feat: add elasticsearch-mcp validation

Build and validate Elasticsearch MCP server for search/indexing.

Changes:
- docker-compose.yml: Updated elasticsearch-mcp to use custom Dockerfile
  and ES_URL env var (not ELASTICSEARCH_URL)
- dockerfiles/elasticsearch-mcp/Dockerfile: Added custom Dockerfile with
  fix to pass "stdio" subcommand to ENTRYPOINT
- STATUS.md: Added elasticsearch-mcp as validated MCP (v0.2.1, 22MB)

Validation:
- Container builds successfully from Rust source (22MB)
- Fixed Dockerfile to pass "stdio" subcommand to entry point
- MCP protocol handshake verified with initialize request
- Protocol version 2024-11-05 confirmed
- Server name: rmcp, version 0.2.1
- Requires ES_URL environment variable (not ELASTICSEARCH_URL)
- NOTE: Server is deprecated, superseded by Elastic Agent Builder
- Tested with proper --name flag for container

STATUS.md

@@ -30,6 +30,7 @@ Last validated: 2026-01-22
 - cloudron-mcp: Built (v0.1.0) - stdio-based, requires CLOUDRON_URL
 - docker-mcp: Built (v0.1.0) - stdio-based, Python-based, requires Docker socket
 - drawio-mcp: Built (v1.4.0) - stdio-based, TypeScript/pnpm, requires DRAWIO_URL
+- elasticsearch-mcp: Built (v0.2.1) - stdio-based, Rust-based, requires ES_URL
 - bash-language-server: Built (v5.6.0) - configured in crush.json via wrapper script
 - docker-language-server: Built (v0.0.0) - configured in crush.json via wrapper script
 - marksman: Built (2025-12-13) - configured in crush.json via wrapper script
@@ -55,6 +56,7 @@ Last validated: 2026-01-22
 | cloudron-mcp | Built | Container built from source (374MB). Fixed Dockerfile CMD to use dist/server.js. MCP stdio-based, requires CLOUDRON_URL env var. Version 0.1.0. |
 | docker-mcp | Built | Container built from Python source (188MB). Uses uv package manager. MCP stdio-based, requires Docker socket mount (/var/run/docker.sock). Version 0.1.0. |
 | drawio-mcp | Built | Container built from TypeScript source (302MB). Uses pnpm package manager. MCP stdio-based, requires DRAWIO_URL env var. Version 1.4.0. |
+| elasticsearch-mcp | Built | Container built from Rust source (22MB). Fixed Dockerfile to pass "stdio" subcommand. MCP stdio-based, requires ES_URL env var. NOTE: Server is deprecated. Version 0.2.1. |
 | bash-language-server | Built | Container built using prebuilt npm package (190MB). LSP configured in crush.json via wrapper script. Version 5.6.0. |
 | docker-language-server | Built | Container built from Go source (49.2MB). LSP configured in crush.json via wrapper script. Version 0.0.0. |
 | marksman | Built | Container built from prebuilt binary (144MB). LSP configured in crush.json via wrapper script. Version 2025-12-13. |

docker-compose.yml

@@ -385,11 +385,11 @@ services:
     image: kneldevstack-aimiddleware-elasticsearch-mcp
     build:
       context: ./vendor/mcp-server-elasticsearch
-      dockerfile: Dockerfile
+      dockerfile: ../../dockerfiles/elasticsearch-mcp/Dockerfile
     container_name: kneldevstack-aimiddleware-elasticsearch-mcp
     restart: unless-stopped
     environment:
-      - ELASTICSEARCH_URL=${ELASTICSEARCH_URL:-http://localhost:9200}
+      - ES_URL=${ES_URL:-http://localhost:9200}
       - ELASTICSEARCH_USERNAME=${ELASTICSEARCH_USERNAME}
       - ELASTICSEARCH_PASSWORD=${ELASTICSEARCH_PASSWORD}
     ports:

dockerfiles/elasticsearch-mcp/Dockerfile

@@ -0,0 +1,28 @@
+# Copyright Elasticsearch B.V. and contributors
+# SPDX-License-Identifier: Apache-2.0
+
+FROM rust:1.89@sha256:c50cd6e20c46b0b36730b5eb27289744e4bb8f32abc90d8c64ca09decf4f55ba AS builder
+
+WORKDIR /app
+
+COPY Cargo.toml Cargo.lock ./
+
+# Cache dependencies
+RUN mkdir -p ./src/bin && \
+    echo "pub fn main() {}" > ./src/bin/elasticsearch-core-mcp-server.rs && \
+    cargo build --release
+
+COPY src ./src/
+
+RUN cargo build --release
+
+#--------------------------------------------------------------------------------------------------
+
+FROM cgr.dev/chainguard/wolfi-base:latest
+
+COPY --from=builder /app/target/release/elasticsearch-core-mcp-server /usr/local/bin/elasticsearch-core-mcp-server
+
+ENV CONTAINER_MODE=true
+
+EXPOSE 8080/tcp
+ENTRYPOINT ["/usr/local/bin/elasticsearch-core-mcp-server", "stdio"]