python-lvm: Add example code for python-lvm.for-upstream

Basic example code for using python-lvm.

Originally written by agrover but fixed and improved by tasleson.

Signed-off-by: Andy Grover <agrover@redhat.com>

1 files changed, 107 insertions, 0 deletions

diff --git a/liblvm/python/example.py b/liblvm/python/example.py
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+++ b/liblvm/python/example.py
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+#-----------------------------
+#Python example code:
+#-----------------------------
+
+import lvm
+
+# Note: This example will create a logical unit, tag it and
+# 	delete it, don't run this on production box!
+
+#Dump information about PV
+def print_pv(pv):
+    print 'PV name: ', pv.getName(), ' ID: ', pv.getUuid(), 'Size: ', pv.getSize()
+
+
+#Dump some information about a specific volume group
+def print_vg(h, vg_name):
+    #Open read only
+    vg = h.vgOpen(vg_name, 'r')
+
+    print 'Volume group:', vg_name, 'Size: ', vg.getSize()
+
+    #Retrieve a list of Physical volumes for this volume group
+    pv_list = vg.listPVs()
+
+    #Print out the physical volumes
+    for p in pv_list:
+        print_pv(p)
+
+    #Get a list of logical volumes in this volume group
+    lv_list = vg.listLVs()
+    if len(lv_list):
+        for l in lv_list:
+            print 'LV name: ', l.getName(), ' ID: ', l.getUuid()
+    else:
+        print 'No logical volumes present!'
+
+    vg.close()
+
+#Returns the name of a vg with space available
+def find_vg_with_free_space(h):
+    free_space = 0
+    rc = None
+
+    vg_names = l.listVgNames()
+    for v in vg_names:
+        vg = h.vgOpen(v, 'r')
+        c_free = vg.getFreeSize()
+        if c_free > free_space:
+            free_space = c_free
+            rc = v
+        vg.close()
+
+    return rc
+
+#Walk through the volume groups and fine one with space in which we can
+#create a new logical volume
+def create_delete_logical_volume(h):
+    vg_name = find_vg_with_free_space(h)
+
+    print 'Using volume group ', vg_name, ' for example'
+
+    if vg_name:
+        vg = h.vgOpen(vg_name, 'w')
+        lv = vg.createLvLinear('python_lvm_ok_to_delete', vg.getFreeSize())
+
+        if lv:
+            print 'New lv, id= ', lv.getUuid()
+
+            #Create a tag
+            lv.addTag('Demo_tag')
+
+            #Get the tags
+            tags = lv.getTags()
+            for t in tags:
+                #Remove tag
+                lv.removeTag(t)
+
+            #Try to rename
+            lv.rename("python_lvm_ok_to_be_removed_shortly")
+            print 'LV name= ', lv.getName()
+
+            lv.deactivate()
+            lv.remove()
+
+        vg.close()
+    else:
+        print 'No free space available to create demo lv!'
+
+if __name__ == '__main__':
+    #Create a new LVM instance
+    l = lvm.Liblvm()
+
+    #What version
+    print 'lvm version=', l.getVersion()
+
+    #Get a list of volume group names
+    vg_names = l.listVgNames()
+
+    #For each volume group display some information about each of them
+    for vg_i in vg_names:
+        print_vg(l, vg_i)
+
+    #Demo creating a logical volume
+    create_delete_logical_volume(l)
+
+    #Close
+    l.close()