From: Julio Faracco <jcfaracco(a)gmail.com&gt; There is a lots of possibilities to retrieve hostname information from domain. Libvirt could use lease information from dnsmasq to get current hostname too. QEMU supports QEMU-agent but it can use lease source. See 'domifaddr' as an example. This commit still adds lease options for QEMU. It will get the first hostname available from domain networks. Signed-off-by: Julio Faracco <jcfaracco(a)gmail.com&gt; --- include/libvirt/libvirt-domain.h | 10 +++++ src/driver-hypervisor.h | 1 + src/libvirt-domain.c | 7 +++- src/openvz/openvz_driver.c | 30 +++++++++----- src/qemu/qemu_driver.c | 67 +++++++++++++++++++++++++++----- src/remote/remote_protocol.x | 1 + src/remote_protocol-structs | 1 + src/test/test_driver.c | 1 + tools/virsh-domain.c | 25 +++++++++++- 9 files changed, 120 insertions(+), 23 deletions(-) diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h index a2f007568c..cc3d6ed0ca 100644 --- a/include/libvirt/libvirt-domain.h +++ b/include/libvirt/libvirt-domain.h @@ -1554,6 +1554,7 @@ int virDomainGetMaxVcpus (virDomainPtr domain); int virDomainGetSecurityLabel (virDomainPtr domain, virSecurityLabelPtr seclabel); char * virDomainGetHostname (virDomainPtr domain, + unsigned int source, unsigned int flags); int virDomainGetSecurityLabelList (virDomainPtr domain, virSecurityLabelPtr* seclabels); @@ -4790,6 +4791,15 @@ typedef struct _virTypedParameter virMemoryParameter; */ typedef virMemoryParameter *virMemoryParameterPtr; +typedef enum { + VIR_DOMAIN_HOSTNAME_SRC_LEASE = 0, /* Parse DHCP lease file */ + VIR_DOMAIN_HOSTNAME_SRC_AGENT = 1, /* Query qemu guest agent */ + +# ifdef VIR_ENUM_SENTINELS + VIR_DOMAIN_HOSTNAME_SRC_LAST +# endif +} virDomainHostnameSource; + typedef enum { VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_LEASE = 0, /* Parse DHCP lease file */ VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_AGENT = 1, /* Query qemu guest agent */ diff --git a/src/driver-hypervisor.h b/src/driver-hypervisor.h index 4afd8f6ec5..6338a3ab73 100644 --- a/src/driver-hypervisor.h +++ b/src/driver-hypervisor.h @@ -156,6 +156,7 @@ typedef char * typedef char * (*virDrvDomainGetHostname)(virDomainPtr domain, + unsigned int source, unsigned int flags); typedef unsigned long long diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c index 51fb79cddd..6aa093d8af 100644 --- a/src/libvirt-domain.c +++ b/src/libvirt-domain.c @@ -11017,6 +11017,7 @@ virDomainGetDiskErrors(virDomainPtr dom, /** * virDomainGetHostname: * @domain: a domain object + * @source: one of the virDomainHostnameSource constants * @flags: extra flags; not used yet, so callers should always pass 0 * * Get the hostname for that domain. @@ -11028,7 +11029,9 @@ virDomainGetDiskErrors(virDomainPtr dom, * NULL if there was an error. */ char * -virDomainGetHostname(virDomainPtr domain, unsigned int flags) +virDomainGetHostname(virDomainPtr domain, + unsigned int source, + unsigned int flags) { virConnectPtr conn; @@ -11043,7 +11046,7 @@ virDomainGetHostname(virDomainPtr domain, unsigned int flags) if (conn->driver->domainGetHostname) { char *ret; - ret = conn->driver->domainGetHostname(domain, flags); + ret = conn->driver->domainGetHostname(domain, source, flags); if (!ret) goto error; return ret; diff --git a/src/openvz/openvz_driver.c b/src/openvz/openvz_driver.c index e07b3b302d..363eb5522a 100644 --- a/src/openvz/openvz_driver.c +++ b/src/openvz/openvz_driver.c @@ -295,7 +295,9 @@ openvzSetDiskQuota(virDomainDefPtr vmdef, static char * -openvzDomainGetHostname(virDomainPtr dom, unsigned int flags) +openvzDomainGetHostname(virDomainPtr dom, + unsigned int source, + unsigned int flags) { char *hostname = NULL; struct openvz_driver *driver = dom->conn->privateData; @@ -305,15 +307,25 @@ openvzDomainGetHostname(virDomainPtr dom, unsigned int flags) if (!(vm = openvzDomObjFromDomain(driver, dom->uuid))) return NULL; - hostname = openvzVEGetStringParam(dom, "hostname"); - if (hostname == NULL) - goto cleanup; + switch (source) { + default: + hostname = openvzVEGetStringParam(dom, "hostname"); + if (hostname == NULL) + goto cleanup; - /* vzlist prints an unset hostname as '-' */ - if (STREQ(hostname, "-")) { - virReportError(VIR_ERR_OPERATION_FAILED, - _("Hostname of '%s' is unset"), vm->def->name); - VIR_FREE(hostname); + /* vzlist prints an unset hostname as '-' */ + if (STREQ(hostname, "-")) { + virReportError(VIR_ERR_OPERATION_FAILED, + _("Hostname of '%s' is unset"), vm->def->name); + VIR_FREE(hostname); + } + break; + case VIR_DOMAIN_HOSTNAME_SRC_AGENT: + case VIR_DOMAIN_HOSTNAME_SRC_LEASE: + virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, + _("Unknown hostname data source %d"), + source); + break; } cleanup: diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 669c12d6ca..afcd5e8571 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -20085,11 +20085,17 @@ qemuConnectGetCPUModelNames(virConnectPtr conn, static char * qemuDomainGetHostname(virDomainPtr dom, + unsigned int source, unsigned int flags) { virQEMUDriverPtr driver = dom->conn->privateData; virDomainObjPtr vm = NULL; qemuAgentPtr agent; + char macaddr[VIR_MAC_STRING_BUFLEN]; + g_autoptr(virNetwork) network = NULL; + virNetworkDHCPLeasePtr *leases = NULL; + int n_leases; + size_t i, j; char *hostname = NULL; virCheckFlags(0, NULL); @@ -20100,21 +20106,62 @@ qemuDomainGetHostname(virDomainPtr dom, if (virDomainGetHostnameEnsureACL(dom->conn, vm->def) < 0) goto cleanup; - if (qemuDomainObjBeginAgentJob(driver, vm, QEMU_AGENT_JOB_QUERY) < 0) - goto cleanup; - if (virDomainObjCheckActive(vm) < 0) goto endjob; - if (!qemuDomainAgentAvailable(vm, true)) - goto endjob; + switch (source) { + default: + case VIR_DOMAIN_HOSTNAME_SRC_AGENT: + if (qemuDomainObjBeginAgentJob(driver, vm, QEMU_AGENT_JOB_QUERY) < 0) + goto cleanup; - agent = qemuDomainObjEnterAgent(vm); - ignore_value(qemuAgentGetHostname(agent, &hostname)); - qemuDomainObjExitAgent(vm, agent); + if (!qemuDomainAgentAvailable(vm, true)) + goto endjob; - endjob: - qemuDomainObjEndAgentJob(vm); + agent = qemuDomainObjEnterAgent(vm); + ignore_value(qemuAgentGetHostname(agent, &hostname)); + qemuDomainObjExitAgent(vm, agent); + + endjob: + qemuDomainObjEndAgentJob(vm); + break; + case VIR_DOMAIN_HOSTNAME_SRC_LEASE: + for (i = 0; i < vm->def->nnets; i++) { + if (vm->def->nets[i]->type != VIR_DOMAIN_NET_TYPE_NETWORK) + continue; + + virMacAddrFormat(&(vm->def->nets[i]->mac), macaddr); + virObjectUnref(network); + network = virNetworkLookupByName(dom->conn, + vm->def->nets[i]->data.network.name); + + if ((n_leases = virNetworkGetDHCPLeases(network, macaddr, + &leases, 0)) < 0) + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("There is no available hostname %d"), + source); + + for (j = 0; j < n_leases; j++) { + virNetworkDHCPLeasePtr lease = leases[j]; + if (lease->hostname) { + hostname = g_strdup(lease->hostname); + + for (j = 0; j < n_leases; j++) + virNetworkDHCPLeaseFree(leases[j]); + + VIR_FREE(leases); + + goto cleanup; + } + } + + for (j = 0; j < n_leases; j++) + virNetworkDHCPLeaseFree(leases[j]); + + VIR_FREE(leases); + } + break; + } cleanup: virDomainObjEndAPI(&vm); diff --git a/src/remote/remote_protocol.x b/src/remote/remote_protocol.x index 23e42d17b1..8d09f605da 100644 --- a/src/remote/remote_protocol.x +++ b/src/remote/remote_protocol.x @@ -1467,6 +1467,7 @@ struct remote_domain_get_cpu_stats_ret { struct remote_domain_get_hostname_args { remote_nonnull_domain dom; + unsigned int source; unsigned int flags; }; diff --git a/src/remote_protocol-structs b/src/remote_protocol-structs index 9ad7a857e0..dd9d1ec6fa 100644 --- a/src/remote_protocol-structs +++ b/src/remote_protocol-structs @@ -3543,4 +3543,5 @@ enum remote_procedure { REMOTE_PROC_DOMAIN_GET_GUEST_INFO = 418, REMOTE_PROC_CONNECT_SET_IDENTITY = 419, REMOTE_PROC_DOMAIN_AGENT_SET_RESPONSE_TIMEOUT = 420, + REMOTE_PROC_DOMAIN_GET_HOSTNAME = 421, }; diff --git a/src/test/test_driver.c b/src/test/test_driver.c index 5883722d60..0cbda81c67 100644 --- a/src/test/test_driver.c +++ b/src/test/test_driver.c @@ -2028,6 +2028,7 @@ testDomainReset(virDomainPtr dom, static char * testDomainGetHostname(virDomainPtr domain, + unsigned int source G_GNUC_UNUSED, unsigned int flags) { char *ret = NULL; diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index 6be9780836..141b141a10 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -11669,6 +11669,10 @@ static const vshCmdInfo info_domhostname[] = { static const vshCmdOptDef opts_domhostname[] = { VIRSH_COMMON_OPT_DOMAIN_FULL(VIR_CONNECT_LIST_DOMAINS_ACTIVE), + {.name = "source", + .type = VSH_OT_STRING, + .flags = VSH_OFLAG_NONE, + .help = N_("address source: 'lease' or 'agent'")}, {.name = NULL} }; @@ -11678,21 +11682,38 @@ cmdDomHostname(vshControl *ctl, const vshCmd *cmd) char *hostname; virDomainPtr dom; bool ret = false; + const char *sourcestr = NULL; + int source = -1; /* Use default value. Drivers can have its own default. */ if (!(dom = virshCommandOptDomain(ctl, cmd, NULL))) return false; - hostname = virDomainGetHostname(dom, 0); + if (vshCommandOptStringReq(ctl, cmd, "source", &sourcestr) < 0) + goto error; + + if (sourcestr) { + if (STREQ(sourcestr, "lease")) { + source = VIR_DOMAIN_HOSTNAME_SRC_LEASE; + } else if (STREQ(sourcestr, "agent")) { + source = VIR_DOMAIN_HOSTNAME_SRC_AGENT; + } else { + vshError(ctl, _("Unknown data source '%s'"), sourcestr); + goto error; + } + } + + hostname = virDomainGetHostname(dom, source, 0); if (hostname == NULL) { vshError(ctl, "%s", _("failed to get hostname")); goto error; } vshPrint(ctl, "%s\n", hostname); + + VIR_FREE(hostname); ret = true; error: - VIR_FREE(hostname); virshDomainFree(dom); return ret; } -- 2.20.1

On Sun, Nov 24, 2019 at 21:24:07 +0100, Peter Krempa wrote: More specifically we must never add or change parameters of existing APIs and data types as other applications using libvirt would fail to compile after the change.

From: Julio Faracco <jcfaracco(a)gmail.com&gt; Using lease information from dnsmasq, libvirt can retrieve hostname information. LXC documentation says that hostname can be 'lxc.uts.name', but if an user runs 'hostnamectl' and change hostname during container execution, it will reflect the command output. This option could fix this. Signed-off-by: Julio Faracco <jcfaracco(a)gmail.com&gt; --- src/lxc/lxc_driver.c | 71 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c index ea86451b09..999e74fcc8 100644 --- a/src/lxc/lxc_driver.c +++ b/src/lxc/lxc_driver.c @@ -5317,6 +5317,76 @@ lxcDomainGetCPUStats(virDomainPtr dom, return ret; } +static char * +lxcDomainGetHostname(virDomainPtr dom, + unsigned int source, + unsigned int flags) +{ + virDomainObjPtr vm = NULL; + char macaddr[VIR_MAC_STRING_BUFLEN]; + g_autoptr(virNetwork) network = NULL; + virNetworkDHCPLeasePtr *leases = NULL; + int n_leases; + size_t i, j; + char *hostname = NULL; + + virCheckFlags(0, NULL); + + if (!(vm = lxcDomObjFromDomain(dom))) + return NULL; + + if (virDomainGetHostnameEnsureACL(dom->conn, vm->def) < 0) + goto cleanup; + + switch (source) { + default: + case VIR_DOMAIN_HOSTNAME_SRC_LEASE: + for (i = 0; i < vm->def->nnets; i++) { + if (vm->def->nets[i]->type != VIR_DOMAIN_NET_TYPE_NETWORK) + continue; + + virMacAddrFormat(&(vm->def->nets[i]->mac), macaddr); + virObjectUnref(network); + network = virNetworkLookupByName(dom->conn, + vm->def->nets[i]->data.network.name); + + if ((n_leases = virNetworkGetDHCPLeases(network, macaddr, + &leases, 0)) < 0) + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("There is no available hostname %d"), + source); + + for (j = 0; j < n_leases; j++) { + virNetworkDHCPLeasePtr lease = leases[j]; + if (lease->hostname) { + hostname = g_strdup(lease->hostname); + + for (j = 0; j < n_leases; j++) + virNetworkDHCPLeaseFree(leases[j]); + + VIR_FREE(leases); + + goto cleanup; + } + } + + for (j = 0; j < n_leases; j++) + virNetworkDHCPLeaseFree(leases[j]); + + VIR_FREE(leases); + } + break; + case VIR_DOMAIN_HOSTNAME_SRC_AGENT: + virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, + _("Unknown hostname data source %d"), + source); + break; + } + + cleanup: + virDomainObjEndAPI(&vm); + return hostname; +} static int lxcNodeGetFreePages(virConnectPtr conn, @@ -5463,6 +5533,7 @@ static virHypervisorDriver lxcHypervisorDriver = { .domainSetMetadata = lxcDomainSetMetadata, /* 1.1.3 */ .domainGetMetadata = lxcDomainGetMetadata, /* 1.1.3 */ .domainGetCPUStats = lxcDomainGetCPUStats, /* 1.2.2 */ + .domainGetHostname = lxcDomainGetHostname, /* 5.9.0 */ .nodeGetMemoryParameters = lxcNodeGetMemoryParameters, /* 0.10.2 */ .nodeSetMemoryParameters = lxcNodeSetMemoryParameters, /* 0.10.2 */ .domainSendProcessSignal = lxcDomainSendProcessSignal, /* 1.0.1 */ -- 2.20.1