Metamask-extension: Firefox plugin does not connect to private network

[generalpiston]

Expected Behavior

Connect to private network that is not localhost should work in firefox.

Actual Behavior

Loads infinitely.

Browser

Firefox

Operating System

Mac OS X 10.12.6

Extra

Testing in chrome and it works. Only a firefox issue.

[danfinlay]

You'll have to look at the Network tab of the background inspector to see why the request is failing:

https://metamask.helpscoutdocs.com/article/21-how-to-get-logs-and-help-metamask-support-and-diagnose-your-issue

[generalpiston]

@danfinlay apparenty you need to turn on debugging in firefox to see network events. Here's are the logged network events:

Apparently there's an OPTIONS request which isn't completing.

Request Headers

OPTIONS / HTTP/1.1
Host: mobidex.io:8545
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:59.0) Gecko/20100101 Firefox/59.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Access-Control-Request-Method: POST
Access-Control-Request-Headers: content-type
Origin: moz-extension://e3f3eef1-98b4-fe43-ab50-db2eb160bd7d
Connection: keep-alive

[danfinlay]

Could you also try switching your network provider in MetaMask? Just try switching the network to another one (like "Main") and back again.

[danfinlay]

The OPTIONS request seems to be going to mobidex.io, and that's strange, I don't know of any requests we make to mobidex.

@danjm @kumavis look familiar to you?

[generalpiston]

@danfinlay I set it up to point to mobidex. That endpoint is just a parity node.

I've switched back and forth between several networks, but connecting to a non-local parity node does not work in Firefox. It works just fine in chrome.

[Tbaut]

Same problem here with the beta version, running Parity locally. I can't show you my logs because I don't have the ability to show the console from the popup (ctrl+shift+i opens it but asks to reload... and I couldn't manage to get the tab reload without closing)

[petri]

Same issue here, running Parity locally as well. Connecting to it using Metamask on Chrome works fine, and connecting to other networks works fine in both.

[vincentserpoul]

Same here, local parity, it's the OPTIONS request that doesn't go through

I will try to see if we can simply allow the OPTIONS request in parity

[danfinlay]

Since this works in Chrome and not Firefox, I think this may be fixed on our master branch.

The problem is that Mozilla has stopped merging our new versions, because they've had some issues reproducing our builds (our builds are not perfectly deterministic).

We are making Firefox publication a high priority, but in the meanwhile, for proper behavior, you may need to use another browser.

[danfinlay]

@kumavis thinks this looks like a CORS issue. We should write a blog post about that.

[vincentserpoul]

definitely a CORS issue.
Is there anything we can do to help?

[danfinlay]

On Geth, there's a flag for setting the CORS setting. I don't know what local client you're using, you'll have to configure it correctly:
https://metamask.helpscoutdocs.com/article/29-using-a-local-node

[petri]

Perhaps relevant (when using Parity): https://github.com/paritytech/parity/issues/7541

[Tbaut]

Launching parity with --jsonrpc-cors all allows metamask to connect indeed, it would be safer by only allowing metamask's domain, may someone point me to the right one? (Reminder, I can't check myself and open the dev console on metamask for some reason)

[danfinlay]

The cors domain will vary depending on the browser you're using. In Chrome, it's chrome-extension://nkbihfbeogaeaoehlefnkodbefgpgknn. Let us know if you research and find the domain for other browsers.

https://metamask.helpscoutdocs.com/article/29-using-a-local-node

[Tbaut]

Hey Dan, the issue is for Firefox.

[vincentserpoul]

parity --jsonrpc-cors all indeed works.
I tried to set it with other values, according to the request I make (for instance http://localhost:8545), but no success.
I'm running in docker, so that might be the reason.

I only use this for dev, so I don't really mind the --jsonrpc-cors all

[Tbaut]

@danfinlay could you please provide me the domain for firefox, I wouldn't want for security reasons to tell users to leave --jsonrpc-cors open to any app.

[vincentserpoul]

@Tbaut --rpccorsdomain=moz-extension://36ff4990-4bdd-4d81-bbd7-91fcbcae8d06

[Tbaut]

Thanks, however, it didn't work with this domain. It might be architecture specific.

[vincentserpoul]

are you using geth or parity?
If it doesn't work, just go to firefox, type about:debugging in the address
launch the debug window for metamask
Launch metamask and click on the network panel.
Click on any of the request, you should see the domain in the headers.

I'm using firefox 61.0b2 developer edition on archlinux

[AyushyaChitransh]

I am using parity, and faced the same issue. I was able to connect to remote RPC using web3-console but was unable to connect to same RPC using metamask.

However, on using --jsonrpc-cors all I was able to get it working using metamask also.

[Tbaut]

Thanks @vincentserpoul for the walkthrough. I'm now using successfuly --jsonrpc-cors moz-extension://ae62fc16-c916-4c24-9a36-97f5a850f25c on parity.
@AyushyaChitransh, consider specific domain rather than all as this reduces the attack surface.

[danfinlay]

Is anyone here having a problem that isn't solved by running their local node with a CORs flag?

Closing until someone can confirm this is our issue.