fix(fast-time-server): build container image from Cargo workspace root

The crate's Cargo.toml uses workspace inheritance (.workspace = true)
for every package field and dependency. The previous Containerfile
copied only the crate-local Cargo.toml into the build context, which
caused cargo to fail with 'failed to find a workspace root' (exit 101)
the moment PR #5305 added this crate to the root workspace.

Rewrite the Containerfile to copy the root Cargo.toml/Cargo.lock and
the workspace members (crates/, a2a-agents/, mcp-servers/rust/), then
build with 'cargo build --release -p fast-time-server'. The build now
runs from the repo root; see the compose and Makefile changes in
sibling commits for the matching wiring.

Also remove the orphan Dockerfile: it had the identical bug, no
consumers in the repo (no Makefile, compose, CI, or Helm reference
it), and an inconsistent port (8880 vs the 9080 the README documents).
Add Containerfile to the .dockerignore allow-list for parity with the
slow-time-server pattern.

Signed-off-by: Jonathan Springer <jps@s390x.com>
(cherry picked from commit 6034102)

Author: jonpspri

.dockerignore

@@ -35,6 +35,7 @@ attic/
 !mcp-servers/rust/fast-time-server/Cargo.toml
 !mcp-servers/rust/fast-time-server/src/
 !mcp-servers/rust/fast-time-server/src/**
+!mcp-servers/rust/fast-time-server/Containerfile
 !mcp-servers/rust/filesystem-server/
 !mcp-servers/rust/filesystem-server/Cargo.toml
 !mcp-servers/rust/filesystem-server/src/

mcp-servers/rust/fast-time-server/Containerfile

@@ -1,41 +1,43 @@
 # syntax=docker/dockerfile:1
 # ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 # fast-time-server - Ultra-fast MCP server in Rust for performance testing
-# Multi-stage build for minimal image size (~15MB)
+#
+# This image is built from the workspace root so the crate's `Cargo.toml`
+# can resolve `.workspace = true` inheritance from the root manifest.
+#
+# Build (from the repo root):
+#   docker build -f mcp-servers/rust/fast-time-server/Containerfile -t IMG .
+#
+# Or via the crate's Makefile (handles the relative path automatically):
+#   cd mcp-servers/rust/fast-time-server && make container-build
 # ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
 
 # =============================================================================
-# Build stage - Rust compilation
+# Build stage - Rust compilation against the full Cargo workspace
 # =============================================================================
 FROM docker.io/rustlang/rust:nightly-slim AS builder
 
 WORKDIR /app
 
-# Install build dependencies
 RUN apt-get update && apt-get install -y --no-install-recommends \
-    pkg-config \
+        pkg-config \
     && rm -rf /var/lib/apt/lists/*
 
-# Copy manifests first for dependency caching
-COPY Cargo.toml Cargo.lock* ./
+# Copy the Cargo workspace. All members declared in the root manifest must
+# exist on disk for `cargo build -p ...` to parse the workspace, even though
+# only fast-time-server and its transitive deps actually get compiled.
+COPY Cargo.toml Cargo.lock ./
+COPY crates ./crates
+COPY a2a-agents ./a2a-agents
+COPY mcp-servers/rust ./mcp-servers/rust
 
-# Create dummy src to cache dependencies (Docker layer caching optimization)
-RUN mkdir src && echo "fn main() {}" > src/main.rs
-RUN cargo build --release && rm -rf src target/release/deps/fast_time_server* target/release/.fingerprint/fast-time-server*
-
-# Copy actual source
-COPY src ./src
-
-# Build release binary (touch to ensure mtime is newer than cached artifacts)
-RUN touch src/main.rs && cargo build --release
+RUN cargo build --release -p fast-time-server
 
 # =============================================================================
-# Runtime stage - Minimal distroless-like image
+# Runtime stage - Minimal Debian image with just the compiled binary
 # =============================================================================
 FROM docker.io/library/debian:trixie-slim
 
-# Install runtime deps (ca-certificates + curl for health checks) and create
-# the non-root mcpuser in a single layer.
 RUN apt-get update && apt-get install -y --no-install-recommends \
         ca-certificates \
         curl \
@@ -45,26 +47,21 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 
 WORKDIR /app
 
-# Copy binary from builder
 COPY --from=builder /app/target/release/fast-time-server /app/fast-time-server
 
 USER mcpuser
 
-# Expose default port
 EXPOSE 9080
 
-# Environment configuration
 ENV BIND_ADDRESS=0.0.0.0:9080
 ENV RUST_LOG=info
 
-# Labels for container registry
 LABEL org.opencontainers.image.title="fast-time-server"
 LABEL org.opencontainers.image.description="Ultra-fast MCP server in Rust for performance testing"
 LABEL org.opencontainers.image.source="https://github.com/IBM/mcp-context-forge"
 LABEL org.opencontainers.image.vendor="IBM"
 LABEL org.opencontainers.image.licenses="Apache-2.0"
 
-# Health check using curl (more reliable than wget in slim images)
 HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
     CMD curl -sf http://localhost:9080/health || exit 1