terraform/terraform/state_add.go

374 lines
11 KiB
Go

package terraform
import (
"fmt"
)
// Add adds the item in the state at the given address.
//
// The item can be a ModuleState, ResourceState, or InstanceState. Depending
// on the item type, the address may or may not be valid. For example, a
// module cannot be moved to a resource address, however a resource can be
// moved to a module address (it retains the same name, under that resource).
//
// The item can also be a []*ModuleState, which is the case for nested
// modules. In this case, Add will expect the zero-index to be the top-most
// module to add and will only nest children from there. For semantics, this
// is equivalent to module => module.
//
// The full semantics of Add:
//
// ┌───────────────────┬───────────────────┬───────────────────┐
// │ Module Address │ Resource Address │ Instance Address │
// ┌─────────────────┼───────────────────┼───────────────────┼───────────────────┤
// │ ModuleState │ ✓ │ x │ x │
// ├─────────────────┼───────────────────┼───────────────────┼───────────────────┤
// │ ResourceState │ ✓ │ ✓ │ maybe* │
// ├─────────────────┼───────────────────┼───────────────────┼───────────────────┤
// │ Instance State │ ✓ │ ✓ │ ✓ │
// └─────────────────┴───────────────────┴───────────────────┴───────────────────┘
//
// *maybe - Resources can be added at an instance address only if the resource
// represents a single instance (primary). Example:
// "aws_instance.foo" can be moved to "aws_instance.bar.tainted"
//
func (s *State) Add(fromAddrRaw string, toAddrRaw string, raw interface{}) error {
// Parse the address
toAddr, err := ParseResourceAddress(toAddrRaw)
if err != nil {
return err
}
// Parse the from address
fromAddr, err := ParseResourceAddress(fromAddrRaw)
if err != nil {
return err
}
// Determine the types
from := detectValueAddLoc(raw)
to := detectAddrAddLoc(toAddr)
// Find the function to do this
fromMap, ok := stateAddFuncs[from]
if !ok {
return fmt.Errorf("invalid source to add to state: %T", raw)
}
f, ok := fromMap[to]
if !ok {
return fmt.Errorf("invalid destination: %s (%d)", toAddr, to)
}
// Call the migrator
if err := f(s, fromAddr, toAddr, raw); err != nil {
return err
}
// Prune the state
s.prune()
return nil
}
func stateAddFunc_Module_Module(s *State, fromAddr, addr *ResourceAddress, raw interface{}) error {
// raw can be either *ModuleState or []*ModuleState. The former means
// we're moving just one module. The latter means we're moving a module
// and children.
root := raw
var rest []*ModuleState
if list, ok := raw.([]*ModuleState); ok {
// We need at least one item
if len(list) == 0 {
return fmt.Errorf("module move with no value to: %s", addr)
}
// The first item is always the root
root = list[0]
if len(list) > 1 {
rest = list[1:]
}
}
// Get the actual module state
src := root.(*ModuleState).deepcopy()
// If the target module exists, it is an error
path := append([]string{"root"}, addr.Path...)
if s.ModuleByPath(path) != nil {
return fmt.Errorf("module target is not empty: %s", addr)
}
// Create it and copy our outputs and dependencies
mod := s.AddModule(path)
mod.Outputs = src.Outputs
mod.Dependencies = src.Dependencies
// Go through the resources perform an add for each of those
for k, v := range src.Resources {
resourceKey, err := ParseResourceStateKey(k)
if err != nil {
return err
}
// Update the resource address for this
addrCopy := *addr
addrCopy.Type = resourceKey.Type
addrCopy.Name = resourceKey.Name
addrCopy.Index = resourceKey.Index
// Perform an add
if err := s.Add(fromAddr.String(), addrCopy.String(), v); err != nil {
return err
}
}
// Add all the children if we have them
for _, item := range rest {
// If item isn't a descendent of our root, then ignore it
if !src.IsDescendent(item) {
continue
}
// It is! Strip the leading prefix and attach that to our address
extra := item.Path[len(src.Path):]
addrCopy := addr.Copy()
addrCopy.Path = append(addrCopy.Path, extra...)
// Add it
s.Add(fromAddr.String(), addrCopy.String(), item)
}
return nil
}
func stateAddFunc_Resource_Module(
s *State, from, to *ResourceAddress, raw interface{}) error {
// Build the more specific to addr
addr := *to
addr.Type = from.Type
addr.Name = from.Name
return s.Add(from.String(), addr.String(), raw)
}
func stateAddFunc_Resource_Resource(s *State, fromAddr, addr *ResourceAddress, raw interface{}) error {
// raw can be either *ResourceState or []*ResourceState. The former means
// we're moving just one resource. The latter means we're moving a count
// of resources.
if list, ok := raw.([]*ResourceState); ok {
// We need at least one item
if len(list) == 0 {
return fmt.Errorf("resource move with no value to: %s", addr)
}
// If there is an index, this is an error since we can't assign
// a set of resources to a single index
if addr.Index >= 0 && len(list) > 1 {
return fmt.Errorf(
"multiple resources can't be moved to a single index: "+
"%s => %s", fromAddr, addr)
}
// Add each with a specific index
for i, rs := range list {
addrCopy := addr.Copy()
addrCopy.Index = i
if err := s.Add(fromAddr.String(), addrCopy.String(), rs); err != nil {
return err
}
}
return nil
}
src := raw.(*ResourceState).deepcopy()
// Initialize the resource
resourceRaw, exists := stateAddInitAddr(s, addr)
if exists {
return fmt.Errorf("resource exists and not empty: %s", addr)
}
resource := resourceRaw.(*ResourceState)
resource.Type = src.Type
resource.Dependencies = src.Dependencies
resource.Provider = src.Provider
// Move the primary
if src.Primary != nil {
addrCopy := *addr
addrCopy.InstanceType = TypePrimary
addrCopy.InstanceTypeSet = true
if err := s.Add(fromAddr.String(), addrCopy.String(), src.Primary); err != nil {
return err
}
}
// Move all deposed
if len(src.Deposed) > 0 {
resource.Deposed = src.Deposed
}
return nil
}
func stateAddFunc_Instance_Instance(s *State, fromAddr, addr *ResourceAddress, raw interface{}) error {
src := raw.(*InstanceState).DeepCopy()
// Create the instance
instanceRaw, _ := stateAddInitAddr(s, addr)
instance := instanceRaw.(*InstanceState)
// Set it
instance.Set(src)
return nil
}
func stateAddFunc_Instance_Module(
s *State, from, to *ResourceAddress, raw interface{}) error {
addr := *to
addr.Type = from.Type
addr.Name = from.Name
return s.Add(from.String(), addr.String(), raw)
}
func stateAddFunc_Instance_Resource(
s *State, from, to *ResourceAddress, raw interface{}) error {
addr := *to
addr.InstanceType = TypePrimary
addr.InstanceTypeSet = true
return s.Add(from.String(), addr.String(), raw)
}
// stateAddFunc is the type of function for adding an item to a state
type stateAddFunc func(s *State, from, to *ResourceAddress, item interface{}) error
// stateAddFuncs has the full matrix mapping of the state adders.
var stateAddFuncs map[stateAddLoc]map[stateAddLoc]stateAddFunc
func init() {
stateAddFuncs = map[stateAddLoc]map[stateAddLoc]stateAddFunc{
stateAddModule: {
stateAddModule: stateAddFunc_Module_Module,
},
stateAddResource: {
stateAddModule: stateAddFunc_Resource_Module,
stateAddResource: stateAddFunc_Resource_Resource,
},
stateAddInstance: {
stateAddInstance: stateAddFunc_Instance_Instance,
stateAddModule: stateAddFunc_Instance_Module,
stateAddResource: stateAddFunc_Instance_Resource,
},
}
}
// stateAddLoc is an enum to represent the location where state is being
// moved from/to. We use this for quick lookups in a function map.
type stateAddLoc uint
const (
stateAddInvalid stateAddLoc = iota
stateAddModule
stateAddResource
stateAddInstance
)
// detectAddrAddLoc detects the state type for the given address. This
// function is specifically not unit tested since we consider the State.Add
// functionality to be comprehensive enough to cover this.
func detectAddrAddLoc(addr *ResourceAddress) stateAddLoc {
if addr.Name == "" {
return stateAddModule
}
if !addr.InstanceTypeSet {
return stateAddResource
}
return stateAddInstance
}
// detectValueAddLoc determines the stateAddLoc value from the raw value
// that is some State structure.
func detectValueAddLoc(raw interface{}) stateAddLoc {
switch raw.(type) {
case *ModuleState:
return stateAddModule
case []*ModuleState:
return stateAddModule
case *ResourceState:
return stateAddResource
case []*ResourceState:
return stateAddResource
case *InstanceState:
return stateAddInstance
default:
return stateAddInvalid
}
}
// stateAddInitAddr takes a ResourceAddress and creates the non-existing
// resources up to that point, returning the empty (or existing) interface
// at that address.
func stateAddInitAddr(s *State, addr *ResourceAddress) (interface{}, bool) {
addType := detectAddrAddLoc(addr)
// Get the module
path := append([]string{"root"}, addr.Path...)
exists := true
mod := s.ModuleByPath(path)
if mod == nil {
mod = s.AddModule(path)
exists = false
}
if addType == stateAddModule {
return mod, exists
}
// Add the resource
resourceKey := (&ResourceStateKey{
Name: addr.Name,
Type: addr.Type,
Index: addr.Index,
}).String()
exists = true
resource, ok := mod.Resources[resourceKey]
if !ok {
resource = &ResourceState{Type: addr.Type}
resource.init()
mod.Resources[resourceKey] = resource
exists = false
}
if addType == stateAddResource {
return resource, exists
}
// Get the instance
exists = true
instance := &InstanceState{}
switch addr.InstanceType {
case TypePrimary, TypeTainted:
if v := resource.Primary; v != nil {
instance = resource.Primary
} else {
exists = false
}
case TypeDeposed:
idx := addr.Index
if addr.Index < 0 {
idx = 0
}
if len(resource.Deposed) > idx {
instance = resource.Deposed[idx]
} else {
resource.Deposed = append(resource.Deposed, instance)
exists = false
}
}
return instance, exists
}