Remove support for the Cedar-14 stack (#1110)

Since the stack is end of life and builds have been disabled:
https://devcenter.heroku.com/changelog-items/1943

There are only two temporarily exempted customers using Python, who
can switch to the Cedar-14 support branch if they still need to build
their Python apps (most of which haven't been built recently).

Closes @W-8054727@.

.travis.yml

@@ -23,10 +23,6 @@ jobs:
 
 env:
   jobs:
-    - STACK=cedar-14 TEST_CMD=test/run-deps
-    - STACK=cedar-14 TEST_CMD=test/run-versions
-    - STACK=cedar-14 TEST_CMD=test/run-features
-
     - STACK=heroku-16 TEST_CMD=test/run-deps
     - STACK=heroku-16 TEST_CMD=test/run-versions
     - STACK=heroku-16 TEST_CMD=test/run-features

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- Remove support for the Cedar-14 stack (#1110).
 
 ## v184 (2020-10-21)
 

Makefile

@@ -2,22 +2,17 @@
 .PHONY: check test builder-image buildenv deploy-runtimes tools
 
 STACK ?= heroku-18
-STACKS ?= cedar-14 heroku-16 heroku-18 heroku-20
+STACKS ?= heroku-16 heroku-18 heroku-20
 TEST_CMD ?= test/run-versions && test/run-features && test/run-deps
 ENV_FILE ?= builds/dockerenv.default
 BUILDER_IMAGE_PREFIX := heroku-python-build
 
-ifeq ($(STACK),cedar-14)
-	# Cedar-14 doesn't have a build image varient.
-	STACK_IMAGE_TAG := heroku/cedar:14
-else
-	# Converts a stack name of `heroku-NN` to its build Docker image tag of `heroku/heroku:NN-build`.
-	STACK_IMAGE_TAG := heroku/$(subst -,:,$(STACK))-build
-endif
+# Converts a stack name of `heroku-NN` to its build Docker image tag of `heroku/heroku:NN-build`.
+STACK_IMAGE_TAG := heroku/$(subst -,:,$(STACK))-build
 
 check:
 	@shellcheck -x bin/compile bin/detect bin/release bin/test-compile bin/utils bin/warnings bin/default_pythons
-	@shellcheck -x bin/steps/collectstatic bin/steps/eggpath-fix  bin/steps/eggpath-fix2 bin/steps/gdal bin/steps/geo-libs bin/steps/mercurial bin/steps/nltk bin/steps/pip-install bin/steps/pip-uninstall bin/steps/pipenv bin/steps/pipenv-python-version bin/steps/pylibmc bin/steps/python
+	@shellcheck -x bin/steps/collectstatic bin/steps/eggpath-fix  bin/steps/eggpath-fix2 bin/steps/gdal bin/steps/geo-libs bin/steps/mercurial bin/steps/nltk bin/steps/pip-install bin/steps/pip-uninstall bin/steps/pipenv bin/steps/pipenv-python-version bin/steps/python
 	@shellcheck -x bin/steps/hooks/*
 
 test:

bin/compile

@@ -35,17 +35,20 @@ ENV_DIR=$3
 # Export Path variables, for use in sub-scripts.
 export BUILD_DIR CACHE_DIR ENV_DIR
 
+if [[ "${STACK}" == "cedar-14" ]]; then
+  puts-warn "The Cedar-14 stack is no longer supported by the latest release of this buildpack."
+  puts-warn "Please switch to the Cedar-14 support branch by using this buildpack URL:"
+  puts-warn "https://github.com/heroku/heroku-buildpack-python#cedar-14"
+  puts-warn "For instructions on how to change the buildpacks used by an app, see:"
+  puts-warn "https://devcenter.heroku.com/articles/buildpacks#setting-a-buildpack-on-an-application"
+  exit 1
+fi
+
 # Set the base URL for downloading buildpack assets like Python runtimes.
 # The user can provide BUILDPACK_S3_BASE_URL to specify a custom target.
 # Note: this is designed for non-Heroku use, as it does not use the user-provided
 # environment variable mechanism (the ENV_DIR).
-if [[ "${STACK}" == "cedar-14" ]]; then
-  # Since Cedar-14 is EOL on 2020-11-02 it's not worth migrating it to the new bucket.
-  DEFAULT_S3_BASE_URL='https://lang-python.s3.amazonaws.com'
-else
-  DEFAULT_S3_BASE_URL='https://heroku-buildpack-python.s3.amazonaws.com'
-fi
-S3_BASE_URL="${BUILDPACK_S3_BASE_URL:-${DEFAULT_S3_BASE_URL}}"
+S3_BASE_URL="${BUILDPACK_S3_BASE_URL:-"https://heroku-buildpack-python.s3.amazonaws.com"}"
 # This has to be exported since it's used by the geo-libs step which is run in a subshell.
 # TODO: Stop exporting once the geo-libs step is removed or no longer uses `sub_env`.
 export S3_BASE_URL
@@ -66,7 +69,8 @@ PYPY27="pypy2.7"
 PYPY36="pypy3.6"
 
 # Which stack is used (for binary downloading), if none is provided (e.g. outside of Heroku)?
-DEFAULT_PYTHON_STACK="cedar-14"
+# TODO: Remove this and require that STACK be set explicitly.
+DEFAULT_PYTHON_STACK="heroku-18"
 
 # Common Problem Warnings:
 # This section creates a temporary file in which to stick the output of `pip install`.
@@ -131,7 +135,7 @@ export PYTHONUNBUFFERED=1
 # Set the locale to a well-known and expected standard.
 export LANG=en_US.UTF-8
 # `~/.heroku/vendor` is an place where the buildpack may stick pre-build binaries for known
-# C dependencies (e.g. libmemcached on cedar-14). This section configures Python (GCC, more specifically)
+# C dependencies. This section configures Python (GCC, more specifically)
 # and pip to automatically include these paths when building binaries.
 export C_INCLUDE_PATH=/app/.heroku/vendor/include:/app/.heroku/python/include:$C_INCLUDE_PATH
 export CPLUS_INCLUDE_PATH=/app/.heroku/vendor/include:/app/.heroku/python/include:$CPLUS_INCLUDE_PATH
@@ -265,12 +269,7 @@ source "$BIN_DIR/steps/eggpath-fix"
 # shellcheck source=bin/steps/mercurial
 source "$BIN_DIR/steps/mercurial"
 
-# Pylibmc support.
-# On cedar-14, libmemcached was not available. The buildpack provides its own version, instead.
-# shellcheck source=bin/steps/pylibmc
-source "$BIN_DIR/steps/pylibmc"
-
-# Support for Geo libraries. This is deprecated functionality, only functional on cedar-14.
+# Support for Geo libraries. This is deprecated functionality.
 # It is undocumented.
 # shellcheck source=bin/steps/geo-libs
 sub_env "$BIN_DIR/steps/geo-libs"

bin/steps/pylibmc

@@ -1,37 +0,0 @@
-#!/usr/bin/env bash
-
-# This script serves as the Pylibmc build step of the
-# [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python)
-# compiler.
-#
-# A [buildpack](https://devcenter.heroku.com/articles/buildpacks) is an
-# adapter between a Python application and Heroku's runtime.
-#
-# This script is invoked by [`bin/compile`](/).
-
-if [[ "$STACK" != "cedar-14" ]]; then
-    # libmemcached is pre-installed in the stack image so there is no need to vendor it.
-    return 0
-fi
-
-# The location of the pre-compiled libmemcached binary.
-VENDORED_MEMCACHED="${S3_BASE_URL}/${STACK}/libraries/vendor/libmemcache.tar.gz"
-
-# Syntax sugar.
-# shellcheck source=bin/utils
-source "$BIN_DIR/utils"
-
-# If pylibmc exists within requirements, use vendored libmemcached.
-if (pip-grep -s requirements.txt pylibmc &> /dev/null) then
-
-  if [ ! -d ".heroku/vendor/lib/sasl2" ]; then
-    echo "-----> Noticed pylibmc. Bootstrapping libmemcached."
-    mkdir -p .heroku/vendor
-    # Download and extract libmemcached into target vendor directory.
-    curl "$VENDORED_MEMCACHED" -s | tar zxv -C .heroku/vendor &> /dev/null
-    mcount "steps.vendor.pylibmc"
-  fi
-
-  LIBMEMCACHED=$(pwd)/vendor
-  export LIBMEMCACHED
-fi

bin/warnings

@@ -12,16 +12,6 @@ old-platform() {
   fi
 }
 
-pylibmc-missing() {
-  if grep -qi 'fatal error: libmemcached/memcached.h: No such file or directory' "$WARNINGS_LOG"; then
-    echo
-    puts-warn "Hello! There was a problem with your build related to libmemcache."
-    puts-warn "The Python library 'pylibmc' must be explicitly specified in 'requirements.txt' in order to build correctly."
-    puts-warn "Once you do that, everything should work as expected.   -- Much Love, Heroku."
-    mcount 'warnings.libmemcache'
-  fi
-}
-
 scipy-included() {
   if grep -qi 'running setup.py install for scipy' "$WARNINGS_LOG"; then
     echo
@@ -58,7 +48,6 @@ six-included() {
 
 show-warnings() {
   old-platform
-  pylibmc-missing
   scipy-included
   distribute-included
   six-included

builds/cedar-14.Dockerfile

@@ -1,21 +0,0 @@
-FROM heroku/cedar:14
-
-ENV WORKSPACE_DIR="/app/builds" \
-    S3_BUCKET="lang-python" \
-    S3_PREFIX="cedar-14/" \
-    STACK="cedar-14"
-
-RUN apt-get update \
-    && DEBIAN_FRONTEND=noninteractive apt-get install --no-install-recommends -y \
-        libsqlite3-dev \
-        python3-pip \
-        realpath \
-    && rm -rf /var/lib/apt/lists/*
-
-WORKDIR /app
-
-COPY requirements.txt /app/
-# Can't use `--disable-pip-version-check --no-cache-dir` since not supported by Ubuntu 14.04's pip.
-RUN pip3 install -r /app/requirements.txt
-
-COPY . /app

builds/libraries/vendor/libmemcache

@@ -1,45 +0,0 @@
-#!/usr/bin/env bash
-# Build Path: /app/.heroku/vendor/
-
-OUT_PREFIX=$1
-
-if [[ $S3_PREFIX != "cedar-14" ]]; then
-    echo "libmemcached only needs to be built for cedar-14, since newer stacks include it in the base image"
-    exit 1
-fi
-
-# fail hard
-set -o pipefail
-# fail harder
-set -eux
-
-DEFAULT_VERSION="1.0.18"
-dep_version=${VERSION:-$DEFAULT_VERSION}
-dep_dirname=libmemcached-${dep_version}
-dep_archive_name=${dep_dirname}.tar.gz
-dep_url=https://launchpad.net/libmemcached/1.0/${dep_version}/+download/${dep_archive_name}
-
-# SASL Support.
-echo "-----> Building cyrus-sasl 2.1.26…"
-
-curl -LO ftp://ftp.cyrusimap.org/cyrus-sasl/cyrus-sasl-2.1.26.tar.gz
-# FTP doesn't play well with piping into tar xz
-tar xzf cyrus-sasl-2.1.26.tar.gz
-
-pushd cyrus-sasl-2.1.26
-./configure --prefix=${OUT_PREFIX} --with-plugindir=${OUT_PREFIX}lib/sasl2 --with-configdir=${OUT_PREFIX}lib/sasl2
-
-make -s -j 9
-make install -s
-popd
-
-echo "-----> Building libmemcached ${dep_version}…"
-
-curl -L ${dep_url} | tar xz
-pushd ${dep_dirname}
-CPPFLAGS=-I${OUT_PREFIX}/include LDFLAGS=-L${OUT_PREFIX}/lib ./configure --prefix=${OUT_PREFIX} --without-memcached
-make -s -j 9
-make install -s
-popd
-
-echo "-----> Done."

test/run-features

@@ -80,10 +80,6 @@ testPipenvPythonVersion2_7() {
 }
 
 testPipenvPythonFullVersion() {
-  # Python 3.7+ requires newer libssl than is present on Cedar-14.
-  if [[ "${STACK}" = "cedar-14" ]]; then
-    return
-  fi
   compile "pipenv-full-version"
   assertCaptured "3.7.8"
   # Can't use `assertCapturedSuccess` since stderr contains:
@@ -140,7 +136,7 @@ testHooks() {
     SOME_APP_CONFIG_VAR
     STACK
   )
-  if [[ "${STACK}" == "cedar-14" || "${STACK}" == "heroku-16" ]]; then
+  if [[ "${STACK}" == "heroku-16" ]]; then
     # Remove "OLDPWD" from expected_env_vars since for bash <4.4 it's not exported to subshells:
     # https://github.com/heroku/heroku-buildpack-python/pull/1011#issuecomment-665117835
     read -ra expected_env_vars <<< "${expected_env_vars[@]/OLDPWD/}"

test/run-versions

@@ -112,10 +112,6 @@ testPython3_6_warn() {
 }
 
 testPython3_7() {
-  # Python 3.7+ requires newer libssl than is present on Cedar-14.
-  if [[ "${STACK}" = "cedar-14" ]]; then
-    return
-  fi
   compile "python3_7"
   assertCaptured "Installing ${LATEST_37}"
   assertNotCaptured "security update"
@@ -125,10 +121,6 @@ testPython3_7() {
 }
 
 testPython3_7_warn() {
-  # Python 3.7+ requires newer libssl than is present on Cedar-14.
-  if [[ "${STACK}" = "cedar-14" ]]; then
-    return
-  fi
   compile "python3_7_warn"
   assertCaptured "Installing python-3.7.8"
   assertCaptured "security update!"
@@ -137,10 +129,6 @@ testPython3_7_warn() {
 }
 
 testPython3_8() {
-  # Python 3.7+ requires newer libssl than is present on Cedar-14.
-  if [[ "${STACK}" = "cedar-14" ]]; then
-    return
-  fi
   compile "python3_8"
   assertCaptured "Installing ${LATEST_38}"
   assertNotCaptured "security update"
@@ -150,10 +138,6 @@ testPython3_8() {
 }
 
 testPython3_8_warn() {
-  # Python 3.7+ requires newer libssl than is present on Cedar-14.
-  if [[ "${STACK}" = "cedar-14" ]]; then
-    return
-  fi
   compile "python3_8_warn"
   assertCaptured "Installing python-3.8.5"
   assertCaptured "security update!"
@@ -162,10 +146,6 @@ testPython3_8_warn() {
 }
 
 testPython3_9() {
-  # Cedar-14 is EOL, so we're not building new major Python versions for it.
-  if [[ "${STACK}" = "cedar-14" ]]; then
-    return
-  fi
   compile "python3_9"
   assertCaptured "Installing ${LATEST_39}"
   assertNotCaptured "security update"
@@ -175,10 +155,6 @@ testPython3_9() {
 }
 
 testPython3_9_warn() {
-  # Cedar-14 is EOL, so we're not building new major Python versions for it.
-  if [[ "${STACK}" = "cedar-14" ]]; then
-    return
-  fi
   # Can't test the version warning until there is at least one old version of Python 3.9.
   if [[ "${LATEST_39}" = "python-3.9.0" ]]; then
     return