Make cli argument vars to be slice of string

This change allows passing multiple variables files as input to
CLI. Order of files is important as overlapped keys in yaml or json
files will be overwritten by subsequent file.

This change is backwards compatible as CLI library makes the slice
definition to be repetition of the --vars argument. Using goss with
single file produces same outputs with the code change as it was before.

Usage:
```
./goss --vars file1.yaml --vars file2.yaml
```

Signed-off-by: Ondrej Vasko <[email protected]>

Author: Lirt

cmd/goss/goss.go

@@ -42,10 +42,9 @@ func newRuntimeConfigFromCLI(c *cli.Context) *util.Config {
 		Spec:              c.GlobalString("gossfile"),
 		Timeout:           c.Duration("timeout"),
 		Username:          c.String("username"),
-		Vars:              c.GlobalString("vars"),
+		VarsFiles:         c.GlobalStringSlice("vars"),
 		VarsInline:        c.GlobalString("vars-inline"),
 	}
-
 	if c.Bool("no-color") {
 		util.WithNoColor()(cfg)
 	}
@@ -83,9 +82,9 @@ func main() {
 			Usage:  "Goss file to read from / write to",
 			EnvVar: "GOSS_FILE",
 		},
-		cli.StringFlag{
+		cli.StringSliceFlag{
 			Name:   "vars",
-			Usage:  "json/yaml file containing variables for template",
+			Usage:  "json/yaml file containing variables for template. Can be specified multiple times. When specified multiple times it will load variables from all files. Map keys that overlap will be overriden by subsequent file that defines them.",
 			EnvVar: "GOSS_VARS",
 		},
 		cli.StringFlag{

docs/cli.md

@@ -22,7 +22,7 @@ COMMANDS:
 
 GLOBAL OPTIONS:
    --gossfile value, -g value  Goss file to read from / write to (default: "./goss.yaml") [$GOSS_FILE]
-   --vars value                json/yaml file containing variables for template [$GOSS_VARS]
+   --vars value                json/yaml file containing variables for template. Can be specified multiple times. When specified multiple times it will load variables from all files. Map keys that overlap will be overriden by subsequent file that defines them. [$GOSS_VARS]
    --vars-inline value         json/yaml string containing variables for template (overwrites vars) [$GOSS_VARS_INLINE]
    --package value             Package type to use [rpm, deb, apk, pacman]
    --help, -h                  show help
@@ -42,7 +42,7 @@ GLOBAL OPTIONS:
     * `json`
 
 `--vars <varfile>`
-:   The file to read variables from when rendering gossfile [templates](gossfile.md#templates).
+:   The files to read variables from when rendering gossfile [templates](gossfile.md#templates).
 
     Valid formats:
 

serve.go

@@ -38,7 +38,7 @@ func newHealthHandler(c *util.Config) (*healthHandler, error) {
 	color.NoColor = true
 	cache := cache.New(c.Cache, 30*time.Second)
 
-	cfg, err := getGossConfig(c.Vars, c.VarsInline, c.Spec)
+	cfg, err := getGossConfig(c.VarsFiles, c.VarsInline, c.Spec)
 	if err != nil {
 		return nil, err
 	}

store.go

@@ -10,6 +10,7 @@ import (
 	"sort"
 	"strings"
 
+	"dario.cat/mergo"
 	"gopkg.in/yaml.v3"
 
 	"github.com/goss-org/goss/resource"
@@ -73,22 +74,30 @@ func (t *TmplVars) Env() map[string]string {
 	return env
 }
 
-func loadVars(varsFile string, varsInline string) (map[string]any, error) {
-	vars, err := varsFromFile(varsFile)
-	if err != nil {
-		return nil, fmt.Errorf("loading vars file '%s'\n%w", varsFile, err)
+func loadVars(varsFiles []string, varsInline string) (map[string]any, error) {
+	mergedVars := map[string]any{}
+
+	// Later defined vars file overwrites values of the previous files
+	// in places where the keys overlap.
+	for _, varsFile := range varsFiles {
+		vars, err := varsFromFile(varsFile)
+		if err != nil {
+			return nil, fmt.Errorf("loading vars file '%s'\n%w", varsFile, err)
+		}
+		mergo.Merge(&mergedVars, vars, mergo.WithOverride)
 	}
 
 	varsExtra, err := varsFromString(varsInline)
 	if err != nil {
 		return nil, fmt.Errorf("loading inline vars\n%w", err)
 	}
 
+	// Note: This algorithm replaces value under key even if it's nested map
 	for k, v := range varsExtra {
-		vars[k] = v
+		mergedVars[k] = v
 	}
 
-	return vars, nil
+	return mergedVars, nil
 }
 
 func varsFromFile(varsFile string) (map[string]any, error) {
@@ -162,7 +171,7 @@ func ReadJSONData(data []byte, detectFormat bool) (GossConfig, error) {
 func RenderJSON(c *util.Config) (string, error) {
 	var err error
 	debug = c.Debug
-	currentTemplateFilter, err = NewTemplateFilter(c.Vars, c.VarsInline)
+	currentTemplateFilter, err = NewTemplateFilter(c.VarsFiles, c.VarsInline)
 	if err != nil {
 		return "", err
 	}

store_test.go

@@ -129,11 +129,22 @@ func Test_loadVars(t *testing.T) {
 	fileNil, fileNilClose := fileMaker(``)
 	defer fileNilClose()
 
-	fileSimple, fileSimpleClose := fileMaker(`{a: a}`)
-	defer fileSimpleClose()
+	fileSimple1, fileSimpleClose1 := fileMaker(`{a: a}`)
+	defer fileSimpleClose1()
+	fileSimple2, fileSimpleClose2 := fileMaker(`{b: b}`)
+	defer fileSimpleClose2()
+	fileSimple3, fileSimpleClose3 := fileMaker(`{a: overriden, c: c}`)
+	defer fileSimpleClose3()
+
+	fileComplex1, fileComplexClose1 := fileMaker(`{vars: {a: a}}`)
+	defer fileComplexClose1()
+	fileComplex2, fileComplexClose2 := fileMaker(`{vars: {b: b}}`)
+	defer fileComplexClose2()
+	fileComplex3, fileComplexClose3 := fileMaker(`{vars: {a: overriden}}`)
+	defer fileComplexClose3()
 
 	type args struct {
-		varsFile   string
+		varsFiles  []string
 		varsInline string
 	}
 	tests := []struct {
@@ -145,7 +156,7 @@ func Test_loadVars(t *testing.T) {
 		{
 			name: "both_empty",
 			args: args{
-				varsFile:   fileEmpty,
+				varsFiles:  []string{fileEmpty},
 				varsInline: `{}`,
 			},
 			want:    map[string]any{},
@@ -154,7 +165,7 @@ func Test_loadVars(t *testing.T) {
 		{
 			name: "both_nil",
 			args: args{
-				varsFile:   fileNil,
+				varsFiles:  []string{fileNil},
 				varsInline: `{}`,
 			},
 			want:    map[string]any{},
@@ -163,7 +174,7 @@ func Test_loadVars(t *testing.T) {
 		{
 			name: "file_empty",
 			args: args{
-				varsFile:   fileEmpty,
+				varsFiles:  []string{fileEmpty},
 				varsInline: `{b: b}`,
 			},
 			want: map[string]any{
@@ -174,7 +185,7 @@ func Test_loadVars(t *testing.T) {
 		{
 			name: "inline_empty",
 			args: args{
-				varsFile:   fileSimple,
+				varsFiles:  []string{fileSimple1},
 				varsInline: `{}`,
 			},
 			want: map[string]any{
@@ -185,7 +196,7 @@ func Test_loadVars(t *testing.T) {
 		{
 			name: "no_overwrite",
 			args: args{
-				varsFile:   fileSimple,
+				varsFiles:  []string{fileSimple1},
 				varsInline: `{b: b}`,
 			},
 			want: map[string]any{
@@ -197,7 +208,7 @@ func Test_loadVars(t *testing.T) {
 		{
 			name: "overwrite",
 			args: args{
-				varsFile:   fileSimple,
+				varsFiles:  []string{fileSimple1},
 				varsInline: `{a: c, b: b}`,
 			},
 			want: map[string]any{
@@ -206,10 +217,75 @@ func Test_loadVars(t *testing.T) {
 			},
 			wantErr: false,
 		},
+		{
+			name: "multiple files, non-overlapped keys, no inline vars",
+			args: args{
+				varsFiles:  []string{fileSimple1, fileSimple2},
+				varsInline: `{}`,
+			},
+			want: map[string]any{
+				"a": "a",
+				"b": "b",
+			},
+			wantErr: false,
+		},
+		{
+			name: "multiple files, overlapped keys, no inline vars",
+			args: args{
+				varsFiles:  []string{fileSimple1, fileSimple2, fileSimple3},
+				varsInline: `{}`,
+			},
+			want: map[string]any{
+				"a": "overriden",
+				"b": "b",
+				"c": "c",
+			},
+			wantErr: false,
+		},
+		{
+			name: "multiple files, overlapped keys, inline vars",
+			args: args{
+				varsFiles:  []string{fileSimple1, fileSimple2, fileSimple3},
+				varsInline: `{c: overriden, b: b}`,
+			},
+			want: map[string]any{
+				"a": "overriden",
+				"b": "b",
+				"c": "overriden",
+			},
+			wantErr: false,
+		},
+		{
+			name: "multiple nested files",
+			args: args{
+				varsFiles:  []string{fileComplex1, fileComplex2, fileComplex3},
+				varsInline: `{}`,
+			},
+			want: map[string]any{
+				"vars": map[string]any{
+					"a": "overriden",
+					"b": "b",
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name: "multiple nested files and inline variables",
+			args: args{
+				varsFiles:  []string{fileComplex1, fileComplex2, fileComplex3},
+				varsInline: `{vars: { c: c }}`,
+			},
+			want: map[string]any{
+				"vars": map[string]any{
+					"c": "c",
+				},
+			},
+			wantErr: false,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got, err := loadVars(tt.args.varsFile, tt.args.varsInline)
+			got, err := loadVars(tt.args.varsFiles, tt.args.varsInline)
 
 			assert.Equal(t, tt.want, got, "map contents")
 			assert.Equal(t, tt.wantErr, err != nil, "has error")

template.go

@@ -16,10 +16,10 @@ import (
 type TemplateFilter func([]byte) ([]byte, error)
 
 // NewTemplateFilter creates a new Template Filter based in the file and inline variables.
-func NewTemplateFilter(varsFile string, varsInline string) (func([]byte) ([]byte, error), error) {
-	vars, err := loadVars(varsFile, varsInline)
+func NewTemplateFilter(varsFiles []string, varsInline string) (func([]byte) ([]byte, error), error) {
+	vars, err := loadVars(varsFiles, varsInline)
 	if err != nil {
-		return nil, fmt.Errorf("failed while loading vars file %q: %v", varsFile, err)
+		return nil, fmt.Errorf("failed while loading vars file %q: %v", varsFiles, err)
 	}
 
 	tVars := &TmplVars{Vars: vars}

util/config.go

@@ -52,7 +52,7 @@ type Config struct {
 	CAFile                string
 	CertFile              string
 	KeyFile               string
-	Vars                  string
+	VarsFiles             []string
 	VarsInline            string
 	DisabledResourceTypes []string
 }
@@ -90,7 +90,7 @@ func NewConfig(opts ...ConfigOption) (rc *Config, err error) {
 		Spec:                  "",
 		Timeout:               0,
 		Username:              "",
-		Vars:                  "",
+		VarsFiles:             []string{},
 		VarsInline:            "",
 	}
 
@@ -206,10 +206,10 @@ func WithDebug() ConfigOption {
 	}
 }
 
-// WithVarsFile is a json or yaml file containing variables to pass to the validator
-func WithVarsFile(file string) ConfigOption {
+// WithVarsFiles is a json or yaml file containing variables to pass to the validator
+func WithVarsFiles(files []string) ConfigOption {
 	return func(c *Config) error {
-		c.Vars = file
+		c.VarsFiles = files
 		return nil
 	}
 }

util/config_test.go

@@ -1,6 +1,7 @@
 package util
 
 import (
+	"reflect"
 	"testing"
 )
 
@@ -28,14 +29,25 @@ func TestWithVarsString(t *testing.T) {
 	}
 }
 
-func TestWithVarsFile(t *testing.T) {
-	c, err := NewConfig(WithVarsFile("/nonexisting"))
+func TestWithVarsFiles(t *testing.T) {
+	files := []string{"/nonexisting"}
+	c, err := NewConfig(WithVarsFiles(files))
 	if err != nil {
 		t.Fatal(err.Error())
 	}
 
-	if c.Vars != "/nonexisting" {
-		t.Fatalf("expected '/nonexisting' got %q", c.Vars)
+	if !reflect.DeepEqual(c.VarsFiles, files) {
+		t.Fatalf("expected %s got %q", files, c.VarsFiles)
+	}
+
+	files = []string{"/nonexisting", "/second", "third"}
+	c, err = NewConfig(WithVarsFiles(files))
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	if !reflect.DeepEqual(c.VarsFiles, files) {
+		t.Fatalf("expected %s got %q", files, c.VarsFiles)
 	}
 }
 

validate.go

@@ -18,13 +18,13 @@ import (
 	"github.com/goss-org/goss/util"
 )
 
-func getGossConfig(vars string, varsInline string, specFile string) (cfg *GossConfig, err error) {
+func getGossConfig(varsFiles []string, varsInline string, specFile string) (cfg *GossConfig, err error) {
 	// handle stdin
 	var fh *os.File
 	var path, source string
 	var gossConfig GossConfig
 
-	currentTemplateFilter, err = NewTemplateFilter(vars, varsInline)
+	currentTemplateFilter, err = NewTemplateFilter(varsFiles, varsInline)
 	if err != nil {
 		return nil, err
 	}
@@ -85,7 +85,7 @@ func getOutputer(c *bool, format string) (outputs.Outputer, error) {
 // ValidateResults performs validation and provides programmatic access to validation results
 // no retries or outputs are supported
 func ValidateResults(c *util.Config) (results <-chan []resource.TestResult, err error) {
-	gossConfig, err := getGossConfig(c.Vars, c.VarsInline, c.Spec)
+	gossConfig, err := getGossConfig(c.VarsFiles, c.VarsInline, c.Spec)
 	if err != nil {
 		return nil, err
 	}
@@ -104,7 +104,7 @@ func Validate(c *util.Config) (code int, err error) {
 	if err != nil {
 		return 1, err
 	}
-	gossConfig, err := getGossConfig(c.Vars, c.VarsInline, c.Spec)
+	gossConfig, err := getGossConfig(c.VarsFiles, c.VarsInline, c.Spec)
 	if err != nil {
 		return 78, err
 	}