Add GitHub Codespaces integration

.devcontainer/Dockerfile

@@ -0,0 +1,15 @@
+FROM ubuntu:focal
+ARG APT_PACKAGES_DEPS="automake autotools-dev bsdmainutils build-essential libboost-filesystem-dev libboost-system-dev libboost-test-dev libboost-thread-dev libdb-dev libdb++-dev libevent-dev libminiupnpc-dev libqrencode-dev libqt5core5a libqt5dbus5 libqt5gui5 libtool libzmq3-dev pkg-config python3 qttools5-dev qttools5-dev-tools"
+ARG APT_PACKAGES_DEVENV="apt-utils bear black clang clang-tidy cppcheck curl dialog emacs flake8 gdb git htop isort less links lsb-release lsof lynx man manpages manpages-dev manpages-posix mc mypy net-tools netcat procps pydocstyle pyflakes3 pylama pylint python3-autopep8 python3-jedi python3-pip shellcheck sudo vim wget yapf3"
+ARG DEBIAN_FRONTEND="noninteractive"
+ARG LOGIN_GID=1000
+ARG LOGIN_UID=1000
+ARG LOGIN_USERNAME="vscode"
+ARG PYPI_PACKAGES_DEVENV="prospector==1.3.0 rope==0.18.0"
+RUN apt-get update \
+    && apt-get install --no-install-recommends -y ${APT_PACKAGES_DEPS} ${APT_PACKAGES_DEVENV} 2>&1 \
+    && pip3 install ${PYPI_PACKAGES_DEVENV} \
+    && groupadd --gid ${LOGIN_GID} ${LOGIN_USERNAME} \
+    && useradd -s /bin/bash --uid ${LOGIN_UID} --gid ${LOGIN_GID} -m ${LOGIN_USERNAME} \
+    && echo "${LOGIN_USERNAME} ALL=(root) NOPASSWD:ALL" > /etc/sudoers.d/${LOGIN_USERNAME} \
+    && chmod 0440 /etc/sudoers.d/${LOGIN_USERNAME}

.devcontainer/devcontainer.json

@@ -0,0 +1,21 @@
+{
+    "postCreateCommand": "./autogen.sh && ./configure --with-incompatible-bdb && make -C src/ bench/data/block413567.raw.h config/bitcoin-config.h test/data/asmap.raw.h",
+    "build": {
+        "dockerfile": "Dockerfile"
+    },
+    "runArgs": [
+        "--cap-add=SYS_PTRACE",
+        "--security-opt",
+        "seccomp=unconfined"
+    ],
+    "remoteUser": "vscode",
+    "settings": {
+        "terminal.integrated.shell.linux": "/bin/bash",
+        "terminal.integrated.shellArgs.linux": ["-l"]
+    },
+    "name": "",
+    "extensions": [
+        "ms-python.python",
+        "ms-vscode.cpptools"
+    ]
+}

.vscode/c_cpp_properties.json

@@ -0,0 +1,19 @@
+{
+    "configurations": [
+        {
+            "defines": [
+                "HAVE_CONFIG_H"
+            ],
+            "includePath": [
+                "${workspaceFolder}/src/**",
+                "/usr/include/"
+            ],
+            "intelliSenseMode": "gcc-x64",
+            "name": "",
+            "compilerPath": "/usr/bin/gcc",
+            "cppStandard": "gnu++11",
+            "cStandard": "gnu11"
+        }
+    ],
+    "version": 4
+}

.vscode/settings.json

@@ -0,0 +1,66 @@
+{
+    "extensions.ignoreRecommendations": true,
+    "extensions.showRecommendationsOnlyOnDemand": true,
+    "files.exclude": {
+        "**/*.a": true,
+        "**/*.cpp.log": true,
+        "**/*.la": true,
+        "**/*.lo": true,
+        "**/*.moc": true,
+        "**/*.o": true,
+        "**/.deps/": true,
+        "**/.dirstamp": true,
+        "**/.libs/": true,
+        "**/aclocal.m4": true,
+        "**/autom4te.cache/": true,
+        "**/config.log": true,
+        "**/config.status": true,
+        "**/configure": true,
+        "**/libtool": true,
+        "**/Makefile.in": true,
+        "**/moc_*.cpp": true,
+        "**/stamp-h1": true,
+        "build-aux/compile": true,
+        "build-aux/config.guess": true,
+        "build-aux/config.sub": true,
+        "build-aux/depcomp": true,
+        "build-aux/install-sh": true,
+        "build-aux/ltmain.sh": true,
+        "build-aux/missing": true,
+        "build-aux/test-driver": true,
+        "libbitcoinconsensus.pc": true,
+        "Makefile": true,
+        "share/qt/Info.plist": true,
+        "share/setup.nsi": true,
+        "src/bench/bench_bitcoin": true,
+        "src/bench/data/block413567.raw.h": true,
+        "src/bitcoin-cli": true,
+        "src/bitcoin-tx": true,
+        "src/bitcoin-wallet": true,
+        "src/bitcoind": true,
+        "src/config/bitcoin-config.h": true,
+        "src/config/bitcoin-config.h.in": true,
+        "src/Makefile": true,
+        "src/Makefile.in": true,
+        "src/obj/": true,
+        "src/qt/bitcoin-qt": true,
+        "src/qt/test/test_bitcoin-qt": true,
+        "src/secp256k1/exhaustive_tests": true,
+        "src/secp256k1/exhaustive_tests.log": true,
+        "src/secp256k1/exhaustive_tests.trs": true,
+        "src/secp256k1/gen_context": true,
+        "src/secp256k1/libsecp256k1.pc": true,
+        "src/secp256k1/Makefile": true,
+        "src/secp256k1/test-suite.log": true,
+        "src/secp256k1/tests": true,
+        "src/secp256k1/tests.log": true,
+        "src/secp256k1/tests.trs": true,
+        "src/test-suite.log": true,
+        "src/test/test_bitcoin": true,
+        "src/univalue/Makefile": true,
+        "src/univalue/test-suite.log": true,
+        "src/univalue/univalue-config.h": true,
+        "src/univalue/univalue-config.h.in": true
+    },
+    "telemetry.enableTelemetry": false
+}