docker-php-ext-install intl fails

[robbydooo]

Hi Guys,

I have been trying to enable the intl extension and I have been running into troubles as it keeps failing.

I get:

checking for icu-config... no
checking for location of ICU headers and libraries... not found
configure: error: Unable to detect ICU prefix or no failed. Please verify ICU install prefix and make sure icu-config works.

I fixed this by running:
apt-get install libicu-dev

Rerunning the docker-php-ext-install intl then fails again with the following:

Checking whether g++ accepts -g... no
checking how to run the C++ preprocessor... /lib/cpp
configure: error: in `/usr/src/php/ext/intl':
configure: error: C++ preprocessor "/lib/cpp" fails sanity check
See `config.log' for more details

Is this a bug? The container doesn't appear to have the C++ compiler installed.
To fix i used:
apt-get install g++

Now the extension installs as expected.

I am using php:5.6-apache for reference.

Hope this helps.

Thanks,
Rob

[yosifkit]

That is as expected. We only install the minimal requirement to run php; any dependencies of extra modules you add would need to be added as well. Some packages could just be required for building the new module and could then be combined in one RUN line so that an apt-get purge could remove the items no longer needed.

[tianon]

Adding g++ seems reasonable though, IMO, since it's needed to compile some
of the core modules.

[robbydooo]

Thanks for the response, I would say from an outsiders point of view that the name "docker-php-ext-install" to me at least indicates that the script is installing the extension and any dependencies.

The issue is that unless you know which dependencies are required to install an extension you end up running it several times to find out where it fails and then google the error :-) .

Im not suggesting that you should add every dependency under the sun to the container, I am just explaining that the current implementation has some confusion to it.

I don't like describing a problem unless I can suggest something to resolve it although this is a difficult one.

So here are some suggestions:

1. Add an inline message at install time to say that this could fail if you do not install the dependencies. (Better than letting it fail without knowing why)
2. When an extension is added to the container, store the list of dependencies required and run an apt-get against them. (If you want to install the extension you are going to need them!)
3. The same as number 2 but maybe with a flag to either install or not install the dependencies incase you want to manually control this.

I am just trying to think of ways of removing barriers for people who want to use the image but then get stuck when they need to install the dependencies.

If I can help at all with the documentation for docker-php-ext-install let me know as I only stumbled upon this by accident reading the other issues.

[moacirosa]

I'm not sure but after facing the same problem (solved in the same way @robbydooo did) I've realized that Symfony Standard Edition (through its symfony/intl component) and CakePHP >= 3 both depend on intl php extension.

I've found some references to intl extension in Zend2 and Wordpress as well. Then considering that some important PHP frameworks/libs require (or at least make use of this extension) this extension it could be interesting make it easier to enable it.

What do you think guys?

[wiktor-obrebski]

+1 for intl available by default.

[jacobalberty]

Random thrown in suggestion, why include a manifest of extensions in addition to the script that provides preinstall and postinstall commands (g++ isnt likely to be needed AFTER intl is installed so may as well remove it and clean up after install)

[baptistedonaux]

+1 same fail. And +1 to enable intl by default !

[mbohal]

I don't think it would be a good idea to enable intl be default.

I use docker for development only, so I might see things from a different perspective, but I like having to deal with my dependencies. It allows me to have a good idea of what has to be installed at the production environment. Silently installed dependencies could lead to a missing dependency on production.

[docteurklein]

Even if it's not included by default, it would be cool if we provide an example of a way to install it (docment an example Dockerfile or something).

[docteurklein]

A working example:

FROM php:5.6
RUN apt-get update && apt-get install -y zlib1g-dev libicu-dev g++
RUN docker-php-ext-configure intl
RUN docker-php-ext-install intl

[robbydooo]

I agree that it is not the requirement to install by default as such but I would expect docker-php-ext-install/docker-php-ext-configure to not die in the current way.

To me it doesn't make sense to have a tool that should install libraries fail because the required dependancies are not installed. I would expect it to at least throw a useful error (E.g run apt get install XYZ).

Maybe there should be another script docker-php-install-ext-dependencies that docker-php-ext-install could call if they are not installed to handle this issue.

Based on the required extensions it could build a list of dependencies to install and install them. You could then add a flag to the docker-php-ext-install such as --install-dependencies to auto handle this.
That way people that wish to handle the dependencies manually can do so and the other people can benefit from an easy install.

What do you think?

[docteurklein]

I agree it's not easy to know what went wrong and which package to install in order to get an extension to work.

But It should be the php (pecl) docs role, not docker-php-ext-*.