IMPORTANT

• Please see the issue wait-on issues with Node.js 18 #811 for a better set of workarounds. The descriptions below were before I got into understanding the root cause better. I don't however want to delete the text in this issue even if it is no longer up to date. (Mar 2, 2023.)

The example-wait-on workflow fails on GitHub in some jobs waiting for localhost after the ubuntu-22.04 runner was migrated to use Node.js 18 as default. GitHub reports that the migration deployed on Feb 18, 2023 on the same date that example-wait-on began failing some of its test jobs. Other test jobs waiting for localhost succeed however.

Problem description

The workflow .github/workflows/example-wait-on.yml fails in jobs:

• wait-using-custom-command-v9 / wait-using-custom-command
• wait-on-vite-v9 / wait-on-vite

The last successful run was on Feb 17, 2023 with ubuntu-22.04 image Version: 20230206.1 using the default Node.js 16.19.0.
The first failed run was on Feb 18, 2023 ubuntu-22.04 image Version: 20230217.1 using the default Node.js 18.14.1.

See https://github.com/cypress-io/github-action/actions/workflows/example-wait-on.yml for workflow history.

wait-using-custom-command

          working-directory: examples/react-scripts
          start: npm start
          wait-on: 'npx wait-on --timeout 5000 http://localhost:3000'

shows

You can now view example-react-scripts in the browser.

  Local:            http://localhost:3000
  On Your Network:  http://10.1.0.40:3000

Note that the development build is not optimized.
To create a production build, use npm run build.

webpack compiled successfully
npm WARN exec The following package was not found and will be installed: wait-on@7.0.1
Error: Timed out waiting for: http://localhost:3000
    at /home/runner/.npm/_npx/04d57496964ca6d1/node_modules/wait-on/lib/wait-on.js:132:31

with wait-on --verbose enabled it shows that wait-on is trying to connect to the IPv6 address ::1, however the react server is only listening on the IPv4 address 127.0.0.1:

npm WARN exec The following package was not found and will be installed: wait-on@7.0.1
waiting for 1 resources: http://localhost:3000
making HTTP(S) head request to  url:http://localhost:3000 ...
  HTTP(S) error for http://localhost:3000 Error: connect ECONNREFUSED ::1:3000

... ECONNREFUSED repeated multiple times

wait-on(1747) Timed out waiting for: http://localhost:3000; exiting with error
Error: Timed out waiting for: http://localhost:3000

wait-on-vite

          working-directory: examples/wait-on-vite
          start: npm run dev
          wait-on: 'http://localhost:5173'

shows

waiting on "http://localhost:5173" with timeout of 60 seconds
/usr/local/bin/npm run dev

> example-wait-on-vite@2.0.0 dev
> vite


  VITE v4.0.4  ready in 261 ms

  ➜  Local:   http://localhost:5173/
  ➜  Network: use --host to expose
http://localhost:5173 timed out on retry 91 of 3, elapsed 90270ms, limit 90000ms
Error: connect ECONNREFUSED 127.0.0.1:5173

Investigation

GitHub ubuntu-22.04 image Version: 20230217.1 is set up as follows:

/etc/hosts

Run cat /etc/hosts
127.0.0.1 localhost

# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
127.0.0.1 cpu-pool.com
127.0.0.1 MiningMadness.com
127.0.0.1 stratum-na.rplant.xyz
127.0.0.1 do-dear.com
127.0.0.1 web.do-dear.com
127.0.0.1 git.workflows.live
10.1.0.51 fv-az589-316.vc0434dfxmkevoezlasxvobd2h.cx.internal.cloudapp.net fv-az589-316

loopback

Run ip address show lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever

Discussion

It is unclear why the wait-on step is causing problems using localhost on GitHub where Cypress manages to successfully test using localhost after the wait-on step when localhost has been substituted by a non-ambiguous alternative (see Workaround section below). Running Cypress tests locally succeeds. So the problem is only on GitHub.

A default installation of Ubuntu only assigns localhost to the ip4 address 127.0.0.1, not to the ip6 address ::1. GitHub however has ::1 localhost ip6-localhost ip6-loopback set up in addition.

Similar issues on GitHub have already been reported in:

• wait-on "localhost" not resolving after upgrading Node.js 16 to 18 #634
• wait-on failure ECONNREFUSED to localhost with Angular and Node.js 18 #760

The example-wait-on workflow uses different combinations of servers and wait-on providers to monitor the availability of a server on the network address localhost. Some succeed others fail.

Workarounds

Use specific localhost

• In wait-using-custom-command replace localhost by 127.0.0.1 and wait for http://127.0.0.1:3000
• In wait-on-vite replace localhost by ip6-localhost and wait for http://ip6-localhost:5173

Tie tests to Node.js 16

Alternatively: If the failing tests are reverted to running under Node.js 16, then they succeed. Add the following:

      - name: Setup Node
        uses: actions/setup-node@v3
        with:
          node-version: 16

Suggestion

Replace the generic term localhost by a specific reference:

• react-scripts 127.0.0.1
• wait-on-vite ip6-localhost

for these webserver which are not listening on both IP stacks.