Access to external resource blocked by CORS policy

Open
#187 3 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
30/100
Issue type
Bug
Clarity
Needs clarification
Activity status
Stale
Tech stack
javascript
Domain
backend

Research direction

Reproduce the prerender request that triggers the CORS preflight, using the Google Fonts URL and the Contentful-backed page described in the report. Compare localhost and production behavior, then establish whether external resources can load during prerendering; done means the behavior is fixed or its production limitation is clearly documented.

Written by the indexing model from the issue text.

Description

When trying to test prerender I get a failure with the following error:

019-08-26T11:15:21.130Z { source: 'javascript',
  level: 'error',
  text:
   'Access to font at \'https://fonts.gstatic.com/s/montserrat/v14/JTURjIg1_i6t8kCHKm45_cJD3gnD_vx3rCs.woff2\' from origin \'http://localhost:2200\' has been blocked by CORS policy: Request header field x-prerender is not allowed by Access-Control-Allow-Headers in preflight response.',
  timestamp: 1566818121129.915,
  url: 'http://localhost:2200/experience/play' }
2019-08-26T11:15:21.131Z - 0 https://fonts.gstatic.com/s/montserrat/v14/JTURjIg1_i6t8kCHKm45_cJD3gnD_vx3rCs.woff2
2019-08-26T11:15:21.131Z { source: 'network',
  level: 'error',
  text: 'Failed to load resource: net::ERR_FAILED',
  timestamp: 1566818121130.127,
  url:
   'https://fonts.gstatic.com/s/montserrat/v14/JTURjIg1_i6t8kCHKm45_cJD3gnD_vx3rCs.woff2',
  networkRequestId: '1000027665.19' }

Google fonts isn't mission critical for render, however I am also loading content dynamically from a CMS (https://contentful.com) that is. Metadata and all content is loaded here. If the policy can't be bypassed then prerender is effectively useless for my use case. I'm not an expert on CORS here, if this is only an issue for localhost then this may not be a problem, however if the same thing would happen on production then it would be a problem.

Any recommendations?

Dominant language
JavaScript
Stars
921
Forks
185
No merged PRs in 30d

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from prerender/prerender-node

All issues in prerender/prerender-node

Similar issues

More JavaScript issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.