Various built-in provisioners improvements:

1. Migrate `chef` provisioner to `schema.Provisioner`:

 * `chef.Provisioner` structure was renamed to `ProvisionerS`and  now it's decoded from `schema.ResourceData` instead of `terraform.ResourceConfig` using simple copy-paste-based solution;
 * Added simple schema without any validation yet.

 2. Support `ValidateFunc` validate function : implemented in `file` and `chef` provisioners.

builtin/bins/provisioner-chef/main.go

@@ -3,13 +3,10 @@ package main
 import (
 	"github.com/hashicorp/terraform/builtin/provisioners/chef"
 	"github.com/hashicorp/terraform/plugin"
-	"github.com/hashicorp/terraform/terraform"
 )
 
 func main() {
 	plugin.Serve(&plugin.ServeOpts{
-		ProvisionerFunc: func() terraform.ResourceProvisioner {
+		ProvisionerFunc: chef.Provisioner,
-			return new(chef.ResourceProvisioner)
-		},
 	})
 }

builtin/provisioners/chef/linux_provisioner.go

@@ -14,7 +14,7 @@ const (
 	installURL = "https://www.chef.io/chef/install.sh"
 )
 
-func (p *Provisioner) linuxInstallChefClient(
+func (p *ProvisionerS) linuxInstallChefClient(
 	o terraform.UIOutput,
 	comm communicator.Communicator) error {
 
@@ -26,7 +26,7 @@ func (p *Provisioner) linuxInstallChefClient(
 	if p.HTTPSProxy != "" {
 		prefix += fmt.Sprintf("https_proxy='%s' ", p.HTTPSProxy)
 	}
-	if p.NOProxy != nil {
+	if p.NOProxy != nil && len(p.NOProxy) > 0 {
 		prefix += fmt.Sprintf("no_proxy='%s' ", strings.Join(p.NOProxy, ","))
 	}
 
@@ -46,7 +46,7 @@ func (p *Provisioner) linuxInstallChefClient(
 	return p.runCommand(o, comm, fmt.Sprintf("%srm -f install.sh", prefix))
 }
 
-func (p *Provisioner) linuxCreateConfigFiles(
+func (p *ProvisionerS) linuxCreateConfigFiles(
 	o terraform.UIOutput,
 	comm communicator.Communicator) error {
 	// Make sure the config directory exists

builtin/provisioners/chef/linux_provisioner_test.go

@@ -125,14 +125,13 @@ func TestResourceProvider_linuxInstallChefClient(t *testing.T) {
 		},
 	}
 
-	r := new(ResourceProvisioner)
 	o := new(terraform.MockUIOutput)
 	c := new(communicator.MockCommunicator)
 
 	for k, tc := range cases {
 		c.Commands = tc.Commands
 
-		p, err := r.decodeConfig(tc.Config)
+		p, err := decodeConfig(getTestResourceData(tc.Config))
 		if err != nil {
 			t.Fatalf("Error: %v", err)
 		}
@@ -264,7 +263,6 @@ func TestResourceProvider_linuxCreateConfigFiles(t *testing.T) {
 		},
 	}
 
-	r := new(ResourceProvisioner)
 	o := new(terraform.MockUIOutput)
 	c := new(communicator.MockCommunicator)
 
@@ -272,7 +270,7 @@ func TestResourceProvider_linuxCreateConfigFiles(t *testing.T) {
 		c.Commands = tc.Commands
 		c.Uploads = tc.Uploads
 
-		p, err := r.decodeConfig(tc.Config)
+		p, err := decodeConfig(getTestResourceData(tc.Config))
 		if err != nil {
 			t.Fatalf("Error: %v", err)
 		}

builtin/provisioners/chef/resource_provisioner.go

@@ -15,12 +15,13 @@ import (
 	"text/template"
 	"time"
 
+	"context"
 	"github.com/hashicorp/terraform/communicator"
 	"github.com/hashicorp/terraform/communicator/remote"
+	"github.com/hashicorp/terraform/helper/schema"
 	"github.com/hashicorp/terraform/terraform"
 	"github.com/mitchellh/go-homedir"
 	"github.com/mitchellh/go-linereader"
-	"github.com/mitchellh/mapstructure"
 )
 
 const (
@@ -81,36 +82,36 @@ enable_reporting false
 {{ end }}
 `
 
-// Provisioner represents a Chef provisioner
+// ProvisionerS represents a Chef provisioner
-type Provisioner struct {
+type ProvisionerS struct {
-	AttributesJSON        string   `mapstructure:"attributes_json"`
+	AttributesJSON        string
-	ClientOptions         []string `mapstructure:"client_options"`
+	ClientOptions         []string
-	DisableReporting      bool     `mapstructure:"disable_reporting"`
+	DisableReporting      bool
-	Environment           string   `mapstructure:"environment"`
+	Environment           string
-	FetchChefCertificates bool     `mapstructure:"fetch_chef_certificates"`
+	FetchChefCertificates bool
-	LogToFile             bool     `mapstructure:"log_to_file"`
+	LogToFile             bool
-	UsePolicyfile         bool     `mapstructure:"use_policyfile"`
+	UsePolicyfile         bool
-	PolicyGroup           string   `mapstructure:"policy_group"`
+	PolicyGroup           string
-	PolicyName            string   `mapstructure:"policy_name"`
+	PolicyName            string
-	HTTPProxy             string   `mapstructure:"http_proxy"`
+	HTTPProxy             string
-	HTTPSProxy            string   `mapstructure:"https_proxy"`
+	HTTPSProxy            string
-	NamedRunList          string   `mapstructure:"named_run_list"`
+	NamedRunList          string
-	NOProxy               []string `mapstructure:"no_proxy"`
+	NOProxy               []string
-	NodeName              string   `mapstructure:"node_name"`
+	NodeName              string
-	OhaiHints             []string `mapstructure:"ohai_hints"`
+	OhaiHints             []string
-	OSType                string   `mapstructure:"os_type"`
+	OSType                string
-	RecreateClient        bool     `mapstructure:"recreate_client"`
+	RecreateClient        bool
-	PreventSudo           bool     `mapstructure:"prevent_sudo"`
+	PreventSudo           bool
-	RunList               []string `mapstructure:"run_list"`
+	RunList               []string
-	SecretKey             string   `mapstructure:"secret_key"`
+	SecretKey             string
-	ServerURL             string   `mapstructure:"server_url"`
+	ServerURL             string
-	SkipInstall           bool     `mapstructure:"skip_install"`
+	SkipInstall           bool
-	SkipRegister          bool     `mapstructure:"skip_register"`
+	SkipRegister          bool
-	SSLVerifyMode         string   `mapstructure:"ssl_verify_mode"`
+	SSLVerifyMode         string
-	UserName              string   `mapstructure:"user_name"`
+	UserName              string
-	UserKey               string   `mapstructure:"user_key"`
+	UserKey               string
-	VaultJSON             string   `mapstructure:"vault_json"`
+	VaultJSON             string
-	Version               string   `mapstructure:"version"`
+	Version               string
 
 	attributes map[string]interface{}
 	vaults     map[string][]string
@@ -125,37 +126,179 @@ type Provisioner struct {
 	useSudo               bool
 
 	// Deprecated Fields
-	ValidationClientName string `mapstructure:"validation_client_name"`
+	ValidationClientName string
-	ValidationKey        string `mapstructure:"validation_key"`
+	ValidationKey        string
 }
 
-// ResourceProvisioner represents a generic chef provisioner
+func Provisioner() terraform.ResourceProvisioner {
-type ResourceProvisioner struct{}
+	return &schema.Provisioner{
+		Schema: map[string]*schema.Schema{
+			"attributes_json": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			"client_options": {
+				Type: schema.TypeList,
+				Elem: schema.Schema{
+					Type: schema.TypeString,
+				},
+				Optional: true,
+			},
+			"disable_reporting": {
+				Type:     schema.TypeBool,
+				Optional: true,
+			},
+			"environment": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			"fetch_chef_certificates": {
+				Type:     schema.TypeBool,
+				Optional: true,
+			},
+			"log_to_file": {
+				Type:     schema.TypeBool,
+				Optional: true,
+			},
+			"use_policyfile": {
+				Type:     schema.TypeBool,
+				Optional: true,
+			},
+			"policy_group": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			"policy_name": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			"http_proxy": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			"https_proxy": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			"no_proxy": {
+				Type: schema.TypeList,
+				Elem: schema.Schema{
+					Type:     schema.TypeString,
+					Optional: true,
+				},
+				Optional: true,
+			},
+			"named_run_list": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			"node_name": {
+				Type:     schema.TypeString,
+				Required: true,
+			},
+			"ohai_hints": {
+				Type: schema.TypeList,
+				Elem: schema.Schema{
+					Type:     schema.TypeString,
+					Optional: true,
+				},
+				Optional: true,
+			},
+			"os_type": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			"recreate_client": {
+				Type:     schema.TypeBool,
+				Optional: true,
+			},
+			"prevent_sudo": {
+				Type:     schema.TypeBool,
+				Optional: true,
+			},
+			"run_list": {
+				Type: schema.TypeList,
+				Elem: schema.Schema{
+					Type:     schema.TypeString,
+					Optional: true,
+				},
+				Optional: true,
+			},
+			"secret_key": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			"server_url": {
+				Type:     schema.TypeString,
+				Required: true,
+			},
+			"skip_install": {
+				Type:     schema.TypeBool,
+				Optional: true,
+			},
+			"skip_register": {
+				Type:     schema.TypeBool,
+				Optional: true,
+			},
+			"ssl_verify_mode": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			"user_name": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			"user_key": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			"vault_json": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
+			"version": {
+				Type:     schema.TypeString,
+				Optional: true,
+			},
 
-func (r *ResourceProvisioner) Stop() error {
+			// Deprecated
-	// Noop for now. TODO in the future.
+			"validation_client_name": {
-	return nil
+				Type:       schema.TypeString,
+				Deprecated: "Please use user_name instead",
+				Optional:   true,
+			},
+
+			"validation_key": {
+				Type:       schema.TypeString,
+				Deprecated: "Please use user_key instead",
+				Optional:   true,
+			},
+		},
+		ApplyFunc:    Apply,
+		ValidateFunc: Validate,
+	}
 }
 
+// TODO: Support context cancelling (Provisioner Stop)
 // Apply executes the file provisioner
-func (r *ResourceProvisioner) Apply(
+func Apply(ctx context.Context) error {
-	o terraform.UIOutput,
+	o := ctx.Value(schema.ProvOutputKey).(terraform.UIOutput)
-	s *terraform.InstanceState,
+	d := ctx.Value(schema.ProvConfigDataKey).(*schema.ResourceData)
-	c *terraform.ResourceConfig) error {
 	// Decode the raw config for this provisioner
-	p, err := r.decodeConfig(c)
+	p, err := decodeConfig(d)
 	if err != nil {
 		return err
 	}
 
 	if p.OSType == "" {
-		switch s.Ephemeral.ConnInfo["type"] {
+		t := d.State().Ephemeral.ConnInfo["type"]
+		switch t {
 		case "ssh", "": // The default connection type is ssh, so if the type is empty assume ssh
 			p.OSType = "linux"
 		case "winrm":
 			p.OSType = "windows"
 		default:
-			return fmt.Errorf("Unsupported connection type: %s", s.Ephemeral.ConnInfo["type"])
+			return fmt.Errorf("Unsupported connection type: %s", t)
 		}
 	}
 
@@ -169,7 +312,7 @@ func (r *ResourceProvisioner) Apply(
 		p.generateClientKey = p.generateClientKeyFunc(linuxKnifeCmd, linuxConfDir, linuxNoOutput)
 		p.configureVaults = p.configureVaultsFunc(linuxGemCmd, linuxKnifeCmd, linuxConfDir)
 		p.runChefClient = p.runChefClientFunc(linuxChefCmd, linuxConfDir)
-		p.useSudo = !p.PreventSudo && s.Ephemeral.ConnInfo["user"] != "root"
+		p.useSudo = !p.PreventSudo && d.State().Ephemeral.ConnInfo["user"] != "root"
 	case "windows":
 		p.cleanupUserKeyCmd = fmt.Sprintf("cd %s && del /F /Q %s", windowsConfDir, p.UserName+".pem")
 		p.createConfigFiles = p.windowsCreateConfigFiles
@@ -184,7 +327,7 @@ func (r *ResourceProvisioner) Apply(
 	}
 
 	// Get a new communicator
-	comm, err := communicator.New(s)
+	comm, err := communicator.New(d.State())
 	if err != nil {
 		return err
 	}
@@ -254,22 +397,16 @@ func (r *ResourceProvisioner) Apply(
 }
 
 // Validate checks if the required arguments are configured
-func (r *ResourceProvisioner) Validate(c *terraform.ResourceConfig) (ws []string, es []error) {
+func Validate(d *schema.ResourceData) (ws []string, es []error) {
-	p, err := r.decodeConfig(c)
+	p, err := decodeConfig(d)
 	if err != nil {
 		es = append(es, err)
 		return ws, es
 	}
 
-	if p.NodeName == "" {
-		es = append(es, errors.New("Key not found: node_name"))
-	}
 	if !p.UsePolicyfile && p.RunList == nil {
 		es = append(es, errors.New("Key not found: run_list"))
 	}
-	if p.ServerURL == "" {
-		es = append(es, errors.New("Key not found: server_url"))
-	}
 	if p.UsePolicyfile && p.PolicyName == "" {
 		es = append(es, errors.New("Policyfile enabled but key not found: policy_name"))
 	}
@@ -284,12 +421,7 @@ func (r *ResourceProvisioner) Validate(c *terraform.ResourceConfig) (ws []string
 		es = append(es, errors.New(
 			"One of user_key or the deprecated validation_key must be provided"))
 	}
-	if p.ValidationClientName != "" {
-		ws = append(ws, "validation_client_name is deprecated, please use user_name instead")
-	}
 	if p.ValidationKey != "" {
-		ws = append(ws, "validation_key is deprecated, please use user_key instead")
-
 		if p.RecreateClient {
 			es = append(es, errors.New(
 				"Cannot use recreate_client=true with the deprecated validation_key, please provide a user_key"))
@@ -303,38 +435,8 @@ func (r *ResourceProvisioner) Validate(c *terraform.ResourceConfig) (ws []string
 	return ws, es
 }
 
-func (r *ResourceProvisioner) decodeConfig(c *terraform.ResourceConfig) (*Provisioner, error) {
+func decodeConfig(d *schema.ResourceData) (*ProvisionerS, error) {
-	p := new(Provisioner)
+	p := decodeDataToProvisioner(d)
-
-	decConf := &mapstructure.DecoderConfig{
-		ErrorUnused:      true,
-		WeaklyTypedInput: true,
-		Result:           p,
-	}
-	dec, err := mapstructure.NewDecoder(decConf)
-	if err != nil {
-		return nil, err
-	}
-
-	// We need to merge both configs into a single map first. Order is
-	// important as we need to make sure interpolated values are used
-	// over raw values. This makes sure that all values are there even
-	// if some still need to be interpolated later on. Without this
-	// the validation will fail when using a variable for a required
-	// parameter (the node_name for example).
-	m := make(map[string]interface{})
-
-	for k, v := range c.Raw {
-		m[k] = v
-	}
-
-	for k, v := range c.Config {
-		m[k] = v
-	}
-
-	if err := dec.Decode(m); err != nil {
-		return nil, err
-	}
 
 	// Make sure the supplied URL has a trailing slash
 	p.ServerURL = strings.TrimSuffix(p.ServerURL, "/") + "/"
@@ -359,17 +461,17 @@ func (r *ResourceProvisioner) decodeConfig(c *terraform.ResourceConfig) (*Provis
 		p.UserKey = p.ValidationKey
 	}
 
-	if attrs, ok := c.Config["attributes_json"].(string); ok && !c.IsComputed("attributes_json") {
+	if attrs, ok := d.GetOk("attributes_json"); ok {
 		var m map[string]interface{}
-		if err := json.Unmarshal([]byte(attrs), &m); err != nil {
+		if err := json.Unmarshal([]byte(attrs.(string)), &m); err != nil {
 			return nil, fmt.Errorf("Error parsing attributes_json: %v", err)
 		}
 		p.attributes = m
 	}
 
-	if vaults, ok := c.Config["vault_json"].(string); ok && !c.IsComputed("vault_json") {
+	if vaults, ok := d.GetOk("vault_json"); ok {
 		var m map[string]interface{}
-		if err := json.Unmarshal([]byte(vaults), &m); err != nil {
+		if err := json.Unmarshal([]byte(vaults.(string)), &m); err != nil {
 			return nil, fmt.Errorf("Error parsing vault_json: %v", err)
 		}
 
@@ -395,7 +497,7 @@ func (r *ResourceProvisioner) decodeConfig(c *terraform.ResourceConfig) (*Provis
 	return p, nil
 }
 
-func (p *Provisioner) deployConfigFiles(
+func (p *ProvisionerS) deployConfigFiles(
 	o terraform.UIOutput,
 	comm communicator.Communicator,
 	confDir string) error {
@@ -469,7 +571,7 @@ func (p *Provisioner) deployConfigFiles(
 	return nil
 }
 
-func (p *Provisioner) deployOhaiHints(
+func (p *ProvisionerS) deployOhaiHints(
 	o terraform.UIOutput,
 	comm communicator.Communicator,
 	hintDir string) error {
@@ -490,7 +592,7 @@ func (p *Provisioner) deployOhaiHints(
 	return nil
 }
 
-func (p *Provisioner) fetchChefCertificatesFunc(
+func (p *ProvisionerS) fetchChefCertificatesFunc(
 	knifeCmd string,
 	confDir string) func(terraform.UIOutput, communicator.Communicator) error {
 	return func(o terraform.UIOutput, comm communicator.Communicator) error {
@@ -501,7 +603,7 @@ func (p *Provisioner) fetchChefCertificatesFunc(
 	}
 }
 
-func (p *Provisioner) generateClientKeyFunc(
+func (p *ProvisionerS) generateClientKeyFunc(
 	knifeCmd string,
 	confDir string,
 	noOutput string) func(terraform.UIOutput, communicator.Communicator) error {
@@ -562,7 +664,7 @@ func (p *Provisioner) generateClientKeyFunc(
 	}
 }
 
-func (p *Provisioner) configureVaultsFunc(
+func (p *ProvisionerS) configureVaultsFunc(
 	gemCmd string,
 	knifeCmd string,
 	confDir string) func(terraform.UIOutput, communicator.Communicator) error {
@@ -596,7 +698,7 @@ func (p *Provisioner) configureVaultsFunc(
 	}
 }
 
-func (p *Provisioner) runChefClientFunc(
+func (p *ProvisionerS) runChefClientFunc(
 	chefCmd string,
 	confDir string) func(terraform.UIOutput, communicator.Communicator) error {
 	return func(o terraform.UIOutput, comm communicator.Communicator) error {
@@ -634,7 +736,7 @@ func (p *Provisioner) runChefClientFunc(
 }
 
 // Output implementation of terraform.UIOutput interface
-func (p *Provisioner) Output(output string) {
+func (p *ProvisionerS) Output(output string) {
 	logFile := path.Join(logfileDir, p.NodeName)
 	f, err := os.OpenFile(logFile, os.O_APPEND|os.O_WRONLY, 0666)
 	if err != nil {
@@ -660,7 +762,7 @@ func (p *Provisioner) Output(output string) {
 }
 
 // runCommand is used to run already prepared commands
-func (p *Provisioner) runCommand(
+func (p *ProvisionerS) runCommand(
 	o terraform.UIOutput,
 	comm communicator.Communicator,
 	command string) error {
@@ -702,7 +804,7 @@ func (p *Provisioner) runCommand(
 	return err
 }
 
-func (p *Provisioner) copyOutput(o terraform.UIOutput, r io.Reader, doneCh chan<- struct{}) {
+func (p *ProvisionerS) copyOutput(o terraform.UIOutput, r io.Reader, doneCh chan<- struct{}) {
 	defer close(doneCh)
 	lr := linereader.New(r)
 	for line := range lr.Ch {
@@ -727,3 +829,58 @@ func retryFunc(timeout time.Duration, f func() error) error {
 		}
 	}
 }
+
+func decodeDataToProvisioner(d *schema.ResourceData) *ProvisionerS {
+	return &ProvisionerS{
+		AttributesJSON:        d.Get("attributes_json").(string),
+		ClientOptions:         getStringList(d.Get("client_options")),
+		DisableReporting:      d.Get("disable_reporting").(bool),
+		Environment:           d.Get("environment").(string),
+		FetchChefCertificates: d.Get("fetch_chef_certificates").(bool),
+		LogToFile:             d.Get("log_to_file").(bool),
+		UsePolicyfile:         d.Get("use_policyfile").(bool),
+		PolicyGroup:           d.Get("policy_group").(string),
+		PolicyName:            d.Get("policy_name").(string),
+		HTTPProxy:             d.Get("http_proxy").(string),
+		HTTPSProxy:            d.Get("https_proxy").(string),
+		NOProxy:               getStringList(d.Get("no_proxy")),
+		NamedRunList:          d.Get("named_run_list").(string),
+		NodeName:              d.Get("node_name").(string),
+		OhaiHints:             getStringList(d.Get("ohai_hints")),
+		OSType:                d.Get("os_type").(string),
+		RecreateClient:        d.Get("recreate_client").(bool),
+		PreventSudo:           d.Get("prevent_sudo").(bool),
+		RunList:               getStringList(d.Get("run_list")),
+		SecretKey:             d.Get("secret_key").(string),
+		ServerURL:             d.Get("server_url").(string),
+		SkipInstall:           d.Get("skip_install").(bool),
+		SkipRegister:          d.Get("skip_register").(bool),
+		SSLVerifyMode:         d.Get("ssl_verify_mode").(string),
+		UserName:              d.Get("user_name").(string),
+		UserKey:               d.Get("user_key").(string),
+		VaultJSON:             d.Get("vault_json").(string),
+		Version:               d.Get("version").(string),
+
+		// Deprecated
+		ValidationClientName: d.Get("validation_client_name").(string),
+		ValidationKey:        d.Get("validation_key").(string),
+	}
+}
+
+func getStringList(v interface{}) []string {
+	if v == nil {
+		return nil
+	}
+	switch l := v.(type) {
+	case []string:
+		return l
+	case []interface{}:
+		arr := make([]string, len(l))
+		for i, x := range l {
+			arr[i] = x.(string)
+		}
+		return arr
+	default:
+		panic(fmt.Sprintf("Unsupported type: %T", v))
+	}
+}

builtin/provisioners/chef/resource_provisioner_test.go

@@ -7,11 +7,18 @@ import (
 
 	"github.com/hashicorp/terraform/communicator"
 	"github.com/hashicorp/terraform/config"
+	"github.com/hashicorp/terraform/helper/schema"
 	"github.com/hashicorp/terraform/terraform"
 )
 
 func TestResourceProvisioner_impl(t *testing.T) {
-	var _ terraform.ResourceProvisioner = new(ResourceProvisioner)
+	var _ terraform.ResourceProvisioner = Provisioner()
+}
+
+func TestProvisioner(t *testing.T) {
+	if err := Provisioner().(*schema.Provisioner).InternalValidate(); err != nil {
+		t.Fatalf("err: %s", err)
+	}
 }
 
 func TestResourceProvider_Validate_good(t *testing.T) {
@@ -23,7 +30,7 @@ func TestResourceProvider_Validate_good(t *testing.T) {
 		"user_name":   "bob",
 		"user_key":    "USER-KEY",
 	})
-	r := new(ResourceProvisioner)
+	r := Provisioner()
 	warn, errs := r.Validate(c)
 	if len(warn) > 0 {
 		t.Fatalf("Warnings: %v", warn)
@@ -37,7 +44,7 @@ func TestResourceProvider_Validate_bad(t *testing.T) {
 	c := testConfig(t, map[string]interface{}{
 		"invalid": "nope",
 	})
-	p := new(ResourceProvisioner)
+	p := Provisioner()
 	warn, errs := p.Validate(c)
 	if len(warn) > 0 {
 		t.Fatalf("Warnings: %v", warn)
@@ -59,7 +66,7 @@ func TestResourceProvider_Validate_computedValues(t *testing.T) {
 		"user_key":        "USER-KEY",
 		"attributes_json": config.UnknownVariableValue,
 	})
-	r := new(ResourceProvisioner)
+	r := Provisioner()
 	warn, errs := r.Validate(c)
 	if len(warn) > 0 {
 		t.Fatalf("Warnings: %v", warn)
@@ -149,14 +156,13 @@ func TestResourceProvider_runChefClient(t *testing.T) {
 		},
 	}
 
-	r := new(ResourceProvisioner)
 	o := new(terraform.MockUIOutput)
 	c := new(communicator.MockCommunicator)
 
 	for k, tc := range cases {
 		c.Commands = tc.Commands
 
-		p, err := r.decodeConfig(tc.Config)
+		p, err := decodeConfig(getTestResourceData(tc.Config))
 		if err != nil {
 			t.Fatalf("Error: %v", err)
 		}
@@ -222,14 +228,13 @@ func TestResourceProvider_fetchChefCertificates(t *testing.T) {
 		},
 	}
 
-	r := new(ResourceProvisioner)
 	o := new(terraform.MockUIOutput)
 	c := new(communicator.MockCommunicator)
 
 	for k, tc := range cases {
 		c.Commands = tc.Commands
 
-		p, err := r.decodeConfig(tc.Config)
+		p, err := decodeConfig(getTestResourceData(tc.Config))
 		if err != nil {
 			t.Fatalf("Error: %v", err)
 		}
@@ -347,14 +352,13 @@ func TestResourceProvider_configureVaults(t *testing.T) {
 		},
 	}
 
-	r := new(ResourceProvisioner)
 	o := new(terraform.MockUIOutput)
 	c := new(communicator.MockCommunicator)
 
 	for k, tc := range cases {
 		c.Commands = tc.Commands
 
-		p, err := r.decodeConfig(tc.Config)
+		p, err := decodeConfig(getTestResourceData(tc.Config))
 		if err != nil {
 			t.Fatalf("Error: %v", err)
 		}
@@ -368,3 +372,7 @@ func TestResourceProvider_configureVaults(t *testing.T) {
 		}
 	}
 }
+
+func getTestResourceData(c *terraform.ResourceConfig) *schema.ResourceData {
+	return schema.TestResourceDataConfig(Provisioner().(*schema.Provisioner).Schema, c)
+}

builtin/provisioners/chef/windows_provisioner.go

@@ -46,7 +46,7 @@ Write-Host 'Installing Chef Client...'
 Start-Process -FilePath msiexec -ArgumentList /qn, /i, $dest -Wait
 `
 
-func (p *Provisioner) windowsInstallChefClient(
+func (p *ProvisionerS) windowsInstallChefClient(
 	o terraform.UIOutput,
 	comm communicator.Communicator) error {
 	script := path.Join(path.Dir(comm.ScriptPath()), "ChefClient.ps1")
@@ -62,7 +62,7 @@ func (p *Provisioner) windowsInstallChefClient(
 	return p.runCommand(o, comm, installCmd)
 }
 
-func (p *Provisioner) windowsCreateConfigFiles(
+func (p *ProvisionerS) windowsCreateConfigFiles(
 	o terraform.UIOutput,
 	comm communicator.Communicator) error {
 	// Make sure the config directory exists

builtin/provisioners/chef/windows_provisioner_test.go

@@ -73,7 +73,6 @@ func TestResourceProvider_windowsInstallChefClient(t *testing.T) {
 		},
 	}
 
-	r := new(ResourceProvisioner)
 	o := new(terraform.MockUIOutput)
 	c := new(communicator.MockCommunicator)
 
@@ -81,7 +80,7 @@ func TestResourceProvider_windowsInstallChefClient(t *testing.T) {
 		c.Commands = tc.Commands
 		c.UploadScripts = tc.UploadScripts
 
-		p, err := r.decodeConfig(tc.Config)
+		p, err := decodeConfig(getTestResourceData(tc.Config))
 		if err != nil {
 			t.Fatalf("Error: %v", err)
 		}
@@ -180,7 +179,6 @@ func TestResourceProvider_windowsCreateConfigFiles(t *testing.T) {
 		},
 	}
 
-	r := new(ResourceProvisioner)
 	o := new(terraform.MockUIOutput)
 	c := new(communicator.MockCommunicator)
 
@@ -188,7 +186,7 @@ func TestResourceProvider_windowsCreateConfigFiles(t *testing.T) {
 		c.Commands = tc.Commands
 		c.Uploads = tc.Uploads
 
-		p, err := r.decodeConfig(tc.Config)
+		p, err := decodeConfig(getTestResourceData(tc.Config))
 		if err != nil {
 			t.Fatalf("Error: %v", err)
 		}

builtin/provisioners/file/resource_provisioner.go

@@ -35,7 +35,8 @@ func Provisioner() terraform.ResourceProvisioner {
 			},
 		},
 
-		ApplyFunc: applyFn,
+		ApplyFunc:    applyFn,
+		ValidateFunc: Validate,
 	}
 }
 
@@ -77,6 +78,21 @@ func applyFn(ctx context.Context) error {
 	}
 }
 
+// Validate checks if the required arguments are configured
+func Validate(d *schema.ResourceData) (ws []string, es []error) {
+	numSrc := 0
+	if _, ok := d.GetOk("source"); ok == true {
+		numSrc++
+	}
+	if _, ok := d.GetOk("content"); ok == true {
+		numSrc++
+	}
+	if numSrc != 1 {
+		es = append(es, fmt.Errorf("Must provide one of 'content' or 'source'"))
+	}
+	return
+}
+
 // getSrc returns the file to use as source
 func getSrc(data *schema.ResourceData) (string, bool, error) {
 	src := data.Get("source").(string)

builtin/provisioners/file/resource_provisioner_test.go

@@ -4,9 +4,20 @@ import (
 	"testing"
 
 	"github.com/hashicorp/terraform/config"
+	"github.com/hashicorp/terraform/helper/schema"
 	"github.com/hashicorp/terraform/terraform"
 )
 
+func TestResourceProvisioner_impl(t *testing.T) {
+	var _ terraform.ResourceProvisioner = Provisioner()
+}
+
+func TestProvisioner(t *testing.T) {
+	if err := Provisioner().(*schema.Provisioner).InternalValidate(); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+}
+
 func TestResourceProvider_Validate_good_source(t *testing.T) {
 	c := testConfig(t, map[string]interface{}{
 		"source":      "/tmp/foo",
@@ -51,6 +62,20 @@ func TestResourceProvider_Validate_bad_not_destination(t *testing.T) {
 	}
 }
 
+func TestResourceProvider_Validate_bad_no_source(t *testing.T) {
+	c := testConfig(t, map[string]interface{}{
+		"destination": "/tmp/bar",
+	})
+	p := Provisioner()
+	warn, errs := p.Validate(c)
+	if len(warn) > 0 {
+		t.Fatalf("Warnings: %v", warn)
+	}
+	if len(errs) == 0 {
+		t.Fatalf("Should have errors")
+	}
+}
+
 func TestResourceProvider_Validate_bad_to_many_src(t *testing.T) {
 	c := testConfig(t, map[string]interface{}{
 		"source":      "nope",

builtin/provisioners/local-exec/resource_provisioner_test.go

@@ -8,9 +8,20 @@ import (
 	"time"
 
 	"github.com/hashicorp/terraform/config"
+	"github.com/hashicorp/terraform/helper/schema"
 	"github.com/hashicorp/terraform/terraform"
 )
 
+func TestResourceProvisioner_impl(t *testing.T) {
+	var _ terraform.ResourceProvisioner = Provisioner()
+}
+
+func TestProvisioner(t *testing.T) {
+	if err := Provisioner().(*schema.Provisioner).InternalValidate(); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+}
+
 func TestResourceProvider_Apply(t *testing.T) {
 	defer os.Remove("test_out")
 	c := testConfig(t, map[string]interface{}{

builtin/provisioners/remote-exec/resource_provisioner_test.go

@@ -16,6 +16,16 @@ import (
 	"github.com/hashicorp/terraform/terraform"
 )
 
+func TestResourceProvisioner_impl(t *testing.T) {
+	var _ terraform.ResourceProvisioner = Provisioner()
+}
+
+func TestProvisioner(t *testing.T) {
+	if err := Provisioner().(*schema.Provisioner).InternalValidate(); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+}
+
 func TestResourceProvider_Validate_good(t *testing.T) {
 	c := testConfig(t, map[string]interface{}{
 		"inline": "echo foo",

helper/schema/provisioner.go

@@ -41,6 +41,11 @@ type Provisioner struct {
 	// information.
 	ApplyFunc func(ctx context.Context) error
 
+	// ValidateFunc is the function for extended validation. This is optional.
+	// It is given a resource data.
+	// Should be provided when Scheme is not enough.
+	ValidateFunc func(*ResourceData) ([]string, []error)
+
 	stopCtx       context.Context
 	stopCtxCancel context.CancelFunc
 	stopOnce      sync.Once
@@ -117,8 +122,30 @@ func (p *Provisioner) Stop() error {
 	return nil
 }
 
-func (p *Provisioner) Validate(c *terraform.ResourceConfig) ([]string, []error) {
+func (p *Provisioner) Validate(config *terraform.ResourceConfig) ([]string, []error) {
-	return schemaMap(p.Schema).Validate(c)
+	if err := p.InternalValidate(); err != nil {
+		return nil, []error{fmt.Errorf(
+			"Internal validation of the provisioner failed! This is always a bug\n"+
+				"with the provisioner itself, and not a user issue. Please report\n"+
+				"this bug:\n\n%s", err)}
+	}
+	w := []string{}
+	e := []error{}
+	if p.Schema != nil {
+		w2, e2 := schemaMap(p.Schema).Validate(config)
+		w = append(w, w2...)
+		e = append(e, e2...)
+	}
+	if p.ValidateFunc != nil {
+		data := &ResourceData{
+			schema: p.Schema,
+			config: config,
+		}
+		w2, e2 := p.ValidateFunc(data)
+		w = append(w, w2...)
+		e = append(e, e2...)
+	}
+	return w, e
 }
 
 // Apply implementation of terraform.ResourceProvisioner interface.

helper/schema/provisioner_test.go

@@ -3,6 +3,7 @@ package schema
 import (
 	"context"
 	"fmt"
+	"reflect"
 	"testing"
 	"time"
 
@@ -14,13 +15,35 @@ func TestProvisioner_impl(t *testing.T) {
 	var _ terraform.ResourceProvisioner = new(Provisioner)
 }
 
+func noopApply(ctx context.Context) error {
+	return nil
+}
+
 func TestProvisionerValidate(t *testing.T) {
 	cases := []struct {
 		Name   string
 		P      *Provisioner
 		Config map[string]interface{}
 		Err    bool
+		Warns  []string
 	}{
+		{
+			Name:   "No ApplyFunc",
+			P:      &Provisioner{},
+			Config: nil,
+			Err:    true,
+		},
+		{
+			Name: "Incorrect schema",
+			P: &Provisioner{
+				Schema: map[string]*Schema{
+					"foo": {},
+				},
+				ApplyFunc: noopApply,
+			},
+			Config: nil,
+			Err:    true,
+		},
 		{
 			"Basic required field",
 			&Provisioner{
@@ -30,9 +53,11 @@ func TestProvisionerValidate(t *testing.T) {
 						Type:     TypeString,
 					},
 				},
+				ApplyFunc: noopApply,
 			},
 			nil,
 			true,
+			nil,
 		},
 
 		{
@@ -44,11 +69,57 @@ func TestProvisionerValidate(t *testing.T) {
 						Type:     TypeString,
 					},
 				},
+				ApplyFunc: noopApply,
 			},
 			map[string]interface{}{
 				"foo": "bar",
 			},
 			false,
+			nil,
+		},
+		{
+			Name: "Warning from property validation",
+			P: &Provisioner{
+				Schema: map[string]*Schema{
+					"foo": {
+						Type:     TypeString,
+						Optional: true,
+						ValidateFunc: func(v interface{}, k string) (ws []string, errors []error) {
+							ws = append(ws, "Simple warning from property validation")
+							return
+						},
+					},
+				},
+				ApplyFunc: noopApply,
+			},
+			Config: map[string]interface{}{
+				"foo": "",
+			},
+			Err:   false,
+			Warns: []string{"Simple warning from property validation"},
+		},
+		{
+			Name: "No schema",
+			P: &Provisioner{
+				Schema:    nil,
+				ApplyFunc: noopApply,
+			},
+			Config: nil,
+			Err:    false,
+		},
+		{
+			Name: "Warning from provisioner ValidateFunc",
+			P: &Provisioner{
+				Schema:    nil,
+				ApplyFunc: noopApply,
+				ValidateFunc: func(*ResourceData) (ws []string, errors []error) {
+					ws = append(ws, "Simple warning from provisioner ValidateFunc")
+					return
+				},
+			},
+			Config: nil,
+			Err:    false,
+			Warns:  []string{"Simple warning from provisioner ValidateFunc"},
 		},
 	}
 
@@ -59,9 +130,12 @@ func TestProvisionerValidate(t *testing.T) {
 				t.Fatalf("err: %s", err)
 			}
 
-			_, es := tc.P.Validate(terraform.NewResourceConfig(c))
+			ws, es := tc.P.Validate(terraform.NewResourceConfig(c))
 			if len(es) > 0 != tc.Err {
-				t.Fatalf("%d: %#v", i, es)
+				t.Fatalf("%d: %#v %s", i, es, es)
+			}
+			if (tc.Warns != nil || len(ws) != 0) && !reflect.DeepEqual(ws, tc.Warns) {
+				t.Fatalf("%d: warnings mismatch, actual: %#v", i, ws)
 			}
 		})
 	}

helper/schema/testing.go

@@ -28,3 +28,10 @@ func TestResourceDataRaw(
 
 	return result
 }
+
+func TestResourceDataConfig(schema map[string]*Schema, config *terraform.ResourceConfig) *ResourceData {
+	return &ResourceData{
+		schema: schema,
+		config: config,
+	}
+}