From 9c1e04d0fa80c73ef0dd4647c103cdb7edb7f580 Mon Sep 17 00:00:00 2001 From: Alessandro Puccetti Date: Fri, 10 Jun 2016 13:09:06 +0200 Subject: nspawn: introduce --notify-ready=[no|yes] (#3474) This the patch implements a notificaiton mechanism from the init process in the container to systemd-nspawn. The switch --notify-ready=yes configures systemd-nspawn to wait the "READY=1" message from the init process in the container to send its own to systemd. --notify-ready=no is equivalent to the previous behavior before this patch, systemd-nspawn notifies systemd with a "READY=1" message when the container is created. This notificaiton mechanism uses socket file with path relative to the contanier "/run/systemd/nspawn/notify". The default values it --notify-ready=no. It is also possible to configure this mechanism from the .nspawn files using NotifyReady. This parameter takes the same options of the command line switch. Before this patch, systemd-nspawn notifies "ready" after the inner child was created, regardless the status of the service running inside it. Now, with --notify-ready=yes, systemd-nspawn notifies when the service is ready. This is really useful when there are dependencies between different contaniers. Fixes https://github.com/systemd/systemd/issues/1369 Based on the work from https://github.com/systemd/systemd/pull/3022 Testing: Boot a OS inside a container with systemd-nspawn. Note: modify the commands accordingly with your filesystem. 1. Create a filesystem where you can boot an OS. 2. sudo systemd-nspawn -D ${HOME}/distros/fedora-23/ sh 2.1. Create the unit file /etc/systemd/system/sleep.service inside the container (You can use the example below) 2.2. systemdctl enable sleep 2.3 exit 3. sudo systemd-run --service-type=notify --unit=notify-test ${HOME}/systemd/systemd-nspawn --notify-ready=yes -D ${HOME}/distros/fedora-23/ -b 4. In a different shell run "systemctl status notify-test" When using --notify-ready=yes the service status is "activating" for 20 seconds before being set to "active (running)". Instead, using --notify-ready=no the service status is marked "active (running)" quickly, without waiting for the 20 seconds. This patch was also test with --private-users=yes, you can test it just adding it at the end of the command at point 3. ------ sleep.service ------ [Unit] Description=sleep After=network.target [Service] Type=oneshot ExecStart=/bin/sleep 20 [Install] WantedBy=multi-user.target ------------ end ------------ --- src/nspawn/nspawn-settings.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'src/nspawn/nspawn-settings.h') diff --git a/src/nspawn/nspawn-settings.h b/src/nspawn/nspawn-settings.h index 1c47e37912..231e6d7266 100644 --- a/src/nspawn/nspawn-settings.h +++ b/src/nspawn/nspawn-settings.h @@ -56,7 +56,8 @@ typedef enum SettingsMask { SETTING_CUSTOM_MOUNTS = 1 << 11, SETTING_WORKING_DIRECTORY = 1 << 12, SETTING_USERNS = 1 << 13, - _SETTINGS_MASK_ALL = (1 << 14) -1 + SETTING_NOTIFY_READY = 1 << 14, + _SETTINGS_MASK_ALL = (1 << 15) -1 } SettingsMask; typedef struct Settings { @@ -73,6 +74,7 @@ typedef struct Settings { char *working_directory; UserNamespaceMode userns_mode; uid_t uid_shift, uid_range; + bool notify_ready; /* [Image] */ int read_only; -- cgit v1.2.3-54-g00ecf