environs: add configuration attributes and access

environs/interface.go

 package environs
 
 import (
         "errors"
         "io"
         "launchpad.net/juju-core/state"
 )
 
 // A EnvironProvider represents a computing and storage provider.
 type EnvironProvider interface {
         // NewConfig returns a new EnvironConfig representing the
         // environment with the given attributes.  Every provider must
         // accept the "name" and "type" keys, holding the name of the
         // environment and the provider type respectively.
         NewConfig(attrs map[string]interface{}) (EnvironConfig, error)
 }
 
 // EnvironConfig represents an environment's configuration.
 type EnvironConfig interface {
-        // Open opens the environment and returns it.
+        // DefaultSeries returns the default series of the configuration.
+        DefaultSeries() string
+
+        // AuthorizedKeys returns the SSH authorized keys of the
+        // environment in standard form.
+        AuthorizedKeys() string
+
+        // Name returns the environment name of the configuration.
+        Name() string
+
+        // Type returns the environment type of the configuration.
+        Type() string
+
+        // Attrs returns the attributes of the configuration.
+        Attrs() map[string]interface{}
+
+        // Change changes the given attributes of the configuration.
+        Change(attrs map[string]interface{}) error
+
+        // Clone returns a copy of the configuration.
+        Clone() EnvironConfig
+
+        // Open opens the environment with the given configuration,
+        // which must have been created with NewConfig.
         Open() (Environ, error)

[fwereade, 2012/07/13 16:08:14]

Still not wild on Open, but not especially bothered really.

 }
 
 var ErrNoDNSName = errors.New("DNS name not allocated")
 
 // Instance represents the provider-specific notion of a machine.
 type Instance interface {
         // Id returns a provider-generated identifier for the Instance.
         Id() string
 
         // DNSName returns the DNS name for the instance.
@@ skipping 79 matching lines @@
         // Name returns the Environ's name.
         Name() string
 
         // Bootstrap initializes the state for the environment,
         // possibly starting one or more instances.
         // If uploadTools is true, the current version of
         // the juju tools will be uploaded and used
         // on the environment's instances.
         Bootstrap(uploadTools bool) error
 
+        // Config returns the configuration of the environment.
+        Config() EnvironConfig

[fwereade, 2012/07/13 16:08:14]

Please no. I can't see any good reason for this at all, and IMO it shouldn't
even be possible to look at a Conn's Environ's config, because it is likely to
be wrong.

+
         // StateInfo returns information on the state initialized
         // by Bootstrap.
         StateInfo() (*state.Info, error)
 
         // SetConfig updates the Environs configuration.
         // Calls to SetConfig do not affect the configuration of
         // values previously obtained from Storage and PublicStorage.
         SetConfig(config EnvironConfig)
 
         // StartInstance asks for a new instance to be created,
@@ skipping 32 matching lines @@
         // yet be visible in the environment, so this method
         // can wait until they are.
         //
         // When Destroy has been called, any Environ referring to the
         // same remote environment may become invalid
         Destroy(insts []Instance) error
 
         // AssignmentPolicy returns the environment's unit assignment policy.
         AssignmentPolicy() state.AssignmentPolicy
 }