test: Add skopeo tests

There is a source test that installs a pre-build, embeded image file
and ensure all the right files are installed. This uses the vfs driver
because then it works everywhere, including the CI (which doesn't do
overlayfs).

Then the is a source test that downloads a minimal image from
a faked registry on localhost.

For the registy API to work the "/v2" entry-point in the webserver has
to be at the root, so there is a symlink in test/data:

  v2 -> sources/org.osbuild.skopeo/data/v2

But otherwise the data is localized to sources/org.osbuild.skopeo.

test/data/sources/org.osbuild.skopeo/cases/empty.json

@@ -0,0 +1,6 @@
+{
+  "expects": "success",
+  "org.osbuild.skopeo": {
+    "items": {}
+  }
+}

test/data/sources/org.osbuild.skopeo/cases/invalid_digest.json

@@ -0,0 +1,14 @@
+{
+  "expects": "error",
+  "org.osbuild.skopeo": {
+    "items": {
+      "sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa": {
+        "image": {
+          "name": "localhost/osbuild/hello",
+          "digest": "sha256:a606d2a723b78633e33932fdc201ec3546c4cf1887fb45f8d3198dde7a39b3f4",
+          "tls-verify": false
+        }
+      }
+    }
+  }
+}

test/data/sources/org.osbuild.skopeo/cases/missing_image.json

@@ -0,0 +1,14 @@
+{
+  "expects": "error",
+  "org.osbuild.skopeo": {
+    "items": {
+      "sha256:805e972fbc4dfa74a616dcaafe0d9e9b4c548b8909b14ffb032aa20fa23d9ad6": {
+        "image": {
+          "name": "localhost/osbuild/wrong",
+          "digest": "sha256:a606d2a723b78633e33932fdc201ec3546c4cf1887fb45f8d3198dde7a39b3f4",
+          "tls-verify": false
+        }
+      }
+    }
+  }
+}

test/data/sources/org.osbuild.skopeo/cases/success.json

@@ -0,0 +1,14 @@
+{
+  "expects": "success",
+  "org.osbuild.skopeo": {
+    "items": {
+      "sha256:805e972fbc4dfa74a616dcaafe0d9e9b4c548b8909b14ffb032aa20fa23d9ad6": {
+        "image": {
+          "name": "localhost/osbuild/hello",
+          "digest": "sha256:a606d2a723b78633e33932fdc201ec3546c4cf1887fb45f8d3198dde7a39b3f4",
+          "tls-verify": false
+        }
+      }
+    }
+  }
+}

test/data/sources/org.osbuild.skopeo/data/v2/osbuild/hello/blobs/sha256:805e972fbc4dfa74a616dcaafe0d9e9b4c548b8909b14ffb032aa20fa23d9ad6

@@ -0,0 +1 @@
+{"created":"2022-02-02T09:04:02.049496094Z","architecture":"amd64","os":"linux","config":{"Env":["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"],"Labels":{"io.buildah.version":"1.23.1"}},"rootfs":{"type":"layers","diff_ids":["sha256:0da97f9fb353a8d6285145bc7a1b75a28652e80f60ab7479bf5b4ae67ffa37e8"]},"history":[{"created":"2022-02-02T09:04:02.050044248Z","created_by":"/bin/sh -c #(nop) COPY file:ac7ec5eb9477808d410f8800080ebdc3aaa81212a142cb9002e7eb4ae8610cd0 in / "}]}

test/data/sources/org.osbuild.skopeo/data/v2/osbuild/hello/manifests/sha256:a606d2a723b78633e33932fdc201ec3546c4cf1887fb45f8d3198dde7a39b3f4

@@ -0,0 +1 @@
+{"schemaVersion":2,"mediaType":"application/vnd.docker.distribution.manifest.v2+json","config":{"mediaType":"application/vnd.docker.container.image.v1+json","size":493,"digest":"sha256:805e972fbc4dfa74a616dcaafe0d9e9b4c548b8909b14ffb032aa20fa23d9ad6"},"layers":[{"mediaType":"application/vnd.docker.image.rootfs.diff.tar.gzip","size":134,"digest":"sha256:e2f43980f5c62d8424c6fd14bb32320c6b34518ff6f1445a5c23e036e55391c7"}]}

test/data/sources/org.osbuild.skopeo/data/v2/osbuild/hello/manifests/sha256:a606d2a723b78633e33932fdc201ec3546c4cf1887fb45f8d3198dde7a39b3f4.mimetype

@@ -0,0 +1 @@
+application/vnd.docker.distribution.manifest.v2+json