Adds checks for container and bootc hosts

dnf/cli/cli.py

@@ -214,7 +214,7 @@ def do_transaction(self, display=()):
             elif 'test' in self.conf.tsflags:
                 logger.info(_("{prog} will only download packages, install gpg keys, and check the "
                               "transaction.").format(prog=dnf.util.MAIN_PROG_UPPER))
-            if dnf.util.is_container():
+            if dnf.util.is_bootc_host():
                 _container_msg = _("""
 *** This system is managed with ostree.  Changes to the system
 *** made with dnf will be lost with the next ostree-based update.

dnf/util.py

@@ -644,29 +644,51 @@ def _is_file_pattern_present(specs):
 
 
 def is_container():
+    """Returns true if DNF is running in a container,
+       false otherwise.
+    """
+    # This attempts to reimplement
+    # https://github.com/ostreedev/ostree-rs-ext/blob/b0d1c1e4748c8708149bb6c92998da623260c4c6/lib/src/container_utils.rs#L20
+    # in python.
+    container_env_var = 'container'
+    container_env_file = '/run/.containerenv'
+    docker_env_file =  '/.dockerenv'
+    # https://stackoverflow.com/questions/20010199/how-to-determine-if-a-process-runs-inside-lxc-docker
+    if os.getenv(container_env_var) is not None or os.path.isfile(docker_env_file) or os.path.isfile(container_env_file):
+        return True
+    else:
+        return False
+
+def is_bootc_host():
     """Returns true is the system is managed as an immutable container,
        false otherwise.  If msg is True, a warning message is displayed
        for the user.
     """
 
-    bootc = '/usr/bin/bootc'
-    ostree = '/sysroot/ostree'
-
-    if os.path.isfile(bootc) and os.access(bootc, os.X_OK):
-        p = subprocess.Popen([bootc, "status", "--json"], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-        (out, err) = p.communicate()
-
-        if p.returncode == 0:
-            # check the output of 'bootc status'
-            j = json.loads(out)
+    ostree_booted = '/run/ostree-booted'
+    usr = '/usr/'
 
-            # XXX: the API from bootc status is evolving
-            status = j.get("status", "")
-            kind = j.get("kind", "")
+    # Check if usr is writtable and we are in a running ostree system.
+    # We want this code to return true only when the system is in locked state. If someone ran
+    # bootc overlay or ostree admin unlock we would want normal DNF path to be ran as it will be
+    # temporary changes (until reboot).
+    if os.path.isfile(ostree_booted) and not os.access(usr, os.X_OK):
+        return True
+    else:
+        return False
 
-            if kind.lower() == "bootchost" and bool(status.get("isContainer", None)):
-                return True
-    elif os.path.isdir(ostree):
+def is_bootc_container():
+    """Returns true if DNF is running inside a bootc container,
+       false otherwise.  If True, some packages like kernel might be
+       installed with that in mind. For example only one kernel is
+       supported on bootc containers and hosts.
+       ## TODO this is not complete right now as it just checks for
+       /ostree/ to exists. Also not in use. ##
+    """
+    sysroot_ostree = '/sysroot/ostree'
+    systemd_env_var = 'INVOCATION_ID'
+    if is_container() and os.path.exists(sysroot_ostree) and not is_bootc_host() and os.getenv(systemd_env_var) is None:
         return True
+    else:
+        return False
 
-    return False