static int context_update_kernel_hostname(Context *c) { const char *static_hn; const char *hn; assert(c); static_hn = c->data[PROP_STATIC_HOSTNAME]; /* /etc/hostname with something other than "localhost" * has the highest preference ... */ if (hostname_is_useful(static_hn)) hn = static_hn; /* ... the transient host name, (ie: DHCP) comes next ... */ else if (!isempty(c->data[PROP_HOSTNAME])) hn = c->data[PROP_HOSTNAME]; /* ... fallback to static "localhost.*" ignored above ... */ else if (!isempty(static_hn)) hn = static_hn; /* ... and the ultimate fallback */ else hn = "localhost"; if (sethostname_idempotent(hn) < 0) return -errno; return 0; }
int hostname_setup(void) { int r; _cleanup_free_ char *b = NULL; const char *hn; bool enoent = false; r = read_hostname_config("/etc/hostname", &b); if (r < 0) { if (r == -ENOENT) enoent = true; else log_warning_errno(r, "Failed to read configured hostname: %m"); hn = NULL; } else hn = b; if (isempty(hn)) { /* Don't override the hostname if it is already set * and not explicitly configured */ if (hostname_is_set()) return 0; if (enoent) log_info("No hostname configured."); hn = "localhost"; } r = sethostname_idempotent(hn); if (r < 0) return log_warning_errno(r, "Failed to set hostname to <%s>: %m", hn); log_info("Set hostname to <%s>.", hn); return 0; }