opentofu/command/state_meta.go
Alisdair McDiarmid c5c1f31db3 backend: Validate remote backend Terraform version
When using the enhanced remote backend, a subset of all Terraform
operations are supported. Of these, only plan and apply can be executed
on the remote infrastructure (e.g. Terraform Cloud). Other operations
run locally and use the remote backend for state storage.

This causes problems when the local version of Terraform does not match
the configured version from the remote workspace. If the two versions
are incompatible, an `import` or `state mv` operation can cause the
remote workspace to be unusable until a manual fix is applied.

To prevent this from happening accidentally, this commit introduces a
check that the local Terraform version and the configured remote
workspace Terraform version are compatible. This check is skipped for
commands which do not write state, and can also be disabled by the use
of a new command-line flag, `-ignore-remote-version`.

Terraform version compatibility is defined as:

- For all releases before 0.14.0, local must exactly equal remote, as
  two different versions cannot share state;
- 0.14.0 to 1.0.x are compatible, as we will not change the state
  version number until at least Terraform 1.1.0;
- Versions after 1.1.0 must have the same major and minor versions, as
  we will not change the state version number in a patch release.

If the two versions are incompatible, a diagnostic is displayed,
advising that the error can be suppressed with `-ignore-remote-version`.
When this flag is used, the diagnostic is still displayed, but as a
warning instead of an error.

Commands which will not write state can assert this fact by calling the
helper `meta.ignoreRemoteBackendVersionConflict`, which will disable the
checks. Those which can write state should instead call the helper
`meta.remoteBackendVersionCheck`, which will return diagnostics for
display.

In addition to these explicit paths for managing the version check, we
have an implicit check in the remote backend's state manager
initialization method. Both of the above helpers will disable this
check. This fallback is in place to ensure that future code paths which
access state cannot accidentally skip the remote version check.
2020-11-19 13:19:40 -05:00

216 lines
6.5 KiB
Go

package command
import (
"fmt"
"sort"
"time"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/states"
"github.com/hashicorp/terraform/states/statemgr"
"github.com/hashicorp/terraform/tfdiags"
backendLocal "github.com/hashicorp/terraform/backend/local"
)
// StateMeta is the meta struct that should be embedded in state subcommands.
type StateMeta struct {
Meta
}
// State returns the state for this meta. This gets the appropriate state from
// the backend, but changes the way that backups are done. This configures
// backups to be timestamped rather than just the original state path plus a
// backup path.
func (c *StateMeta) State() (statemgr.Full, error) {
var realState statemgr.Full
backupPath := c.backupPath
stateOutPath := c.statePath
// use the specified state
if c.statePath != "" {
realState = statemgr.NewFilesystem(c.statePath)
} else {
// Load the backend
b, backendDiags := c.Backend(nil)
if backendDiags.HasErrors() {
return nil, backendDiags.Err()
}
workspace, err := c.Workspace()
if err != nil {
return nil, err
}
// Check remote Terraform version is compatible
remoteVersionDiags := c.remoteBackendVersionCheck(b, workspace)
c.showDiagnostics(remoteVersionDiags)
if remoteVersionDiags.HasErrors() {
return nil, fmt.Errorf("Error checking remote Terraform version")
}
// Get the state
s, err := b.StateMgr(workspace)
if err != nil {
return nil, err
}
// Get a local backend
localRaw, backendDiags := c.Backend(&BackendOpts{ForceLocal: true})
if backendDiags.HasErrors() {
// This should never fail
panic(backendDiags.Err())
}
localB := localRaw.(*backendLocal.Local)
_, stateOutPath, _ = localB.StatePaths(workspace)
if err != nil {
return nil, err
}
realState = s
}
// We always backup state commands, so set the back if none was specified
// (the default is "-", but some tests bypass the flag parsing).
if backupPath == "-" || backupPath == "" {
// Determine the backup path. stateOutPath is set to the resulting
// file where state is written (cached in the case of remote state)
backupPath = fmt.Sprintf(
"%s.%d%s",
stateOutPath,
time.Now().UTC().Unix(),
DefaultBackupExtension)
}
// If the backend is local (which it should always be, given our asserting
// of it above) we can now enable backups for it.
if lb, ok := realState.(*statemgr.Filesystem); ok {
lb.SetBackupPath(backupPath)
}
return realState, nil
}
func (c *StateMeta) lookupResourceInstanceAddr(state *states.State, allowMissing bool, addrStr string) ([]addrs.AbsResourceInstance, tfdiags.Diagnostics) {
target, diags := addrs.ParseTargetStr(addrStr)
if diags.HasErrors() {
return nil, diags
}
targetAddr := target.Subject
var ret []addrs.AbsResourceInstance
switch addr := targetAddr.(type) {
case addrs.ModuleInstance:
// Matches all instances within the indicated module and all of its
// descendent modules.
ms := state.Module(addr)
if ms == nil {
if !allowMissing {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Unknown module",
fmt.Sprintf(`The current state contains no module at %s. If you've just added this module to the configuration, you must run "terraform apply" first to create the module's entry in the state.`, addr),
))
}
break
}
ret = append(ret, c.collectModuleResourceInstances(ms)...)
for _, cms := range state.Modules {
candidateAddr := ms.Addr
if len(candidateAddr) > len(addr) && candidateAddr[:len(addr)].Equal(addr) {
ret = append(ret, c.collectModuleResourceInstances(cms)...)
}
}
case addrs.AbsResource:
// Matches all instances of the specific selected resource.
rs := state.Resource(addr)
if rs == nil {
if !allowMissing {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Unknown resource",
fmt.Sprintf(`The current state contains no resource %s. If you've just added this resource to the configuration, you must run "terraform apply" first to create the resource's entry in the state.`, addr),
))
}
break
}
ret = append(ret, c.collectResourceInstances(addr.Module, rs)...)
case addrs.AbsResourceInstance:
is := state.ResourceInstance(addr)
if is == nil {
if !allowMissing {
diags = diags.Append(tfdiags.Sourceless(
tfdiags.Error,
"Unknown resource instance",
fmt.Sprintf(`The current state contains no resource instance %s. If you've just added its resource to the configuration or have changed the count or for_each arguments, you must run "terraform apply" first to update the resource's entry in the state.`, addr),
))
}
break
}
ret = append(ret, addr)
}
sort.Slice(ret, func(i, j int) bool {
return ret[i].Less(ret[j])
})
return ret, diags
}
func (c *StateMeta) lookupSingleStateObjectAddr(state *states.State, addrStr string) (addrs.Targetable, tfdiags.Diagnostics) {
target, diags := addrs.ParseTargetStr(addrStr)
if diags.HasErrors() {
return nil, diags
}
return target.Subject, diags
}
func (c *StateMeta) lookupResourceInstanceAddrs(state *states.State, addrStrs ...string) ([]addrs.AbsResourceInstance, tfdiags.Diagnostics) {
var ret []addrs.AbsResourceInstance
var diags tfdiags.Diagnostics
for _, addrStr := range addrStrs {
moreAddrs, moreDiags := c.lookupResourceInstanceAddr(state, false, addrStr)
ret = append(ret, moreAddrs...)
diags = diags.Append(moreDiags)
}
return ret, diags
}
func (c *StateMeta) lookupAllResourceInstanceAddrs(state *states.State) ([]addrs.AbsResourceInstance, tfdiags.Diagnostics) {
var ret []addrs.AbsResourceInstance
var diags tfdiags.Diagnostics
for _, ms := range state.Modules {
ret = append(ret, c.collectModuleResourceInstances(ms)...)
}
sort.Slice(ret, func(i, j int) bool {
return ret[i].Less(ret[j])
})
return ret, diags
}
func (c *StateMeta) collectModuleResourceInstances(ms *states.Module) []addrs.AbsResourceInstance {
var ret []addrs.AbsResourceInstance
for _, rs := range ms.Resources {
ret = append(ret, c.collectResourceInstances(ms.Addr, rs)...)
}
return ret
}
func (c *StateMeta) collectResourceInstances(moduleAddr addrs.ModuleInstance, rs *states.Resource) []addrs.AbsResourceInstance {
var ret []addrs.AbsResourceInstance
for key := range rs.Instances {
ret = append(ret, rs.Addr.Instance(key))
}
return ret
}
func (c *StateMeta) lookupAllResources(state *states.State) ([]*states.Resource, tfdiags.Diagnostics) {
var ret []*states.Resource
var diags tfdiags.Diagnostics
for _, ms := range state.Modules {
for _, resource := range ms.Resources {
ret = append(ret, resource)
}
}
return ret, diags
}