add equivalent dependencies for rhel/centos

[joshsleeper]

changes

i did some digging and found the packages that add the required libraries on centos 7, so figured i'd suggest adding them to the docs so it's known information.

fixes

fixes #542

notes

technically this doesn't fix any open issues afaik, but I'll mark it as resolving the issue I opened while attempting to test it.

[CLAassistant]

All committers have signed the CLA.

[kuceb]

Looks like you also need libXtst, which is also a dependency for google-chrome-stable

[kuceb]

we should add libXtst and a -y so you don't have to manually approve them

[joshsleeper]

I was just matching package for package with the existing apt-get call, which doesn't seem to install libXtst.
Curious, is libXtst required to run the Electron version as well, or only Chrome Stable?

Regardless, if you want me to add libXtst, I'd like to add the equivalent dependency to the apt-get command as well.
Any idea what those packages are, or do I need to hunt em down?

Also, I'm fine adding the -y if you really want it, but I'm of the opinion that this seems to be code that a user would copy and paste to run. As such, I kinda feel like it's more appropriate to let the user manually accept the resulting dependencies. Thoughts?

[joshsleeper]

@bkucera any thoughts on my comments?

[kuceb]

I believe Ubuntu ships with that dependency already installed.
Also since must users come from the npm world, where packages are arguably less vetting and verified, and does not ask to confirm every package individually, I think -y is an okay addition

[kuceb]

And yes, it's required for electron

[joshsleeper]

@jennifer-shehane
any input on this?

1. should libXtst be added to both lines?
2. do you agree or disagree with adding -y to the commands?

I'm unsure if the libXtst dep is an actual requirement or not given that all of my systems have it pre-installed and I can't remove it without breaking other dep chains.

I'm also hesitant to add -y to the commands unless the core team likes that approach. @bkucera's stance about most of the users being npm friendly makes sense, but I would counter-point that just because they're npm friendly doesn't mean that the shell should suddenly act like npm. ;)
Either way, I'd defer to your stance on that one.

[kuceb]

we should add -y here too

[bahmutov]

So I was looking at the docs, and I think instead of adding every dependency here in Markdown, without really testing it, we could just

• keep existing list of Debian dependencies (since this is the most common image I believe)
• point at our https://github.com/cypress-io/cypress-docker-images repo where the dependencies are actually used to make and test images. In these docs we can say "for the up-to-date list see Docker image "

If a library is needed to run Cypress, one can always open an issue in cypress-docker-images with a test case that fails to execute, and adding the library solves

[joshsleeper]

what about something like this?

# Dependencies

If you are not using one of the above CI providers then make sure your system has the required dependencies installed.

An up-to-date list of required dependencies for supported platforms can be found in the `Dockerfile` for each platform in the [`cypress-io/cypress-docker-images`](https://github.com/cypress-io/cypress-docker-images) repository

I'm not sure I see the value in keeping only the debian list if we're going to suggest they check the Dockerfiles for an up-to-date list anyway, but if you feel strongly about it I can do that.

edit

upon further thought, I definitely don't like keeping the debian dep list. to your own point, keeping a list of exact deps, untested, here in Markdown, doesn't make a lot of sense. rather than have our debian dep list definitely become out of date at some point, i think we're much better off just directing them to the cypress-docker-images repo so we never have out of date dep docs again.

yay? nay?

[kuceb]

It's pretty easy to test the dependencies, you just spin up a vanilla docker container of "your distro here", then install everything. I just used docker run -it centos:7 bash for example.

[joshsleeper]

Right, but I think @bahmutov's point is that the docs can get out of lockstep with the actual dependencies, whereas referencing the Dockerfiles directly guarantees that when deps change, so do the docs people reference.

[jennifer-shehane]

Should this be closed @bkucera? Anything to pull from this PR?

[kuceb]

I think we should be referencing the dockerfiles like @bahmutov mentioned, so I'm for closing this

[joshsleeper]

Closing as requested!