terraform/internal/states/statefile/version3.go

51 lines
1.3 KiB
Go
Raw Normal View History

statefile: New package for loading and saving state files Whereas the parent directory "states" contains the models that represent state in memory, this package's responsibility is in serializing a subset of that data to a JSON-based file format and then reloading that data back into memory later. For reading, this package supports state file formats going back to version 1, using lightly-adapted versions of the migration code previously used in the "terraform" package. State data is upgraded to the latest version step by step and then transformed into the in-memory state representation, which is distinct from any of the file format structs in this package to enable these to evolve separately. For writing, only the latest version (4) is supported, which is a new format that is a slightly-flattened version of the new in-memory state models introduced in the prior commit. This format retains the outputs from only the root module and it flattens out the module and instance parts of the hierarchy by including the identifiers for these inside the child object. The loader then reconstructs the multi-layer structure we use for more convenient access in memory. For now, the only testing in this package is of round-tripping different versions of state through a read and a write, ensuring the output is as desired. This exercises all of the reading, upgrading, and writing functions but should be augmented in later commits to improve coverage and introduce more focused tests for specific parts of the functionality.
2018-06-08 02:35:55 +02:00
package statefile
import (
"encoding/json"
"fmt"
"github.com/hashicorp/terraform/internal/tfdiags"
statefile: New package for loading and saving state files Whereas the parent directory "states" contains the models that represent state in memory, this package's responsibility is in serializing a subset of that data to a JSON-based file format and then reloading that data back into memory later. For reading, this package supports state file formats going back to version 1, using lightly-adapted versions of the migration code previously used in the "terraform" package. State data is upgraded to the latest version step by step and then transformed into the in-memory state representation, which is distinct from any of the file format structs in this package to enable these to evolve separately. For writing, only the latest version (4) is supported, which is a new format that is a slightly-flattened version of the new in-memory state models introduced in the prior commit. This format retains the outputs from only the root module and it flattens out the module and instance parts of the hierarchy by including the identifiers for these inside the child object. The loader then reconstructs the multi-layer structure we use for more convenient access in memory. For now, the only testing in this package is of round-tripping different versions of state through a read and a write, ensuring the output is as desired. This exercises all of the reading, upgrading, and writing functions but should be augmented in later commits to improve coverage and introduce more focused tests for specific parts of the functionality.
2018-06-08 02:35:55 +02:00
)
func readStateV3(src []byte) (*File, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
sV3 := &stateV3{}
err := json.Unmarshal(src, sV3)
if err != nil {
diags = diags.Append(jsonUnmarshalDiags(err))
return nil, diags
}
file, prepDiags := prepareStateV3(sV3)
diags = diags.Append(prepDiags)
return file, diags
}
func prepareStateV3(sV3 *stateV3) (*File, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
sV4, err := upgradeStateV3ToV4(sV3)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
upgradeFailed,
fmt.Sprintf("Error upgrading state file format from version 3 to version 4: %s.", err),
))
return nil, diags
}
file, prepDiags := prepareStateV4(sV4)
diags = diags.Append(prepDiags)
return file, diags
}
// stateV2 is a representation of the legacy JSON state format version 3.
//
// It is only used to read version 3 JSON files prior to upgrading them to
// the current format.
//
// The differences between version 2 and version 3 are only in the data and
// not in the structure, so stateV3 actually shares the same structs as
// stateV2. Type stateV3 represents that the data within is formatted as
// expected by the V3 format, rather than the V2 format.
type stateV3 stateV2