Split the init container into two init containers. One will cp the co…

…nsul bin and the other will retain all of the existing behaviours (#441)

Co-authored-by: Iryna Shustava <ishustava@users.noreply.github.com>

connect-inject/container_init.go

@@ -12,9 +12,10 @@ import (
 )
 
 const (
-	InjectInitContainerName = "consul-connect-inject-init"
-	MetaKeyPodName          = "pod-name"
-	MetaKeyKubeNS           = "k8s-namespace"
+	InjectInitCopyContainerName = "copy-consul-bin"
+	InjectInitContainerName     = "consul-connect-inject-init"
+	MetaKeyPodName              = "pod-name"
+	MetaKeyKubeNS               = "k8s-namespace"
 )
 
 type initContainerCommandData struct {
@@ -63,6 +64,25 @@ type initContainerCommandUpstreamData struct {
 	Query                   string
 }
 
+// containerInitCopyContainer returns the init container spec for the copy container which places
+// the consul binary into the shared volume.
+func (h *Handler) containerInitCopyContainer() corev1.Container {
+	// Copy the Consul binary from the image to the shared volume.
+	cmd := "cp /bin/consul /consul/connect-inject/consul"
+	return corev1.Container{
+		Name:      InjectInitCopyContainerName,
+		Image:     h.ImageConsul,
+		Resources: h.InitContainerResources,
+		VolumeMounts: []corev1.VolumeMount{
+			corev1.VolumeMount{
+				Name:      volumeName,
+				MountPath: "/consul/connect-inject",
+			},
+		},
+		Command: []string{"/bin/sh", "-ec", cmd},
+	}
+}
+
 // containerInit returns the init container spec for registering the Consul
 // service, setting up the Envoy bootstrap, etc.
 func (h *Handler) containerInit(pod *corev1.Pod, k8sNamespace string) (corev1.Container, error) {
@@ -452,8 +472,4 @@ chmod 444 /consul/connect-inject/acl-token
   {{- if .ConsulNamespace }}
   -namespace="{{ .ConsulNamespace }}" \
   {{- end }}
-  -bootstrap > /consul/connect-inject/envoy-bootstrap.yaml
-
-# Copy the Consul binary
-cp /bin/consul /consul/connect-inject/consul
-`
+  -bootstrap > /consul/connect-inject/envoy-bootstrap.yaml`

connect-inject/container_init_test.go

@@ -105,10 +105,7 @@ EOF
 # Generate the envoy bootstrap code
 /bin/consul connect envoy \
   -proxy-id="${PROXY_SERVICE_ID}" \
-  -bootstrap > /consul/connect-inject/envoy-bootstrap.yaml
-
-# Copy the Consul binary
-cp /bin/consul /consul/connect-inject/consul`,
+  -bootstrap > /consul/connect-inject/envoy-bootstrap.yaml`,
 			"",
 		},
 
@@ -795,10 +792,7 @@ EOF
 /bin/consul connect envoy \
   -proxy-id="${PROXY_SERVICE_ID}" \
   -namespace="default" \
-  -bootstrap > /consul/connect-inject/envoy-bootstrap.yaml
-
-# Copy the Consul binary
-cp /bin/consul /consul/connect-inject/consul`,
+  -bootstrap > /consul/connect-inject/envoy-bootstrap.yaml`,
 			"",
 		},
 
@@ -871,10 +865,7 @@ EOF
 /bin/consul connect envoy \
   -proxy-id="${PROXY_SERVICE_ID}" \
   -namespace="non-default" \
-  -bootstrap > /consul/connect-inject/envoy-bootstrap.yaml
-
-# Copy the Consul binary
-cp /bin/consul /consul/connect-inject/consul`,
+  -bootstrap > /consul/connect-inject/envoy-bootstrap.yaml`,
 			"",
 		},
 
@@ -956,10 +947,7 @@ chmod 444 /consul/connect-inject/acl-token
   -proxy-id="${PROXY_SERVICE_ID}" \
   -token-file="/consul/connect-inject/acl-token" \
   -namespace="non-default" \
-  -bootstrap > /consul/connect-inject/envoy-bootstrap.yaml
-
-# Copy the Consul binary
-cp /bin/consul /consul/connect-inject/consul`,
+  -bootstrap > /consul/connect-inject/envoy-bootstrap.yaml`,
 			"",
 		},
 
@@ -1042,10 +1030,7 @@ chmod 444 /consul/connect-inject/acl-token
   -proxy-id="${PROXY_SERVICE_ID}" \
   -token-file="/consul/connect-inject/acl-token" \
   -namespace="k8snamespace" \
-  -bootstrap > /consul/connect-inject/envoy-bootstrap.yaml
-
-# Copy the Consul binary
-cp /bin/consul /consul/connect-inject/consul`,
+  -bootstrap > /consul/connect-inject/envoy-bootstrap.yaml`,
 			"",
 		},
 
@@ -1446,3 +1431,12 @@ func TestHandlerContainerInit_MeshGatewayModeErrors(t *testing.T) {
 	}
 
 }
+
+// Test that the init copy container has the correct command.
+func TestHandlerContainerInitCopyContainer(t *testing.T) {
+	require := require.New(t)
+	h := Handler{}
+	container := h.containerInitCopyContainer()
+	actual := strings.Join(container.Command, " ")
+	require.Contains(actual, `cp /bin/consul /consul/connect-inject/consul`)
+}

connect-inject/handler.go

@@ -348,9 +348,12 @@ func (h *Handler) Mutate(req *v1beta1.AdmissionRequest) *v1beta1.AdmissionRespon
 			fmt.Sprintf("/spec/containers/%d/env", i))...)
 	}
 
+	// Add the init container which copies the consul binary.
+	initCopyContainer := h.containerInitCopyContainer()
+
 	// Add the init container that registers the service and sets up
 	// the Envoy configuration.
-	container, err := h.containerInit(&pod, req.Namespace)
+	initContainer, err := h.containerInit(&pod, req.Namespace)
 	if err != nil {
 		h.Log.Error("Error configuring injection init container", "err", err, "Request Name", req.Name)
 		return &v1beta1.AdmissionResponse{
@@ -361,7 +364,7 @@ func (h *Handler) Mutate(req *v1beta1.AdmissionRequest) *v1beta1.AdmissionRespon
 	}
 	patches = append(patches, addContainer(
 		pod.Spec.InitContainers,
-		[]corev1.Container{container},
+		[]corev1.Container{initCopyContainer, initContainer},
 		"/spec/initContainers")...)
 
 	// Add the Envoy and Consul sidecars.

connect-inject/handler_test.go

@@ -97,6 +97,10 @@ func TestHandlerHandle(t *testing.T) {
 					Operation: "add",
 					Path:      "/spec/initContainers",
 				},
+				{
+					Operation: "add",
+					Path:      "/spec/initContainers/-",
+				},
 				{
 					Operation: "add",
 					Path:      "/spec/containers/-",
@@ -164,6 +168,10 @@ func TestHandlerHandle(t *testing.T) {
 					Operation: "add",
 					Path:      "/spec/initContainers",
 				},
+				{
+					Operation: "add",
+					Path:      "/spec/initContainers/-",
+				},
 				{
 					Operation: "add",
 					Path:      "/spec/containers/-",
@@ -237,6 +245,10 @@ func TestHandlerHandle(t *testing.T) {
 					Operation: "add",
 					Path:      "/spec/initContainers",
 				},
+				{
+					Operation: "add",
+					Path:      "/spec/initContainers/-",
+				},
 				{
 					Operation: "add",
 					Path:      "/spec/containers/-",
@@ -283,6 +295,10 @@ func TestHandlerHandle(t *testing.T) {
 					Operation: "add",
 					Path:      "/spec/initContainers",
 				},
+				{
+					Operation: "add",
+					Path:      "/spec/initContainers/-",
+				},
 				{
 					Operation: "add",
 					Path:      "/spec/containers/-",
@@ -334,6 +350,10 @@ func TestHandlerHandle(t *testing.T) {
 					Operation: "add",
 					Path:      "/spec/initContainers",
 				},
+				{
+					Operation: "add",
+					Path:      "/spec/initContainers/-",
+				},
 				{
 					Operation: "add",
 					Path:      "/spec/containers/-",