terraform/terraform/resource_address.go

139 lines
3.3 KiB
Go

package terraform
import (
"fmt"
"reflect"
"regexp"
"strconv"
"strings"
)
// ResourceAddress is a way of identifying an individual resource (or,
// eventually, a subset of resources) within the state. It is used for Targets.
type ResourceAddress struct {
// Addresses a resource falling somewhere in the module path
// When specified alone, addresses all resources within a module path
Path []string
// Addresses a specific resource that occurs in a list
Index int
InstanceType InstanceType
Name string
Type string
}
func ParseResourceAddress(s string) (*ResourceAddress, error) {
matches, err := tokenizeResourceAddress(s)
if err != nil {
return nil, err
}
resourceIndex, err := ParseResourceIndex(matches["index"])
if err != nil {
return nil, err
}
instanceType, err := ParseInstanceType(matches["instance_type"])
if err != nil {
return nil, err
}
path := ParseResourcePath(matches["path"])
return &ResourceAddress{
Path: path,
Index: resourceIndex,
InstanceType: instanceType,
Name: matches["name"],
Type: matches["type"],
}, nil
}
func (addr *ResourceAddress) Equals(raw interface{}) bool {
other, ok := raw.(*ResourceAddress)
if !ok {
return false
}
pathMatch := ((len(addr.Path) == 0 && len(other.Path) == 0) ||
reflect.DeepEqual(addr.Path, other.Path))
indexMatch := (addr.Index == -1 ||
other.Index == -1 ||
addr.Index == other.Index)
nameMatch := (addr.Name == "" ||
other.Name == "" ||
addr.Name == other.Name)
typeMatch := (addr.Type == "" ||
other.Type == "" ||
addr.Type == other.Type)
return (pathMatch &&
indexMatch &&
addr.InstanceType == other.InstanceType &&
nameMatch &&
typeMatch)
}
func ParseResourceIndex(s string) (int, error) {
if s == "" {
return -1, nil
}
return strconv.Atoi(s)
}
func ParseResourcePath(s string) []string {
if s == "" {
return nil
}
parts := strings.Split(s, ".")
path := make([]string, 0, len(parts))
for _, s := range parts {
// Due to the limitations of the regexp match below, the path match has
// some noise in it we have to filter out :|
if s == "" || s == "module" {
continue
}
path = append(path, s)
}
return path
}
func ParseInstanceType(s string) (InstanceType, error) {
switch s {
case "", "primary":
return TypePrimary, nil
case "deposed":
return TypeDeposed, nil
case "tainted":
return TypeTainted, nil
default:
return TypeInvalid, fmt.Errorf("Unexpected value for InstanceType field: %q", s)
}
}
func tokenizeResourceAddress(s string) (map[string]string, error) {
// Example of portions of the regexp below using the
// string "aws_instance.web.tainted[1]"
re := regexp.MustCompile(`\A` +
// "module.foo.module.bar" (optional)
`(?P<path>(?:module\.[^.]+\.?)*)` +
// "aws_instance.web" (optional when module path specified)
`(?:(?P<type>[^.]+)\.(?P<name>[^.[]+))?` +
// "tainted" (optional, omission implies: "primary")
`(?:\.(?P<instance_type>\w+))?` +
// "1" (optional, omission implies: "0")
`(?:\[(?P<index>\d+)\])?` +
`\z`)
groupNames := re.SubexpNames()
rawMatches := re.FindAllStringSubmatch(s, -1)
if len(rawMatches) != 1 {
return nil, fmt.Errorf("Problem parsing address: %q", s)
}
matches := make(map[string]string)
for i, m := range rawMatches[0] {
matches[groupNames[i]] = m
}
return matches, nil
}