refactor: Add validation, formatting and errors for kompose conversion

code

Signed-off-by: Nithish <[email protected]>

helpers/component_info.json

@@ -1,5 +1,5 @@
 {
   "name": "meshkit",
   "type": "library",
-  "next_error_code": 11076
+  "next_error_code": 11080
 }

utils/error.go

@@ -22,10 +22,20 @@ var (
 	ErrReadingLocalFileCode          = "11054"
 	ErrGettingLatestReleaseTagCode   = "11055"
 	ErrInvalidProtocol               = errors.New(ErrInvalidProtocolCode, errors.Alert, []string{"invalid protocol: only http, https and file are valid protocols"}, []string{}, []string{"Network protocol is incorrect"}, []string{"Make sure to specify the right network protocol"})
+	ErrMissingFieldCode              = "11076"
+	ErrExpectedTypeMismatchCode      = "11079"
 )
 
+func ErrExpectedTypeMismatch(err error, expectedType string) error {
+	return errors.New(ErrExpectedTypeMismatchCode, errors.Alert, []string{"Expected the type to be: ", expectedType}, []string{err.Error()}, []string{"Invalid manifest"}, []string{"Make sure that the value provided in the manifest has the needed type."})
+}
+
+func ErrMissingField(err error, missingFieldName string) error {
+	return errors.New(ErrMissingFieldCode, errors.Alert, []string{"Missing field or property with name: ", missingFieldName}, []string{err.Error()}, []string{"Invalid manifest"}, []string{"Make sure that the concerned data type has all the required fields/values."})
+}
+
 func ErrUnmarshal(err error) error {
-	return errors.New(ErrUnmarshalCode, errors.Alert, []string{"Unmarshal unknown error: %s"}, []string{err.Error()}, []string{"Invalid object format"}, []string{"Make sure to input a valid JSON object"})
+	return errors.New(ErrUnmarshalCode, errors.Alert, []string{"Unmarshal unknown error: "}, []string{err.Error()}, []string{"Invalid object format"}, []string{"Make sure to input a valid JSON object"})
 }
 
 func ErrUnmarshalInvalid(err error, typ reflect.Type) error {

utils/kubernetes/kompose/convert.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/kubernetes/kompose/pkg/app"
 	"github.com/kubernetes/kompose/pkg/kobject"
+	"github.com/layer5io/meshkit/utils"
 	"gopkg.in/yaml.v2"
 )
 
@@ -15,8 +16,8 @@ var (
 )
 
 // converts a given docker-compose file into kubernetes manifests
-func Convert(dockerCompose string) (string, error) {
-	err := ioutil.WriteFile("temp.data", []byte(dockerCompose), 0666)
+func Convert(dockerCompose []byte) (string, error) {
+	err := utils.CreateFile(dockerCompose, "temp.data", "./")
 	if err != nil {
 		return "", ErrCvrtKompose(err)
 	}

utils/kubernetes/kompose/error.go

@@ -3,9 +3,19 @@ package kompose
 import "github.com/layer5io/meshkit/errors"
 
 const (
-	ErrCvrtKomposeCode = "11075"
+	ErrCvrtKomposeCode         = "11075"
+	ErrNoVersionCode           = "11077"
+	ErrIncompatibleVersionCode = "11078"
 )
 
 func ErrCvrtKompose(err error) error {
 	return errors.New(ErrCvrtKomposeCode, errors.Alert, []string{"Error converting the docker compose file into kubernetes manifests"}, []string{err.Error()}, []string{"Could not convert docker-compose file into kubernetes manifests"}, []string{"Make sure the docker-compose file is valid", ""})
 }
+
+func ErrNoVersion() error {
+	return errors.New(ErrNoVersionCode, errors.Alert, []string{"version not found in the docker compose file"}, []string{"The docker compose file does not have version field in it. The underlying tool that is used for conversion mandates the presence of version field."}, []string{"Since the Docker Compose specification does not mandate the version field from version 3 onwards, most sources do not provide them."}, []string{"Make sure that the compose file has version specified,", "Add any version less than or equal to 3.3 if you cannot get the exact version from the source"})
+}
+
+func ErrIncompatibleVersion() error {
+	return errors.New(ErrIncompatibleVersionCode, errors.Alert, []string{"This version of docker compose file is not compatible."}, []string{"This docker compose file is invalid since it's version is incompatible."}, []string{"docker compose file with version greater than 3.3 is probably being used"}, []string{"Make sure that the compose file has version less than or equal to 3.3,", ""})
+}

utils/kubernetes/kompose/models/composefile.go

@@ -1,8 +1,6 @@
 package models
 
-import "encoding/json"
-
 type DockerComposeFile struct {
-	Version  json.Number `yaml:"version" json:"version"`
+	Version  string      `yaml:"version" json:"version"`
 	Services interface{} `yaml:"services" json:"services"` // more constraints should be added to this type
 }

utils/kubernetes/kompose/utils.go

@@ -1,6 +1,10 @@
 package kompose
 
 import (
+	"fmt"
+	"strconv"
+
+	errors "github.com/layer5io/meshkit/utils"
 	"github.com/layer5io/meshkit/utils/kubernetes/kompose/models"
 	"gopkg.in/yaml.v2"
 )
@@ -11,8 +15,50 @@ func IsManifestADockerCompose(yamlManifest []byte) bool {
 	if err := yaml.Unmarshal(yamlManifest, &data); err != nil {
 		return false
 	}
-	if data.Version == "" {
+	if data.Services == nil {
 		return false
 	}
 	return true
 }
+
+// VaildateDockerComposeFile takes in a manifest and returns validates it
+func VaildateDockerComposeFile(yamlManifest []byte) error {
+	data := models.DockerComposeFile{}
+	if err := yaml.Unmarshal(yamlManifest, &data); err != nil {
+		return errors.ErrUnmarshal(err)
+	}
+	if data.Version == "" {
+		return errors.ErrMissingField(ErrNoVersion(), "Version")
+	}
+	versionFloatVal, err := strconv.ParseFloat(data.Version, 64)
+	if err != nil {
+		return errors.ErrExpectedTypeMismatch(err, "float")
+	} else {
+		if versionFloatVal > 3.3 {
+			// kompose throws a fatal error when version exceeds 3.3
+			// need this till this PR gets merged https://github.com/kubernetes/kompose/pull/1440(move away from libcompose to compose-go)
+			return ErrIncompatibleVersion()
+		}
+	}
+	if data.Services == nil {
+		return errors.ErrMissingField(fmt.Errorf("Services field is missing in the docker compose file"), "Services")
+	}
+	return nil
+}
+
+// FormatComposeFile takes in a pointer to the compose file byte array and formats it so that it is compatible with `Kompose`
+// it expects a validated docker compose file and does not validate
+func FormatComposeFile(yamlManifest *[]byte) error {
+	data := models.DockerComposeFile{}
+	err := yaml.Unmarshal(*yamlManifest, &data)
+	if err != nil {
+		return errors.ErrUnmarshal(err)
+	}
+	data.Version = fmt.Sprintf("%s", data.Version)
+	out, err := yaml.Marshal(data)
+	if err != nil {
+		return errors.ErrMarshal(err)
+	}
+	*yamlManifest = out
+	return nil
+}