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.dockerignore

+.git

Dockerfile

+ARG UPSTREAM=debian:buster
+FROM ${UPSTREAM}
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN apt-get update -yqq
+
+RUN . /etc/os-release \
+&&  apt-get install -yq apt-transport-https ca-certificates curl \
+&&  curl -sSL -o /etc/apt/trusted.gpg.d/php.gpg https://packages.sury.org/php/apt.gpg \
+&&  echo "deb https://packages.sury.org/php/ $VERSION_CODENAME main" > /etc/apt/sources.list.d/php.list \
+&&  apt-get update -yqq
+
+RUN apt-get install -yq php8.0-cli
+
+COPY map-exts.php /usr/local/bin/map-exts.php
+
+ENTRYPOINT ["/usr/local/bin/map-exts.php"]

map-exts.php

+#!/usr/bin/env php
+<?php
+error_reporting(-1);
+
+$argv = $_SERVER['argv'];
+array_shift($argv);
+
+system('. /etc/os-release && echo "$ID-$VERSION_CODENAME":');
+
+foreach($argv as $version) {
+    fputs(STDERR, "\nProcessing PHP ${version}\n");
+    exec("apt-get install -yq php${version}-cli");
+
+    exec("apt-cache search ^php${version}- | awk '/^php${version}-/&&!/-dbg/{print$1}'", $packages, $error);
+    if ($error) {
+        die("code: $error");
+    }
+
+    $lines = [];
+    exec("apt-cache show " . implode(" ", $packages) . " | egrep '^(Package|Provides):'", $lines, $error);
+    if ($error) {
+        die("code: $error");
+    }
+
+    $map = [];
+
+    $package = null;
+    foreach ($lines as $line) {
+        [$header, $content] = explode(': ', $line, 2);
+        switch ($header) {
+            case 'Package':
+                $package = $content;
+                break;
+            case 'Provides':
+                if (!$package) {
+                    fputs(STDERR, "ignoring Provides without Package: $line\n");
+                    continue 2;
+                }
+                $thispackage = $package;
+                $package = null;
+                if (strpos($thispackage, "php${version}-") !== 0) {
+                    continue 2;
+                }
+                $matches = [];
+                preg_match_all("/\\bphp(?:\\Q${version}\\E)?\\-([^ ,]+)/", $content, $matches, PREG_PATTERN_ORDER);
+                if (!$matches) {
+                    continue 2;
+                }
+                $exts = array_unique($matches[1]);
+                if (!$exts) {
+                    continue 2;
+                }
+                foreach ($exts as $ext) {
+                    $map[$ext] = $thispackage;
+                }
+                break;
+            default:
+                fputs(STDERR, "ignoring: $line\n");
+        }
+    }
+
+    $builtins = [];
+    exec("php${version} -n -m | egrep -v '^(\\[|$)'", $builtins, $error);
+    if ($error) {
+        die("code: $error");
+    }
+
+    foreach($builtins as $builtin) {
+        $map[strtolower($builtin)] = 'builtin';
+    }
+
+    ksort($map);
+    printf("  \"%s\":\n", $version);
+    foreach ($map as $ext => $package) {
+        printf("    %s: %s\n", $ext, $package);
+    }
+}