Keep SSH authorized keys in ansible-test setup.

changelogs/fragments/ansible-test-preserve-remote-authorized-keys.yml

@@ -0,0 +1,2 @@
+bugfixes:
+    - ansible-test now preserves existing SSH authorized keys when provisioning a remote host

test/lib/ansible_test/_data/setup/remote.sh

@@ -90,7 +90,8 @@ if [ ! -f "${HOME}/.ssh/id_rsa.pub" ]; then
     chmod 0600 "${HOME}/.ssh/id_rsa.new"
     sed 's/\(BEGIN\|END\) PRIVATE KEY/\1 RSA PRIVATE KEY/' "${HOME}/.ssh/id_rsa" > "${HOME}/.ssh/id_rsa.new"
     mv "${HOME}/.ssh/id_rsa.new" "${HOME}/.ssh/id_rsa"
-    cp "${HOME}/.ssh/id_rsa.pub" "${HOME}/.ssh/authorized_keys"
+    cat "${HOME}/.ssh/id_rsa.pub" >> "${HOME}/.ssh/authorized_keys"
+    chmod 0600 "${HOME}/.ssh/authorized_keys"
     for key in /etc/ssh/ssh_host_*_key.pub; do
         pk=$(cat "${key}")
         echo "localhost ${pk}" >> "${HOME}/.ssh/known_hosts"