provisioner/shell: Add `env_var_format` support to shell provisioner

* Move setting of default EnvVarFormat to the Prepare function
* Add generated hcl2 structure for the updated Shell provisioner config
* Move `EnvVarFormat` field to shared common shell type
* Add description for the `env_var_format` parameter
* Update `env_var_format` when used with `use_env_var_file`

common/shell/shell.go

@@ -39,4 +39,8 @@ type Provisioner struct {
 	// An array of environment variables that will be injected before
 	// your command(s) are executed.
 	Vars []string `mapstructure:"environment_vars"`
+
+	// This is used in the template generation to format environment variables
+	// inside the `ExecuteCommand` template.
+	EnvVarFormat string `mapstructure:"env_var_format"`
 }

provisioner/powershell/provisioner.go

@@ -55,10 +55,6 @@ type Config struct {
 	// can be set high to allow for reboots.
 	StartRetryTimeout time.Duration `mapstructure:"start_retry_timeout"`
 
-	// This is used in the template generation to format environment variables
-	// inside the `ExecuteCommand` template.
-	EnvVarFormat string
-
 	// This is used in the template generation to format environment variables
 	// inside the `ElevatedExecuteCommand` template.
 	ElevatedEnvVarFormat string `mapstructure:"elevated_env_var_format"`

provisioner/powershell/provisioner.hcl2spec.go

@@ -24,10 +24,10 @@ type FlatConfig struct {
 	Scripts                []string          `cty:"scripts"`
 	ValidExitCodes         []int             `mapstructure:"valid_exit_codes" cty:"valid_exit_codes"`
 	Vars                   []string          `mapstructure:"environment_vars" cty:"environment_vars"`
+	EnvVarFormat           *string           `mapstructure:"env_var_format" cty:"env_var_format"`
 	RemoteEnvVarPath       *string           `mapstructure:"remote_env_var_path" cty:"remote_env_var_path"`
 	ElevatedExecuteCommand *string           `mapstructure:"elevated_execute_command" cty:"elevated_execute_command"`
 	StartRetryTimeout      *string           `mapstructure:"start_retry_timeout" cty:"start_retry_timeout"`
-	EnvVarFormat           *string           `cty:"env_var_format"`
 	ElevatedEnvVarFormat   *string           `mapstructure:"elevated_env_var_format" cty:"elevated_env_var_format"`
 	ElevatedUser           *string           `mapstructure:"elevated_user" cty:"elevated_user"`
 	ElevatedPassword       *string           `mapstructure:"elevated_password" cty:"elevated_password"`
@@ -58,10 +58,10 @@ func (*FlatConfig) HCL2Spec() map[string]hcldec.Spec {
 		"scripts":                    &hcldec.AttrSpec{Name: "scripts", Type: cty.List(cty.String), Required: false},
 		"valid_exit_codes":           &hcldec.AttrSpec{Name: "valid_exit_codes", Type: cty.List(cty.Number), Required: false},
 		"environment_vars":           &hcldec.AttrSpec{Name: "environment_vars", Type: cty.List(cty.String), Required: false},
+		"env_var_format":             &hcldec.AttrSpec{Name: "env_var_format", Type: cty.String, Required: false},
 		"remote_env_var_path":        &hcldec.AttrSpec{Name: "remote_env_var_path", Type: cty.String, Required: false},
 		"elevated_execute_command":   &hcldec.AttrSpec{Name: "elevated_execute_command", Type: cty.String, Required: false},
 		"start_retry_timeout":        &hcldec.AttrSpec{Name: "start_retry_timeout", Type: cty.String, Required: false},
-		"env_var_format":             &hcldec.AttrSpec{Name: "env_var_format", Type: cty.String, Required: false},
 		"elevated_env_var_format":    &hcldec.AttrSpec{Name: "elevated_env_var_format", Type: cty.String, Required: false},
 		"elevated_user":              &hcldec.AttrSpec{Name: "elevated_user", Type: cty.String, Required: false},
 		"elevated_password":          &hcldec.AttrSpec{Name: "elevated_password", Type: cty.String, Required: false},

provisioner/shell/provisioner.go

@@ -57,9 +57,10 @@ type Config struct {
 
 	ExpectDisconnect bool `mapstructure:"expect_disconnect"`
 
-	ctx interpolate.Context
 	// name of the tmp environment variable file, if UseEnvVarFile is true
 	envVarFile string
+
+	ctx interpolate.Context
 }
 
 type Provisioner struct {
@@ -82,10 +83,19 @@ func (p *Provisioner) Prepare(raws ...interface{}) error {
 			},
 		},
 	}, raws...)
+
 	if err != nil {
 		return err
 	}
 
+	if p.config.EnvVarFormat == "" {
+		p.config.EnvVarFormat = "%s='%s' "
+
+		if p.config.UseEnvVarFile == true {
+			p.config.EnvVarFormat = "export %s='%s'\n"
+		}
+	}
+
 	if p.config.ExecuteCommand == "" {
 		p.config.ExecuteCommand = "chmod +x {{.Path}}; {{.Vars}} {{.Path}}"
 		if p.config.UseEnvVarFile == true {
@@ -430,21 +440,22 @@ func (p *Provisioner) escapeEnvVars() ([]string, map[string]string) {
 func (p *Provisioner) createEnvVarFileContent() string {
 	keys, envVars := p.escapeEnvVars()
 
-	flattened := ""
-	// Re-assemble vars surrounding value with single quotes and flatten
+	var flattened string
 	for _, key := range keys {
-		flattened += fmt.Sprintf("export %s='%s'\n", key, envVars[key])
+		flattened += fmt.Sprintf(p.config.EnvVarFormat, key, envVars[key])
 	}
 
 	return flattened
 }
 
-func (p *Provisioner) createFlattenedEnvVars() (flattened string) {
+func (p *Provisioner) createFlattenedEnvVars() string {
 	keys, envVars := p.escapeEnvVars()
 
-	// Re-assemble vars surrounding value with single quotes and flatten
+	// Re-assemble vars into specified format and flatten
+	var flattened string
 	for _, key := range keys {
-		flattened += fmt.Sprintf("%s='%s' ", key, envVars[key])
+		flattened += fmt.Sprintf(p.config.EnvVarFormat, key, envVars[key])
 	}
-	return
+
+	return flattened
 }

provisioner/shell/provisioner.hcl2spec.go

@@ -24,6 +24,7 @@ type FlatConfig struct {
 	Scripts             []string          `cty:"scripts"`
 	ValidExitCodes      []int             `mapstructure:"valid_exit_codes" cty:"valid_exit_codes"`
 	Vars                []string          `mapstructure:"environment_vars" cty:"environment_vars"`
+	EnvVarFormat        *string           `mapstructure:"env_var_format" cty:"env_var_format"`
 	InlineShebang       *string           `mapstructure:"inline_shebang" cty:"inline_shebang"`
 	PauseAfter          *string           `mapstructure:"pause_after" cty:"pause_after"`
 	UseEnvVarFile       *bool             `mapstructure:"use_env_var_file" cty:"use_env_var_file"`
@@ -58,6 +59,7 @@ func (*FlatConfig) HCL2Spec() map[string]hcldec.Spec {
 		"scripts":                    &hcldec.AttrSpec{Name: "scripts", Type: cty.List(cty.String), Required: false},
 		"valid_exit_codes":           &hcldec.AttrSpec{Name: "valid_exit_codes", Type: cty.List(cty.Number), Required: false},
 		"environment_vars":           &hcldec.AttrSpec{Name: "environment_vars", Type: cty.List(cty.String), Required: false},
+		"env_var_format":             &hcldec.AttrSpec{Name: "env_var_format", Type: cty.String, Required: false},
 		"inline_shebang":             &hcldec.AttrSpec{Name: "inline_shebang", Type: cty.String, Required: false},
 		"pause_after":                &hcldec.AttrSpec{Name: "pause_after", Type: cty.String, Required: false},
 		"use_env_var_file":           &hcldec.AttrSpec{Name: "use_env_var_file", Type: cty.Bool, Required: false},

provisioner/shell/provisioner_test.go

@@ -286,6 +286,45 @@ func TestProvisioner_createFlattenedEnvVars(t *testing.T) {
 	}
 }
 
+func TestProvisioner_createFlattenedEnvVars_withEnvVarFormat(t *testing.T) {
+	var flattenedEnvVars string
+	config := testConfig()
+
+	userEnvVarTests := [][]string{
+		{},                     // No user env var
+		{"FOO=bar"},            // Single user env var
+		{"FOO=bar's"},          // User env var with single quote in value
+		{"FOO=bar", "BAZ=qux"}, // Multiple user env vars
+		{"FOO=bar=baz"},        // User env var with value containing equals
+		{"FOO==bar"},           // User env var with value starting with equals
+	}
+	expected := []string{
+		`PACKER_BUILDER_TYPE=iso PACKER_BUILD_NAME=vmware `,
+		`FOO=bar PACKER_BUILDER_TYPE=iso PACKER_BUILD_NAME=vmware `,
+		`FOO=bar'"'"'s PACKER_BUILDER_TYPE=iso PACKER_BUILD_NAME=vmware `,
+		`BAZ=qux FOO=bar PACKER_BUILDER_TYPE=iso PACKER_BUILD_NAME=vmware `,
+		`FOO=bar=baz PACKER_BUILDER_TYPE=iso PACKER_BUILD_NAME=vmware `,
+		`FOO==bar PACKER_BUILDER_TYPE=iso PACKER_BUILD_NAME=vmware `,
+	}
+
+	p := new(Provisioner)
+
+	p.config.EnvVarFormat = "%s=%s "
+	p.Prepare(config)
+
+	// Defaults provided by Packer
+	p.config.PackerBuildName = "vmware"
+	p.config.PackerBuilderType = "iso"
+
+	for i, expectedValue := range expected {
+		p.config.Vars = userEnvVarTests[i]
+		flattenedEnvVars = p.createFlattenedEnvVars()
+		if flattenedEnvVars != expectedValue {
+			t.Fatalf("expected flattened env vars to be: %s, got %s.", expectedValue, flattenedEnvVars)
+		}
+	}
+}
+
 func TestProvisioner_createEnvVarFileContent(t *testing.T) {
 	var flattenedEnvVars string
 	config := testConfig()
@@ -326,6 +365,7 @@ export PACKER_BUILD_NAME='vmware'
 	}
 
 	p := new(Provisioner)
+	p.config.UseEnvVarFile = true
 	p.Prepare(config)
 
 	// Defaults provided by Packer
@@ -341,6 +381,55 @@ export PACKER_BUILD_NAME='vmware'
 	}
 }
 
+func TestProvisioner_createEnvVarFileContent_withEnvVarFormat(t *testing.T) {
+	var flattenedEnvVars string
+	config := testConfig()
+
+	userEnvVarTests := [][]string{
+		{},                     // No user env var
+		{"FOO=bar", "BAZ=qux"}, // Multiple user env vars
+		{"FOO=bar=baz"},        // User env var with value containing equals
+		{"FOO==bar"},           // User env var with value starting with equals
+	}
+	expected := []string{
+		`PACKER_BUILDER_TYPE=iso
+PACKER_BUILD_NAME=vmware
+`,
+		`BAZ=qux
+FOO=bar
+PACKER_BUILDER_TYPE=iso
+PACKER_BUILD_NAME=vmware
+`,
+		`FOO=bar=baz
+PACKER_BUILDER_TYPE=iso
+PACKER_BUILD_NAME=vmware
+`,
+		`FOO==bar
+PACKER_BUILDER_TYPE=iso
+PACKER_BUILD_NAME=vmware
+`,
+	}
+
+	p := new(Provisioner)
+
+	p.config.UseEnvVarFile = true
+	//User provided env_var_format without export prefix
+	p.config.EnvVarFormat = "%s=%s\n"
+	p.Prepare(config)
+
+	// Defaults provided by Packer
+	p.config.PackerBuildName = "vmware"
+	p.config.PackerBuilderType = "iso"
+
+	for i, expectedValue := range expected {
+		p.config.Vars = userEnvVarTests[i]
+		flattenedEnvVars = p.createEnvVarFileContent()
+		if flattenedEnvVars != expectedValue {
+			t.Fatalf("expected flattened env vars to be: %q, got %q.", expectedValue, flattenedEnvVars)
+		}
+	}
+}
+
 func TestProvisioner_RemoteFolderSetSuccessfully(t *testing.T) {
 	config := testConfig()
 

provisioner/windows-shell/provisioner.go

@@ -37,10 +37,6 @@ type Config struct {
 	// This can be set high to allow for reboots.
 	StartRetryTimeout time.Duration `mapstructure:"start_retry_timeout"`
 
-	// This is used in the template generation to format environment variables
-	// inside the `ExecuteCommand` template.
-	EnvVarFormat string `mapstructure:"env_var_format"`
-
 	ctx interpolate.Context
 }
 

provisioner/windows-shell/provisioner.hcl2spec.go

@@ -24,8 +24,8 @@ type FlatConfig struct {
 	Scripts             []string          `cty:"scripts"`
 	ValidExitCodes      []int             `mapstructure:"valid_exit_codes" cty:"valid_exit_codes"`
 	Vars                []string          `mapstructure:"environment_vars" cty:"environment_vars"`
-	StartRetryTimeout   *string           `mapstructure:"start_retry_timeout" cty:"start_retry_timeout"`
 	EnvVarFormat        *string           `mapstructure:"env_var_format" cty:"env_var_format"`
+	StartRetryTimeout   *string           `mapstructure:"start_retry_timeout" cty:"start_retry_timeout"`
 }
 
 // FlatMapstructure returns a new FlatConfig.
@@ -52,8 +52,8 @@ func (*FlatConfig) HCL2Spec() map[string]hcldec.Spec {
 		"scripts":                    &hcldec.AttrSpec{Name: "scripts", Type: cty.List(cty.String), Required: false},
 		"valid_exit_codes":           &hcldec.AttrSpec{Name: "valid_exit_codes", Type: cty.List(cty.Number), Required: false},
 		"environment_vars":           &hcldec.AttrSpec{Name: "environment_vars", Type: cty.List(cty.String), Required: false},
-		"start_retry_timeout":        &hcldec.AttrSpec{Name: "start_retry_timeout", Type: cty.String, Required: false},
 		"env_var_format":             &hcldec.AttrSpec{Name: "env_var_format", Type: cty.String, Required: false},
+		"start_retry_timeout":        &hcldec.AttrSpec{Name: "start_retry_timeout", Type: cty.String, Required: false},
 	}
 	return s
 }

website/source/docs/provisioners/shell.html.md.erb

@@ -40,6 +40,11 @@ The example below is fully functional.
     Packer injects some environmental variables by default into the
     environment, as well, which are covered in the section below.
 
+-   `env_var_format` (string) - When we parse the environment\_vars that you
+    provide, this gives us a string template to use in order to make sure that
+    we are setting the environment vars correctly. By default it is `"%s='%s' "`.
+    When used in conjunction with `use_env_var_file` the default is `"export %s='%s'\n"`
+
 -   `use_env_var_file` (boolean) - If true, Packer will write your environment
     variables to a tempfile and source them from that file, rather than
     declaring them inline in our execute\_command. The default