package configs import ( "fmt" "github.com/hashicorp/terraform/internal/addrs" "github.com/hashicorp/hcl/v2" "github.com/zclconf/go-cty/cty" "github.com/zclconf/go-cty/cty/convert" ) // The methods in this file are used by Module.mergeFile to apply overrides // to our different configuration elements. These methods all follow the // pattern of mutating the receiver to incorporate settings from the parameter, // returning error diagnostics if any aspect of the parameter cannot be merged // into the receiver for some reason. // // User expectation is that anything _explicitly_ set in the given object // should take precedence over the corresponding settings in the receiver, // but that anything omitted in the given object should be left unchanged. // In some cases it may be reasonable to do a "deep merge" of certain nested // features, if it is possible to unambiguously correlate the nested elements // and their behaviors are orthogonal to each other. func (p *Provider) merge(op *Provider) hcl.Diagnostics { var diags hcl.Diagnostics if op.Version.Required != nil { p.Version = op.Version } p.Config = MergeBodies(p.Config, op.Config) return diags } func (v *Variable) merge(ov *Variable) hcl.Diagnostics { var diags hcl.Diagnostics if ov.DescriptionSet { v.Description = ov.Description v.DescriptionSet = ov.DescriptionSet } if ov.SensitiveSet { v.Sensitive = ov.Sensitive v.SensitiveSet = ov.SensitiveSet } if ov.Default != cty.NilVal { v.Default = ov.Default } if ov.Type != cty.NilType { v.Type = ov.Type } if ov.ParsingMode != 0 { v.ParsingMode = ov.ParsingMode } // If the override file overrode type without default or vice-versa then // it may have created an invalid situation, which we'll catch now by // attempting to re-convert the value. // // Note that here we may be re-converting an already-converted base value // from the base config. This will be a no-op if the type was not changed, // but in particular might be user-observable in the edge case where the // literal value in config could've been converted to the overridden type // constraint but the converted value cannot. In practice, this situation // should be rare since most of our conversions are interchangable. if v.Default != cty.NilVal { val, err := convert.Convert(v.Default, v.Type) if err != nil { // What exactly we'll say in the error message here depends on whether // it was Default or Type that was overridden here. switch { case ov.Type != cty.NilType && ov.Default == cty.NilVal: // If only the type was overridden diags = append(diags, &hcl.Diagnostic{ Severity: hcl.DiagError, Summary: "Invalid default value for variable", Detail: fmt.Sprintf("Overriding this variable's type constraint has made its default value invalid: %s.", err), Subject: &ov.DeclRange, }) case ov.Type == cty.NilType && ov.Default != cty.NilVal: // Only the default was overridden diags = append(diags, &hcl.Diagnostic{ Severity: hcl.DiagError, Summary: "Invalid default value for variable", Detail: fmt.Sprintf("The overridden default value for this variable is not compatible with the variable's type constraint: %s.", err), Subject: &ov.DeclRange, }) default: diags = append(diags, &hcl.Diagnostic{ Severity: hcl.DiagError, Summary: "Invalid default value for variable", Detail: fmt.Sprintf("This variable's default value is not compatible with its type constraint: %s.", err), Subject: &ov.DeclRange, }) } } else { v.Default = val } } return diags } func (l *Local) merge(ol *Local) hcl.Diagnostics { var diags hcl.Diagnostics // Since a local is just a single expression in configuration, the // override definition entirely replaces the base definition, including // the source range so that we'll send the user to the right place if // there is an error. l.Expr = ol.Expr l.DeclRange = ol.DeclRange return diags } func (o *Output) merge(oo *Output) hcl.Diagnostics { var diags hcl.Diagnostics if oo.Description != "" { o.Description = oo.Description } if oo.Expr != nil { o.Expr = oo.Expr } if oo.SensitiveSet { o.Sensitive = oo.Sensitive o.SensitiveSet = oo.SensitiveSet } // We don't allow depends_on to be overridden because that is likely to // cause confusing misbehavior. if len(oo.DependsOn) != 0 { diags = append(diags, &hcl.Diagnostic{ Severity: hcl.DiagError, Summary: "Unsupported override", Detail: "The depends_on argument may not be overridden.", Subject: oo.DependsOn[0].SourceRange().Ptr(), // the first item is the closest range we have }) } return diags } func (mc *ModuleCall) merge(omc *ModuleCall) hcl.Diagnostics { var diags hcl.Diagnostics if omc.SourceSet { mc.SourceAddr = omc.SourceAddr mc.SourceAddrRange = omc.SourceAddrRange mc.SourceSet = omc.SourceSet } if omc.Count != nil { mc.Count = omc.Count } if omc.ForEach != nil { mc.ForEach = omc.ForEach } if len(omc.Version.Required) != 0 { mc.Version = omc.Version } mc.Config = MergeBodies(mc.Config, omc.Config) if len(omc.Providers) != 0 { mc.Providers = omc.Providers } // We don't allow depends_on to be overridden because that is likely to // cause confusing misbehavior. if len(mc.DependsOn) != 0 { diags = append(diags, &hcl.Diagnostic{ Severity: hcl.DiagError, Summary: "Unsupported override", Detail: "The depends_on argument may not be overridden.", Subject: mc.DependsOn[0].SourceRange().Ptr(), // the first item is the closest range we have }) } return diags } func (r *Resource) merge(or *Resource, rps map[string]*RequiredProvider) hcl.Diagnostics { var diags hcl.Diagnostics if r.Mode != or.Mode { // This is always a programming error, since managed and data resources // are kept in separate maps in the configuration structures. panic(fmt.Errorf("can't merge %s into %s", or.Mode, r.Mode)) } if or.Count != nil { r.Count = or.Count } if or.ForEach != nil { r.ForEach = or.ForEach } if or.ProviderConfigRef != nil { r.ProviderConfigRef = or.ProviderConfigRef if existing, exists := rps[or.ProviderConfigRef.Name]; exists { r.Provider = existing.Type } else { r.Provider = addrs.ImpliedProviderForUnqualifiedType(r.ProviderConfigRef.Name) } } // Provider FQN is set by Terraform during Merge if r.Mode == addrs.ManagedResourceMode { // or.Managed is always non-nil for managed resource mode if or.Managed.Connection != nil { r.Managed.Connection = or.Managed.Connection } if or.Managed.CreateBeforeDestroySet { r.Managed.CreateBeforeDestroy = or.Managed.CreateBeforeDestroy r.Managed.CreateBeforeDestroySet = or.Managed.CreateBeforeDestroySet } if len(or.Managed.IgnoreChanges) != 0 { r.Managed.IgnoreChanges = or.Managed.IgnoreChanges } if or.Managed.PreventDestroySet { r.Managed.PreventDestroy = or.Managed.PreventDestroy r.Managed.PreventDestroySet = or.Managed.PreventDestroySet } if len(or.Managed.Provisioners) != 0 { r.Managed.Provisioners = or.Managed.Provisioners } } r.Config = MergeBodies(r.Config, or.Config) // We don't allow depends_on to be overridden because that is likely to // cause confusing misbehavior. if len(or.DependsOn) != 0 { diags = append(diags, &hcl.Diagnostic{ Severity: hcl.DiagError, Summary: "Unsupported override", Detail: "The depends_on argument may not be overridden.", Subject: or.DependsOn[0].SourceRange().Ptr(), // the first item is the closest range we have }) } return diags }