feat: Come up with a standard to pass configuration to the deployed application

assets/docker/Dockerfile.node.tmpl

@@ -8,4 +8,5 @@ RUN npm test
 FROM gcr.io/distroless/nodejs20-debian11
 COPY --from=build-env /src /src
 WORKDIR /src
+USER nonroot
 CMD ["index.js"]

example/.env.sample

@@ -0,0 +1,4 @@
+MOCK1="value1"
+MOCK2="value2"
+MOCK3:"value3"
+MOCK4 "value4"

src/cli/deploy.go

@@ -20,7 +20,7 @@ func (c *icli) Deploy(cCtx *cli.Context) error {
 		return err
 	}
 
-	return knative.Apply(cCtx.String(namespaceFlag), config, project, c.dockerImage)
+	return knative.Apply(cCtx.String(namespaceFlag), config, project, c.dockerImage, cCtx.String(envVarFileFlag))
 }
 
 func (c icli) DeployCMD() *cli.Command {

src/cli/flags.go

@@ -44,6 +44,7 @@ const (
 	namespaceFlag         string = "namespace"
 	stopOnBuildFlag       string = "stop-on-build"
 	stopOnPushFlag        string = "stop-on-push"
+	envVarFileFlag        string = "env-var-file"
 )
 
 type flags struct {
@@ -100,6 +101,11 @@ func InitFlags() flags {
 					Required: true,
 					Category: "deploy",
 				},
+				&cli.StringFlag{
+					Name:     envVarFileFlag,
+					Value:    ".env",
+					Category: "deploy",
+				},
 			},
 			Registry: []cli.Flag{
 				&cli.StringFlag{

src/cli/init_test.go

@@ -19,6 +19,7 @@ cluster-endpoint: null
 container-registry: %s
 default-branch: main
 dockerfile-name: null
+env-var-file: .env
 registry-user: null
 runtime-version: null
 `,

src/services/k8s/knative.go

@@ -1,10 +1,13 @@
 package k8s
 
 import (
+	"bufio"
 	"bytes"
 	"context"
 	"fmt"
+	"os"
 	"path"
+	"strings"
 	"text/template"
 	"time"
 
@@ -71,7 +74,63 @@ func loadManifest(project *project.Project, dockerImage docker.DockerImage) (*se
 	return service, nil
 }
 
-func Apply(namespace string, config *rest.Config, project *project.Project, dockerImage docker.DockerImage) error {
+func loadEnvFile(envFile string) ([]corev1.EnvVar, error) {
+	var envVarList []corev1.EnvVar
+	if _, err := os.Stat(envFile); err != nil {
+		if os.IsNotExist(err) {
+			log.Info("No environment variables file to Load!")
+		} else {
+			return nil, fmt.Errorf("Error checking %v file: %v", envFile, err)
+		}
+	} else {
+		log.Info(fmt.Sprintf("Environment variables file %s found! Loading..", envFile))
+		file, err := os.Open(envFile)
+		if err != nil {
+			return nil, fmt.Errorf("Error opening %v file: %v", envFile, err)
+		}
+		defer file.Close()
+
+		scanner := bufio.NewScanner(file)
+		envVariables := make(map[string]string)
+
+		checkFormat := func(line string) bool {
+			parts := strings.SplitN(line, "=", 2)
+			return len(parts) == 2
+		}
+
+		for scanner.Scan() {
+			line := scanner.Text()
+			if checkFormat(line) {
+				parts := strings.SplitN(line, "=", 2)
+				key := strings.TrimSpace(parts[0])
+				value := strings.TrimSpace(parts[1])
+				envVariables[key] = value
+			} else {
+				log.Warnf("Environment variables file %v line won't be processed due to invalid format: %s. Accepted: KEY=value", envFile, line)
+			}
+		}
+
+		if err := scanner.Err(); err != nil {
+			return nil, fmt.Errorf("Error reading environment variables file %v: %v", envFile, err)
+		}
+
+		if len(envVariables) > 0 {
+			for key, value := range envVariables {
+				envVar := corev1.EnvVar{
+					Name:  key,
+					Value: value,
+				}
+				envVarList = append(envVarList, envVar)
+			}
+			log.Info(fmt.Sprintf("Environment variables file %v content is now loaded!", envFile))
+		} else {
+			log.Warnf("Environment file %v is empty, Nothing to load!", envFile)
+		}
+	}
+	return envVarList, nil
+}
+
+func Apply(namespace string, config *rest.Config, project *project.Project, dockerImage docker.DockerImage, envFile string) error {
 	log.Info("Deploying Knative service", "host", config.Host, "name", project.Name, "namespace", namespace)
 	ctx, cancel := context.WithTimeout(context.Background(), time.Minute*5)
 	defer cancel()
@@ -105,6 +164,9 @@ func Apply(namespace string, config *rest.Config, project *project.Project, dock
 		return fmt.Errorf("cannot create namespace %s, failed with %v", serviceManifest.ObjectMeta.Namespace, err)
 	}
 
+	envVarList, err := loadEnvFile(envFile)
+	serviceManifest.Spec.Template.Spec.Containers[0].Env = append(serviceManifest.Spec.Template.Spec.Containers[0].Env, envVarList...)
+
 	service, err := servingClient.Services(serviceManifest.ObjectMeta.Namespace).Get(ctx, serviceManifest.ObjectMeta.Name, metav1.GetOptions{})
 	var deployedService *servingv1.Service
 	if err != nil {

src/services/k8s/knative_test.go

@@ -73,3 +73,20 @@ func TestLoadManifest(t *testing.T) {
 	}
 
 }
+
+func TestLoadEnvVars(t *testing.T) {
+
+	fmt.Println("Testing .env sample with mixed accepted & invalid lines")
+	_, err := loadEnvFile(path.Join(root, "example/.env.sample"))
+
+	if err != nil {
+		t.Fatalf(fmt.Sprintf("Error: %v", err))
+	}
+
+	fmt.Println("Testing non existing .env sample file")
+	_, err = loadEnvFile(path.Join(root, "example/.env.non-exist"))
+
+	if err != nil {
+		t.Fatalf(fmt.Sprintf("Error: %v", err))
+	}
+}