Use npm mirrors in tox jobs

Opendev runs a caching mirror for npm packages. Use it when running
yarn install during tox tests. Due to the way yarn.lock files work at
the moment we need to patch the lockfile on the fly to inject the
mirror urls [1]. This can be handlel inside the pip.sh where we patch
the lockfile, run yarn and reset it afterwards.

[1] https://github.com/yarnpkg/yarn/issues/2566

Change-Id: Id1f2daac8327f3110e6beeb2d6391baccfd3ce34

.zuul.yaml

@@ -238,22 +238,20 @@
               - playbooks/zuul-migrate/.*
             nodeset: ubuntu-xenial
             timeout: 4800  # 80 minutes
-            vars:
+            vars: &zuul_tox_vars
                 test_setup_environment:
                     ZUUL_TEST_ROOT: /tmp/zuul-test
+                    YARN_REGISTRY: "https://{{ zuul_site_mirror_fqdn }}:4443/registry.npmjs"
                 tox_environment:
                     ZUUL_TEST_ROOT: /tmp/zuul-test
+                    YARN_REGISTRY: "https://{{ zuul_site_mirror_fqdn }}:4443/registry.npmjs"
         - tox-py38:
             irrelevant-files:
               - zuul/cmd/migrate.py
               - playbooks/zuul-migrate/.*
             timeout: 4800  # 80 minutes
             nodeset: ubuntu-bionic
-            vars:
-                test_setup_environment:
-                    ZUUL_TEST_ROOT: /tmp/zuul-test
-                tox_environment:
-                    ZUUL_TEST_ROOT: /tmp/zuul-test
+            vars: *zuul_tox_vars
         - zuul-build-dashboard-openstack-whitelabel
         - zuul-build-dashboard-software-factory
         - zuul-build-dashboard-opendev
@@ -290,22 +288,14 @@
               - playbooks/zuul-migrate/.*
             nodeset: ubuntu-xenial
             timeout: 4800  # 80 minutes
-            vars:
-                test_setup_environment:
-                    ZUUL_TEST_ROOT: /tmp/zuul-test
-                tox_environment:
-                    ZUUL_TEST_ROOT: /tmp/zuul-test
+            vars: *zuul_tox_vars
         - tox-py38:
             irrelevant-files:
               - zuul/cmd/migrate.py
               - playbooks/zuul-migrate/.*
             timeout: 4800  # 80 minutes
             nodeset: ubuntu-bionic
-            vars:
-                test_setup_environment:
-                    ZUUL_TEST_ROOT: /tmp/zuul-test
-                tox_environment:
-                    ZUUL_TEST_ROOT: /tmp/zuul-test
+            vars: *zuul_tox_vars
         - zuul-build-dashboard
         - nodejs-run-lint:
             vars:

tools/pip.sh

@@ -42,8 +42,18 @@ then
     mkdir -p zuul/web/static
     ln -sfn ../zuul/web/static web/build
     pushd web/
-        yarn install
+        if [[ -n "${YARN_REGISTRY}" ]]
+        then
+            echo "Using yarn registry: ${YARN_REGISTRY}"
+            sed -i "s#https://registry.yarnpkg.com#${YARN_REGISTRY}#" yarn.lock
+        fi
+        yarn install --verbose
         yarn build
+        if [[ -n "${YARN_REGISTRY}" ]]
+        then
+            echo "Resetting yarn registry"
+            sed -i "s#${YARN_REGISTRY}#https://registry.yarnpkg.com#" yarn.lock
+        fi
     popd
 fi
 pip install $*

tox.ini

@@ -23,6 +23,7 @@ passenv =
   OS_LOG_DEFAULTS
   OS_STDERR_CAPTURE
   OS_STDOUT_CAPTURE
+  YARN_REGISTRY
   ZUUL_MYSQL_HOST
   ZUUL_POSTGRES_HOST
   ZUUL_TEST_ROOT