cc_ssh_import_id: add Alpine support and add doas support (#4277)

Add Alpine to distros supported by this module.

If sudo is not available then try and use doas as an alternative
if it is available.

cloudinit/config/cc_ssh_import_id.py

@@ -19,7 +19,7 @@
 from cloudinit.settings import PER_INSTANCE
 
 # https://launchpad.net/ssh-import-id
-distros = ["ubuntu", "debian", "cos"]
+distros = ["alpine", "cos", "debian", "ubuntu"]
 
 SSH_IMPORT_ID_BINARY = "ssh-import-id"
 MODULE_DESCRIPTION = """\
@@ -152,13 +152,24 @@ def import_ssh_ids(ids, user):
     # I'm including the `--preserve-env` here as a one-off, but we should
     # have a better way of setting env earlier in boot and using it later.
     # Perhaps a 'set_env' module?
-    cmd = [
-        "sudo",
-        "--preserve-env=https_proxy",
-        "-Hu",
-        user,
-        SSH_IMPORT_ID_BINARY,
-    ] + ids
+    if subp.which("sudo"):
+        cmd = [
+            "sudo",
+            "--preserve-env=https_proxy",
+            "-Hu",
+            user,
+            SSH_IMPORT_ID_BINARY,
+        ] + ids
+    elif subp.which("doas"):
+        cmd = [
+            "doas",
+            "-u",
+            user,
+            SSH_IMPORT_ID_BINARY,
+        ] + ids
+    else:
+        LOG.error("Neither sudo nor doas available! Unable to import SSH ids.")
+        return
     LOG.debug("Importing SSH ids for user %s.", user)
 
     try:

tests/unittests/config/test_cc_ssh_import_id.py

@@ -76,3 +76,52 @@ def test_skip_inapplicable_configs(self, m_which, cfg, log, caplog):
         cloud = get_cloud("ubuntu")
         cc_ssh_import_id.handle("name", cfg, cloud, [])
         assert log in caplog.text
+
+    @mock.patch("cloudinit.ssh_util.pwd.getpwnam")
+    @mock.patch("cloudinit.config.cc_ssh_import_id.subp.subp")
+    @mock.patch("cloudinit.subp.which")
+    def test_use_sudo(self, m_which, m_subp, m_getpwnam):
+        """Check that sudo is available and use that"""
+        m_which.return_value = "/usr/bin/ssh-import-id"
+        ids = ["waffle"]
+        user = "bob"
+        cc_ssh_import_id.import_ssh_ids(ids, user)
+        m_subp.assert_called_once_with(
+            [
+                "sudo",
+                "--preserve-env=https_proxy",
+                "-Hu",
+                user,
+                "ssh-import-id",
+            ]
+            + ids,
+            capture=False,
+        )
+
+    @mock.patch("cloudinit.ssh_util.pwd.getpwnam")
+    @mock.patch("cloudinit.config.cc_ssh_import_id.subp.subp")
+    @mock.patch("cloudinit.subp.which")
+    def test_use_doas(self, m_which, m_subp, m_getpwnam):
+        """Check that doas is available and use that"""
+        m_which.side_effect = [None, "/usr/bin/doas"]
+        ids = ["waffle"]
+        user = "bob"
+        cc_ssh_import_id.import_ssh_ids(ids, user)
+        m_subp.assert_called_once_with(
+            ["doas", "-u", user, "ssh-import-id"] + ids, capture=False
+        )
+
+    @mock.patch("cloudinit.ssh_util.pwd.getpwnam")
+    @mock.patch("cloudinit.config.cc_ssh_import_id.subp.subp")
+    @mock.patch("cloudinit.subp.which")
+    def test_use_neither_sudo_nor_doas(
+        self, m_which, m_subp, m_getpwnam, caplog
+    ):
+        """Test when neither sudo nor doas is available"""
+        m_which.return_value = None
+        ids = ["waffle"]
+        user = "bob"
+        cc_ssh_import_id.import_ssh_ids(ids, user)
+        assert (
+            "Neither sudo nor doas available! Unable to import SSH ids"
+        ) in caplog.text