[PATCH] rpcbind.service: Not pulling the rpcbind.target

[PATCH] rpcbind.service: Not pulling the rpcbind.target

[Steve Dickson]

According to systemd.special(7) manpage:

rpcbind.target
    The portmapper/rpcbind pulls in this target and orders itself before it, to indicate its availability. systemd automatically adds dependencies of type After= for this target unit to all SysV init script service units with an LSB header referring to the "$portmap" facility.

Signed-off-by: Steve Dickson <steved@redhat.com>
---
 systemd/rpcbind.service.in | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/systemd/rpcbind.service.in b/systemd/rpcbind.service.in
index f8cfa9f..2b49c24 100644
--- a/systemd/rpcbind.service.in
+++ b/systemd/rpcbind.service.in
@@ -6,8 +6,8 @@ RequiresMountsFor=@statedir@
 
 # Make sure we use the IP addresses listed for
 # rpcbind.socket, no matter how this unit is started.
-Wants=rpcbind.socket
-After=rpcbind.socket
+Wants=rpcbind.socket rpcbind.target
+After=rpcbind.socket rpcbind.target
 
 [Service]
 Type=notify
-- 
2.14.3

Re: [systemd-devel] [PATCH] rpcbind.service: Not pulling the rpcbind.target

[Uoti Urpala]

On Thu, 2017-12-14 at 12:05 -0500, Steve Dickson wrote:
> According to systemd.special(7) manpage:
> 
> rpcbind.target
>     The portmapper/rpcbind pulls in this target and orders itself
> before it, to indicate its availability. systemd automatically adds
> dependencies of type After= for this target unit to all SysV init
> script service units with an LSB header referring to the "$portmap"
> facility.


> diff --git a/systemd/rpcbind.service.in b/systemd/rpcbind.service.in
> index f8cfa9f..2b49c24 100644
> --- a/systemd/rpcbind.service.in
> +++ b/systemd/rpcbind.service.in
> @@ -6,8 +6,8 @@ RequiresMountsFor=@statedir@
>  
>  # Make sure we use the IP addresses listed for
>  # rpcbind.socket, no matter how this unit is started.
> -Wants=rpcbind.socket
> -After=rpcbind.socket
> +Wants=rpcbind.socket rpcbind.target
> +After=rpcbind.socket rpcbind.target

Is this needed when the service has socket activation support? If the
only interaction with it is through the socket, it shouldn't matter
even if the service is not actually up yet - clients can already open
connections to the socket regardless.

And regardless, that "After" for rpcbind.target seems backwards.
Shouldn't it be "Before", so that the target being up signals that the
service has already been started?

Not directly related, but if that comment is accurate and the socket
should be used "no matter what", perhaps that should be "Requires"
instead of "Wants" so that if the socket could not be opened for some
reason, the service fails instead of starting without socket
activation?

Re: [systemd-devel] [PATCH] rpcbind.service: Not pulling the rpcbind.target

[Steve Dickson]

On 12/14/2017 12:48 PM, Uoti Urpala wrote:
> On Thu, 2017-12-14 at 12:05 -0500, Steve Dickson wrote:
>> According to systemd.special(7) manpage:
>>
>> rpcbind.target
>>     The portmapper/rpcbind pulls in this target and orders itself
>> before it, to indicate its availability. systemd automatically adds
>> dependencies of type After= for this target unit to all SysV init
>> script service units with an LSB header referring to the "$portmap"
>> facility.
> 
> 
>> diff --git a/systemd/rpcbind.service.in b/systemd/rpcbind.service.in
>> index f8cfa9f..2b49c24 100644
>> --- a/systemd/rpcbind.service.in
>> +++ b/systemd/rpcbind.service.in
>> @@ -6,8 +6,8 @@ RequiresMountsFor=@statedir@
>>  
>>  # Make sure we use the IP addresses listed for
>>  # rpcbind.socket, no matter how this unit is started.
>> -Wants=rpcbind.socket
>> -After=rpcbind.socket
>> +Wants=rpcbind.socket rpcbind.target
>> +After=rpcbind.socket rpcbind.target
> 
> Is this needed when the service has socket activation support? If the
> only interaction with it is through the socket, it shouldn't matter
> even if the service is not actually up yet - clients can already open
> connections to the socket regardless.
Well things are working as is... but this man page paragraph 
was pointed out to me so I though these Wants and After were needed.

So you saying this patch is not needed? 
 
> 
> And regardless, that "After" for rpcbind.target seems backwards.
> Shouldn't it be "Before", so that the target being up signals that the
> service has already been started?
I think this makes sense... So if the patch is needed I'll add
Before=rpcbind.target and remove the target from the After=

> 
> Not directly related, but if that comment is accurate and the socket
> should be used "no matter what", perhaps that should be "Requires"
> instead of "Wants" so that if the socket could not be opened for some
> reason, the service fails instead of starting without socket
> activation?
> 
I was afraid of opening a can a worms here... :-) 

So you are saying Wants and After should be changed to 

Requires=rpcbind.socket
Before=rpcbind.target

steved

Re: [systemd-devel] [PATCH] rpcbind.service: Not pulling the rpcbind.target

[Uoti Urpala]

On Thu, 2017-12-14 at 13:24 -0500, Steve Dickson wrote:
> 
> On 12/14/2017 12:48 PM, Uoti Urpala wrote:
> > On Thu, 2017-12-14 at 12:05 -0500, Steve Dickson wrote:
> > > +Wants=rpcbind.socket rpcbind.target
> > > +After=rpcbind.socket rpcbind.target
> > 
> > Is this needed when the service has socket activation support? If the
> > only interaction with it is through the socket, it shouldn't matter
> > even if the service is not actually up yet - clients can already open
> > connections to the socket regardless.
> 
> Well things are working as is... but this man page paragraph 
> was pointed out to me so I though these Wants and After were needed.
> 
> So you saying this patch is not needed?

I'm not familiar enough with rpcbind stuff to say with certainty that
it wouldn't be needed, but at least it seems plausible to me that it
would not be. The mechanism described on the man page is a way to
implement ordering if needed, but if the early availability of the
socket means ordering is never an issue, then it can be ignored.


> > And regardless, that "After" for rpcbind.target seems backwards.
> > Shouldn't it be "Before", so that the target being up signals that the
> > service has already been started?
> 
> I think this makes sense... So if the patch is needed I'll add
> Before=rpcbind.target and remove the target from the After=

Yes.

> > Not directly related, but if that comment is accurate and the socket
> > should be used "no matter what", perhaps that should be "Requires"
> > instead of "Wants" so that if the socket could not be opened for some
> > reason, the service fails instead of starting without socket
> > activation?
> > 
> 
> I was afraid of opening a can a worms here... :-) 
> 
> So you are saying Wants and After should be changed to 
> 
> Requires=rpcbind.socket
> Before=rpcbind.target

Depends on the exact semantics you want. "Wants" means that systemd
will try to start the socket if the service is started, but will
continue with the service start even if the dependency fails.
"Requires" guarantees that the service will never be started without
the socket active - if opening the socket fails, then the service start
will return failure too. If you know that the socket unit should always
be used, or the service will either fail or do the wrong thing without
it (such as open a socket with parameters different from what was
configured for the socket unit, and which the admin didn't expect) then
 Requires may be more appropriate.

Re: [systemd-devel] [PATCH] rpcbind.service: Not pulling the rpcbind.target

[Steve Dickson]

On 12/14/2017 01:47 PM, Uoti Urpala wrote:
> On Thu, 2017-12-14 at 13:24 -0500, Steve Dickson wrote:
>>
>> On 12/14/2017 12:48 PM, Uoti Urpala wrote:
>>> On Thu, 2017-12-14 at 12:05 -0500, Steve Dickson wrote:
>>>> +Wants=rpcbind.socket rpcbind.target
>>>> +After=rpcbind.socket rpcbind.target
>>>
>>> Is this needed when the service has socket activation support? If the
>>> only interaction with it is through the socket, it shouldn't matter
>>> even if the service is not actually up yet - clients can already open
>>> connections to the socket regardless.
>>
>> Well things are working as is... but this man page paragraph 
>> was pointed out to me so I though these Wants and After were needed.
>>
>> So you saying this patch is not needed?
> 
> I'm not familiar enough with rpcbind stuff to say with certainty that
> it wouldn't be needed, but at least it seems plausible to me that it
> would not be. The mechanism described on the man page is a way to
> implement ordering if needed, but if the early availability of the
> socket means ordering is never an issue, then it can be ignored.
> 
> 
>>> And regardless, that "After" for rpcbind.target seems backwards.
>>> Shouldn't it be "Before", so that the target being up signals that the
>>> service has already been started?
>>
>> I think this makes sense... So if the patch is needed I'll add
>> Before=rpcbind.target and remove the target from the After=
> 
> Yes.
> 
>>> Not directly related, but if that comment is accurate and the socket
>>> should be used "no matter what", perhaps that should be "Requires"
>>> instead of "Wants" so that if the socket could not be opened for some
>>> reason, the service fails instead of starting without socket
>>> activation?
>>>
>>
>> I was afraid of opening a can a worms here... :-) 
>>
>> So you are saying Wants and After should be changed to 
>>
>> Requires=rpcbind.socket
>> Before=rpcbind.target
> 
> Depends on the exact semantics you want. "Wants" means that systemd
> will try to start the socket if the service is started, but will
> continue with the service start even if the dependency fails.
> "Requires" guarantees that the service will never be started without
> the socket active - if opening the socket fails, then the service start
> will return failure too. If you know that the socket unit should always
> be used, or the service will either fail or do the wrong thing without
> it (such as open a socket with parameters different from what was
> configured for the socket unit, and which the admin didn't expect) then
>  Requires may be more appropriate.
I think I agree with you... thanks!

steved.

> 
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Re: [systemd-devel] [PATCH] rpcbind.service: Not pulling the rpcbind.target

[Lennart Poettering]

On Do, 14.12.17 12:05, Steve Dickson (steved@redhat.com) wrote:

> According to systemd.special(7) manpage:
> 
> rpcbind.target
>     The portmapper/rpcbind pulls in this target and
>     orders itself before it, to indicate its availability. systemd
>     automatically adds dependencies of type After= for this target
>     unit to all SysV init script service units with an LSB header
>     referring to the "$portmap" facility.
> 
> Signed-off-by: Steve Dickson <steved@redhat.com>
> ---
>  systemd/rpcbind.service.in | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/systemd/rpcbind.service.in b/systemd/rpcbind.service.in
> index f8cfa9f..2b49c24 100644
> --- a/systemd/rpcbind.service.in
> +++ b/systemd/rpcbind.service.in
> @@ -6,8 +6,8 @@ RequiresMountsFor=@statedir@
>  
>  # Make sure we use the IP addresses listed for
>  # rpcbind.socket, no matter how this unit is started.
> -Wants=rpcbind.socket
> -After=rpcbind.socket
> +Wants=rpcbind.socket rpcbind.target
> +After=rpcbind.socket rpcbind.target

The last line should be:

After=rpcbind.socket
Before=rpcbind.target

Lennart

-- 
Lennart Poettering, Red Hat