From 9fe3eafde4d9c85c740384f0ed214b6930d96fee Mon Sep 17 00:00:00 2001
From: Alec Thomas <alec@swapoff.org>
Date: Thu, 12 Oct 2023 11:55:03 +1100
Subject: [PATCH] fix: include JAR dependencies in Kotlin deploys

By adding the following fragment to the POM:

```xml
<execution>
    <id>copy-dependencies</id>
    <phase>compile</phase>
    <goals>
        <goal>copy-dependencies</goal>
    </goals>
    <configuration>
        <outputDirectory>${project.build.directory}/dependency</outputDirectory>
        <includeScope>runtime</includeScope>
    </configuration>
</execution>
```

`ftl deploy ./target` will upload all dependendcies as well as compiled
source. This actually works super well in practice, and I think we can
completely remove the need for building a custom `ftl-runner` Docker
image.

One issue is that this now results in the runners having to download
quite a few MB of artefacts on each deploy, but we can mitigate this by
making the controller->runner artefact download process incremental too,
and have each runner maintain its own cache. Probably something for
later though, as it's generally pretty fast so far.
---
 backend/common/download/download.go             |  5 +++++
 examples/echo-kotlin/pom.xml                    | 17 ++++++++++++++---
 .../xyz/block/ftl/generator/ModuleGenerator.kt  |  4 ++--
 3 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/backend/common/download/download.go b/backend/common/download/download.go
index b8edd6e58d..5fefc6c9f2 100644
--- a/backend/common/download/download.go
+++ b/backend/common/download/download.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"os"
 	"path/filepath"
+	"time"
 
 	"connectrpc.com/connect"
 	"github.com/alecthomas/errors"
@@ -23,6 +24,8 @@ func Artefacts(ctx context.Context, client ftlv1connect.ControllerServiceClient,
 	if err != nil {
 		return errors.WithStack(err)
 	}
+	start := time.Now()
+	count := 0
 	var digest string
 	var w *os.File
 	for stream.Receive() {
@@ -32,6 +35,7 @@ func Artefacts(ctx context.Context, client ftlv1connect.ControllerServiceClient,
 			if w != nil {
 				w.Close()
 			}
+			count++
 			if !filepath.IsLocal(artefact.Path) {
 				return errors.Errorf("path %q is not local", artefact.Path)
 			}
@@ -59,5 +63,6 @@ func Artefacts(ctx context.Context, client ftlv1connect.ControllerServiceClient,
 	if w != nil {
 		w.Close()
 	}
+	logger.Infof("Downloaded %d artefacts in %s", count, time.Since(start))
 	return errors.WithStack(stream.Err())
 }
diff --git a/examples/echo-kotlin/pom.xml b/examples/echo-kotlin/pom.xml
index 796e37332a..284a914d0f 100644
--- a/examples/echo-kotlin/pom.xml
+++ b/examples/echo-kotlin/pom.xml
@@ -1,6 +1,6 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 
     <modelVersion>4.0.0</modelVersion>
     <groupId>xyz.block</groupId>
@@ -86,6 +86,17 @@
                             </artifactItems>
                         </configuration>
                     </execution>
+                    <execution>
+                        <id>copy-dependencies</id>
+                        <phase>compile</phase>
+                        <goals>
+                            <goal>copy-dependencies</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>${project.build.directory}/dependency</outputDirectory>
+                            <includeScope>runtime</includeScope>
+                        </configuration>
+                    </execution>
                 </executions>
             </plugin>
             <!-- Run the Wire compiler -->
@@ -133,4 +144,4 @@
             </plugin>
         </plugins>
     </build>
-</project>
+</project>
\ No newline at end of file
diff --git a/kotlin-runtime/ftl-generator/src/main/kotlin/xyz/block/ftl/generator/ModuleGenerator.kt b/kotlin-runtime/ftl-generator/src/main/kotlin/xyz/block/ftl/generator/ModuleGenerator.kt
index 0f7daaa88c..42385911e2 100644
--- a/kotlin-runtime/ftl-generator/src/main/kotlin/xyz/block/ftl/generator/ModuleGenerator.kt
+++ b/kotlin-runtime/ftl-generator/src/main/kotlin/xyz/block/ftl/generator/ModuleGenerator.kt
@@ -175,7 +175,7 @@ class ModuleGenerator() {
       """
       module = "${module}"
       language = "kotlin"
-      deploy = ["main", "classes"]
+      deploy = ["main", "classes", "dependency"]
       """.trimIndent()
     )
 
@@ -183,7 +183,7 @@ class ModuleGenerator() {
     mainFile.writeText(
       """
       #!/bin/bash
-      exec java -cp ftl/jars/ftl-runtime.jar:classes xyz.block.ftl.main.MainKt
+      exec java -cp "classes:$(printf %s: dependency/*.jar)" xyz.block.ftl.main.MainKt
       """.trimIndent(),
     )
     mainFile.setPosixFilePermissions(