feat: add healthcheck to echoserver container image

The integration tests need the echoserver to be healthy before starting,
to avoid failing due to the server not listening.

This bumps the echoserver version to 0.3.0.

testing/v8serialize-echo/Dockerfile

@@ -2,6 +2,7 @@ ARG DENO_VERSION NODE_VERSION DNT_NODE_VERSION DNT_DENO_VERSION
 
 FROM denoland/deno:${DENO_VERSION:-alpine} AS echoserver-deno
 
+RUN apk add --no-cache curl
 COPY main.ts .
 USER deno
 
@@ -15,6 +16,10 @@ EXPOSE 8000
 
 CMD ["run", "--no-remote", "--allow-net", "--allow-env", "main.ts"]
 
+HEALTHCHECK --start-period=20s --start-interval=1s \
+  CMD curl --fail --silent --show-error -o /dev/null \
+    "http://localhost:${V8SERIALIZE_PORT:?}/?healthcheck"
+
 
 FROM denoland/deno:bin-${DNT_DENO_VERSION:-latest} AS dnt-deno
 
@@ -33,7 +38,7 @@ RUN npm pack ./npm
 FROM node:${NODE_VERSION:-alpine} AS echoserver-node
 ARG ECHOSERVER_VERSION
 
-RUN apk add --no-cache tini
+RUN apk add --no-cache tini curl
 WORKDIR /app
 
 RUN --mount=from=npm-package,source=/build/,target=/build/ \
@@ -50,3 +55,7 @@ USER node
 
 ENTRYPOINT ["/sbin/tini", "--", "docker-entrypoint.sh"]
 CMD ["-e", "require('v8serialize-echoserver').main()"]
+
+HEALTHCHECK --start-period=20s --start-interval=1s \
+  CMD curl --fail --silent --show-error -o /dev/null \
+    "http://localhost:${V8SERIALIZE_PORT:?}/?healthcheck"

testing/v8serialize-echo/docker-bake.hcl

@@ -1,4 +1,3 @@
-ECHOSERVER_VERSION = "0.1.0"
 DNT_NODE_VERSION = "22"
 DNT_DENO_VERSION = "1.46.1"
 

testing/v8serialize-echo/main.ts

@@ -5,7 +5,7 @@ import consumers from "node:stream/consumers";
 import { inspect } from "node:util";
 import v8 from "node:v8";
 
-export const ECHOSERVER_VERSION = "0.2.0";
+export const ECHOSERVER_VERSION = "0.3.0";
 
 function parseSettings() {
   const logWithColor: boolean = env.V8SERIALIZE_LOG_WITH_COLOR === "true";