Add explicit versioning support to launch config

README.md

@@ -2,6 +2,23 @@
 
 Generate code from launch YML
 
+1. [Running](#running)
+2. [Migrating to use in a Golang repo](#migrating-to-use-in-a-golang-repo)
+3. [Dependency overrides](#dependency-overrides)
+
+```sh
+$ launch-gen --help
+Usage of ./bin/launch-gen:
+  -d string
+        Dependency name to override. You can provide multiple dependencies in the format dep1:replacementDep1,dep2:replacementDep2,...
+  -o string
+        optional output to file. Default is stdout
+  -p string
+        optional package name (default "main")
+  -skip-dependency value
+        Dependency to skip generating wag clients. Can be added mulitple times e.g. -skip-dependency a -skip-dependency b
+```
+
 ## Running
 
 Build it
@@ -74,3 +91,44 @@ generate:
 6. Run `make generate`. `launch.go` should be within the specified directory.
 
 7. Call `InitLaunchConfig()` during startup of your program, and use it when needed.
+
+## Dependencies
+
+By default, each dependency listed in `dependencies` will generate the following in `launch.go`:
+
+1. An import of the service's client package – see below
+2. The addition of a struct member for the service's `Client` type in the `Dependencies` struct
+3. Constructing the client via discovery in `InitLaunchConfig()`
+4. Returning the constructed client in the `LaunchConfig`
+
+By default, `launch-gen` will map a service name specified in `dependencies` to a package of the form `github.com/Clever/[SERVICE_NAME]/gen-go/client`, matching the client package generated by WAG. For example, a dependency on `my-service` generates an import of package `github.com/Clever/my-service/gen-go/client`. You can customize the generated package name using the features documented below.
+
+### Versions
+
+If your service's module name and correspondingly its package names include the major version in the format `v2`, `v3`, and so on, you can specify the dependency in the format `my-service@vN`, where `my-service` is the service name and `N` is a whole number representing the major version.
+
+This mapping assumes that the major version `vN` is appended to the default package name as a suffix:
+
+```
+my-service@v2 -> github.com/Clever/my-service/gen-go/client/v2
+```
+
+This mapping matches the convention used by WAG for services with a major version greater than 1. If your service dependency uses a different format, continue reading to [`Overrides`](#overrides) for greater control over the package name.
+
+### Overrides
+
+You can optionally override the package name for a service client dependency with the `-d` arg. Specifying `-d` will change the import statement in the generated `launch.go`. Originally, this option was also used to support services with a major version specified in the package and module names; this use case is now supported directly with the [Versions](#versions) syntax, although you can still achieve the same output with `-d`.
+
+Dependency mappings are defined as a colon-separated pair of strings, as in `configuredDependency:replacementDependency`. You can specify multiple overrides with a comma-separated string of these mappings: `dependency1:replacementDependency1,dependency2:replacementDependency2`.
+
+Since `launch.go` depends on the `client` package within each module, `launch-gen` appends a `/gen-go/client` suffix to the module name to specific the service's client package. If you override the dependency, you **must** specify the whole package path yourself; `launch-gen` will not automatically insert the `/gen-go/client` path anywhere in the override package name, since it cannot assume any particular format.
+
+```sh
+$ launch-gen -d "servica-a:service-a/gen-go/client/v4,service-b:api-b-client/special/unique/client"
+# service-a -> github.com/Clever/service-a/gen-go/client/v4
+# service-b -> github.com/Clever/api-b-client/special/unique/client
+```
+
+### Skipping
+
+If you don't want to generate the package client at all, you can prevent that behavior by specifying `-skip-dependency SERVICE_NAME`. This argument can be specified multiple times.

dependencies.go

@@ -0,0 +1,118 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"regexp"
+	"strings"
+
+	. "github.com/dave/jennifer/jen"
+)
+
+type ServiceDependency struct {
+	name     string
+	version  string
+	override string
+}
+
+func parseOverrideDependencies(overrideDependenciesString *string, dependencies []string) map[string]string {
+
+	// parsing through the list of overrides to make an original:new string map
+
+	overrideDependenciesMap := make(map[string]string)
+
+	if overrideDependenciesString == nil || *overrideDependenciesString == "" {
+		return overrideDependenciesMap
+	}
+
+	overrideDependenciesList := strings.Split(*overrideDependenciesString, ",")
+	for _, overrideRule := range overrideDependenciesList {
+		depReplacementArr := strings.Split(overrideRule, ":")
+
+		if len(depReplacementArr) != 2 || depReplacementArr[1] == "" {
+			log.Fatal("usage: invalid formatting for the -d flag")
+		}
+
+		flag := 0
+		for _, d := range dependencies {
+			if d == depReplacementArr[0] {
+				flag = 1
+				break
+			}
+		}
+
+		if flag == 0 {
+			log.Fatal(depReplacementArr[0], " is not a dependency specified in the provided yaml file")
+		}
+
+		overrideDependenciesMap[depReplacementArr[0]] = depReplacementArr[1]
+	}
+
+	return overrideDependenciesMap
+}
+
+func parseDependencies(
+	launchConfig *LaunchYML,
+	skipDependencies flagsSet,
+	overridesMap map[string]string,
+) []ServiceDependency {
+	versionedModuleRegex := regexp.MustCompile("(?i)^([a-z][a-z0-9-_]+)@(v[0-9]+)$")
+	parsed := []ServiceDependency{}
+	for _, d := range launchConfig.Dependencies {
+		// skip
+		if _, ok := skipDependencies[d]; ok {
+			continue
+		}
+
+		// check for override
+		overridePath, hasOverride := overridesMap[d]
+		if hasOverride {
+			parsed = append(parsed, ServiceDependency{name: d, override: overridePath})
+			continue
+		}
+
+		// check for configured version
+		submatches := versionedModuleRegex.FindStringSubmatch(d)
+		if len(submatches) == 3 {
+			parsed = append(parsed, ServiceDependency{name: submatches[1], version: submatches[2]})
+			continue
+		}
+
+		// default: just the name
+		parsed = append(parsed, ServiceDependency{name: d})
+	}
+
+	return parsed
+}
+
+func (d ServiceDependency) packageName() string {
+	// with wagv9 onwards /gen-go/client is after the service name in the package path
+	importPackage := fmt.Sprintf("%s/gen-go/client", d.name)
+	if d.override != "" {
+		importPackage = d.override
+	} else if d.version != "" {
+		importPackage = fmt.Sprintf("%s/%s", importPackage, d.version)
+	}
+
+	return fmt.Sprintf("github.com/Clever/%s", importPackage)
+}
+
+func mapDependenciesToCode(dependencies []ServiceDependency) []Code {
+	imports := []Code{}
+	for _, d := range dependencies {
+		identifier := Id(strings.Title(toPublicVar(d.name)))
+
+		// // with wagv9 onwards /gen-go/client is after the service name in the package path
+		// importPackage := fmt.Sprintf("%s/gen-go/client", d.name)
+		// if d.override != "" {
+		// 	importPackage = d.override
+		// } else if d.version != "" {
+		// 	importPackage = fmt.Sprintf("%s/%s", importPackage, d.version)
+		// }
+
+		statement := identifier.Qual(d.packageName(), "Client")
+		imports = append(imports, statement)
+	}
+
+	return imports
+}

dependencies_test.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParseDependencies(t *testing.T) {
+	fakeConfig := &LaunchYML{
+		Dependencies: []string{
+			"service-a",
+			"service-b",
+			"service-c@v4",
+			"service-d",
+		},
+	}
+
+	skip := flagsSet{}
+	skip.Set("service-b")
+	result := parseDependencies(fakeConfig, skip, map[string]string{
+		"service-d": "service-d/custom/package/path",
+	})
+
+	assert.Equal(t, []ServiceDependency{
+		{
+			name: "service-a",
+		},
+		{
+			name:    "service-c",
+			version: "v4",
+		},
+		{
+			name:     "service-d",
+			override: "service-d/custom/package/path",
+		},
+	}, result)
+}

fixtures/launch1.expected

@@ -2,6 +2,7 @@ package packagename
 
 import (
 	client1 "github.com/Clever/dapple/gen-go/client"
+	v2 "github.com/Clever/il-config-service/gen-go/client/v2"
 	v9 "github.com/Clever/wag/clientconfig/v9"
 	client "github.com/Clever/workflow-manager/gen-go/client"
 	trace "go.opentelemetry.io/otel/sdk/trace"
@@ -23,6 +24,7 @@ type LaunchConfig struct {
 type Dependencies struct {
 	WorkflowManager client.Client
 	Dapple          client1.Client
+	IlConfigService v2.Client
 }
 
 // Environment has environment variables and their values
@@ -55,6 +57,10 @@ func InitLaunchConfig(exp *trace.SpanExporter) LaunchConfig {
 	if err != nil {
 		log.Fatalf("discovery error: %s", err)
 	}
+	ilConfigService, err := v2.NewFromDiscovery(v9.WithTracing("il-config-service", exporter))
+	if err != nil {
+		log.Fatalf("discovery error: %s", err)
+	}
 	return LaunchConfig{
 		AwsResources: AwsResources{
 			S3ReadAndWriteMe: getS3NameByEnv("read-and-write-me"),
@@ -63,6 +69,7 @@ func InitLaunchConfig(exp *trace.SpanExporter) LaunchConfig {
 		},
 		Deps: Dependencies{
 			Dapple:          dapple,
+			IlConfigService: ilConfigService,
 			WorkflowManager: workflowManager,
 		},
 		Env: Environment{

fixtures/launch1.yml

@@ -6,6 +6,7 @@ dependencies:
   - workflow-manager
   - dapple
   - dependency-to-skip
+  - il-config-service@v2
 aws:
   s3:
     read:

fixtures/launch2.expected

@@ -2,6 +2,7 @@ package packagename
 
 import (
 	v5 "github.com/Clever/dapple/gen-go/client/v5"
+	v2 "github.com/Clever/il-config-service/gen-go/client/v2"
 	v9 "github.com/Clever/wag/clientconfig/v9"
 	client "github.com/Clever/workflow-manager/gen-go/client"
 	trace "go.opentelemetry.io/otel/sdk/trace"
@@ -23,6 +24,7 @@ type LaunchConfig struct {
 type Dependencies struct {
 	WorkflowManager client.Client
 	Dapple          v5.Client
+	IlConfigService v2.Client
 }
 
 // Environment has environment variables and their values
@@ -55,6 +57,10 @@ func InitLaunchConfig(exp *trace.SpanExporter) LaunchConfig {
 	if err != nil {
 		log.Fatalf("discovery error: %s", err)
 	}
+	ilConfigService, err := v2.NewFromDiscovery(v9.WithTracing("il-config-service", exporter))
+	if err != nil {
+		log.Fatalf("discovery error: %s", err)
+	}
 	return LaunchConfig{
 		AwsResources: AwsResources{
 			S3ReadAndWriteMe: getS3NameByEnv("read-and-write-me"),
@@ -63,6 +69,7 @@ func InitLaunchConfig(exp *trace.SpanExporter) LaunchConfig {
 		},
 		Deps: Dependencies{
 			Dapple:          dapple,
+			IlConfigService: ilConfigService,
 			WorkflowManager: workflowManager,
 		},
 		Env: Environment{

fixtures/launch2.yml

@@ -6,6 +6,7 @@ dependencies:
   - workflow-manager
   - dapple
   - dependency-to-skip
+  - il-config-service@v2
 aws:
   s3:
     read: