terraform/terraform/state_upgrade_v2_to_v3.go

143 lines
4.3 KiB
Go

package terraform
import (
"fmt"
"log"
"regexp"
"sort"
"strconv"
"strings"
)
// The upgrade process from V2 to V3 state does not affect the structure,
// so we do not need to redeclare all of the structs involved - we just
// take a deep copy of the old structure and assert the version number is
// as we expect.
func upgradeStateV2ToV3(old *State) (*State, error) {
new := old.DeepCopy()
// Ensure the copied version is v2 before attempting to upgrade
if new.Version != 2 {
return nil, fmt.Errorf("Cannot apply v2->v3 state upgrade to " +
"a state which is not version 2.")
}
// Set the new version number
new.Version = 3
// Change the counts for things which look like maps to use the %
// syntax. Remove counts for empty collections - they will be added
// back in later.
for _, module := range new.Modules {
for _, resource := range module.Resources {
// Upgrade Primary
if resource.Primary != nil {
upgradeAttributesV2ToV3(resource.Primary)
}
// Upgrade Deposed
if resource.Deposed != nil {
for _, deposed := range resource.Deposed {
upgradeAttributesV2ToV3(deposed)
}
}
}
}
return new, nil
}
func upgradeAttributesV2ToV3(instanceState *InstanceState) error {
collectionKeyRegexp := regexp.MustCompile(`^(.*\.)#$`)
collectionSubkeyRegexp := regexp.MustCompile(`^([^\.]+)\..*`)
// Identify the key prefix of anything which is a collection
var collectionKeyPrefixes []string
for key := range instanceState.Attributes {
if submatches := collectionKeyRegexp.FindAllStringSubmatch(key, -1); len(submatches) > 0 {
collectionKeyPrefixes = append(collectionKeyPrefixes, submatches[0][1])
}
}
sort.Strings(collectionKeyPrefixes)
log.Printf("[STATE UPGRADE] Detected the following collections in state: %v", collectionKeyPrefixes)
// This could be rolled into fewer loops, but it is somewhat clearer this way, and will not
// run very often.
for _, prefix := range collectionKeyPrefixes {
// First get the actual keys that belong to this prefix
var potentialKeysMatching []string
for key := range instanceState.Attributes {
if strings.HasPrefix(key, prefix) {
potentialKeysMatching = append(potentialKeysMatching, strings.TrimPrefix(key, prefix))
}
}
sort.Strings(potentialKeysMatching)
var actualKeysMatching []string
for _, key := range potentialKeysMatching {
if submatches := collectionSubkeyRegexp.FindAllStringSubmatch(key, -1); len(submatches) > 0 {
actualKeysMatching = append(actualKeysMatching, submatches[0][1])
} else {
if key != "#" {
actualKeysMatching = append(actualKeysMatching, key)
}
}
}
actualKeysMatching = uniqueSortedStrings(actualKeysMatching)
// Now inspect the keys in order to determine whether this is most likely to be
// a map, list or set. There is room for error here, so we log in each case. If
// there is no method of telling, we remove the key from the InstanceState in
// order that it will be recreated. Again, this could be rolled into fewer loops
// but we prefer clarity.
oldCountKey := fmt.Sprintf("%s#", prefix)
// First, detect "obvious" maps - which have non-numeric keys (mostly).
hasNonNumericKeys := false
for _, key := range actualKeysMatching {
if _, err := strconv.Atoi(key); err != nil {
hasNonNumericKeys = true
}
}
if hasNonNumericKeys {
newCountKey := fmt.Sprintf("%s%%", prefix)
instanceState.Attributes[newCountKey] = instanceState.Attributes[oldCountKey]
delete(instanceState.Attributes, oldCountKey)
log.Printf("[STATE UPGRADE] Detected %s as a map. Replaced count = %s",
strings.TrimSuffix(prefix, "."), instanceState.Attributes[newCountKey])
}
// Now detect empty collections and remove them from state.
if len(actualKeysMatching) == 0 {
delete(instanceState.Attributes, oldCountKey)
log.Printf("[STATE UPGRADE] Detected %s as an empty collection. Removed from state.",
strings.TrimSuffix(prefix, "."))
}
}
return nil
}
// uniqueSortedStrings removes duplicates from a slice of strings and returns
// a sorted slice of the unique strings.
func uniqueSortedStrings(input []string) []string {
uniquemap := make(map[string]struct{})
for _, str := range input {
uniquemap[str] = struct{}{}
}
output := make([]string, len(uniquemap))
i := 0
for key := range uniquemap {
output[i] = key
i = i + 1
}
sort.Strings(output)
return output
}