Performance issues to connect to Cypress Dashboard when behind a proxy

[Roemer]

Current behavior

When running Cypress behind a corporate proxy, there is always a 1 minute overhead for each Cypress run when connecting to the Cypress Dashboard. The problem seems to be the "preflight" request, which first tries to connect to api-proxy.cypress.io without the system-wide defined proxy and then after 1 minute, it tries api.cypress.io with the correct proxy which then responds immediately.

Desired behavior

No response

Test code to reproduce

This is a bit harder to reproduce easily. You need a setup where internet access is blocked unless a specific proxy is used, then define this proxy as http_proxy and https_proxy environment variable and run Cypress.

Cypress Version

13.5.0

Node version

v18.17.1

Operating System

Docker Container (Debian)

Debug Logs

cypress:server:cloud:api request to url: POST https://api-proxy.cypress.io/preflight with params: {"body":{"apiUrl":"https://api.cypress.io/","dependencies":{},"errors":[],"projectId":"xxx","ciBuildId":"rbl-test-05","testingType":"e2e","parallel":true},"headers":{"x-route-version":"1","x-cypress-request-attempt":0,"x-os-name":"linux","x-cypress-version":"13.5.0"}} and token: undefined +0ms

--------- Lots of process_profiler entries

cypress:server:cloud:api request to url: POST https://api.cypress.io/preflight with params: {"body":{"apiUrl":"https://api.cypress.io/","dependencies":{},"errors":[],"projectId":"xxx","ciBuildId":"rbl-test-05","testingType":"e2e","parallel":true},"headers":{"x-route-version":"1","x-cypress-request-attempt":0,"x-os-name":"linux","x-cypress-version":"13.5.0"}} and token: undefined +1m
cypress:network:agent addRequest called { isHttps: true, href: 'https://api.cypress.io/preflight' } +0ms
cypress:network:agent got family { family: undefined, href: 'https://api.cypress.io/preflight' } +1ms
cypress:network:agent Creating proxied socket for https://api.cypress.io/preflight through http://myproxy:3128 +3ms
cypress:network:connect successfully connected { opts: { port: 3128, host: 'myproxy', useTls: false, getDelayMsForRetry: [Function (anonymous)] }, iteration: 0 } +0ms
cypress:network:agent Proxy socket for https://api.cypress.io/preflight established +9ms
cypress:server:cloud:api response { apiUrl: 'https://api.cypress.io/', encrypt: false } +415ms

Other

No response

[Roemer]

I created a MR which potentially fixes this issue here: https://github.com/cypress-io/cypress/pull/28340

[jennifer-shehane]

We had some reports previously that running Cypress was slower when connected to the Cloud, but we were unable to reproduce it at the time. We'll take a look.

[Roemer]

Any news here? The issue is visible by using a local proxy (eg. Fiddler) and redirecting cypress to Fiddler. Then you see in Fiddlers log, that the first request (which is to api-proxy.cypress.io) is not visible in Fiddler (because it does not use the proxy at all) and then the second request (to api.cypress.io) is visible in Fiddler.

[Roemer]

We still need to use a workaround to get an immediate (fail) response for the first request:

echo "127.0.0.1    api-proxy.cypress.io" >> /etc/hosts

It works but having a correct solution would still be the preferred way.

[jennifer-shehane]

@Roemer Can you provide a repo that would reproduce the issue? For us to run?

[Roemer]

A repo would not be enough, you need a specific network setup to reproduce it. Basically, if you have a setup that blocks any internet access but allow connecting via a proxy, you would see that the first request to api-proxy.cypress.io is blocked and never reaches the proxy and then the second request to api.cypress.io would come thru the proxy and work.

[Roemer]

This issue is still pending and the corresponding PR was closed. It is almost impossible to create a sample repo / test for the issue as this needs a specific networking setup (which is often used by corporates). If a dev would look at the (now closed PR), it is fairly obvious that is it currently broken.