[Touch-packages] [Bug 1577844] Re: Drop unnecessary blocking of all net udev rules
** No longer affects: ifupdown (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to ifupdown in Ubuntu. https://bugs.launchpad.net/bugs/1577844 Title: Drop unnecessary blocking of all net udev rules Status in cloud-init package in Ubuntu: Triaged Bug description: cloud-inits networking setup currently jumps through a lot of bad hoops to make sure that ifup@ does not run until after cloud-init- local.service. This includes blocking udev rules for an indefinite time, which is racy, a potential deadlock, and highly non-elegant. This is also not necessary: while ifupdown's net udev rule certainly can fire before cloud-init-local, it only asynchronously starts ifup@.service which will be deferred until after network-pre.target and thus after cloud-init-local.service. --- Original description, which turned out to be completely false and just us being misled: ifup@.service can (and often does) run for a particular interface before networking.service runs. This is brittle as during early boot ifup is prone to fail: / might still be read-only, /var might not yet exist or be writable, dhclient-enter-hooks.d/ or if-up.d/ hooks might silently fail, etc. It is also unnecessary as networking.service will bring up all "auto" and all present "allow-hotplug" interfaces anyway, and it runs at the right time. We should make either 80-ifupdown.rules or ifup@.service ignore events until networking.service is active, or wait until after it has run (slower, but avoids race conditions when hotplug events happen while networking.service is running). Thus we need to add After=networking.service to ifup@.service, so that this only does stuff after doing the "coldplug" configuration. This also affects cloud-init's setup of networking: this currently jumps through a lot of bad hoops to make sure that ifup@ does not run until after cloud-init-local.service. This includes blocking udev rules for an indefinite time, which is racy, a potential deadlock, and highly non-elegant. https://bugs.debian.org/752919 is related to this issue. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1577844/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1577844] Re: Drop unnecessary blocking of all net udev rules
** Branch linked: lp:~smoser/cloud-init/trunk.fix-networking -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to ifupdown in Ubuntu. https://bugs.launchpad.net/bugs/1577844 Title: Drop unnecessary blocking of all net udev rules Status in cloud-init package in Ubuntu: Triaged Status in ifupdown package in Ubuntu: Invalid Bug description: cloud-inits networking setup currently jumps through a lot of bad hoops to make sure that ifup@ does not run until after cloud-init- local.service. This includes blocking udev rules for an indefinite time, which is racy, a potential deadlock, and highly non-elegant. This is also not necessary: while ifupdown's net udev rule certainly can fire before cloud-init-local, it only asynchronously starts ifup@.service which will be deferred until after network-pre.target and thus after cloud-init-local.service. --- Original description, which turned out to be completely false and just us being misled: ifup@.service can (and often does) run for a particular interface before networking.service runs. This is brittle as during early boot ifup is prone to fail: / might still be read-only, /var might not yet exist or be writable, dhclient-enter-hooks.d/ or if-up.d/ hooks might silently fail, etc. It is also unnecessary as networking.service will bring up all "auto" and all present "allow-hotplug" interfaces anyway, and it runs at the right time. We should make either 80-ifupdown.rules or ifup@.service ignore events until networking.service is active, or wait until after it has run (slower, but avoids race conditions when hotplug events happen while networking.service is running). Thus we need to add After=networking.service to ifup@.service, so that this only does stuff after doing the "coldplug" configuration. This also affects cloud-init's setup of networking: this currently jumps through a lot of bad hoops to make sure that ifup@ does not run until after cloud-init-local.service. This includes blocking udev rules for an indefinite time, which is racy, a potential deadlock, and highly non-elegant. https://bugs.debian.org/752919 is related to this issue. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1577844/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1577844] Re: Drop unnecessary blocking of all net udev rules
** Changed in: cloud-init (Ubuntu) Importance: Undecided => Medium -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to ifupdown in Ubuntu. https://bugs.launchpad.net/bugs/1577844 Title: Drop unnecessary blocking of all net udev rules Status in cloud-init package in Ubuntu: Triaged Status in ifupdown package in Ubuntu: Invalid Bug description: cloud-inits networking setup currently jumps through a lot of bad hoops to make sure that ifup@ does not run until after cloud-init- local.service. This includes blocking udev rules for an indefinite time, which is racy, a potential deadlock, and highly non-elegant. This is also not necessary: while ifupdown's net udev rule certainly can fire before cloud-init-local, it only asynchronously starts ifup@.service which will be deferred until after network-pre.target and thus after cloud-init-local.service. --- Original description, which turned out to be completely false and just us being misled: ifup@.service can (and often does) run for a particular interface before networking.service runs. This is brittle as during early boot ifup is prone to fail: / might still be read-only, /var might not yet exist or be writable, dhclient-enter-hooks.d/ or if-up.d/ hooks might silently fail, etc. It is also unnecessary as networking.service will bring up all "auto" and all present "allow-hotplug" interfaces anyway, and it runs at the right time. We should make either 80-ifupdown.rules or ifup@.service ignore events until networking.service is active, or wait until after it has run (slower, but avoids race conditions when hotplug events happen while networking.service is running). Thus we need to add After=networking.service to ifup@.service, so that this only does stuff after doing the "coldplug" configuration. This also affects cloud-init's setup of networking: this currently jumps through a lot of bad hoops to make sure that ifup@ does not run until after cloud-init-local.service. This includes blocking udev rules for an indefinite time, which is racy, a potential deadlock, and highly non-elegant. https://bugs.debian.org/752919 is related to this issue. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1577844/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1577844] Re: Drop unnecessary blocking of all net udev rules
Also note that blocking the uevents will not actually work for the renaming if there is an initramfs involved. I. e. it will work in containers, but not QEMU or bare metal. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to ifupdown in Ubuntu. https://bugs.launchpad.net/bugs/1577844 Title: Drop unnecessary blocking of all net udev rules Status in cloud-init package in Ubuntu: Triaged Status in ifupdown package in Ubuntu: Invalid Bug description: cloud-inits networking setup currently jumps through a lot of bad hoops to make sure that ifup@ does not run until after cloud-init- local.service. This includes blocking udev rules for an indefinite time, which is racy, a potential deadlock, and highly non-elegant. This is also not necessary: while ifupdown's net udev rule certainly can fire before cloud-init-local, it only asynchronously starts ifup@.service which will be deferred until after network-pre.target and thus after cloud-init-local.service. --- Original description, which turned out to be completely false and just us being misled: ifup@.service can (and often does) run for a particular interface before networking.service runs. This is brittle as during early boot ifup is prone to fail: / might still be read-only, /var might not yet exist or be writable, dhclient-enter-hooks.d/ or if-up.d/ hooks might silently fail, etc. It is also unnecessary as networking.service will bring up all "auto" and all present "allow-hotplug" interfaces anyway, and it runs at the right time. We should make either 80-ifupdown.rules or ifup@.service ignore events until networking.service is active, or wait until after it has run (slower, but avoids race conditions when hotplug events happen while networking.service is running). Thus we need to add After=networking.service to ifup@.service, so that this only does stuff after doing the "coldplug" configuration. This also affects cloud-init's setup of networking: this currently jumps through a lot of bad hoops to make sure that ifup@ does not run until after cloud-init-local.service. This includes blocking udev rules for an indefinite time, which is racy, a potential deadlock, and highly non-elegant. https://bugs.debian.org/752919 is related to this issue. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1577844/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
[Touch-packages] [Bug 1577844] Re: Drop unnecessary blocking of all net udev rules
some futher thought one reason for the blocking of udev was to have the .link files that cloud-init wrote apply. It turns out that systemd.link will only rename devices once (based on a property in the devices /sys that says it has been renamed). So, for cloud-init to have these apply we will probably have to unbind and bind the device to clear that. that will also generate a hotplug event to get the device changed. http://paste.ubuntu.com/16220589/ ** Attachment added: "unlink and relink script" https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1577844/+attachment/4655826/+files/unlink-link-dev -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to ifupdown in Ubuntu. https://bugs.launchpad.net/bugs/1577844 Title: Drop unnecessary blocking of all net udev rules Status in cloud-init package in Ubuntu: Triaged Status in ifupdown package in Ubuntu: Invalid Bug description: cloud-inits networking setup currently jumps through a lot of bad hoops to make sure that ifup@ does not run until after cloud-init- local.service. This includes blocking udev rules for an indefinite time, which is racy, a potential deadlock, and highly non-elegant. This is also not necessary: while ifupdown's net udev rule certainly can fire before cloud-init-local, it only asynchronously starts ifup@.service which will be deferred until after network-pre.target and thus after cloud-init-local.service. --- Original description, which turned out to be completely false and just us being misled: ifup@.service can (and often does) run for a particular interface before networking.service runs. This is brittle as during early boot ifup is prone to fail: / might still be read-only, /var might not yet exist or be writable, dhclient-enter-hooks.d/ or if-up.d/ hooks might silently fail, etc. It is also unnecessary as networking.service will bring up all "auto" and all present "allow-hotplug" interfaces anyway, and it runs at the right time. We should make either 80-ifupdown.rules or ifup@.service ignore events until networking.service is active, or wait until after it has run (slower, but avoids race conditions when hotplug events happen while networking.service is running). Thus we need to add After=networking.service to ifup@.service, so that this only does stuff after doing the "coldplug" configuration. This also affects cloud-init's setup of networking: this currently jumps through a lot of bad hoops to make sure that ifup@ does not run until after cloud-init-local.service. This includes blocking udev rules for an indefinite time, which is racy, a potential deadlock, and highly non-elegant. https://bugs.debian.org/752919 is related to this issue. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1577844/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
