On 10/13/2011 04:53 AM, Daniel P. Berrange wrote:
From: "Daniel P. Berrange"<berrange@redhat.com>
I finally got fed up of typing URIs when using virsh....
This adds support for a libvirt client configuration file either /etc/libvirt/libvirt.conf for privileged clients, or $HOME/.libvirt/libvirt.conf for unprivileged clients.
Cool idea! Potential problem - our testsuite uses -c test:///default (or similar); there's a case where we _don't_ want to use alias lookup. But I guess if valid alias names cannot contain ':', then the presence of ':' in the target name is sufficient to prove that we don't want to use aliases. [This is a review as I go reply, so I'll see what the code actually does...]
+<h2> +<a name="URI_config">Configuring URI aliases</a> +</h2> + +<p> +To simplify live for administrators, it is possible to setup URI aliases in a
s/live/life/
+libvirt client configuration file. The configuration file is<code>/etc/libvirt/libvirt.conf</code> +for the root user, or<code>$HOME/.libvirt/libvirt.conf</code> for any unprivileged user.
Really? Shouldn't it instead be that /etc is for qemu:///system, and $HOME/.libvirt is for any user, _including root_, for qemu:///session.
+<p> + A URI alias should be a string made up from the characters +<code>a-Z, 0-9, _, -</code>. Following the<code>=</code> + can be any libvirt URI string, including arbitrary URI parameters. + URI aliases will apply to any application opening a libvirt + connection, unless it has explicitly passed the<code>VIR_CONNECT_NO_ALIASES</code> + parameter to<code>virConnectOpenAuth</code>.
Should we document that aliases are not consulted if the non-NULL connection name includes ':'?
+++ b/include/libvirt/libvirt.h.in @@ -843,7 +843,8 @@ typedef virNodeMemoryStats *virNodeMemoryStatsPtr; * Flags when opening a connection to a hypervisor */ typedef enum { - VIR_CONNECT_RO = 1, /* A readonly connection */ + VIR_CONNECT_RO = (1<< 0), /* A readonly connection */ + VIR_CONNECT_NO_ALIASES = (1<< 1), /* Don't try to resolve URI aliases */
At first glance, I didn't see a use for this bit: it seems like the decision to use aliases is unambiguous - if the name contains ':', there is no alias, and if it lacks ':', then the only way it can succeed is if an alias lookup is successful. Oh, I see - you use VIR_CONNECT_NO_ALIASES to force failure rather than attempt an alias lookup for the case where name has no ':'. Okay, it makes sense.
}
+static char * +virConnectConfigFile(void) +{ + char *path; + if (geteuid() == 0) { + if (virAsprintf(&path, "%s/libvirt/libvirt.conf", + SYSCONFDIR)< 0) + goto no_memory;
Hmm, while I asked above whether qemu:///session for root should use ~root/.libvirt, the code matches your documentation. So if you like my idea, then this needs a tweak (probably pass in a parameter for whether the connection itself is system vs. session).
+static int +virConnectOpenFindURIAliasMatch(virConfValuePtr value, const char *alias, char **uri) +{ + virConfValuePtr entry; + if (value->type != VIR_CONF_LIST) { + virLibConnError(VIR_ERR_INTERNAL_ERROR, "%s",
Fair enough - only a coding error would trigger this error.
+ _("Expected a list for 'uri_aliases' config parameter")); + return -1; + } + + entry = value->list; + while (entry) { + char *offset; + size_t safe; + + if (entry->type != VIR_CONF_STRING) { + virLibConnError(VIR_ERR_INTERNAL_ERROR, "%s",
Wouldn't VIR_ERR_CONF_SYNTAX go better here?
+ _("Expected a string for 'uri_aliases' config parameter list entry")); + return -1; + } + + if (!(offset = strchr(entry->str, '='))) { + virLibConnError(VIR_ERR_INTERNAL_ERROR,
and here
+ _("Malformed 'uri_aliases' config entry '%s', expected 'alias=uri://host/path'"), + entry->str); + return -1; + } + + safe = strspn(entry->str, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_-"); + if (safe< (offset - entry->str)) { + virLibConnError(VIR_ERR_INTERNAL_ERROR,
and here
+static int +virConnectOpenResolveURIAlias(const char *alias, char **uri) +{ + char *config = NULL; + int ret = -1; + virConfPtr conf = NULL; + virConfValuePtr value = NULL; + + *uri = NULL; + + /* Short circuit to avoid doing URI alias resolution + * when it clearly isn't an alias */ + if (strchr(alias, '/') || + strchr(alias, ':')) + return 0;
Aha, I was right - no alias lookup on full URIs.
diff --git a/src/libvirt.conf b/src/libvirt.conf new file mode 100644 index 0000000..ffe8c21 --- /dev/null +++ b/src/libvirt.conf @@ -0,0 +1,13 @@ +
Why a leading blank line? ACK with nits fixed. -- Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org