[libvirt] [PATCH v2] systemd: Modernize machine naming

[Daniel P. Berrange]

On Wed, Feb 03, 2016 at 03:27:27PM +0100, Martin Kletzander wrote:
> So, systemd-machined has this philosophy that machine names are like
> hostnames and hence should follow the same rules.  But we always allowed
> international characters in domain names.  Thus we need to modify the
> machine name we are passing to systemd.
> 
> In order to change some machinenames that we will be passing to systemd,
> we also need to call TerminateMachine at the end of a lifetime of a
> domain.  Even for domains that were started with older libvirt.  That
> can be achieved thanks to virSystemdGetMachineNameByPID().  And because
> we can change machine names, we can get rid of the inconsistent and
> pointless escaping of domain names when creating machine names.
> 
> So this patch modifies the naming in the following way.  It creates the
> name as <drivername>-<id>-<name> where invalid hostname characters are
> stripped out of the name and if the resulting name is longer, it
> truncates it to 64 characters.  That way we can start domains we
> couldn't start before.  Well, at least on systemd.
> 
> To make it work all together, the machineName (which is needed only for
> systemd) is saved in domain's private data.  That way the generation is
> moved to the driver and we don't need to pass various unnecessary
> arguments to cgroup functions.
> 
> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1282846
> 
> Signed-off-by: Martin Kletzander <mkletzan at redhat.com>
> diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c
> index da0df7ae7a5e..4aed5d20b818 100644
> --- a/src/util/vircgroup.c
> +++ b/src/util/vircgroup.c
> @@ -43,6 +43,7 @@
>  #include "vircgrouppriv.h"
> 
>  #include "virutil.h"
> +#include "viruuid.h"
>  #include "viralloc.h"
>  #include "virerror.h"
>  #include "virlog.h"
> @@ -243,12 +244,14 @@ static bool
>  virCgroupValidateMachineGroup(virCgroupPtr group,
>                                const char *name,
>                                const char *drivername,
> +                              const unsigned char *uuid,
>                                bool stripEmulatorSuffix)
>  {
>      size_t i;
>      bool valid = false;
>      char *partname;
>      char *scopename;
> +    char uuidstr[VIR_UUID_STRING_BUFLEN];
> 
>      if (virAsprintf(&partname, "%s.libvirt-%s",
>                      name, drivername) < 0)
> @@ -263,6 +266,8 @@ virCgroupValidateMachineGroup(virCgroupPtr group,
>      if (virCgroupPartitionEscape(&scopename) < 0)
>          goto cleanup;
> 
> +    virUUIDFormat(uuid, uuidstr);
> +
>      for (i = 0; i < VIR_CGROUP_CONTROLLER_LAST; i++) {
>          char *tmp;
> 
> @@ -290,6 +295,7 @@ virCgroupValidateMachineGroup(virCgroupPtr group,
>          tmp++;
> 
>          if (STRNEQ(tmp, name) &&
> +            STRNEQ(tmp, uuidstr) &&
>              STRNEQ(tmp, partname) &&
>              STRNEQ(tmp, scopename)) {
>              VIR_DEBUG("Name '%s' for controller '%s' does not match "


I don't think we need this anymore, which would mean removing the
uuid parameter you added to several methods in this file.


Regards,
Daniel
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