package/skopeo: add target variant

Skopeo can be used to manipulate container images, and so can be useful
on target devices that are going to be used as a host to run containers.

So, add a target variant for skopeo.

... with a runtime test while at it.

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Christian Stewart <christian@aperture.us>
Cc: Yann E. MORIN <yann.morin@orange.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>

support/testing/tests/package/test_skopeo.py

@@ -0,0 +1,41 @@
+import infra.basetest
+import json
+import os
+
+
+class TestSkopeo(infra.basetest.BRTest):
+    config = infra.basetest.BASIC_TOOLCHAIN_CONFIG + \
+        """
+        BR2_PER_PACKAGE_DIRECTORIES=y
+        BR2_SYSTEM_DHCP="eth0"
+        BR2_PACKAGE_CA_CERTIFICATES=y
+        BR2_PACKAGE_SKOPEO=y
+        BR2_PACKAGE_HOST_GO_BIN=y
+        BR2_TARGET_ROOTFS_CPIO=y
+        # BR2_TARGET_ROOTFS_TAR is not set
+        """
+
+    def test_run(self):
+        cpio_file = os.path.join(self.builddir, "images", "rootfs.cpio")
+        self.emulator.boot(arch="armv5",
+                           kernel="builtin",
+                           options=["-initrd", cpio_file, "-nic", "user,model=rtl8139"])
+        self.emulator.login()
+
+        self.assertRunOk("skopeo --version", timeout=30)
+
+        # First, check we can reach the default registry: docker.io
+        output, _ = self.emulator.run(
+            "skopeo inspect docker://busybox:latest",
+            timeout=60,
+        )
+        bb_info = json.loads("".join(output))
+        self.assertEqual(bb_info["Name"], "docker.io/library/busybox")
+
+        # Now, check we can reach an arbitrary registry: quay.io
+        output, _ = self.emulator.run(
+            "skopeo inspect docker://quay.io/quay/busybox:latest",
+            timeout=60,
+        )
+        skopeo_info = json.loads("".join(output))
+        self.assertEqual(skopeo_info["Name"], "quay.io/quay/busybox")