terraform/states/statefile/version2.go

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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/tfdiags"
)
func readStateV2(src []byte) (*File, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
sV2 := &stateV2{}
err := json.Unmarshal(src, sV2)
if err != nil {
diags = diags.Append(jsonUnmarshalDiags(err))
return nil, diags
}
file, prepDiags := prepareStateV2(sV2)
diags = diags.Append(prepDiags)
return file, diags
}
func prepareStateV2(sV2 *stateV2) (*File, tfdiags.Diagnostics) {
var diags tfdiags.Diagnostics
sV3, err := upgradeStateV2ToV3(sV2)
if err != nil {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
upgradeFailed,
fmt.Sprintf("Error upgrading state file format from version 2 to version 3: %s.", err),
))
return nil, diags
}
file, prepDiags := prepareStateV3(sV3)
diags = diags.Append(prepDiags)
return file, diags
}
// stateV2 is a representation of the legacy JSON state format version 2.
//
// It is only used to read version 2 JSON files prior to upgrading them to
// the current format.
type stateV2 struct {
// Version is the state file protocol version.
Version int `json:"version"`
// TFVersion is the version of Terraform that wrote this state.
TFVersion string `json:"terraform_version,omitempty"`
// Serial is incremented on any operation that modifies
// the State file. It is used to detect potentially conflicting
// updates.
Serial int64 `json:"serial"`
// Lineage is set when a new, blank state is created and then
// never updated. This allows us to determine whether the serials
// of two states can be meaningfully compared.
// Apart from the guarantee that collisions between two lineages
// are very unlikely, this value is opaque and external callers
// should only compare lineage strings byte-for-byte for equality.
Lineage string `json:"lineage"`
// Remote is used to track the metadata required to
// pull and push state files from a remote storage endpoint.
Remote *remoteStateV2 `json:"remote,omitempty"`
// Backend tracks the configuration for the backend in use with
// this state. This is used to track any changes in the backend
// configuration.
Backend *backendStateV2 `json:"backend,omitempty"`
// Modules contains all the modules in a breadth-first order
Modules []*moduleStateV2 `json:"modules"`
}
type remoteStateV2 struct {
// Type controls the client we use for the remote state
Type string `json:"type"`
// Config is used to store arbitrary configuration that
// is type specific
Config map[string]string `json:"config"`
}
type outputStateV2 struct {
// Sensitive describes whether the output is considered sensitive,
// which may lead to masking the value on screen in some cases.
Sensitive bool `json:"sensitive"`
// Type describes the structure of Value. Valid values are "string",
// "map" and "list"
Type string `json:"type"`
// Value contains the value of the output, in the structure described
// by the Type field.
Value interface{} `json:"value"`
}
type moduleStateV2 struct {
// Path is the import path from the root module. Modules imports are
// always disjoint, so the path represents amodule tree
Path []string `json:"path"`
// Locals are kept only transiently in-memory, because we can always
// re-compute them.
Locals map[string]interface{} `json:"-"`
// Outputs declared by the module and maintained for each module
// even though only the root module technically needs to be kept.
// This allows operators to inspect values at the boundaries.
Outputs map[string]*outputStateV2 `json:"outputs"`
// Resources is a mapping of the logically named resource to
// the state of the resource. Each resource may actually have
// N instances underneath, although a user only needs to think
// about the 1:1 case.
Resources map[string]*resourceStateV2 `json:"resources"`
// Dependencies are a list of things that this module relies on
// existing to remain intact. For example: an module may depend
// on a VPC ID given by an aws_vpc resource.
//
// Terraform uses this information to build valid destruction
// orders and to warn the user if they're destroying a module that
// another resource depends on.
//
// Things can be put into this list that may not be managed by
// Terraform. If Terraform doesn't find a matching ID in the
// overall state, then it assumes it isn't managed and doesn't
// worry about it.
Dependencies []string `json:"depends_on"`
}
type resourceStateV2 struct {
// This is filled in and managed by Terraform, and is the resource
// type itself such as "mycloud_instance". If a resource provider sets
// this value, it won't be persisted.
Type string `json:"type"`
// Dependencies are a list of things that this resource relies on
// existing to remain intact. For example: an AWS instance might
// depend on a subnet (which itself might depend on a VPC, and so
// on).
//
// Terraform uses this information to build valid destruction
// orders and to warn the user if they're destroying a resource that
// another resource depends on.
//
// Things can be put into this list that may not be managed by
// Terraform. If Terraform doesn't find a matching ID in the
// overall state, then it assumes it isn't managed and doesn't
// worry about it.
Dependencies []string `json:"depends_on"`
// Primary is the current active instance for this resource.
// It can be replaced but only after a successful creation.
// This is the instances on which providers will act.
Primary *instanceStateV2 `json:"primary"`
// Deposed is used in the mechanics of CreateBeforeDestroy: the existing
// Primary is Deposed to get it out of the way for the replacement Primary to
// be created by Apply. If the replacement Primary creates successfully, the
// Deposed instance is cleaned up.
//
// If there were problems creating the replacement Primary, the Deposed
// instance and the (now tainted) replacement Primary will be swapped so the
// tainted replacement will be cleaned up instead.
//
// An instance will remain in the Deposed list until it is successfully
// destroyed and purged.
Deposed []*instanceStateV2 `json:"deposed"`
// Provider is used when a resource is connected to a provider with an alias.
// If this string is empty, the resource is connected to the default provider,
// e.g. "aws_instance" goes with the "aws" provider.
// If the resource block contained a "provider" key, that value will be set here.
Provider string `json:"provider"`
}
type instanceStateV2 struct {
// A unique ID for this resource. This is opaque to Terraform
// and is only meant as a lookup mechanism for the providers.
ID string `json:"id"`
// Attributes are basic information about the resource. Any keys here
// are accessible in variable format within Terraform configurations:
// ${resourcetype.name.attribute}.
Attributes map[string]string `json:"attributes"`
// Meta is a simple K/V map that is persisted to the State but otherwise
// ignored by Terraform core. It's meant to be used for accounting by
// external client code. The value here must only contain Go primitives
// and collections.
Meta map[string]interface{} `json:"meta"`
// Tainted is used to mark a resource for recreation.
Tainted bool `json:"tainted"`
}
type backendStateV2 struct {
Type string `json:"type"` // Backend type
ConfigRaw json.RawMessage `json:"config"` // Backend raw config
Hash uint64 `json:"hash"` // Hash of portion of configuration from config files
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
}