{"id":3299,"date":"2018-04-26T12:20:48","date_gmt":"2018-04-26T16:20:48","guid":{"rendered":"https:\/\/antipaucity.com\/?p=3299"},"modified":"2018-04-26T12:20:48","modified_gmt":"2018-04-26T16:20:48","slug":"dont-use-symlinks-unless-you-know-you-can","status":"publish","type":"post","link":"https:\/\/merikebi.warrenmyers.com\/?p=3299","title":{"rendered":"don’t use symlinks unless you *know* you can"},"content":{"rendered":"

I first ran into this on Solaris in the context of [then] Opsware SAS<\/a> (then HP SA<\/a>, now owned by Microfocus). Bind mounts might be OK … so unless the tarball has symlinks included, don’t use them – they get traversed differently than “real” directories.<\/p>\n

In short, when directory traversals are done, sometimes it looks at the permissions bits and if the first character is not a d<\/code> (for a symlink, it’s always an l<\/code>), many processes can fail.<\/p>\n

Symlinking files<\/em> is [possibly] a different story: though permissions are usually wonky on symlinks (most often lrwxrwxrwx<\/code> vs -rw-r--r--<\/code>, for example), since you cannot traverse into a file (whereas you can into a directory), it’s generally<\/strong> ok<\/p>\n

Also – sometimes when directory listings are pulled, the symlink is fully-dereferenced, and something that appears<\/em> to be in, say, $SPLUNK_HOME\/etc\/deployment_apps<\/code> but is reall<\/em>y in, say, \/some\/other\/place<\/code>, there are some times when {{Splunk}} will decide not<\/em> to deploy it, because it’s not where it “belongs”.<\/p>\n

Also – checksums can be computed on the symlink<\/em> and not the actual file, in some (perhaps all) instances: so if, for example, you have the same outputs.conf<\/code> in several apps by way of symlink, and you change it in one, the checksum for all the others may (and typically do) not get updated … so you can be left in an inconsistent state for your configs (because not all locations that should’ve received the updated outputs.conf<\/code> have received it, since they’re symlinks and not a real file, and the checksum may not update on those particular apps).<\/p>\n

Moral of the story?<\/h4>\n

Unless you really know what you’re doing, never use symlinks with {{Splunk}}.<\/p>\n","protected":false},"excerpt":{"rendered":"

I first ran into this on Solaris in the context of [then] Opsware SAS (then HP SA, now owned by Microfocus). Bind mounts might be OK … so unless the tarball has symlinks included, don’t use them – they get traversed differently than “real” directories. In short, when directory traversals are done, sometimes it looks …
Continue reading don’t use symlinks unless you *know* you can<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_hide_featured_image":false,"_jetpack_featured_image_duplicate_dismissed":0,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[41],"tags":[705,740],"keyring_services":[],"class_list":["post-3299","post","type-post","status-publish","format-standard","hentry","category-technical","tag-splunk","tag-symlink"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/merikebi.warrenmyers.com\/index.php?rest_route=\/wp\/v2\/posts\/3299","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/merikebi.warrenmyers.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/merikebi.warrenmyers.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/merikebi.warrenmyers.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/merikebi.warrenmyers.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3299"}],"version-history":[{"count":0,"href":"https:\/\/merikebi.warrenmyers.com\/index.php?rest_route=\/wp\/v2\/posts\/3299\/revisions"}],"wp:attachment":[{"href":"https:\/\/merikebi.warrenmyers.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3299"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/merikebi.warrenmyers.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3299"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/merikebi.warrenmyers.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3299"},{"taxonomy":"keyring_services","embeddable":true,"href":"https:\/\/merikebi.warrenmyers.com\/index.php?rest_route=%2Fwp%2Fv2%2Fkeyring_services&post=3299"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}