Try with a custom "feature"

.devcontainer/devcontainer.json

@@ -28,10 +28,12 @@
 			"command": "alias k=kubectl"
 		},
 		"ghcr.io/devcontainers-contrib/features/rclone:1": {},
-		"./k3d": {},
-    "ghcr.io/devcontainers/features/nix:1": {
-      "flakeUrl": "https://github.com/eikek/devshell-tools"
-    }
+    "./k3d": {},
+    "ghcr.io/devcontainers/features/java:1": {
+        "version": "21",
+        "jdkDistro": "open"
+    },
+    "./solr": {}
 	},
 	"overrideFeatureInstallOrder": [
 		"ghcr.io/devcontainers-contrib/features/poetry",

.devcontainer/solr/devcontainer-feature.json

@@ -0,0 +1,18 @@
+{
+    "name": "solr",
+    "id": "solr",
+    "version": "1.0.0",
+    "description": "A feature adding solr",
+    "options": {
+      "solr_version": {
+        "type": "string",
+        "description": "solr version to install",
+        "proposals": ["9.8.0"],
+        "default": "9.8.0"
+      }
+    },
+  "installsAfter": [
+    "ghcr.io/devcontainers/features/java",
+    "ghcr.io/devcontainers-contrib/features/bash-command"
+  ],
+}

.devcontainer/solr/install.sh

@@ -0,0 +1,16 @@
+#!/bin/sh
+set -e
+
+echo "Activation SOLR feature"
+
+download_url="https://dlcdn.apache.org/solr/solr/$SOLR_VERSION/solr-$SOLR_VERSION.tgz"
+
+curl -sSL -o solr.tgz "$download_url"
+mkdir -p /opt
+tar -C /opt -xzf solr.tgz
+ln -snf "/opt/solr-$SOLR_VERSION" /opt/solr
+ln -snf /opt/solr/bin/solr /usr/local/bin/solr
+mkdir -p /opt/solr/server/logs
+chmod 777 /opt/solr/server/logs
+chmod 777 /opt/solr/bin
+chown -R vscode:vscode "/opt/solr-$SOLR_VERSION"