This allows upstart scripts to detect that they are in a container and modify their behavior accordingly. In this way, the same ubuntu maverick or natty image with the 'lxcguest' package installed can be booted on bare metal, in kvm, or as a libvirt or liblxc container. Signed-off-by: Chuck Short <zulcss(a)ubuntu.com&gt; Signed-off-by: Serge Hallyn <serge.hallyn(a)ubuntu.com&gt; --- src/lxc/lxc_container.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c index 9ae93b5..a70aeeb 100644 --- a/src/lxc/lxc_container.c +++ b/src/lxc/lxc_container.c @@ -112,6 +112,7 @@ static virCommandPtr lxcContainerBuildInitCmd(virDomainDefPtr vmDef) virCommandAddEnvString(cmd, "PATH=/bin:/sbin"); virCommandAddEnvString(cmd, "TERM=linux"); + virCommandAddEnvString(cmd, "container=libvirt");

virCommandAddEnvPair(cmd, "LIBVIRT_LXC_UUID", uuidstr); virCommandAddEnvPair(cmd, "LIBVIRT_LXC_NAME", vmDef->name);

>> @@ -112,6 +112,7 @@ static virCommandPtr lxcContainerBuildInitCmd(virDomainDefPtr vmDef) >> >> virCommandAddEnvString(cmd, "PATH=/bin:/sbin"); >> virCommandAddEnvString(cmd, "TERM=linux"); >> + virCommandAddEnvString(cmd, "container=libvirt"); > > POSIX reserves lowercase env names for the user. Is upstart really > using a lower case name, or should this be an upper case name? No upstart isn't doing anything itself :) Just blame me - the upstart scripts I put into lxcguest do in fact check for lower-case. What do you mean by 'for the user'? For the user to type into the boot args, or something else?

>> virCommandAddEnvPair(cmd, "LIBVIRT_LXC_UUID", uuidstr); >> virCommandAddEnvPair(cmd, "LIBVIRT_LXC_NAME", vmDef->name); > > Can upstart be taught to look for LIBIVRT_LXC_UUID instead? That's a possibility, yes. It just makes it less symmetric to the liblxc case, but if you prefer that I see no reason why it wouldn't work.

This allows upstart scripts to detect that they are in a container and modify their behavior accordingly. In this way, the same ubuntu maverick or natty image with the 'lxcguest' package installed can be booted on bare metal, in kvm, or as a libvirt or liblxc container. Signed-off-by: Chuck Short <zulcss(a)ubuntu.com&gt; Signed-off-by: Serge Hallyn <serge.hallyn(a)ubuntu.com&gt; --- src/lxc/lxc_container.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c index 9ae93b5..a70aeeb 100644 --- a/src/lxc/lxc_container.c +++ b/src/lxc/lxc_container.c @@ -112,6 +112,7 @@ static virCommandPtr lxcContainerBuildInitCmd(virDomainDefPtr vmDef) virCommandAddEnvString(cmd, "PATH=/bin:/sbin"); virCommandAddEnvString(cmd, "TERM=linux"); + virCommandAddEnvString(cmd, "container=libvirt"); virCommandAddEnvPair(cmd, "LIBVIRT_LXC_UUID", uuidstr); virCommandAddEnvPair(cmd, "LIBVIRT_LXC_NAME", vmDef->name);

Quoting Daniel P. Berrange (berrange(a)redhat.com): > On Mon, May 16, 2011 at 09:47:02AM -0500, Serge Hallyn wrote: > > This allows upstart scripts to detect that they are in a container > > and modify their behavior accordingly. > > > > In this way, the same ubuntu maverick or natty image with the 'lxcguest' > > package installed can be booted on bare metal, in kvm, or as a > > libvirt or liblxc container. > > > > Signed-off-by: Chuck Short <zulcss(a)ubuntu.com&gt; > > Signed-off-by: Serge Hallyn <serge.hallyn(a)ubuntu.com&gt; > > --- > > src/lxc/lxc_container.c | 1 + > > 1 files changed, 1 insertions(+), 0 deletions(-) > > > > diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c > > index 9ae93b5..a70aeeb 100644 > > --- a/src/lxc/lxc_container.c > > +++ b/src/lxc/lxc_container.c > > @@ -112,6 +112,7 @@ static virCommandPtr lxcContainerBuildInitCmd(virDomainDefPtr vmDef) > > > > virCommandAddEnvString(cmd, "PATH=/bin:/sbin"); > > virCommandAddEnvString(cmd, "TERM=linux"); > > + virCommandAddEnvString(cmd, "container=libvirt"); > > virCommandAddEnvPair(cmd, "LIBVIRT_LXC_UUID", uuidstr); > > virCommandAddEnvPair(cmd, "LIBVIRT_LXC_NAME", vmDef->name); > > I've no objection to this, but IMHO the value should be > > container=libvirt-lxc So long as it is guaranteed that henceforth LIBVIRT_LXC_UUID=x will always be passed to init, that suffices. But I worry about it changing in 6 or 12 months to a slightly different name, or not always being passed. Do you think there is any chance of that happening?

On 05/17/2011 08:40 AM, Serge Hallyn wrote: >>> +++ b/src/lxc/lxc_container.c >>> @@ -112,6 +112,7 @@ static virCommandPtr lxcContainerBuildInitCmd(virDomainDefPtr vmDef) >>> >>> virCommandAddEnvString(cmd, "PATH=/bin:/sbin"); >>> virCommandAddEnvString(cmd, "TERM=linux"); >>> + virCommandAddEnvString(cmd, "container=libvirt"); >>> virCommandAddEnvPair(cmd, "LIBVIRT_LXC_UUID", uuidstr); >>> virCommandAddEnvPair(cmd, "LIBVIRT_LXC_NAME", vmDef->name); >> >> I've no objection to this, but IMHO the value should be >> >> container=libvirt-lxc > > So long as it is guaranteed that henceforth LIBVIRT_LXC_UUID=x will always > be passed to init, that suffices. But I worry about it changing in 6 or > 12 months to a slightly different name, or not always being passed. Do > you think there is any chance of that happening? No risk of change. Libvirt is documented as providing a stable library, and LIBVIRT_LXC_UUID is externally visible, therefore it is now part of our documented interface and we cannot change it without breaking backwards compatibility. You can safely use $LIBVIRT_LXC_UUID. Since Daniel was okay with also adding $container, do you want to keep this patch under consideration, or are you okay dropping it in favor of $LIBVIRT_LXC_UUID?