Fix Devcontainer build errors (#4647)

Devcontainer Dockerfile has been updated to use Ubuntu 24.04 as the
base. Now devcontainer builds without errors. Tested with Podman on
Linux and Docker Desktop on Windows.

To avoid re-downloading and re-compiling whenever the container is
deleted, a named volume is mounted at /home/ubuntu/.cache.

Closes #4065

.devcontainer/devcontainer.json

@@ -5,8 +5,22 @@
 {
   "name": "carbon-lang",
   "build": {
-    "dockerfile": "../docker/ubuntu2204/base/Dockerfile"
+    "dockerfile": "../docker/ubuntu2404/base/Dockerfile"
   },
+  "mounts": [
+    {
+      "source": "carbon-cache",
+      "target": "/home/ubuntu/.cache",
+      "type": "volume"
+    }
+  ],
+  "containerUser": "ubuntu",
+  "remoteUser": "ubuntu",
+  // When using devcontainer with podman, you may see /workspace being owned
+  // by root. To work around this, uncomment the following lines
+  // "runArgs": [
+  //   "--userns=keep-id"
+  // ],
   "customizations": {
     "vscode": {
       "extensions": [

docker/README.md

@@ -15,31 +15,31 @@ ubuntu:22.04
 Building the base image is required.
 
 ```
-docker build -t carbon-ubuntu2204-base ./ubuntu2204/base
+docker build -t carbon-ubuntu2404-base ./ubuntu2404/base
 ```
 
 Build image using git repository
 
 ```bash
-docker build -t carbon-ubuntu2204 ./ubuntu2204/github
+docker build -t carbon-ubuntu2404 ./ubuntu2404/github
 ```
 
 Build image using copy instruction
 
 ```bash
-docker build -f ./ubuntu2204/Dockerfile -t carbon-ubuntu2204 ..
+docker build -f ./ubuntu2404/Dockerfile -t carbon-ubuntu2404 ..
 ```
 
 Run image
 
 ```bash
-docker run carbon-ubuntu2204
+docker run carbon-ubuntu2404
 ```
 
 Run image using specific file
 
 ```bash
-docker run carbon-ubuntu2204 bazel run //explorer -- ./explorer/testdata/print/format_only.carbon
+docker run carbon-ubuntu2404 bazel run //explorer -- ./explorer/testdata/print/format_only.carbon
 ```
 
 ### Using a mounted volume
@@ -51,5 +51,5 @@ cd ..
 ```
 
 ```bash
-docker run -w "/carbon-lang" -v "${PWD}:/carbon-lang" "carbon-ubuntu2204-base" bazel run "//explorer" -- "./explorer/testdata/print/format_only.carbon"
+docker run -w "/carbon-lang" -v "${PWD}:/carbon-lang" "carbon-ubuntu2404-base" bazel run "//explorer" -- "./explorer/testdata/print/format_only.carbon"
 ```

docker/ubuntu2404/Dockerfile

@@ -2,7 +2,7 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-FROM carbon-ubuntu2204-base as carbon-ubuntu2204-build
+FROM carbon-ubuntu2404-base as carbon-ubuntu2404-build
 
 COPY . /carbon-lang
 WORKDIR /carbon-lang
@@ -10,6 +10,6 @@ WORKDIR /carbon-lang
 # Build
 RUN bazel build //explorer
 
-FROM carbon-ubuntu2204-build
+FROM carbon-ubuntu2404-build
 
 CMD ["bazel", "run", "//explorer", "--", "./explorer/testdata/print/format_only.carbon"]

docker/ubuntu2404/base/Dockerfile

@@ -2,7 +2,7 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-FROM ubuntu:22.04 as carbon-ubuntu2204-base
+FROM ubuntu:24.04 as carbon-ubuntu2404-base
 
 # Install apt tools:
 #   git: Used by VS Code.
@@ -16,9 +16,11 @@ RUN apt-get update && \
   gnupg \
   golang \
   python3-pip \
-  python3.9 \
+  python3 \
   software-properties-common \
-  wget
+  wget \
+  nodejs \
+  npm
 
 ENV PATH="/root/go/bin:${PATH}"
 
@@ -32,13 +34,16 @@ RUN go install github.com/bazelbuild/buildtools/buildifier@5.1.0
 # Install LLVM from apt.llvm.org.
 RUN wget https://apt.llvm.org/llvm.sh
 RUN chmod +x llvm.sh
-RUN ./llvm.sh 15 all
+RUN ./llvm.sh 18 all
 RUN rm llvm.sh
 
 # Add the lib dir to the PATH. This helps Bazel find clang and VS Code find
 # clangd, without version suffixes.
-ENV PATH="/usr/lib/llvm-15/bin:${PATH}"
+ENV PATH="/usr/lib/llvm-18/bin:${PATH}"
 
 # Update pip and install black and pre-commit.
-RUN pip3 install -U pip
-RUN pip3 install black pre-commit
+RUN pip3 install black pre-commit --break-system-packages
+
+# Create .cache directory with proper ownership. We will mount a named volume
+# at this location to allow caching of bazel build files.
+RUN mkdir /home/ubuntu/.cache && chown -R ubuntu:ubuntu /home/ubuntu/.cache

docker/ubuntu2404/github/Dockerfile

@@ -2,7 +2,7 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-FROM carbon-ubuntu2204-base as carbon-ubuntu2204-github-build
+FROM carbon-ubuntu2404-base as carbon-ubuntu2404-github-build
 
 # Clone git repository
 RUN git clone https://github.com/carbon-language/carbon-lang
@@ -15,6 +15,6 @@ RUN pre-commit install
 # Build
 RUN bazel build //explorer
 
-FROM carbon-ubuntu2204-github-build
+FROM carbon-ubuntu2404-github-build
 
 CMD ["bazel", "run", "//explorer", "--", "./explorer/testdata/print/format_only.carbon"]