[libvirt] [PATCH] daemon: add option to read host uuid from /etc/machine-id
Nikolay Shirokovskiy
nshirokovskiy at virtuozzo.com
Mon Apr 25 14:38:28 UTC 2016
Daemon config parameter switch between reading host uuid
either from smbios or machine-id:
host_uuid_source = "smbios|machine-id"
Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy at virtuozzo.com>
---
daemon/libvirtd-config.c | 2 ++
daemon/libvirtd-config.h | 1 +
daemon/libvirtd.c | 38 +++++++++++++++++++++++++++++++++++---
daemon/libvirtd.conf | 14 ++++++++++----
src/libvirt_private.syms | 1 +
src/util/viruuid.c | 31 ++++++++++++++++++++++---------
src/util/viruuid.h | 3 +++
7 files changed, 74 insertions(+), 16 deletions(-)
diff --git a/daemon/libvirtd-config.c b/daemon/libvirtd-config.c
index 7a448f9..45280e9 100644
--- a/daemon/libvirtd-config.c
+++ b/daemon/libvirtd-config.c
@@ -374,6 +374,7 @@ daemonConfigFree(struct daemonConfig *data)
VIR_FREE(data->crl_file);
VIR_FREE(data->host_uuid);
+ VIR_FREE(data->host_uuid_source);
VIR_FREE(data->log_filters);
VIR_FREE(data->log_outputs);
@@ -463,6 +464,7 @@ daemonConfigLoadOptions(struct daemonConfig *data,
GET_CONF_UINT(conf, filename, audit_logging);
GET_CONF_STR(conf, filename, host_uuid);
+ GET_CONF_STR(conf, filename, host_uuid_source);
GET_CONF_UINT(conf, filename, log_level);
GET_CONF_STR(conf, filename, log_filters);
diff --git a/daemon/libvirtd-config.h b/daemon/libvirtd-config.h
index 3e1971d..672e9ad 100644
--- a/daemon/libvirtd-config.h
+++ b/daemon/libvirtd-config.h
@@ -28,6 +28,7 @@
struct daemonConfig {
char *host_uuid;
+ char *host_uuid_source;
int listen_tls;
int listen_tcp;
diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c
index 7ec02ad..ca1ec7a 100644
--- a/daemon/libvirtd.c
+++ b/daemon/libvirtd.c
@@ -1076,6 +1076,39 @@ static int migrateProfile(void)
return ret;
}
+static int
+daemonSetupHostUUID(const struct daemonConfig *config)
+{
+ static const char *machine_id = "/etc/machine-id";
+ char buf[VIR_UUID_STRING_BUFLEN];
+ const char *uuid;
+
+ if (config->host_uuid) {
+ uuid = config->host_uuid;
+ } else if (!config->host_uuid_source ||
+ STREQ(config->host_uuid_source, "smbios")) {
+ /* set host uuid in lazy manner*/
+ return 0;
+ } else if (STREQ(config->host_uuid_source, "machine-id")) {
+ if (virUUIDRead(machine_id, buf, sizeof(buf)) < 0) {
+ VIR_ERROR(_("Can't read %s"), machine_id);
+ return -1;
+ }
+
+ uuid = buf;
+ } else {
+ VIR_ERROR(_("invalid UUID source: %s"), config->host_uuid_source);
+ return -1;
+ }
+
+ if (virSetHostUUIDStr(uuid)) {
+ VIR_ERROR(_("invalid host UUID: %s"), uuid);
+ return -1;
+ }
+
+ return 0;
+}
+
/* Print command-line usage. */
static void
daemonUsage(const char *argv0, bool privileged)
@@ -1295,9 +1328,8 @@ int main(int argc, char **argv) {
exit(EXIT_FAILURE);
}
- if (config->host_uuid &&
- virSetHostUUIDStr(config->host_uuid) < 0) {
- VIR_ERROR(_("invalid host UUID: %s"), config->host_uuid);
+ if (daemonSetupHostUUID(config) < 0) {
+ VIR_ERROR(_("Can't setup host uuid"));
exit(EXIT_FAILURE);
}
diff --git a/daemon/libvirtd.conf b/daemon/libvirtd.conf
index d2c439c..eaae680 100644
--- a/daemon/libvirtd.conf
+++ b/daemon/libvirtd.conf
@@ -410,10 +410,15 @@
###################################################################
# UUID of the host:
-# Provide the UUID of the host here in case the command
-# 'dmidecode -s system-uuid' does not provide a valid uuid. In case
-# 'dmidecode' does not provide a valid UUID and none is provided here, a
-# temporary UUID will be generated.
+# host uuid is read from one of host uuid sources specified
+# in host_uuid_source. Possible values are 'smbios' and 'machine-id'.
+# First option will set host uuid from 'dmidecode -s system-uuid',
+# while second will read it from /etc/machine-id. uuid source
+# defaults to smbios. Other option is to specify host uuid
+# right here in host_uuid option, in this case host_uuid_source
+# will not be taken into account. In case uuid value in
+# smbios is invalid temporary host uuid will be generated.
+#
# Keep the format of the example UUID below. UUID must not have all digits
# be the same.
@@ -421,6 +426,7 @@
# it with the output of the 'uuidgen' command and then
# uncomment this entry
#host_uuid = "00000000-0000-0000-0000-000000000000"
+#host_uuid_source = "smbios"
###################################################################
# Keepalive protocol:
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 2b55369..e5823b2 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2512,6 +2512,7 @@ virUUIDFormat;
virUUIDGenerate;
virUUIDIsValid;
virUUIDParse;
+virUUIDRead;
# util/virxml.h
diff --git a/src/util/viruuid.c b/src/util/viruuid.c
index 16e57db..721eac0 100644
--- a/src/util/viruuid.c
+++ b/src/util/viruuid.c
@@ -231,21 +231,34 @@ getDMISystemUUID(char *uuid, int len)
};
while (paths[i]) {
- int fd = open(paths[i], O_RDONLY);
- if (fd >= 0) {
- if (saferead(fd, uuid, len - 1) == len - 1) {
- uuid[len - 1] = '\0';
- VIR_FORCE_CLOSE(fd);
- return 0;
- }
- VIR_FORCE_CLOSE(fd);
- }
+ if (virUUIDRead(paths[i], uuid, len) == 0)
+ return 0;
i++;
}
return -1;
}
+int
+virUUIDRead(const char *file, char *uuid, int len)
+{
+ int fd;
+ ssize_t sz;
+
+ fd = open(file, O_RDONLY);
+ if (fd < 0)
+ return -1;
+
+ if ((sz = saferead(fd, uuid, len - 1)) < 0)
+ goto cleanup;
+
+ uuid[sz] = '\0';
+
+ cleanup:
+ VIR_FORCE_CLOSE(fd);
+ return sz < 0 ? -1 : 0;
+}
+
/**
* setHostUUID
diff --git a/src/util/viruuid.h b/src/util/viruuid.h
index 5790a17..94bf1ac 100644
--- a/src/util/viruuid.h
+++ b/src/util/viruuid.h
@@ -47,6 +47,9 @@
int virSetHostUUIDStr(const char *host_uuid);
int virGetHostUUID(unsigned char *host_uuid) ATTRIBUTE_NONNULL(1);
+int virUUIDRead(const char *file, char *uuid, int len)
+ ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+
int virUUIDIsValid(unsigned char *uuid);
int virUUIDGenerate(unsigned char *uuid);
--
1.8.3.1
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