[libvirt] [PATCH 3/6] storage: netfs: Support lookup of glusterfs pool sources

[Peter Krempa]

https://bugzilla.redhat.com/show_bug.cgi?id=1072714

Use the "gluster" command line tool to retrieve information about remote
volumes on a gluster server to allow storage pool source lookup.

Unfortunately gluster doesn't provide a management library so that we
could use that directly, instead the RPC calls are hardcoded in the
command line tool.
---
 configure.ac                     |  6 +++
 src/storage/storage_backend.c    | 86 ++++++++++++++++++++++++++++++++++++++++
 src/storage/storage_backend.h    |  4 ++
 src/storage/storage_backend_fs.c |  5 +++
 4 files changed, 101 insertions(+)

diff --git a/configure.ac b/configure.ac
index 73efffa..b60da1c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1936,6 +1936,12 @@ if test "$with_storage_gluster" = "yes"; then
 fi
 AM_CONDITIONAL([WITH_STORAGE_GLUSTER], [test "$with_storage_gluster" = "yes"])

+if test "$with_storage_fs" = "yes" ||
+   test "$with_storage_gluster" = "yes"; then
+  AC_PATH_PROG([GLUSTER_CLI], [gluster], [], [$PATH:/sbin:/usr/sbin])
+  AC_DEFINE_UNQUOTED([GLUSTER_CLI], ["$GLUSTER_CLI"],
+    [Location or name of the gluster command line tool])
+fi

 LIBPARTED_CFLAGS=
 LIBPARTED_LIBS=
diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c
index 5b3b536..c7e4688 100644
--- a/src/storage/storage_backend.c
+++ b/src/storage/storage_backend.c
@@ -1640,3 +1640,89 @@ virStorageBackendStablePath(virStoragePoolObjPtr pool,

     return stablepath;
 }
+
+#ifdef GLUSTER_CLI
+int
+virStorageBackendFindGlusterPoolSources(const char *host,
+                                        int pooltype,
+                                        virStoragePoolSourceListPtr list)
+{
+    char *outbuf = NULL;
+    virCommandPtr cmd = NULL;
+    xmlDocPtr doc = NULL;
+    xmlXPathContextPtr ctxt = NULL;
+    xmlNodePtr *nodes = NULL;
+    virStoragePoolSource *src = NULL;
+    size_t i;
+    int nnodes;
+    int rc;
+
+    int ret = -1;
+
+    cmd = virCommandNewArgList(GLUSTER_CLI,
+                               "--xml",
+                               "--log-file=/dev/null",
+                               "volume", "info", "all", NULL);
+
+    virCommandAddArgFormat(cmd, "--remote-host=%s", host);
+    virCommandSetOutputBuffer(cmd, &outbuf);
+
+    if (virCommandRun(cmd, &rc) < 0)
+        goto cleanup;
+
+    if (rc != 0) {
+        VIR_INFO("failed to query host '%s' for gluster volumes: %s",
+                 host, outbuf);
+        ret = 0;
+        goto cleanup;
+    }
+
+    if (!(doc = virXMLParseStringCtxt(outbuf, _("(gluster_cli_output)"),
+                                      &ctxt)))
+        goto cleanup;
+
+    if ((nnodes = virXPathNodeSet("//volumes/volume", ctxt, &nodes)) <= 0) {
+        VIR_INFO("no gluster volumes available on '%s'", host);
+        ret = 0;
+        goto cleanup;
+    }
+
+    for (i = 0; i < nnodes; i++) {
+        ctxt->node = nodes[i];
+
+        if (!(src = virStoragePoolSourceListNewSource(list)))
+            goto cleanup;
+
+        if (!(src->dir = virXPathString("string(//name)", ctxt))) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("failed to extract gluster volume name"));
+            goto cleanup;
+        }
+
+        if (VIR_ALLOC_N(src->hosts, 1) < 0)
+            goto cleanup;
+        src->nhost = 1;
+
+        if (VIR_STRDUP(src->hosts[0].name, host) < 0)
+            goto cleanup;
+
+        src->format = pooltype;
+    }
+
+    ret = 0;
+
+ cleanup:
+    VIR_FREE(outbuf);
+    virCommandFree(cmd);
+    return ret;
+}
+#else /* #ifdef GLUSTER_CLI */
+int
+virStorageBackendFindGlusterPoolSources(const char *host ATTRIBUTE_UNUSED,
+                                        int pooltype ATTRIBUTE_UNUSED,
+                                        virStoragePoolSourceListPtr list ATTRIBUTE_UNUSED)
+{
+    VIR_INFO("gluster cli tool not installed");
+    return 0;
+}
+#endif /* #ifdef GLUSTER_CLI */
diff --git a/src/storage/storage_backend.h b/src/storage/storage_backend.h
index 2034a22..042ecfa 100644
--- a/src/storage/storage_backend.h
+++ b/src/storage/storage_backend.h
@@ -87,6 +87,10 @@ int virStorageBackendFindFSImageTool(char **tool);
 virStorageBackendBuildVolFrom
 virStorageBackendFSImageToolTypeToFunc(int tool_type);

+int virStorageBackendFindGlusterPoolSources(const char *host,
+                                            int pooltype,
+                                            virStoragePoolSourceListPtr list);
+

 typedef struct _virStorageBackend virStorageBackend;
 typedef virStorageBackend *virStorageBackendPtr;
diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c
index 8fb03c5..fd53691 100644
--- a/src/storage/storage_backend_fs.c
+++ b/src/storage/storage_backend_fs.c
@@ -316,6 +316,11 @@ virStorageBackendFileSystemNetFindPoolSources(virConnectPtr conn ATTRIBUTE_UNUSE

     virStorageBackendFileSystemNetFindNFSPoolSources(&state);

+    if (virStorageBackendFindGlusterPoolSources(state.host,
+                                                VIR_STORAGE_POOL_NETFS_GLUSTERFS,
+                                                &state.list) < 0)
+        goto cleanup;
+
     if (!(ret = virStoragePoolSourceListFormat(&state.list)))
         goto cleanup;

-- 
1.9.1