docker 中编译 PHP 的 event 扩展出错

[salamanderMH]

问题

这是我编译好的镜像 salamandermh/php-cli:7.1 然后查看docker run -it salamandermh/php-cli:7.1 bash发现

php -m
PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/local/lib/php/extensions/no-debug-non-zts-20160303/event.so' - Error relocating /usr/local/lib/php/extensions/no-debug-non-zts-20160303/event.so: php_sockets_le_socket: symbol not found in Unknown on line 0
[PHP Modules]
bcmath
bz2
Core
ctype
curl
date
dom
fileinfo
filter
ftp
gd
hash
iconv
imagick
json
libxml
mbstring
mongodb
mysqli
mysqlnd
openssl
pcntl
pcre
PDO
pdo_mysql
pdo_sqlite
Phar
posix
readline
redis
Reflection
session
SimpleXML
sockets
SPL
sqlite3
standard
swoole
tokenizer
xml
xmlreader
xmlwriter
xsl
Zend OPcache
zip
zlib

[Zend Modules]
Zend OPcache

php_sockets_le_socket: symbol not found in Unknown on line 0, 看样子是 sockets 扩展没找到,但是sockets扩展已经加载了,不知道是哪里没配置对

Dockerfile在这里

[salamanderMH]

解决了,是扩展加载顺序问题

because event was being loaded before sockets from the .ini's in /usr/local/etc/php/conf.d

Going into your image, the ordering of these files determines which are loaded first
```
/usr/local/etc/php/conf.d # ls -al
total 28
drwxr-xr-x 2 root root 4096 Jul 9 20:39 .
drwxr-xr-x 7 root root 4096 Jul 9 20:01 ..
-rw-r--r-- 1 root root 19 Jul 9 18:39 docker-php-ext-event.ini
-rw-r--r-- 1 root root 82 Jul 9 18:39 docker-php-ext-opcache.ini
-rw-r--r-- 1 root root 23 Jul 9 18:38 docker-php-ext-pdo_mysql.ini
-rw-r--r-- 1 root root 21 Jul 9 18:38 docker-php-ext-sockets.ini
-rw-r--r-- 1 root root 20 Jun 28 02:48 docker-php-ext-sodium.ini
```
`docker-php-ext-enable` allows for a flag to change the `.ini` name, so doing a `docker-php-ext-enable --ini-name zz-event.ini event` has it load in last.

正确的 Dockerfile
```
FROM php:7.1.30-cli-alpine3.9

# Packages
RUN apk add --no-cache \
autoconf \
build-base \
linux-headers \
libevent-dev \
openldap-dev \
imagemagick-dev

RUN docker-php-ext-install sockets pdo_mysql opcache

RUN docker-php-ext-enable opcache && \
pecl install event-2.5.3 && \
docker-php-ext-enable --ini-name zz-event.ini event


ENV COMPOSER_ALLOW_SUPERUSER 1
ENV COMPOSER_HOME /tmp
ENV COMPOSER_VERSION 1.5.1


RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/bin --filename=composer \
&& composer --ansi --version --no-interaction

VOLUME /var/www
WORKDIR /var/www

CMD [ "php", "./public/server.php" ]
```





[github issue]( https://github.com/docker-library/php/issues/857)