terraform/terraform/upgrade_resource_state.go

204 lines
7.4 KiB
Go

package terraform
import (
"encoding/json"
"fmt"
"log"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/configs/configschema"
"github.com/hashicorp/terraform/providers"
"github.com/hashicorp/terraform/states"
"github.com/hashicorp/terraform/tfdiags"
"github.com/zclconf/go-cty/cty"
)
// upgradeResourceState will, if necessary, run the provider-defined upgrade
// logic against the given state object to make it compliant with the
// current schema version. This is a no-op if the given state object is
// already at the latest version.
//
// If any errors occur during upgrade, error diagnostics are returned. In that
// case it is not safe to proceed with using the original state object.
func upgradeResourceState(addr addrs.AbsResourceInstance, provider providers.Interface, src *states.ResourceInstanceObjectSrc, currentSchema *configschema.Block, currentVersion uint64) (*states.ResourceInstanceObjectSrc, tfdiags.Diagnostics) {
// Remove any attributes from state that are not present in the schema.
// This was previously taken care of by the provider, but data sources do
// not go through the UpgradeResourceState process.
//
// Legacy flatmap state is already taken care of during conversion.
// If the schema version is be changed, then allow the provider to handle
// removed attributes.
if len(src.AttrsJSON) > 0 && src.SchemaVersion == currentVersion {
src.AttrsJSON = stripRemovedStateAttributes(src.AttrsJSON, currentSchema.ImpliedType())
}
if addr.Resource.Resource.Mode != addrs.ManagedResourceMode {
// We only do state upgrading for managed resources.
return src, nil
}
stateIsFlatmap := len(src.AttrsJSON) == 0
// TODO: This should eventually use a proper FQN.
providerType := addr.Resource.Resource.ImpliedProvider()
if src.SchemaVersion > currentVersion {
log.Printf("[TRACE] upgradeResourceState: can't downgrade state for %s from version %d to %d", addr, src.SchemaVersion, currentVersion)
var diags tfdiags.Diagnostics
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Resource instance managed by newer provider version",
// This is not a very good error message, but we don't retain enough
// information in state to give good feedback on what provider
// version might be required here. :(
fmt.Sprintf("The current state of %s was created by a newer provider version than is currently selected. Upgrade the %s provider to work with this state.", addr, providerType),
))
return nil, diags
}
// If we get down here then we need to upgrade the state, with the
// provider's help.
// If this state was originally created by a version of Terraform prior to
// v0.12, this also includes translating from legacy flatmap to new-style
// representation, since only the provider has enough information to
// understand a flatmap built against an older schema.
if src.SchemaVersion != currentVersion {
log.Printf("[TRACE] upgradeResourceState: upgrading state for %s from version %d to %d using provider %q", addr, src.SchemaVersion, currentVersion, providerType)
} else {
log.Printf("[TRACE] upgradeResourceState: schema version of %s is still %d; calling provider %q for any other minor fixups", addr, currentVersion, providerType)
}
req := providers.UpgradeResourceStateRequest{
TypeName: addr.Resource.Resource.Type,
// TODO: The internal schema version representations are all using
// uint64 instead of int64, but unsigned integers aren't friendly
// to all protobuf target languages so in practice we use int64
// on the wire. In future we will change all of our internal
// representations to int64 too.
Version: int64(src.SchemaVersion),
}
if stateIsFlatmap {
req.RawStateFlatmap = src.AttrsFlat
} else {
req.RawStateJSON = src.AttrsJSON
}
resp := provider.UpgradeResourceState(req)
diags := resp.Diagnostics
if diags.HasErrors() {
return nil, diags
}
// After upgrading, the new value must conform to the current schema. When
// going over RPC this is actually already ensured by the
// marshaling/unmarshaling of the new value, but we'll check it here
// anyway for robustness, e.g. for in-process providers.
newValue := resp.UpgradedState
if errs := newValue.Type().TestConformance(currentSchema.ImpliedType()); len(errs) > 0 {
for _, err := range errs {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Invalid resource state upgrade",
fmt.Sprintf("The %s provider upgraded the state for %s from a previous version, but produced an invalid result: %s.", providerType, addr, tfdiags.FormatError(err)),
))
}
return nil, diags
}
new, err := src.CompleteUpgrade(newValue, currentSchema.ImpliedType(), uint64(currentVersion))
if err != nil {
// We already checked for type conformance above, so getting into this
// codepath should be rare and is probably a bug somewhere under CompleteUpgrade.
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Failed to encode result of resource state upgrade",
fmt.Sprintf("Failed to encode state for %s after resource schema upgrade: %s.", addr, tfdiags.FormatError(err)),
))
}
return new, diags
}
// stripRemovedStateAttributes deletes any attributes no longer present in the
// schema, so that the json can be correctly decoded.
func stripRemovedStateAttributes(state []byte, ty cty.Type) []byte {
jsonMap := map[string]interface{}{}
err := json.Unmarshal(state, &jsonMap)
if err != nil {
// we just log any errors here, and let the normal decode process catch
// invalid JSON.
log.Printf("[ERROR] UpgradeResourceState: %s", err)
return state
}
// if no changes were made, we return the original state to ensure nothing
// was altered in the marshaling process.
if !removeRemovedAttrs(jsonMap, ty) {
return state
}
js, err := json.Marshal(jsonMap)
if err != nil {
// if the json map was somehow mangled enough to not marhsal, something
// went horribly wrong
panic(err)
}
return js
}
// strip out the actual missing attributes, and return a bool indicating if any
// changes were made.
func removeRemovedAttrs(v interface{}, ty cty.Type) bool {
modified := false
// we're only concerned with finding maps that correspond to object
// attributes
switch v := v.(type) {
case []interface{}:
switch {
// If these aren't blocks the next call will be a noop
case ty.IsListType() || ty.IsSetType():
eTy := ty.ElementType()
for _, eV := range v {
modified = removeRemovedAttrs(eV, eTy) || modified
}
}
return modified
case map[string]interface{}:
switch {
case ty.IsMapType():
// map blocks aren't yet supported, but handle this just in case
eTy := ty.ElementType()
for _, eV := range v {
modified = removeRemovedAttrs(eV, eTy) || modified
}
return modified
case ty == cty.DynamicPseudoType:
log.Printf("[DEBUG] UpgradeResourceState: ignoring dynamic block: %#v\n", v)
return false
case ty.IsObjectType():
attrTypes := ty.AttributeTypes()
for attr, attrV := range v {
attrTy, ok := attrTypes[attr]
if !ok {
log.Printf("[DEBUG] UpgradeResourceState: attribute %q no longer present in schema", attr)
delete(v, attr)
modified = true
continue
}
modified = removeRemovedAttrs(attrV, attrTy) || modified
}
return modified
default:
// This shouldn't happen, and will fail to decode further on, so
// there's no need to handle it here.
log.Printf("[WARN] UpgradeResourceState: unexpected type %#v for map in json state", ty)
return false
}
}
return modified
}