Add filtering to ListServers APIs

nova/nova.go

 // The nova package provides a way to access the OpenStack Compute APIs.
 // See http://docs.openstack.org/api/openstack-compute/2/content/.
 package nova
 
 import (
         "encoding/base64"
         "fmt"
         "launchpad.net/goose/client"
         goosehttp "launchpad.net/goose/http"
         "net/http"
         "net/url"
 )
 
 const (
         apiFlavors            = "/flavors"
         apiFlavorsDetail      = "/flavors/detail"
         apiServers            = "/servers"
         apiServersDetail      = "/servers/detail"
         apiSecurityGroups     = "/os-security-groups"
         apiSecurityGroupRules = "/os-security-group-rules"
         apiFloatingIPs        = "/os-floating-ips"
 )
 
 const (

[jameinel, 2012/12/04 13:01:45]

I wonder if these should be typed as well as grouped as strings.
type Status string
StatusActive = Status("ACTIVE")
and such.
I don't know if we win much yet, but something to consider.

[wallyworld, 2012/12/05 00:46:41]

I considered it but then filter.Add(key, value) would need to cast value to
string each time and it didn't seem worth it. Filter uses an embedded url.Values
type and the Add() method comes from there. It takes string arguments. Also,
Add() is used for other filter keys like 'name' etc so it seems easier just to
keep everything as string.

         // Server status values.
         StatusActive       = "ACTIVE"        // The server is active.
         StatusBuild        = "BUILD"         // The server has not finished the original build process.
         StatusDeleted      = "DELETED"       // The server is deleted.
         StatusError        = "ERROR"         // The server is in error.
         StatusHardReboot   = "HARD_REBOOT"   // The server is hard rebooting.
         StatusPassword     = "PASSWORD"      // The password is being reset on the server.
         StatusReboot       = "REBOOT"        // The server is in a soft reboot state.
         StatusRebuild      = "REBUILD"       // The server is currently being rebuilt from an image.
         StatusRescue       = "RESCUE"        // The server is in rescue mode.
@@ skipping 24 matching lines @@
         return &Client{client}
 }
 
 // ----------------------------------------------------------------------------
 // Filtering helper.
 
 // Filter builds filtering parameters to be used in an OpenStack query which supports
 // filtering.  For example:
 //
 //     filter := NewFilter()
-//     filter.Add("name", "server_name")
-//     filter.Add("status", "ACTIVE")
+//     filter.Add(nova.FilterServer, "server_name")
+//     filter.Add(nova.FilterStatus, nova.StatusBuild)
 //     resp, err := nova.ListServers(filter)

[jameinel, 2012/12/04 13:01:45]

Maybe it wouldn't help, as we don't have "filter.AddStatus()" we just have
filter.Add(). Should we have typed Add?

[wallyworld, 2012/12/05 00:46:41]

Add is used for all sorts of filter keys: status, name etc. We could have
AddStatus(), AddName() etc for each, and these methods would call Add() after
casting the value to a string if required (eg name would be passed as a string
directly, status as a const). But I'm not sure it's worth it? Having said that,
the code comment above should have been "filter.Add(nova.FilterStatus,
nova.StatusActive)" which I will fix.

 //
 type Filter struct {
         url.Values
 }
 
 // NewFilter creates a new Filter.
 func NewFilter() *Filter {
         return &Filter{make(url.Values)}
 }
 
@@ skipping 386 matching lines @@
                 } `json:"removeFloatingIp"`
         }
         req.RemoveFloatingIP.Address = address
 
         url := fmt.Sprintf("%s/%s/action", apiServers, serverId)
         requestData := goosehttp.RequestData{ReqValue: req, ExpectedStatus: []int{http.StatusAccepted}}
         err := c.client.SendRequest(client.POST, "compute", url, &requestData,
                 "failed to remove floating ip %s to server %s", address, serverId)
         return err
 }