ci: Use esbuild to build RTS (#27310)

This fixes RTS build to use `esbuild`.

1. This means the whole `node_modules` won't need to be copied over to
the Docker image. There's unused insignifant _test_ files in there, that
don't add any value, but are causing irrelevant CVEs to be reported on
our Docker image. See example at
https://github.com/appsmithorg/appsmith-ee/pull/2349.

2. Much faster. Not that RTS build is our slow point, but still. Perhaps
we can move client to `esbuild` too. 🙂

## Why are we doing this?

The current method of loading RTS into the Docker image means that _all_
contents of _all_ dependencies are copied over. The whole
`node_modules`. But several of these packages include _test_ files too,
that aren't needed at runtime at all. One of such test files is creating
a false alert for a CVE on our Docker image. Has absolutely no relevance
and impact, but it's there.

To fix that, I [had to `rm -rf /opt/appsmith/rts/node_modules/*/test` in
the Docker
image](https://github.com/appsmithorg/appsmith-ee/pull/2349/files). This
felt very hacky, and very dirty. It felt like we're introducing more
debt and more duct tape around the current build process.

So, `esbuild`.

## Where is `esbuild` coming from?

We're using `esbuild` v0.18.20 only, while the latest is v0.19.3. We
need to update `design-system`'s storybook dependency, I think, to get a
more recent version of `esbuild`. I'm yet to figure this out and can use
some help. 🙂

Dockerfile

@@ -78,7 +78,7 @@ COPY ${PLUGIN_JARS} backend/plugins/
 COPY ./app/client/build editor/
 
 # Add RTS - Application Layer
-COPY ./app/client/packages/rts/package.json ./app/client/packages/rts/dist rts/
+COPY ./app/client/packages/rts/dist rts/
 
 RUN cd ./utils && npm install --only=prod && npm install --only=prod -g . && cd - \
   && chmod 0644 /etc/cron.d/* \

app/client/packages/rts/build.sh

@@ -3,18 +3,18 @@
 set -o errexit
 
 cd "$(dirname "$0")"
-rm -rf dist/
-# This is required for the first time build as node_modules is not present in the image
-yarn install --immutable
-yarn tsc && yarn tsc-alias
-# Install only production dependencies
-YARN_NM_HOISTING_LIMITS=workspaces yarn workspaces focus --production appsmith-rts
 
-# Copying node_modules directory into dist as rts server requires production dependencies to run server build properly.
-# This was previously being done in dockerfile which was copying the symlinks to image rather than the whole directory of shared modules (e.g. AST)
-# Also, we copy node_modules with -L flag in order to follow the symlinks for @shared folder and copy the contents instead of just the symlink
-cp -RL node_modules ./dist
-# Delete production dependencies
-rm -rf node_modules
-# Restore all dependencies
+root="$(git rev-parse --show-toplevel)"
+
 yarn install --immutable
+yarn run tsc --noEmit
+
+rm -rf dist
+exec "$root/app/client/node_modules/.bin/esbuild" src/server.ts \
+  --bundle \
+  --minify \
+  --sourcemap \
+  --platform=node \
+  --target="$(node --version | sed s/v/node/)" \
+  --outdir=dist/bundle \
+  --external:dtrace-provider

app/client/packages/rts/src/server.ts

@@ -1,5 +1,4 @@
 import http from "http";
-import path from "path";
 import express from "express";
 import { Server } from "socket.io";
 import type { LogLevelDesc } from "loglevel";
@@ -35,16 +34,10 @@ const io = new Server(server, {
   path: RTS_BASE_PATH,
 });
 
-// Initializing Sockets
 initializeSockets(io);
 
 // parse incoming json requests
 app.use(express.json({ limit: "5mb" }));
-// Initializing Routes
-app.use(express.static(path.join(__dirname, "static")));
-app.get("/", (_, res) => {
-  res.redirect("/index.html");
-});
 
 app.use(`${RTS_BASE_API_PATH}/ast`, ast_routes);
 app.use(`${RTS_BASE_API_PATH}`, health_check_routes);

deploy/docker/fs/opt/appsmith/templates/supervisord/application_process/rts.conf

@@ -1,5 +1,5 @@
 [program:rts]
-directory=/opt/appsmith/rts
+directory=/opt/appsmith/rts/bundle
 command=/opt/appsmith/run-with-env.sh node server.js
 priority=15
 autostart=true