Enable passing of integer value for pool-set action

Enable passing of an integer to the pool-set function.  Due to how juju
appears to parse things on the command line, setting type to string
causes it to fail to accept '3', "3" or 3 as a string.  Only "'3'"
works.  However, if we remove the type from actions.yaml and do the
validation in the charm, any value can be passed.

Depends-On: I6081c23af61fd5e872982ff477b0a5cb27141d11

Change-Id: Idf3468d9ae28dafc09c86f08b7f8c6470a665b7a
Closes-Bug: #1838650

actions.yaml

@@ -256,7 +256,10 @@ pool-set:
       type: string
       description: "Any valid Ceph key from http://docs.ceph.com/docs/master/rados/operations/pools/#set-pool-values"
     value:
-      type: string
+      # LP: #1838650 - unfortunately, Juju appears to consider '3' on the
+      # command line as not being a string, and has to be quoted as "'3'".  So,
+      # we actually let the charm do the verification, and let any value
+      # through here.
       description: "The value to set"
   required:
     - key

actions/pool_set.py

@@ -32,7 +32,8 @@ if __name__ == '__main__':
                'value': value}
 
     try:
-        handle_set_pool_value(service='admin', request=request)
+        # Bug: #1838650 -- force coercion to an int for the value if required.
+        handle_set_pool_value(service='admin', request=request, coerce=True)
     except CalledProcessError as e:
         log(str(e))
         action_fail("Setting pool key: {} and value: {} failed with "

lib/charms_ceph/broker.py

@@ -540,11 +540,13 @@ def handle_remove_cache_tier(request, service):
     pool.remove_cache_tier(cache_pool=cache_pool)
 
 
-def handle_set_pool_value(request, service):
+def handle_set_pool_value(request, service, coerce=False):
     """Sets an arbitrary pool value.
 
     :param request: dict of request operations and params
     :param service: The ceph client to run the command under.
+    :param coerce: Try to parse/coerce the value into the correct type.
+                   Used by the action code that only gets Str from Juju
     :returns: dict. exit-code and reason if not 0
     """
     # Set arbitrary pool values
@@ -558,6 +560,16 @@ def handle_set_pool_value(request, service):
 
     # Get the validation method
     validator_params = POOL_KEYS[params['key']]
+    # BUG: #1838650 - the function needs to try to coerce the value param to
+    # the type required for the validator to pass.  Note, if this blows, then
+    # the param isn't parsable to the correct type.
+    if coerce:
+        try:
+            params['value'] = validator_params[0](params['value'])
+        except ValueError:
+            raise RuntimeError("Value {} isn't of type {}"
+                               .format(params['value'], validator_params[0]))
+    # end of BUG: #1838650
     if len(validator_params) == 1:
         # Validate that what the user passed is actually legal per Ceph's rules
         validator(params['value'], validator_params[0])