github.com/vtorhonen/terraform@v0.9.0-beta2.0.20170307220345-5d894e4ffda7/builtin/providers/consul/resource_consul_keys_migrate.go (about)

     1  package consul
     2  
     3  import (
     4  	"fmt"
     5  	"log"
     6  	"strings"
     7  
     8  	"github.com/hashicorp/terraform/helper/schema"
     9  	"github.com/hashicorp/terraform/terraform"
    10  )
    11  
    12  func resourceConsulKeysMigrateState(
    13  	v int, is *terraform.InstanceState, meta interface{}) (*terraform.InstanceState, error) {
    14  	switch v {
    15  	case 0:
    16  		log.Println("[INFO] Found consul_keys State v0; migrating to v1")
    17  		return resourceConsulKeysMigrateStateV0toV1(is)
    18  	default:
    19  		return is, fmt.Errorf("Unexpected schema version: %d", v)
    20  	}
    21  }
    22  
    23  func resourceConsulKeysMigrateStateV0toV1(is *terraform.InstanceState) (*terraform.InstanceState, error) {
    24  	if is.Empty() || is.Attributes == nil {
    25  		log.Println("[DEBUG] Empty InstanceState; nothing to migrate.")
    26  		return is, nil
    27  	}
    28  
    29  	log.Printf("[DEBUG] Attributes before migration: %#v", is.Attributes)
    30  
    31  	res := resourceConsulKeys()
    32  	keys, err := readV0Keys(is, res)
    33  	if err != nil {
    34  		return is, err
    35  	}
    36  	if err := clearV0Keys(is); err != nil {
    37  		return is, err
    38  	}
    39  	if err := writeV1Keys(is, res, keys); err != nil {
    40  		return is, err
    41  	}
    42  
    43  	log.Printf("[DEBUG] Attributes after migration: %#v", is.Attributes)
    44  	return is, nil
    45  }
    46  
    47  func readV0Keys(
    48  	is *terraform.InstanceState,
    49  	res *schema.Resource,
    50  ) (*schema.Set, error) {
    51  	reader := &schema.MapFieldReader{
    52  		Schema: res.Schema,
    53  		Map:    schema.BasicMapReader(is.Attributes),
    54  	}
    55  	result, err := reader.ReadField([]string{"key"})
    56  	if err != nil {
    57  		return nil, err
    58  	}
    59  
    60  	oldKeys, ok := result.Value.(*schema.Set)
    61  	if !ok {
    62  		return nil, fmt.Errorf("Got unexpected value from state: %#v", result.Value)
    63  	}
    64  	return oldKeys, nil
    65  }
    66  
    67  func clearV0Keys(is *terraform.InstanceState) error {
    68  	for k := range is.Attributes {
    69  		if strings.HasPrefix(k, "key.") {
    70  			delete(is.Attributes, k)
    71  		}
    72  	}
    73  	return nil
    74  }
    75  
    76  func writeV1Keys(
    77  	is *terraform.InstanceState,
    78  	res *schema.Resource,
    79  	keys *schema.Set,
    80  ) error {
    81  	writer := schema.MapFieldWriter{
    82  		Schema: res.Schema,
    83  	}
    84  	if err := writer.WriteField([]string{"key"}, keys); err != nil {
    85  		return err
    86  	}
    87  	for k, v := range writer.Map() {
    88  		is.Attributes[k] = v
    89  	}
    90  
    91  	return nil
    92  }