[libvirt] [PATCH 2/2] lxc: set a hostname based on the container name

Set a transient hostname on containers. The hostname is computed from the container name, only keeping the valid characters [a-zA-Z0-9-] in it. This filtering is based on RFC 1123 and allows a digit to start the hostname. --- src/lxc/lxc_container.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c index b7216d6ee..96fceaf1b 100644 --- a/src/lxc/lxc_container.c +++ b/src/lxc/lxc_container.c @@ -2159,6 +2159,37 @@ static int lxcContainerSetUserGroup(virCommandPtr cmd, return 0; } +static const char hostname_validchars[] = + "abcdefghijklmnopqrstuvwxyz" + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "0123456789-"; + +static int lxcContainerSetHostname(virDomainDefPtr def) +{ + int ret = -1; + char *name = NULL; + char *hostname = NULL; + + /* Filter the VM name to get a valid hostname */ + if (VIR_STRDUP(name, def->name) < 0) + goto cleanup; + + /* RFC 1123 allows 0-9 digits as a first character in hostname */ + virStringFilterChars(name, hostname_validchars); + hostname = name; + if (strlen(name) > 0 && name[0] == '-') + hostname = name + 1; + + if (sethostname(hostname, strlen(hostname)) < 0) { + virReportSystemError(errno, "%s", _("Failed to set hostname")); + goto cleanup; + } + ret = 0; + + cleanup: + VIR_FREE(name); + return ret; +} /** * lxcContainerChild: @@ -2269,6 +2300,10 @@ static int lxcContainerChild(void *data) goto cleanup; } + if (lxcContainerSetHostname(vmDef) < 0) + goto cleanup; + + /* drop a set of root capabilities */ if (lxcContainerDropCapabilities(vmDef, !!hasReboot) < 0) goto cleanup; -- 2.15.1