github.com/codeherentuk/terraform@v0.11.12-beta1/terraform/semantics.go (about)

     1  package terraform
     2  
     3  import (
     4  	"fmt"
     5  	"strings"
     6  
     7  	"github.com/hashicorp/go-multierror"
     8  	"github.com/hashicorp/terraform/config"
     9  	"github.com/hashicorp/terraform/dag"
    10  )
    11  
    12  // GraphSemanticChecker is the interface that semantic checks across
    13  // the entire Terraform graph implement.
    14  //
    15  // The graph should NOT be modified by the semantic checker.
    16  type GraphSemanticChecker interface {
    17  	Check(*dag.Graph) error
    18  }
    19  
    20  // UnorderedSemanticCheckRunner is an implementation of GraphSemanticChecker
    21  // that runs a list of SemanticCheckers against the vertices of the graph
    22  // in no specified order.
    23  type UnorderedSemanticCheckRunner struct {
    24  	Checks []SemanticChecker
    25  }
    26  
    27  func (sc *UnorderedSemanticCheckRunner) Check(g *dag.Graph) error {
    28  	var err error
    29  	for _, v := range g.Vertices() {
    30  		for _, check := range sc.Checks {
    31  			if e := check.Check(g, v); e != nil {
    32  				err = multierror.Append(err, e)
    33  			}
    34  		}
    35  	}
    36  
    37  	return err
    38  }
    39  
    40  // SemanticChecker is the interface that semantic checks across the
    41  // Terraform graph implement. Errors are accumulated. Even after an error
    42  // is returned, child vertices in the graph will still be visited.
    43  //
    44  // The graph should NOT be modified by the semantic checker.
    45  //
    46  // The order in which vertices are visited is left unspecified, so the
    47  // semantic checks should not rely on that.
    48  type SemanticChecker interface {
    49  	Check(*dag.Graph, dag.Vertex) error
    50  }
    51  
    52  // smcUserVariables does all the semantic checks to verify that the
    53  // variables given satisfy the configuration itself.
    54  func smcUserVariables(c *config.Config, vs map[string]interface{}) []error {
    55  	var errs []error
    56  
    57  	cvs := make(map[string]*config.Variable)
    58  	for _, v := range c.Variables {
    59  		cvs[v.Name] = v
    60  	}
    61  
    62  	// Check that all required variables are present
    63  	required := make(map[string]struct{})
    64  	for _, v := range c.Variables {
    65  		if v.Required() {
    66  			required[v.Name] = struct{}{}
    67  		}
    68  	}
    69  	for k, _ := range vs {
    70  		delete(required, k)
    71  	}
    72  	if len(required) > 0 {
    73  		for k, _ := range required {
    74  			errs = append(errs, fmt.Errorf(
    75  				"Required variable not set: %s", k))
    76  		}
    77  	}
    78  
    79  	// Check that types match up
    80  	for name, proposedValue := range vs {
    81  		// Check for "map.key" fields. These stopped working with Terraform
    82  		// 0.7 but we do this to surface a better error message informing
    83  		// the user what happened.
    84  		if idx := strings.Index(name, "."); idx > 0 {
    85  			key := name[:idx]
    86  			if _, ok := cvs[key]; ok {
    87  				errs = append(errs, fmt.Errorf(
    88  					"%s: Overriding map keys with the format `name.key` is no "+
    89  						"longer allowed. You may still override keys by setting "+
    90  						"`name = { key = value }`. The maps will be merged. This "+
    91  						"behavior appeared in 0.7.0.", name))
    92  				continue
    93  			}
    94  		}
    95  
    96  		schema, ok := cvs[name]
    97  		if !ok {
    98  			continue
    99  		}
   100  
   101  		declaredType := schema.Type()
   102  
   103  		switch declaredType {
   104  		case config.VariableTypeString:
   105  			switch proposedValue.(type) {
   106  			case string:
   107  				continue
   108  			}
   109  		case config.VariableTypeMap:
   110  			switch v := proposedValue.(type) {
   111  			case map[string]interface{}:
   112  				continue
   113  			case []map[string]interface{}:
   114  				// if we have a list of 1 map, it will get coerced later as needed
   115  				if len(v) == 1 {
   116  					continue
   117  				}
   118  			}
   119  		case config.VariableTypeList:
   120  			switch proposedValue.(type) {
   121  			case []interface{}:
   122  				continue
   123  			}
   124  		}
   125  		errs = append(errs, fmt.Errorf("variable %s should be type %s, got %s",
   126  			name, declaredType.Printable(), hclTypeName(proposedValue)))
   127  	}
   128  
   129  	// TODO(mitchellh): variables that are unknown
   130  
   131  	return errs
   132  }