{"id":25,"is_content":1,"post_type":"post","post_title":"Can you switch your terminal user as any user defined in \/etc\/passwd?","slug":"can-you-switch-your-terminal-user-as-any-user-defined-in-etc-passwd","source_value":"https:\/\/askubuntu.com\/questions\/1390303\/can-you-switch-your-terminal-user-as-any-user-defined-in-etc-passwd","fake_user_id":60494,"published_at":"2021-05-04T22:42:07.000000Z","view_count":0,"deleted_at":null,"created_at":"2022-02-01T10:07:43.000000Z","updated_at":"2023-03-24T17:18:33.000000Z","content":[{"id":9733289,"post_id":25,"fake_user_id":64284,"content_dec":"<div class=\"s-prose js-post-body\" itemprop=\"text\">&#xD;\n                &#xD;\n<p><strong>Context<\/strong><\/p>\n<p>This is very newbie question but I dont fully grasp <em>unix<\/em> users yet.<\/p>\n<p>If I <code>cat \/etc\/passwd<\/code> there are different users:<\/p>\n<pre><code>me:x:1000:1000:me,,,:\/home\/me:\/bin\/bash\nsystemd-coredump:x:999:999:systemd Core Dumper:\/:\/usr\/sbin\/nologin\nsddm:x:127:134:Simple Desktop Display Manager:\/var\/lib\/sddm:\/bin\/false\nmongodb:x:128:65534::\/home\/mongodb:\/usr\/sbin\/nologin\nsshd:x:129:65534::\/run\/sshd:\/usr\/sbin\/nologin\ntftp:x:130:138:tftp daemon,,,:\/srv\/tftp:\/usr\/sbin\/nologin\n_rpc:x:131:65534::\/run\/rpcbind:\/usr\/sbin\/nologin\n<\/code><\/pre>\n<p>most of them are no login users (so we would say you can't log in unless it is a \/bash user), but if I try this command:<\/p>\n<pre><code>su - mongodb\n<\/code><\/pre>\n<p>it prompts me for a password. Problem is I don't know the password in this case.<\/p>\n<p><strong>Question<\/strong><\/p>\n<ul>\n<li>but does this mean I could switch to this user in the terminal and maybe run the process as systemd-service would do?<\/li>\n<li>so we would say you can't log in unless it is a \/bash user?<\/li>\n<\/ul>\n    <\/div>","created_at":"2023-03-24T17:18:33.000000Z","updated_at":"2023-03-24T17:18:33.000000Z"},{"id":9733290,"post_id":25,"fake_user_id":13898,"content_dec":"<div class=\"s-prose js-post-body\" itemprop=\"text\">&#xD;\n<p>short answer:<\/p>\n<ul>\n<li>yes<\/li>\n<li>yes<\/li>\n<\/ul>\n<p>If you are the super user (id=0) or commonly known as root, you cannot login in to it if shell is set to \/usr\/sbin\/nologin or \/usr\/bin\/false<\/p>\n<p>as per the <a href=\"https:\/\/man7.org\/linux\/man-pages\/man8\/nologin.8.html#:%7E:text=nologin%20displays%20a%20message%20that,instead%20of%20the%20default%20message.\" rel=\"nofollow noreferrer\">manpage<\/a> description of nologin:<\/p>\n<pre><code>   **DESCRIPTION**\n   nologin displays a message that an account is not available and\n   exits non-zero. It is intended as a replacement shell field to\n   deny login access to an account.\n\n   If the file \/etc\/nologin.txt exists, nologin displays its\n   contents to the user instead of the default message.\n\n   The exit status returned by nologin is always 1.\n<\/code><\/pre>\n<p>but (always if you are root or can sudo commands) you can execute a bash as per one user which is noloign user, to impersonate him for troubleshooting<\/p>\n<p>sudo:<\/p>\n<pre><code>sudo -u mongodb \/bin\/bash \n<\/code><\/pre>\n<p>root:<\/p>\n<pre><code>su -s \/bin\/bash mongodb\n<\/code><\/pre>\n<p>Those above command does not execute a login, but just execute a bash with the user permission, in this case as mongodb user.<\/p>\n<p><strong>NOTE:<\/strong> normally thos user are passwordless, that mean even the <em><strong>su -<\/strong><\/em> process ask you for a password that will never match with nothing also empty password.<\/p>\n    <\/div>","created_at":"2023-03-24T17:18:33.000000Z","updated_at":"2023-03-24T17:18:33.000000Z"}],"tags":[{"id":43,"slug":"server","name":"Server","suggest":0,"count":14703,"tag_group_id":null,"description":null},{"id":6,"slug":"bash","name":"Bash","suggest":0,"count":10209,"tag_group_id":null,"description":null},{"id":59,"slug":"permissions","name":"Permissions","suggest":0,"count":6816,"tag_group_id":null,"description":null}],"tagged":[{"id":75,"taggable_id":25,"taggable_type":"App\\Models\\Post","tag_name":"Server","tag_slug":"server","tag":{"id":43,"slug":"server","name":"Server","suggest":0,"count":14703,"tag_group_id":null,"description":null}},{"id":76,"taggable_id":25,"taggable_type":"App\\Models\\Post","tag_name":"Bash","tag_slug":"bash","tag":{"id":6,"slug":"bash","name":"Bash","suggest":0,"count":10209,"tag_group_id":null,"description":null}},{"id":77,"taggable_id":25,"taggable_type":"App\\Models\\Post","tag_name":"Permissions","tag_slug":"permissions","tag":{"id":59,"slug":"permissions","name":"Permissions","suggest":0,"count":6816,"tag_group_id":null,"description":null}}]}