Hi,
Description / Steps to reproduce
================================
When instances are launched, they get the following console/serial configuration :
<serial type="pty">
<log file="/var/lib/nova/instances/e53cf7b4-e11a-445f-b4e3-006120e8d800/console.log" append="off"/>
<target type="isa-serial" port="0"/>
</serial>
<console type="pty">
<log file="/var/lib/nova/instances/e53cf7b4-e11a-445f-b4e3-006120e8d800/console.log" append="off"/>
<target type="serial" port="0"/>\n
</console>
If I look at the permissions for the console.log I see :
[root@<snip> nova]# ls -l /var/lib/nova/instances/e53cf7b4-e11a-445f-b4e3-006120e8d800/console.log
-rw-------. 1 nova openstack 0 Jan 30 11:09 /var/lib/nova/instances/e53cf7b4-e11a-445f-b4e3-006120e8d800/console.log
[root@<snip> nova]#
If I then live migrate the instance to another host (or complete a resize operation), virtlogd deletes the console.log and then recreates it as root:root.
[root@<snip> nova]# ls -l /var/lib/nova/instances/e53cf7b4-e11a-445f-b4e3-006120e8d800/console.log
-rw-------. 1 root root 0 Jan 30 11:14 /var/lib/nova/instances/e53cf7b4-e11a-445f-b4e3-006120e8d800/console.log
[root@<snip> nova]#
This looks to be because when the instance is configured with append="off", it ends up setting trunc to True in https://github.com/libvirt/libvirt/blob/93575f345116fe1413f6fe3109227b8be2f416da/src/util/virrotatingfile.c#L260-L265 and deletes the console log before recreating. As virtlogd is running as root and it doesn't seem to chown anything, it becomes root:root.
The first migration completes successfully but subsequent ones fail due to permissions errors trying to access the console.log.
If I change virt/libvirt/config.py to set append="on", the log isn't recreated (but I know have a problem with an ever growing log file).
Expected result
===============
Console.log still have nova:openstack ownership
Actual result
=============
Console.log has root:root ownership
Environment
===========
This is a libvirt + KVM environment on CentOS 7.
nova - 16.0.3
libvirt - 3.2.0-14.el7_4.7
qemu - 2.9.0-16.el7_4.13.1
In /etc/libvirt/qemu.conf, I have the following configured :
user = "nova"
group = "openstack"
dynamic_ownership = 0
SElinux is enabled, and if I set it to permissive and make it error for that folder, I get records like :
(virtlogd attempting delete)
time->Tue Jan 30 12:43:27 2018
type=PROCTITLE msg=audit(1517276607.013:90227): proctitle="/usr/sbin/virtlogd"
type=PATH msg=audit(1517276607.013:90227): item=1 name="/var/lib/nova/instances/e53cf7b4-e11a-445f-b4e3-006120e8d800/console.log" inode=1898807 dev=00:27 mode=0100600 ouid=162 ogid=1100 rdev=00:00 obj=system_u:object_r:nfs_t:s0 objtype=DELETE
type=PATH msg=audit(1517276607.013:90227): item=0 name="/var/lib/nova/instances/e53cf7b4-e11a-445f-b4e3-006120e8d800/" inode=1898806 dev=00:27 mode=040755 ouid=162 ogid=1100 rdev=00:00 obj=system_u:object_r:nfs_t:s0 objtype=PARENT
type=CWD msg=audit(1517276607.013:90227): cwd="/"
type=SYSCALL msg=audit(1517276607.013:90227): arch=c000003e syscall=87 success=yes exit=0 a0=7f406c000d30 a1=7f406c000cd9 a2=0 a3=6e6f632f36353935 items=2 ppid=1 pid=25859 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="virtlogd" exe="/usr/sbin/virtlogd" subj=system_u:system_r:virtlogd_t:s0-s0:c0.c1023
type=AVC msg=audit(1517276607.013:90227): avc: denied { unlink } for pid=25859 comm="virtlogd" name="console.log" dev="0:39" ino=1898807 scontext=system_u:system_r:virtlogd_t:s0-s0:c0.c1023 tcontext=system_u:object_r:nfs_t:s0 tclass=file
type=AVC msg=audit(1517276607.013:90227): avc: denied { remove_name } for pid=25859 comm="virtlogd" name="console.log" dev="0:39" ino=1898807 scontext=system_u:system_r:virtlogd_t:s0-s0:c0.c1023 tcontext=system_u:object_r:nfs_t:s0 tclass=dir
type=AVC msg=audit(1517276607.013:90227): avc: denied { write } for pid=25859 comm="virtlogd" name="e53cf7b4-e11a-445f-b4e3-006120e8d8006" dev="0:39" ino=1898806 scontext=system_u:system_r:virtlogd_t:s0-s0:c0.c1023 tcontext=system_u:object_r:nfs_t:s0 tclass=dir
(virtlogd attempting create)
time->Tue Jan 30 12:43:27 2018
type=PROCTITLE msg=audit(1517276607.018:90231): proctitle="/usr/sbin/virtlogd"
type=PATH msg=audit(1517276607.018:90231): item=1 name="/var/lib/nova/instances/e53cf7b4-e11a-445f-b4e3-006120e8d800/console.log" inode=1898807 dev=00:27 mode=0100600 ouid=0 ogid=99 rdev=00:00 obj=system_u:object_r:nfs_t:s0 objtype=NORMAL
type=PATH msg=audit(1517276607.018:90231): item=0 name="/var/lib/nova/instances/e53cf7b4-e11a-445f-b4e3-006120e8d800/" inode=1898806 dev=00:27 mode=040755 ouid=162 ogid=1100 rdev=00:00 obj=system_u:object_r:nfs_t:s0 objtype=PARENT
type=CWD msg=audit(1517276607.018:90231): cwd="/"
type=SYSCALL msg=audit(1517276607.018:90231): arch=c000003e syscall=2 success=yes exit=15 a0=7f406c000d30 a1=80441 a2=180 a3=7f406c000d90 items=2 ppid=1 pid=25859 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="virtlogd" exe="/usr/sbin/virtlogd" subj=system_u:system_r:virtlogd_t:s0-s0:c0.c1023
type=AVC msg=audit(1517276607.018:90231): avc: denied { create } for pid=25859 comm="virtlogd" name="console.log" scontext=system_u:system_r:virtlogd_t:s0-s0:c0.c1023 tcontext=system_u:object_r:nfs_t:s0 tclass=file
type=AVC msg=audit(1517276607.018:90231): avc: denied { add_name } for pid=25859 comm="virtlogd" name="console.log" scontext=system_u:system_r:virtlogd_t:s0-s0:c0.c1023 tcontext=system_u:object_r:nfs_t:s0 tclass=dir
Looks related to https:/