[RFC-007] Flux cmd support for GitHub provider: This commit includes the following changes -

- Add flux create secret githubapp command that accepts and validates the inputs to create a github app secret with options to export the secret yaml or create the secret directly in the Kubernetes cluster

- Add tests for flux create secret githubapp command

- Add flux create source git command that accepts and validates the inputs to create a gitrepository source with for github provider with options to export the source yaml or create the github gitrepository source directly in the Kubernetes cluster.

- Add tests for flux create source git command for github provider.

Signed-off-by: Dipti Pai <diptipai89@outlook.com>

pkg/manifestgen/sourcesecret/options.go

@@ -75,6 +75,12 @@ type Options struct {
 	VerificationCrts    []VerificationCrt
 	TrustPolicy         []byte
 	Address             string
+
+	// GitHub App options
+	GitHubAppID             string
+	GitHubAppInstallationID string
+	GitHubAppPrivateKey     string
+	GitHubAppBaseURL        string
 }
 
 type VerificationCrt struct {

pkg/manifestgen/sourcesecret/sourcesecret.go

@@ -31,6 +31,7 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"sigs.k8s.io/yaml"
 
+	"github.com/fluxcd/pkg/auth/github"
 	"github.com/fluxcd/pkg/ssh"
 
 	"github.com/fluxcd/flux2/v2/pkg/manifestgen"
@@ -190,6 +191,22 @@ func buildSecret(keypair *ssh.KeyPair, hostKey, dockerCfg []byte, options Option
 		secret.StringData[TrustPolicyKey] = string(options.TrustPolicy)
 	}
 
+	if options.GitHubAppID != "" {
+		secret.StringData[github.AppIDKey] = options.GitHubAppID
+	}
+
+	if options.GitHubAppInstallationID != "" {
+		secret.StringData[github.AppInstallationIDKey] = options.GitHubAppInstallationID
+	}
+
+	if options.GitHubAppPrivateKey != "" {
+		secret.StringData[github.AppPrivateKey] = options.GitHubAppPrivateKey
+	}
+
+	if options.GitHubAppBaseURL != "" {
+		secret.StringData[github.AppBaseUrlKey] = options.GitHubAppBaseURL
+	}
+
 	return
 }