allow infra cli to add email aliases

cli/email_alias.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strings"
+
+	"github.com/badoux/checkmail"
+	"github.com/brianvoe/gofakeit/v6"
+	"github.com/golang/glog"
+	"github.com/pkg/errors"
+)
+
+const (
+	addEmailAliasUseCase           = "add-email-alias"
+	emailAliasFlagName             = "forward-to"
+	fromEmailDomainFlagName        = "from-domain"
+	emailAliasesConfigFileRelative = "/modules/kubernetes/mailserver/extra/aliases.txt"
+)
+
+func addEmailAlias(gitFs *GitFS, to, fromDomain string) (string, error) {
+	if err := checkmail.ValidateFormat(to); err != nil {
+		return "", errors.Wrapf(err, fmt.Sprintf("failed to create new email aliases because invalid input format: %s", to))
+	}
+	if err := checkmail.ValidateHost(to); err != nil {
+		return "", errors.Wrapf(err, fmt.Sprintf("failed to create new email aliases because domain for %s does not exist", to))
+	}
+	aliasEmail := generateRandomEmail(fromDomain)
+	glog.Infof("Adding %s -> %s alias to %s", aliasEmail, to, emailAliasesConfigFileRelative)
+	contents := fmt.Sprintf("%s %s", aliasEmail, to)
+
+	// Read existing contents
+	fRead, err := (*gitFs.fs).OpenFile(emailAliasesConfigFileRelative, os.O_RDONLY, 0644)
+	if err != nil {
+		return "", errors.Wrapf(err, "failed to open file where email aliases are recorded")
+	}
+	fileContentsBytes, err := ioutil.ReadAll(fRead)
+	if err != nil {
+		return "", errors.Wrapf(err, "failed to read existing aliases file")
+	}
+	defer fRead.Close()
+	newContents := getAddedAliasContents(string(fileContentsBytes), aliasEmail, to)
+
+	// Write new contents
+	fWrite, err := (*gitFs.fs).OpenFile(emailAliasesConfigFileRelative, os.O_WRONLY, 0644)
+	if err != nil {
+		return "", errors.Wrapf(err, "failed to open file where new email alias will be added")
+	}
+	defer fWrite.Close()
+
+	glog.Infof("writing new contents to file: %s", newContents)
+	fRead.Write([]byte(newContents))
+
+	if _, err = fWrite.Write([]byte(contents)); err != nil {
+		return "", errors.Wrapf(err, "failed to write config to file")
+	}
+	return aliasEmail, nil
+}
+
+func generateRandomEmail(fromDomain string) string {
+	return fmt.Sprintf("%s-%s-generated%s", strings.ToLower(gofakeit.Adverb()), strings.ToLower(gofakeit.FirstName()), fromDomain)
+}
+
+func getPostFixAlias(from, to string) string {
+	return fmt.Sprintf("%s %s", from, to)
+}
+
+func getAddedAliasContents(currentContents, from, to string) string {
+	glog.Infof("Existingcontent: %s", currentContents)
+	lines := strings.Split(currentContents, "\n")
+	newLines := []string{}
+	// If `to` already has an alias, overwrite it
+	for _, l := range lines {
+		if !strings.HasSuffix(l, to) {
+			newLines = append(newLines, l)
+		}
+	}
+	newLines = append(newLines, getPostFixAlias(from, to))
+	return strings.Join(newLines, "\n")
+}