buildkite: allow to run containerd tests on arm64

k8s.gcr.io/busybox:latest doesn't have the arm variant, so
let's use the upstream busybox and create /etc/recolv.conf symlink.

PiperOrigin-RevId: 450059917

.buildkite/pipeline.yaml

@@ -236,35 +236,30 @@ steps:
     label: ":docker: Containerd 1.4.3 tests"
     command: make containerd-test-1.4.3
     agents:
-      arch: "amd64"
       os: "ubuntu"
   - <<: *common
     label: ":docker: Containerd 1.5.4 tests (cgroupv1)"
     command: make containerd-test-1.5.4
     agents:
       cgroup: "v1"
-      arch: "amd64"
       os: "ubuntu"
   - <<: *common
     label: ":docker: Containerd 1.5.4 tests (cgroupv2)"
     command: make containerd-test-1.5.4
     agents:
       cgroup: "v2"
-      arch: "amd64"
       os: "ubuntu"
   - <<: *common
     label: ":docker: Containerd 1.6.0-rc.4 tests (cgroupv1)"
     command: make containerd-test-1.6.0-rc.4
     agents:
       cgroup: "v1"
-      arch: "amd64"
       os: "ubuntu"
   - <<: *common
     label: ":docker: Containerd 1.6.0-rc.4 tests (cgroupv2)"
     command: make containerd-test-1.6.0-rc.4
     agents:
       cgroup: "v2"
-      arch: "amd64"
       os: "ubuntu"
 
   # Check the website builds.

Makefile

@@ -312,7 +312,7 @@ fsstress-test: load-basic $(RUNTIME_BIN)
 .PHONY: fsstress-test
 
 # Specific containerd version tests.
-containerd-test-%: load-basic_alpine load-basic_python load-basic_busybox load-basic_resolv load-basic_httpd load-basic_ubuntu $(RUNTIME_BIN)
+containerd-test-%: load-basic_alpine load-basic_python load-basic_busybox load-basic_symlink-resolv load-basic_httpd load-basic_ubuntu $(RUNTIME_BIN)
 	@$(call install_runtime,$(RUNTIME),) # Clear flags.
 	@sudo tools/install_containerd.sh $*
 ifeq (,$(STAGED_BINARIES))

images/basic/resolv/Dockerfile

@@ -1 +0,0 @@
-FROM k8s.gcr.io/busybox:latest

images/basic/symlink-resolv/Dockerfile

@@ -0,0 +1,3 @@
+FROM busybox
+
+ADD resolv.tar /

test/root/crictl_test.go

@@ -181,8 +181,8 @@ func TestMountOverSymlinks(t *testing.T) {
 	}
 	defer cleanup()
 
-	spec := SimpleSpec("busybox", "basic/resolv", []string{"sleep", "1000"}, nil)
-	podID, contID, err := crictl.StartPodAndContainer(containerdRuntime, "basic/resolv", Sandbox("default"), spec)
+	spec := SimpleSpec("busybox", "basic/symlink-resolv", []string{"sleep", "1000"}, nil)
+	podID, contID, err := crictl.StartPodAndContainer(containerdRuntime, "basic/symlink-resolv", Sandbox("default"), spec)
 	if err != nil {
 		t.Fatalf("start failed: %v", err)
 	}