github.com/graywolf-at-work-2/terraform-vendor@v1.4.5/internal/cloud/migration.go (about)

     1  package cloud
     2  
     3  import (
     4  	"github.com/hashicorp/terraform/internal/configs"
     5  	legacy "github.com/hashicorp/terraform/internal/legacy/terraform"
     6  )
     7  
     8  // Most of the logic for migrating into and out of "cloud mode" actually lives
     9  // in the "command" package as part of the general backend init mechanisms,
    10  // but we have some cloud-specific helper functionality here.
    11  
    12  // ConfigChangeMode is a rough way to think about different situations that
    13  // our backend change and state migration codepaths need to distinguish in
    14  // the context of Cloud integration mode.
    15  type ConfigChangeMode rune
    16  
    17  //go:generate go run golang.org/x/tools/cmd/stringer -type ConfigChangeMode
    18  
    19  const (
    20  	// ConfigMigrationIn represents when the configuration calls for using
    21  	// Cloud mode but the working directory state disagrees.
    22  	ConfigMigrationIn ConfigChangeMode = '↘'
    23  
    24  	// ConfigMigrationOut represents when the working directory state calls
    25  	// for using Cloud mode but the working directory state disagrees.
    26  	ConfigMigrationOut ConfigChangeMode = '↖'
    27  
    28  	// ConfigChangeInPlace represents when both the working directory state
    29  	// and the config call for using Cloud mode, and so there might be
    30  	// (but won't necessarily be) cloud settings changing, but we don't
    31  	// need to do any actual migration.
    32  	ConfigChangeInPlace ConfigChangeMode = '↻'
    33  
    34  	// ConfigChangeIrrelevant represents when the config and working directory
    35  	// state disagree but neither calls for using Cloud mode, and so the
    36  	// Cloud integration is not involved in dealing with this.
    37  	ConfigChangeIrrelevant ConfigChangeMode = '🤷'
    38  )
    39  
    40  // DetectConfigChangeType encapsulates the fiddly logic for deciding what kind
    41  // of Cloud configuration change we seem to be making, based on the existing
    42  // working directory state (if any) and the current configuration.
    43  //
    44  // This is a pretty specialized sort of thing focused on finicky details of
    45  // the way we currently model working directory settings and config, so its
    46  // signature probably won't survive any non-trivial refactoring of how
    47  // the CLI layer thinks about backends/state storage.
    48  func DetectConfigChangeType(wdState *legacy.BackendState, config *configs.Backend, haveLocalStates bool) ConfigChangeMode {
    49  	// Although externally the cloud integration isn't really a "backend",
    50  	// internally we treat it a bit like one just to preserve all of our
    51  	// existing interfaces that assume backends. "cloud" is the placeholder
    52  	// name we use for it, even though that isn't a backend that's actually
    53  	// available for selection in the usual way.
    54  	wdIsCloud := wdState != nil && wdState.Type == "cloud"
    55  	configIsCloud := config != nil && config.Type == "cloud"
    56  
    57  	// "uninit" here means that the working directory is totally uninitialized,
    58  	// even taking into account the possibility of implied local state that
    59  	// therefore doesn't typically require explicit "terraform init".
    60  	wdIsUninit := wdState == nil && !haveLocalStates
    61  
    62  	switch {
    63  	case configIsCloud:
    64  		switch {
    65  		case wdIsCloud || wdIsUninit:
    66  			// If config has cloud and the working directory is completely
    67  			// uninitialized then we assume we're doing the initial activation
    68  			// of this working directory for an already-migrated-to-cloud
    69  			// remote state.
    70  			return ConfigChangeInPlace
    71  		default:
    72  			// Otherwise, we seem to be migrating into cloud mode from a backend.
    73  			return ConfigMigrationIn
    74  		}
    75  	default:
    76  		switch {
    77  		case wdIsCloud:
    78  			// If working directory is already cloud but config isn't, we're
    79  			// migrating away from cloud to a backend.
    80  			return ConfigMigrationOut
    81  		default:
    82  			// Otherwise, this situation seems to be something unrelated to
    83  			// cloud mode and so outside of our scope here.
    84  			return ConfigChangeIrrelevant
    85  		}
    86  	}
    87  
    88  }
    89  
    90  func (m ConfigChangeMode) InvolvesCloud() bool {
    91  	switch m {
    92  	case ConfigMigrationIn, ConfigMigrationOut, ConfigChangeInPlace:
    93  		return true
    94  	default:
    95  		return false
    96  	}
    97  }
    98  
    99  func (m ConfigChangeMode) IsCloudMigration() bool {
   100  	switch m {
   101  	case ConfigMigrationIn, ConfigMigrationOut:
   102  		return true
   103  	default:
   104  		return false
   105  	}
   106  }