github.com/simonswine/terraform@v0.9.0-beta2/config/config_terraform.go (about)

     1  package config
     2  
     3  import (
     4  	"fmt"
     5  	"strings"
     6  
     7  	"github.com/hashicorp/go-version"
     8  	"github.com/mitchellh/hashstructure"
     9  )
    10  
    11  // Terraform is the Terraform meta-configuration that can be present
    12  // in configuration files for configuring Terraform itself.
    13  type Terraform struct {
    14  	RequiredVersion string   `hcl:"required_version"` // Required Terraform version (constraint)
    15  	Backend         *Backend // See Backend struct docs
    16  }
    17  
    18  // Validate performs the validation for just the Terraform configuration.
    19  func (t *Terraform) Validate() []error {
    20  	var errs []error
    21  
    22  	if raw := t.RequiredVersion; raw != "" {
    23  		// Check that the value has no interpolations
    24  		rc, err := NewRawConfig(map[string]interface{}{
    25  			"root": raw,
    26  		})
    27  		if err != nil {
    28  			errs = append(errs, fmt.Errorf(
    29  				"terraform.required_version: %s", err))
    30  		} else if len(rc.Interpolations) > 0 {
    31  			errs = append(errs, fmt.Errorf(
    32  				"terraform.required_version: cannot contain interpolations"))
    33  		} else {
    34  			// Check it is valid
    35  			_, err := version.NewConstraint(raw)
    36  			if err != nil {
    37  				errs = append(errs, fmt.Errorf(
    38  					"terraform.required_version: invalid syntax: %s", err))
    39  			}
    40  		}
    41  	}
    42  
    43  	if t.Backend != nil {
    44  		errs = append(errs, t.Backend.Validate()...)
    45  	}
    46  
    47  	return errs
    48  }
    49  
    50  // Backend is the configuration for the "backend" to use with Terraform.
    51  // A backend is responsible for all major behavior of Terraform's core.
    52  // The abstraction layer above the core (the "backend") allows for behavior
    53  // such as remote operation.
    54  type Backend struct {
    55  	Type      string
    56  	RawConfig *RawConfig
    57  
    58  	// Hash is a unique hash code representing the original configuration
    59  	// of the backend. This won't be recomputed unless Rehash is called.
    60  	Hash uint64
    61  }
    62  
    63  // Hash returns a unique content hash for this backend's configuration
    64  // as a uint64 value.
    65  func (b *Backend) Rehash() uint64 {
    66  	// If we have no backend, the value is zero
    67  	if b == nil {
    68  		return 0
    69  	}
    70  
    71  	// Use hashstructure to hash only our type with the config.
    72  	code, err := hashstructure.Hash(map[string]interface{}{
    73  		"type":   b.Type,
    74  		"config": b.RawConfig.Raw,
    75  	}, nil)
    76  
    77  	// This should never happen since we have just some basic primitives
    78  	// so panic if there is an error.
    79  	if err != nil {
    80  		panic(err)
    81  	}
    82  
    83  	return code
    84  }
    85  
    86  func (b *Backend) Validate() []error {
    87  	if len(b.RawConfig.Interpolations) > 0 {
    88  		return []error{fmt.Errorf(strings.TrimSpace(errBackendInterpolations))}
    89  	}
    90  
    91  	return nil
    92  }
    93  
    94  const errBackendInterpolations = `
    95  terraform.backend: configuration cannot contain interpolations
    96  
    97  The backend configuration is loaded by Terraform extremely early, before
    98  the core of Terraform can be initialized. This is necessary because the backend
    99  dictates the behavior of that core. The core is what handles interpolation
   100  processing. Because of this, interpolations cannot be used in backend
   101  configuration.
   102  
   103  If you'd like to parameterize backend configuration, we recommend using
   104  partial configuration with the "-backend-config" flag to "terraform init".
   105  `