Re: [systemd-devel] Launching a unit in response to a D-Bus signal
On 01/10/12 23:53, Mirco Tischler wrote: 2012/10/2 Kok, Auke-jan H auke-jan.h@intel.com: On Mon, Oct 1, 2012 at 4:58 AM, Matthew Booth mbo...@redhat.com wrote: I have a requirement to restart squid whenever the VPN goes up or down[1]. Reading around, it seems that the way to do this would be in response to the relevant D-Bus signal, which seems to be this one: signal sender=:1.6 - dest=(null destination) serial=269 path=/org/freedesktop/NetworkManager/ActiveConnection/2; interface=org.freedesktop.NetworkManager.VPN.Connection; member=VpnStateChanged I expected that systemd would allow me to do this, but as far as I can tell it doesn't (I'm using F17). I can obviously write my own daemon to do this, but it seems to me that a daemon just for this would be a waste. I think this sounds like a good fit for systemd. Is it anything anybody's looked at? The problem with listening on a specific DBus message is that it requires you to implement much more of DBus than systemd internally can. I'm not sure it's a good idea to put something that complex into systemd. Your alternatives are to write a simple DBus frontend, or perhaps a Network Manager plugin (if there is such a thing, I know connman has the concept of plugins). You can certainly socket activate a dummy service that doesn't actually listen on DBus but instead executes `systemctl restart squid.service` based on the BusName only. Systemd will likely however not appreciate the unhandled socket, but it may be worth a try. Auke Systemd isn't really the right place to do network related stuff, imo. Such things are better dealt with in the network connection manager, where the information is already available. NetworkManager has a mechanism to execute custom scripts in /etc/NetworkManager/dispatcher.d on network events. For details take a look at the man page, support for explicit actions on vpn-up/down is mentioned there. Thanks. I've submitted a patch to fix squid's existing dispatcher script and this is now working for me. I'll bow to collective experience on whether systemd is the correct place for this, but with a sysadmin hat on it just felt like the right place to be putting something which performed an action in response to a system event. Matt -- Matthew Booth, RHCA, RHCSS Red Hat Engineering, Virtualisation Team GPG ID: D33C3490 GPG FPR: 3733 612D 2D05 5458 8A8A 1600 3441 EA19 D33C 3490 ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Launching a unit in response to a D-Bus signal
On 10/01/2012 10:53 PM, Mirco Tischler wrote: Systemd isn't really the right place to do network related stuff, imo. Such things are better dealt with in the network connection manager, where the information is already available. NetworkManager has a mechanism to execute custom scripts in /etc/NetworkManager/dispatcher.d on network events. For details take a look at the man page, support for explicit actions on vpn-up/down is mentioned there. Arguably systemd is the correct place under CoreOS to unite and manage network connections JBG ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Launching a unit in response to a D-Bus signal
2012/10/2 Jóhann B. Guðmundsson johan...@gmail.com: On 10/01/2012 10:53 PM, Mirco Tischler wrote: Systemd isn't really the right place to do network related stuff, imo. Such things are better dealt with in the network connection manager, where the information is already available. NetworkManager has a mechanism to execute custom scripts in /etc/NetworkManager/dispatcher.d on network events. For details take a look at the man page, support for explicit actions on vpn-up/down is mentioned there. Arguably systemd is the correct place under CoreOS to unite and manage network connections JBG How do you do that? systemd doesn't have any support to manage network connections. It lacks information about the state of the network devices and cannot configure them as well. In Matthew's case creating a dispatcher script that issues a systemctl restart squid.service on vpn state changes looks like a correct solution to me. Do you have a better idea? Mirco ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Launching a unit in response to a D-Bus signal
On 10/02/2012 12:47 PM, Mirco Tischler wrote: How do you do that? systemd doesn't have any support to manage network connections. It lacks information about the state of the network devices and cannot configure them as well. Today systemd cant but in the future it might depending on how things progress. From my point of view an single network management application should be integrated into the init system in this case systemd/CoreOS. It just begs the question to what extent as to complexity. In the end the solution what ever it might be needs to be something that can be light enough to be on embedded but flexible enough to handle complex server environment with the desktop falling somewhere between those two. I'm very well that a lot of people think forking is fun but I just dont tend to agree with that for something that is fundamental part of the underlying OS as network management is and should be from my pov. JBG ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
[systemd-devel] Launching a unit in response to a D-Bus signal
I have a requirement to restart squid whenever the VPN goes up or down[1]. Reading around, it seems that the way to do this would be in response to the relevant D-Bus signal, which seems to be this one: signal sender=:1.6 - dest=(null destination) serial=269 path=/org/freedesktop/NetworkManager/ActiveConnection/2; interface=org.freedesktop.NetworkManager.VPN.Connection; member=VpnStateChanged I expected that systemd would allow me to do this, but as far as I can tell it doesn't (I'm using F17). I can obviously write my own daemon to do this, but it seems to me that a daemon just for this would be a waste. I think this sounds like a good fit for systemd. Is it anything anybody's looked at? Thanks, Matt [1] It's not directly relevant to this post, but the reason is that squid doesn't pick up the new nameservers until it's restarted. P.S. I'm not subscribed. -- Matthew Booth, RHCA, RHCSS Red Hat Engineering, Virtualisation Team GPG ID: D33C3490 GPG FPR: 3733 612D 2D05 5458 8A8A 1600 3441 EA19 D33C 3490 ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Launching a unit in response to a D-Bus signal
2012/10/2 Kok, Auke-jan H auke-jan.h@intel.com: On Mon, Oct 1, 2012 at 4:58 AM, Matthew Booth mbo...@redhat.com wrote: I have a requirement to restart squid whenever the VPN goes up or down[1]. Reading around, it seems that the way to do this would be in response to the relevant D-Bus signal, which seems to be this one: signal sender=:1.6 - dest=(null destination) serial=269 path=/org/freedesktop/NetworkManager/ActiveConnection/2; interface=org.freedesktop.NetworkManager.VPN.Connection; member=VpnStateChanged I expected that systemd would allow me to do this, but as far as I can tell it doesn't (I'm using F17). I can obviously write my own daemon to do this, but it seems to me that a daemon just for this would be a waste. I think this sounds like a good fit for systemd. Is it anything anybody's looked at? The problem with listening on a specific DBus message is that it requires you to implement much more of DBus than systemd internally can. I'm not sure it's a good idea to put something that complex into systemd. Your alternatives are to write a simple DBus frontend, or perhaps a Network Manager plugin (if there is such a thing, I know connman has the concept of plugins). You can certainly socket activate a dummy service that doesn't actually listen on DBus but instead executes `systemctl restart squid.service` based on the BusName only. Systemd will likely however not appreciate the unhandled socket, but it may be worth a try. Auke Systemd isn't really the right place to do network related stuff, imo. Such things are better dealt with in the network connection manager, where the information is already available. NetworkManager has a mechanism to execute custom scripts in /etc/NetworkManager/dispatcher.d on network events. For details take a look at the man page, support for explicit actions on vpn-up/down is mentioned there. Mirco ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
