{"id":5124,"date":"2020-10-29T20:25:45","date_gmt":"2020-10-29T19:25:45","guid":{"rendered":"https:\/\/rakhesh.com\/?p=5124"},"modified":"2020-10-29T20:25:45","modified_gmt":"2020-10-29T19:25:45","slug":"openbsd-rc-d-paper-a-good-read","status":"publish","type":"post","link":"https:\/\/rakhesh.com\/linux-bsd\/openbsd-rc-d-paper-a-good-read\/","title":{"rendered":"OpenBSD rc.d paper — a good read!"},"content":{"rendered":"

Quick shoutout to this paper<\/a> on the OpenBSD rc.d<\/code> system from 2016. I chanced upon it while trying to read up on the rc.d<\/code> system and it was a pleasure. :) It’s very clearly written with a lot of fun stuff sprinkled over …<\/p>\n

This is a good one – on the difference between a daemon and a service. I like how they clarified that right off the bat and how rc.d<\/code> only manages daemons. Simple!<\/p>\n

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…it is needed to understand and differentiate the concept of daemon and service. A daemon is just your usual evil program configured to run in the background (e.g. sshd, ntpd) while a service is a \u201cfacility\u201d (e.g. pf, ipsec, check_quotas); rc.d only handles daemons<\/p>\n<\/blockquote>\n

 <\/p>\n

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FreeBSD and NetBSD rc.d and rcorder could have been the obvious choice but again, they provided too much. The rc.d scripts are also too flexible (which can be a feature but not in our case) and the framework provides a dependency-based dynamic start-up ordering which was against our goals because we wanted tokeep full control over the start-up sequence. It is our opinion that automatic determination of daemon start-up is pointless because if a machine is running a very large number of services in production, that’s a bad system design in the first place and it’s easier to order a small number by hand than to debug issues with automatic ordering<\/span>.<\/p>\n<\/blockquote>\n

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The first rule we enforced upon ourselves was to use the already available and standard facility for signaling daemons: kill(1). The use of PID files was discarded for the usual reasons (racy, left-over files…).<\/span> We knew it would not be enough for everything out there (some daemons require a helper to cleanly shutdown…) but it was good enough that we could make it a default. That’s the reason why something like start-stop-daemon(8) to control creation and termination of the daemon processes was not considered. Since the whole rc framework was just a bunch of shell scripts, extending it meant that we had to keep using shell, for better or worse.<\/p>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"

Quick shoutout to this paper on the OpenBSD rc.d system from 2016. I chanced upon it while trying to read up on the rc.d system and it was a pleasure. :) It’s very clearly written with a lot of fun stuff sprinkled over … This is a good one – on the difference between a … Continue reading OpenBSD rc.d paper — a good read!<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[76],"tags":[268],"jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/rakhesh.com\/wp-json\/wp\/v2\/posts\/5124"}],"collection":[{"href":"https:\/\/rakhesh.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rakhesh.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rakhesh.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/rakhesh.com\/wp-json\/wp\/v2\/comments?post=5124"}],"version-history":[{"count":0,"href":"https:\/\/rakhesh.com\/wp-json\/wp\/v2\/posts\/5124\/revisions"}],"wp:attachment":[{"href":"https:\/\/rakhesh.com\/wp-json\/wp\/v2\/media?parent=5124"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rakhesh.com\/wp-json\/wp\/v2\/categories?post=5124"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rakhesh.com\/wp-json\/wp\/v2\/tags?post=5124"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}