cloud/shepherd/equinix/manager: embed test_agent

Change-Id: Iee2c1f68350412a49fae9fe2b80ab70a12b1a618
Reviewed-on: https://review.monogon.dev/c/monogon/+/1505
Tested-by: Jenkins CI
Reviewed-by: Serge Bazanski <serge@monogon.tech>
diff --git a/cloud/shepherd/equinix/manager/test_agent/BUILD.bazel b/cloud/shepherd/equinix/manager/test_agent/BUILD.bazel
index 8f03070..699082d 100644
--- a/cloud/shepherd/equinix/manager/test_agent/BUILD.bazel
+++ b/cloud/shepherd/equinix/manager/test_agent/BUILD.bazel
@@ -1,4 +1,5 @@
 load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+load("//build/static_binary_tarball:def.bzl", "static_binary_tarball")
 
 go_binary(
     name = "test_agent",
@@ -18,3 +19,10 @@
         "@org_golang_google_protobuf//proto",
     ],
 )
+
+# Used by container_images, forces a static build of the test_agent.
+static_binary_tarball(
+    name = "test_agent_layer",
+    executable = ":test_agent",
+    visibility = ["//visibility:public"],
+)