github.com/kcburge/terraform@v0.11.12-beta1/configs/version_constraint.go (about)

     1  package configs
     2  
     3  import (
     4  	"fmt"
     5  
     6  	version "github.com/hashicorp/go-version"
     7  	"github.com/hashicorp/hcl2/hcl"
     8  	"github.com/zclconf/go-cty/cty"
     9  	"github.com/zclconf/go-cty/cty/convert"
    10  )
    11  
    12  // VersionConstraint represents a version constraint on some resource
    13  // (e.g. Terraform Core, a provider, a module, ...) that carries with it
    14  // a source range so that a helpful diagnostic can be printed in the event
    15  // that a particular constraint does not match.
    16  type VersionConstraint struct {
    17  	Required  version.Constraints
    18  	DeclRange hcl.Range
    19  }
    20  
    21  func decodeVersionConstraint(attr *hcl.Attribute) (VersionConstraint, hcl.Diagnostics) {
    22  	ret := VersionConstraint{
    23  		DeclRange: attr.Range,
    24  	}
    25  
    26  	val, diags := attr.Expr.Value(nil)
    27  	var err error
    28  	val, err = convert.Convert(val, cty.String)
    29  	if err != nil {
    30  		diags = append(diags, &hcl.Diagnostic{
    31  			Severity: hcl.DiagError,
    32  			Summary:  "Invalid version constraint",
    33  			Detail:   fmt.Sprintf("A string value is required for %s.", attr.Name),
    34  			Subject:  attr.Expr.Range().Ptr(),
    35  		})
    36  		return ret, diags
    37  	}
    38  
    39  	if val.IsNull() {
    40  		// A null version constraint is strange, but we'll just treat it
    41  		// like an empty constraint set.
    42  		return ret, diags
    43  	}
    44  
    45  	constraintStr := val.AsString()
    46  	constraints, err := version.NewConstraint(constraintStr)
    47  	if err != nil {
    48  		// NewConstraint doesn't return user-friendly errors, so we'll just
    49  		// ignore the provided error and produce our own generic one.
    50  		diags = append(diags, &hcl.Diagnostic{
    51  			Severity: hcl.DiagError,
    52  			Summary:  "Invalid version constraint",
    53  			Detail:   "This string does not use correct version constraint syntax.", // Not very actionable :(
    54  			Subject:  attr.Expr.Range().Ptr(),
    55  		})
    56  		return ret, diags
    57  	}
    58  
    59  	ret.Required = constraints
    60  	return ret, diags
    61  }