package schema import ( "reflect" "strings" "sync" "github.com/hashicorp/terraform/terraform" ) // ResourceData is used to query and set the attributes of a resource. // // ResourceData is the primary argument received for CRUD operations on // a resource as well as configuration of a provider. It is a powerful // structure that can be used to not only query data, but check for changes, // define partial state updates, etc. // // The most relevant methods to take a look at are Get, Set, and Partial. type ResourceData struct { // Settable (internally) schema map[string]*Schema config *terraform.ResourceConfig state *terraform.InstanceState diff *terraform.InstanceDiff // Don't set multiReader *MultiLevelFieldReader setWriter *MapFieldWriter newState *terraform.InstanceState partial bool partialMap map[string]struct{} once sync.Once } // getSource represents the level we want to get for a value (internally). // Any source less than or equal to the level will be loaded (whichever // has a value first). type getSource byte const ( getSourceState getSource = 1 << iota getSourceConfig getSourceDiff getSourceSet getSourceExact // Only get from the _exact_ level getSourceLevelMask getSource = getSourceState | getSourceConfig | getSourceDiff | getSourceSet ) // getResult is the internal structure that is generated when a Get // is called that contains some extra data that might be used. type getResult struct { Value interface{} ValueProcessed interface{} Computed bool Exists bool Schema *Schema } var getResultEmpty getResult // Get returns the data for the given key, or nil if the key doesn't exist // in the schema. // // If the key does exist in the schema but doesn't exist in the configuration, // then the default value for that type will be returned. For strings, this is // "", for numbers it is 0, etc. // // If you want to test if something is set at all in the configuration, // use GetOk. func (d *ResourceData) Get(key string) interface{} { v, _ := d.GetOk(key) return v } // GetChange returns the old and new value for a given key. // // HasChange should be used to check if a change exists. It is possible // that both the old and new value are the same if the old value was not // set and the new value is. This is common, for example, for boolean // fields which have a zero value of false. func (d *ResourceData) GetChange(key string) (interface{}, interface{}) { o, n := d.getChange(key, getSourceState, getSourceDiff|getSourceExact) return o.Value, n.Value } // GetOk returns the data for the given key and whether or not the key // has been set. // // The first result will not necessarilly be nil if the value doesn't exist. // The second result should be checked to determine this information. func (d *ResourceData) GetOk(key string) (interface{}, bool) { r := d.getRaw(key, getSourceSet) return r.Value, r.Exists && !r.Computed } func (d *ResourceData) getRaw(key string, level getSource) getResult { var parts []string if key != "" { parts = strings.Split(key, ".") } return d.get(parts, level) } // HasChange returns whether or not the given key has been changed. func (d *ResourceData) HasChange(key string) bool { o, n := d.GetChange(key) // If the type implements the Equal interface, then call that // instead of just doing a reflect.DeepEqual. An example where this is // needed is *Set if eq, ok := o.(Equal); ok { return !eq.Equal(n) } return !reflect.DeepEqual(o, n) } // Partial turns partial state mode on/off. // // When partial state mode is enabled, then only key prefixes specified // by SetPartial will be in the final state. This allows providers to return // partial states for partially applied resources (when errors occur). func (d *ResourceData) Partial(on bool) { d.partial = on if on { if d.partialMap == nil { d.partialMap = make(map[string]struct{}) } } else { d.partialMap = nil } } // Set sets the value for the given key. // // If the key is invalid or the value is not a correct type, an error // will be returned. func (d *ResourceData) Set(key string, value interface{}) error { d.once.Do(d.init) return d.setWriter.WriteField(strings.Split(key, "."), value) } // SetPartial adds the key to the final state output while // in partial state mode. The key must be a root key in the schema (i.e. // it cannot be "list.0"). // // If partial state mode is disabled, then this has no effect. Additionally, // whenever partial state mode is toggled, the partial data is cleared. func (d *ResourceData) SetPartial(k string) { if d.partial { d.partialMap[k] = struct{}{} } } // Id returns the ID of the resource. func (d *ResourceData) Id() string { var result string if d.state != nil { result = d.state.ID } if d.newState != nil { result = d.newState.ID } return result } // ConnInfo returns the connection info for this resource. func (d *ResourceData) ConnInfo() map[string]string { if d.newState != nil { return d.newState.Ephemeral.ConnInfo } if d.state != nil { return d.state.Ephemeral.ConnInfo } return nil } // SetId sets the ID of the resource. If the value is blank, then the // resource is destroyed. func (d *ResourceData) SetId(v string) { d.once.Do(d.init) d.newState.ID = v } // SetConnInfo sets the connection info for a resource. func (d *ResourceData) SetConnInfo(v map[string]string) { d.once.Do(d.init) d.newState.Ephemeral.ConnInfo = v } // State returns the new InstanceState after the diff and any Set // calls. func (d *ResourceData) State() *terraform.InstanceState { var result terraform.InstanceState result.ID = d.Id() // If we have no ID, then this resource doesn't exist and we just // return nil. if result.ID == "" { return nil } // In order to build the final state attributes, we read the full // attribute set as a map[string]interface{}, write it to a MapFieldWriter, // and then use that map. rawMap := make(map[string]interface{}) for k, _ := range d.schema { source := getSourceSet if d.partial { source = getSourceState if _, ok := d.partialMap[k]; ok { source = getSourceSet } } raw := d.get([]string{k}, source) if raw.Exists && !raw.Computed { rawMap[k] = raw.Value if raw.ValueProcessed != nil { rawMap[k] = raw.ValueProcessed } } } mapW := &MapFieldWriter{Schema: d.schema} if err := mapW.WriteField(nil, rawMap); err != nil { return nil } result.Attributes = mapW.Map() result.Ephemeral.ConnInfo = d.ConnInfo() // TODO: This is hacky and we can remove this when we have a proper // state writer. We should instead have a proper StateFieldWriter // and use that. for k, schema := range d.schema { if schema.Type != TypeMap { continue } if result.Attributes[k] == "" { delete(result.Attributes, k) } } if v := d.Id(); v != "" { result.Attributes["id"] = d.Id() } return &result } func (d *ResourceData) init() { // Initialize the field that will store our new state var copyState terraform.InstanceState if d.state != nil { copyState = *d.state } d.newState = ©State // Initialize the map for storing set data d.setWriter = &MapFieldWriter{Schema: d.schema} // Initialize the reader for getting data from the // underlying sources (config, diff, etc.) readers := make(map[string]FieldReader) var stateAttributes map[string]string if d.state != nil { stateAttributes = d.state.Attributes readers["state"] = &MapFieldReader{ Schema: d.schema, Map: BasicMapReader(stateAttributes), } } if d.config != nil { readers["config"] = &ConfigFieldReader{ Schema: d.schema, Config: d.config, } } if d.diff != nil { readers["diff"] = &DiffFieldReader{ Schema: d.schema, Diff: d.diff, Source: &MultiLevelFieldReader{ Levels: []string{"state", "config"}, Readers: readers, }, } } readers["set"] = &MapFieldReader{ Schema: d.schema, Map: BasicMapReader(d.setWriter.Map()), } d.multiReader = &MultiLevelFieldReader{ Levels: []string{ "state", "config", "diff", "set", }, Readers: readers, } } func (d *ResourceData) diffChange( k string) (interface{}, interface{}, bool, bool) { // Get the change between the state and the config. o, n := d.getChange(k, getSourceState, getSourceConfig|getSourceExact) if !o.Exists { o.Value = nil } if !n.Exists { n.Value = nil } // Return the old, new, and whether there is a change return o.Value, n.Value, !reflect.DeepEqual(o.Value, n.Value), n.Computed } func (d *ResourceData) getChange( key string, oldLevel getSource, newLevel getSource) (getResult, getResult) { var parts, parts2 []string if key != "" { parts = strings.Split(key, ".") parts2 = strings.Split(key, ".") } o := d.get(parts, oldLevel) n := d.get(parts2, newLevel) return o, n } func (d *ResourceData) get(addr []string, source getSource) getResult { d.once.Do(d.init) level := "set" flags := source & ^getSourceLevelMask exact := flags&getSourceExact != 0 source = source & getSourceLevelMask if source >= getSourceSet { level = "set" } else if source >= getSourceDiff { level = "diff" } else if source >= getSourceConfig { level = "config" } else { level = "state" } // Build the address of the key we're looking for and ask the FieldReader for i, v := range addr { if v[0] == '~' { addr[i] = v[1:] } } var result FieldReadResult var err error if exact { result, err = d.multiReader.ReadFieldExact(addr, level) } else { result, err = d.multiReader.ReadFieldMerge(addr, level) } if err != nil { panic(err) } // If the result doesn't exist, then we set the value to the zero value if result.Value == nil { if schemaL := addrToSchema(addr, d.schema); len(schemaL) > 0 { schema := schemaL[len(schemaL)-1] result.Value = result.ValueOrZero(schema) } } // Transform the FieldReadResult into a getResult. It might be worth // merging these two structures one day. return getResult{ Value: result.Value, ValueProcessed: result.ValueProcessed, Computed: result.Computed, Exists: result.Exists, } }