add prefer_fqdn_over_hostname config option (#859)

the above option allows the user to control the behavior of a distro
hostname selection if both short hostname and FQDN are supplied.
If `prefer_fqdn_over_hostname` is true the FQDN will be selected as
hostname; if false the hostname will be selected

LP: #1921004

1 files changed, 17 insertions, 0 deletions

diff --git a/tests/integration_tests/modules/test_set_hostname.py b/tests/integration_tests/modules/test_set_hostname.py
index 2bfa403d..e7f7f6b6 100644
--- a/tests/integration_tests/modules/test_set_hostname.py
+++ b/tests/integration_tests/modules/test_set_hostname.py
@@ -24,6 +24,13 @@ hostname: cloudinit1
 fqdn: cloudinit2.i9n.cloud-init.io
 """
 
+USER_DATA_PREFER_FQDN = """\
+#cloud-config
+prefer_fqdn_over_hostname: {}
+hostname: cloudinit1
+fqdn: cloudinit2.test.io
+"""
+
 
 @pytest.mark.ci
 class TestHostname:
@@ -33,6 +40,16 @@ class TestHostname:
         hostname_output = client.execute("hostname")
         assert "cloudinit2" in hostname_output.strip()
 
+    @pytest.mark.user_data(USER_DATA_PREFER_FQDN.format(True))
+    def test_prefer_fqdn(self, client):
+        hostname_output = client.execute("hostname")
+        assert "cloudinit2.test.io" in hostname_output.strip()
+
+    @pytest.mark.user_data(USER_DATA_PREFER_FQDN.format(False))
+    def test_prefer_short_hostname(self, client):
+        hostname_output = client.execute("hostname")
+        assert "cloudinit1" in hostname_output.strip()
+
     @pytest.mark.user_data(USER_DATA_FQDN)
     def test_hostname_and_fqdn(self, client):
         hostname_output = client.execute("hostname")