Code review comment for ~redriver/cloud-init:frbsd-azure-branch

one more issue I found is the user information provided by Azure cannot override the default one. The reason is: Stages.Modules.cfg depends on helpers.ConfigMerger to merge the cfg. But the internal function helpers._read_cfg says env_configs overrides datasource_configs. See the comments below. It also mentions the input config overrides env_config, but on Azure, the user information comes from datasource, how can I get input config ahead of datasource?

The quick fix is move "cfgs.extend(self._get_datasource_configs())" ahead of "cfgs.extend(self._get_env_configs())".

I also wonder why Ubuntu on Azure does not encounter this issue. It looks like Ubuntu on Azure invokes cloudinitlocal, but I'm still confused how Ubuntu can override env_configs.

    def _read_cfg(self):
        # Input config files override
        # env config files which
        # override instance configs
        # which override datasource
        # configs which override
        # base configuration
        cfgs = []
        if self._fns:
            for c_fn in self._fns:
                try:
                    cfgs.append(util.read_conf(c_fn))
                except Exception:
                    util.logexc(LOG, "Failed loading of configuration from %s",
                                c_fn)

        cfgs.extend(self._get_env_configs())
        cfgs.extend(self._get_instance_configs())
        cfgs.extend(self._get_datasource_configs())
        if self._base_cfg:
            cfgs.append(self._base_cfg)
        return util.mergemanydict(cfgs)