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/flag/flag.go

@@ -17,6 +17,7 @@ limitations under the License.
 package flag
 
 import (
+	"fmt"
 	"net/http"
 	"time"
 
@@ -24,6 +25,7 @@ import (
 
 	fv1 "github.com/fission/fission/pkg/apis/core/v1"
 	flagkey "github.com/fission/fission/pkg/fission-cli/flag/key"
+	"github.com/fission/fission/pkg/fission-cli/util"
 )
 
 type (
@@ -198,6 +200,7 @@ var (
 	SpecDelete     = Flag{Type: Bool, Name: flagkey.SpecDelete, Usage: "Allow apply to delete resources that no longer exist in the specification"}
 	SpecDry        = Flag{Type: Bool, Name: flagkey.SpecDry, Usage: "View the generated specs"}
 	SpecValidation = Flag{Type: String, Name: flagkey.SpecValidate, Usage: "Turns server side validations of Fission objects on/off"}
+	SpecIgnore     = Flag{Type: String, Name: flagkey.SpecIgnore, Usage: fmt.Sprintf("File containing specs to be ingored inside --specdir, defaults to %v", util.SPEC_IGNORE_FILE)}
 
 	SupportOutput = Flag{Type: String, Name: flagkey.SupportOutput, Short: "o", Usage: "Output directory to save dump archive/files", DefaultValue: flagkey.DefaultSpecOutputDir}
 	SupportNoZip  = Flag{Type: Bool, Name: flagkey.SupportNoZip, Usage: "Save dump information into multiple files instead of single zip file"}

pkg/fission-cli/flag/key/key.go

@@ -151,6 +151,7 @@ const (
 	SpecDelete   = "delete"
 	SpecDry      = "dry"
 	SpecValidate = "validation"
+	SpecIgnore   = "specignore"
 
 	SupportOutput = Output
 	SupportNoZip  = "nozip"