tests/upgrade: switch to downloading ostree tarball

The OSTree repo in Fedora can be slow and might go away one day.
Since we know exactly the path updates are going to take let's
just download pre-built tarballs with an OSTree repo inside
that has exactly the contents that this upgrade will need.

The tarballs for this purpose can be created with the script in [1].
You can download the tarball into the external data directory before
running the test to have it exist and be used:

```
curl -o src/config/tests/kola/upgrade/extended/data/ostree-repo.tar \
    https://fcos-upgrade-test-fixtures.s3.us-east-1.amazonaws.com/ostree-repo-testing-x86_64-starting-f34.tar
cosa buildfetch --artifact=qemu --decompress --build=34.20210427.2.0
cosa kola run --build=34.20210427.2.0 --tag extended-upgrade
rm src/config/tests/kola/upgrade/extended/data/ostree-repo.tar
```

[1] https://github.com/coreos/fedora-coreos-releng-automation/pull/231

tests/kola/upgrade/extended/test.sh

@@ -3,7 +3,9 @@
 ##   # - needs-internet: to pull updates
 ##   tags: "needs-internet"
 ##   # Extend the timeout since a lot of updates/reboots can happen.
-##   timeoutMin: 75
+##   timeoutMin: 50
+##   # Bigger disk since we copy in the OSTree tarball
+##   minDisk: 30
 ##   # Only run this test when specifically requested.
 ##   requiredTag: extended-upgrade
 ##   description: Verify upgrade works.
@@ -56,6 +58,36 @@ set -eux -o pipefail
 need_restart='false'
 arch=$(arch)
 
+# If there is an ostree repo archive tarball, let's extract/use it.
+if [ -f "$KOLA_EXT_DATA/ostree-repo.tar" ]; then
+    tar -C /srv/ -xf "$KOLA_EXT_DATA/ostree-repo.tar"
+    rm -vf "$KOLA_EXT_DATA/ostree-repo.tar"
+
+    # Switch to pulling from local ostree repo
+    cat <<'EOF' > /etc/ostree/remotes.d/fedora.conf
+[remote "fedora"]
+url=file:///srv/
+gpg-verify=true
+gpgkeypath=/etc/pki/rpm-gpg/
+EOF
+
+    # make writable by all so below zincati ExecStartPre copy over it
+    chmod 666 /etc/ostree/remotes.d/fedora.conf
+
+    # The oci migration script had a check for the URL to make sure we only
+    # migrated the people who were using the defaults so we need to switch
+    # it back when the oci migration happens.
+    # https://github.com/coreos/fedora-coreos-config/blob/d4c815329d88dd9dbaf1902a2b60a08df4b41c1a/overlay.d/35oci-migration/usr/libexec/coreos-oci-rebase#L43
+    mkdir -p /etc/systemd/system/zincati.service.d
+    cat <<'EOF' > /etc/systemd/system/zincati.service.d/005-fixup-remote-url.conf
+[Service]
+ExecStartPre=/bin/bash -c \
+  "test -f /usr/lib/systemd/system/zincati.service.d/010-oci-migration.conf && \
+      cp -v /usr/etc/ostree/remotes.d/fedora.conf /etc/ostree/remotes.d/fedora.conf || true"
+EOF
+    need_restart='true'
+fi
+
 # delete the disabling of updates that was done by the test framework
 if [ -f /etc/zincati/config.d/90-disable-auto-updates.toml ]; then
     rm -f /etc/zincati/config.d/90-disable-auto-updates.toml
@@ -235,6 +267,10 @@ selinux-sanity-check() {
         paths="$(echo "${mislabeled}" | grep "Would relabel" | cut -d ' ' -f 3)"
         found=""
         while read -r path; do
+            # Add in a glob exception for /var/srv since that's where our OSTree repo is
+            if [[ "${path}" =~ /var/srv ]]; then
+                 continue
+            fi
             if [[ "${exceptions[$path]:-noexception}" == 'noexception' ]]; then
                 echo "Unexpected mislabeled file found: ${path}"
                 found="1"