feature: Added '--specignore' option to pass file containing specs to be ignored for fission spec commands (#2239)

- New flag `--specignore` has been added for command fission spec [list | validate | apply | destroy]
- This flag is optional.
- The default spec ignore file name is `.specignore`, if the flag is not used
- The spec ignore file existence will be checked in the `--specdir` path
- If spec ignore file is passed to the flag, with a name other than .specignore and if it does not exist in the `--specdir` path then an error will be returned.
- `--specdir` will be the root path against which the patterns will be evaluated
- The behaviour of the spec ignore file will be similar to .gitignore (only for yml and yaml files). For reference: http://git-scm.com/docs/gitignore

pkg/fission-cli/util/util.go

@@ -25,7 +25,7 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/fission/fission/pkg/controller/client/rest"
+	ignore "github.com/sabhiram/go-gitignore"
 
 	"github.com/hashicorp/go-multierror"
 	"github.com/pkg/errors"
@@ -38,6 +38,7 @@ import (
 	"k8s.io/client-go/tools/clientcmd"
 
 	"github.com/fission/fission/pkg/controller/client"
+	"github.com/fission/fission/pkg/controller/client/rest"
 	"github.com/fission/fission/pkg/fission-cli/cliwrapper/cli"
 	"github.com/fission/fission/pkg/fission-cli/console"
 	flagkey "github.com/fission/fission/pkg/fission-cli/flag/key"
@@ -317,6 +318,33 @@ func GetSpecDir(input cli.Input) string {
 	return specDir
 }
 
+func GetSpecIgnore(input cli.Input) string {
+	specIgnoreFile := input.String(flagkey.SpecIgnore)
+	if len(specIgnoreFile) == 0 {
+		specIgnoreFile = SPEC_IGNORE_FILE
+	}
+	return specIgnoreFile
+}
+
+// GetSpecIgnoreParser reads the specignore file and returns the ignore.IgnoreParser
+// if the specignore file does not exist it returns empty ignore.IgnoreParser
+func GetSpecIgnoreParser(specDir, specIgnore string) (ignore.IgnoreParser, error) {
+
+	specIgnorePath := filepath.Join(specDir, specIgnore)
+
+	// check for existence of spec ignore file
+	if _, err := os.Stat(specIgnorePath); errors.Is(err, os.ErrNotExist) {
+		// return error if it's custom spec ignore file
+		if specIgnore != SPEC_IGNORE_FILE {
+			return nil, errors.Errorf("Spec ignore file '%s' doesn't exist. "+
+				"Please check the file path: '%s'", specIgnore, specIgnorePath)
+		}
+		return ignore.CompileIgnoreLines(), nil
+	}
+
+	return ignore.CompileIgnoreFile(specIgnorePath)
+}
+
 func GetValidationFlag(input cli.Input) bool {
 	validationFlag := input.String(flagkey.SpecValidate)
 	// if flag has not been set, we return true to turn on validation by default