
diff --git a/config/crd/bases/actions.summerwind.dev_runnerreplicasets.yaml b/config/crd/bases/actions.summerwind.dev_runnerreplicasets.yaml
index c23bfe9a..d3580df5 100644
--- a/config/crd/bases/actions.summerwind.dev_runnerreplicasets.yaml
+++ b/config/crd/bases/actions.summerwind.dev_runnerreplicasets.yaml
@@ -433,6 +433,9 @@ spec:
                       type: array
                     dockerEnabled:
                       type: boolean
+                    dockerMTU:
+                      format: int64
+                      type: integer
                     dockerdContainerResources:
                       description: ResourceRequirements describes the compute resource requirements.
                       properties:
diff --git a/config/crd/bases/actions.summerwind.dev_runners.yaml b/config/crd/bases/actions.summerwind.dev_runners.yaml
index 4e5e947b..090f1af6 100644
--- a/config/crd/bases/actions.summerwind.dev_runners.yaml
+++ b/config/crd/bases/actions.summerwind.dev_runners.yaml
@@ -398,6 +398,9 @@ spec:
               type: array
             dockerEnabled:
               type: boolean
+            dockerMTU:
+              format: int64
+              type: integer
             dockerdContainerResources:
               description: ResourceRequirements describes the compute resource requirements.
               properties:
diff --git a/controllers/runner_controller.go b/controllers/runner_controller.go
index 99056212..02c512bf 100644
--- a/controllers/runner_controller.go
+++ b/controllers/runner_controller.go
@@ -530,6 +530,15 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 		},
 	}
 
+	if mtu := runner.Spec.DockerMTU; mtu != nil && dockerdInRunner {
+		pod.Spec.Containers[0].Env = append(pod.Spec.Containers[0].Env, []corev1.EnvVar{
+			{
+				Name:  "MTU",
+				Value: fmt.Sprintf("%d", *runner.Spec.DockerMTU),
+			},
+		}...)
+	}
+
 	if !dockerdInRunner && dockerEnabled {
 		runnerVolumeName := "runner"
 		runnerVolumeMountPath := "/runner"
@@ -612,6 +621,15 @@ func (r *RunnerReconciler) newPod(runner v1alpha1.Runner) (corev1.Pod, error) {
 			Resources: runner.Spec.DockerdContainerResources,
 		})
 
+		if mtu := runner.Spec.DockerMTU; mtu != nil {
+			pod.Spec.Containers[1].Env = append(pod.Spec.Containers[1].Env, []corev1.EnvVar{
+				{
+					Name:  "DOCKERD_ROOTLESS_ROOTLESSKIT_MTU",
+					Value: fmt.Sprintf("%d", *runner.Spec.DockerMTU),
+				},
+			}...)
+		}
+
 	}
 
 	if len(runner.Spec.Containers) != 0 {
diff --git a/runner/startup.sh b/runner/startup.sh
index fc4cf51b..0fcb1eaa 100644
--- a/runner/startup.sh
+++ b/runner/startup.sh
@@ -33,5 +33,9 @@ for process in "${processes[@]}"; do
     fi
 done
 
+if [ -n "${MTU}" ]; then
+  ifconfig docker0 mtu ${MTU} up
+fi
+
 # Wait processes to be running
 entrypoint.sh