Update shim to build using bazel.

The go.mod dependency tree for the shim was somehow contradictory. After
resolving these issues (e.g. explicitly imported k8s 1.14, pulling a
specific dbus version), and adding all dependencies, the shim can now be
build as part of the regular bazel tree.

As part of this process, minor cleanup was done in all the source files:
headers were standardized (and include "The gVisor Authors" in addition
to the "The containerd Authors" if originally derived from containerd
sources), and comments were cleaned up to meet coding standards.

This change makes the containerd installation dynamic, so that multiple
versions can be tested, and drops the static installer for the VM image
itself.

This change also updates test/root/crictl_test.go and related utilities,
so that the containerd tests can be run on any version (and in cases
where it applies, they can be run on both v1 and v2 as parameterized
tests).

BUILD

@@ -69,7 +69,10 @@ go_path(
     name = "gopath",
     mode = "link",
     deps = [
+        # Main binary.
         "//runsc",
+        "//shim/v1:gvisor-containerd-shim",
+        "//shim/v2:containerd-shim-runsc-v1",
 
         # Packages that are not dependencies of //runsc.
         "//pkg/sentry/kernel/memevent",

Makefile

@@ -121,6 +121,22 @@ tests: ## Runs all local ptrace system call tests.
 	@$(MAKE) test OPTIONS="--test_tag_filters runsc_ptrace test/syscalls/..."
 .PHONY: tests
 
+containerd-test-%: ## Runs a local containerd test.
+containerd-test-%: load-basic_alpine load-basic_python load-basic_busybox load-basic_resolv load-basic_httpd
+containerd-test-%: install-test-runtime
+	@CONTAINERD_VERSION=$* $(MAKE) sudo TARGETS="tools/installers:containerd"
+	@$(MAKE) sudo TARGETS="test/root:root_test" ARGS="-test.v"
+
+# Note that we can't run containerd-test-1.1.8 tests here.
+#
+# Containerd 1.1.8 should work, but because of a bug in loading images locally
+# (https://github.com/kubernetes-sigs/cri-tools/issues/421), we are unable to
+# actually drive the tests. The v1 API is tested exclusively through 1.2.13.
+containerd-tests: ## Runs all supported containerd version tests.
+containerd-tests: containerd-test-1.2.13
+containerd-tests: containerd-test-1.3.4
+containerd-tests: containerd-test-1.4.0-beta.0
+
 ##
 ## Website & documentation helpers.
 ##
@@ -233,11 +249,14 @@ dev: ## Installs a set of local runtimes. Requires sudo.
 
 refresh: ## Refreshes the runtime binary (for development only). Must have called 'dev' or 'test-install' first.
 	@mkdir -p "$(RUNTIME_DIR)"
-	@$(MAKE) copy TARGETS=runsc DESTINATION="$(RUNTIME_BIN)" && chmod 0755 "$(RUNTIME_BIN)"
+	@$(MAKE) copy TARGETS=runsc DESTINATION="$(RUNTIME_BIN)"
+	@$(MAKE) copy TARGETS=shim/v1:gvisor-containerd-shim DESTINATION="$(RUNTIME_DIR)"
+	@$(MAKE) copy TARGETS=shim/v2:containerd-shim-runsc-v1 DESTINATION="$(RUNTIME_DIR)"
 .PHONY: install
 
-test-install: ## Installs the runtime for testing. Requires sudo.
+install-test-runtime: ## Installs the runtime for testing. Requires sudo.
 	@$(MAKE) refresh ARGS="--net-raw --TESTONLY-test-name-env=RUNSC_TEST_NAME --debug --strace --log-packets $(ARGS)"
+	@$(MAKE) configure RUNTIME=runsc
 	@$(MAKE) configure
 	@sudo systemctl restart docker
 .PHONY: install-test