chore(java): use separate autosynth job for README (#161)

* chore(java): use separate autosynth job for README

Split java README generation into a separate, per-repo continuous job running from Kokoro.

We now generate a new job that runs on commits to the primary branch that strictly manages the README.md. This should prevent us from seeing the contextless autosynth PRs which are caused by non-proto/template upstream changes.

Source-Author: Jeff Ching <chingor@google.com>
Source-Date: Tue Sep 29 15:48:03 2020 -0700
Source-Repo: googleapis/synthtool
Source-Sha: e6168630be3e31eede633ba2c6f1cd64248dec1c
Source-Link: googleapis/synthtool@e616863

* build(java): readme.sh should be executable

Source-Author: Jeff Ching <chingor@google.com>
Source-Date: Wed Sep 30 13:20:04 2020 -0700
Source-Repo: googleapis/synthtool
Source-Sha: 0762e8ee2ec21cdfc4d82020b985a104feb0453b
Source-Link: googleapis/synthtool@0762e8e

Author: yoshi-automation

.github/readme/synth.py

@@ -0,0 +1,19 @@
+# Copyright 2020 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""This script is used to synthesize generated the README for this library."""
+
+from synthtool.languages import java
+
+java.custom_templates(["java_library/README.md"])

.kokoro/continuous/readme.cfg

@@ -0,0 +1,55 @@
+# Copyright 2020 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Format: //devtools/kokoro/config/proto/build.proto
+
+env_vars: {
+  key: "TRAMPOLINE_IMAGE"
+  value: "gcr.io/cloud-devrel-kokoro-resources/python-multi"
+}
+
+env_vars: {
+  key: "TRAMPOLINE_BUILD_FILE"
+  value: "github/java-shared-dependencies/.kokoro/readme.sh"
+}
+
+# Build logs will be here
+action {
+  define_artifacts {
+    regex: "**/*sponge_log.xml"
+    regex: "**/*sponge_log.log"
+  }
+}
+
+# The github token is stored here.
+before_action {
+  fetch_keystore {
+    keystore_resource {
+      keystore_config_id: 73713
+      keyname: "yoshi-automation-github-key"
+      # TODO(theacodes): remove this after secrets have globally propagated
+      backend_type: FASTCONFIGPUSH
+    }
+  }
+}
+
+# Common env vars for all repositories and builds.
+env_vars: {
+    key: "GITHUB_USER"
+    value: "yoshi-automation"
+}
+env_vars: {
+    key: "GITHUB_EMAIL"
+    value: "yoshi-automation@google.com"
+}

.kokoro/readme.sh

@@ -0,0 +1,36 @@
+#!/bin/bash
+# Copyright 2020 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -eo pipefail
+
+cd ${KOKORO_ARTIFACTS_DIR}/github/java-shared-dependencies
+
+# Disable buffering, so that the logs stream through.
+export PYTHONUNBUFFERED=1
+
+# Kokoro exposes this as a file, but the scripts expect just a plain variable.
+export GITHUB_TOKEN=$(cat ${KOKORO_KEYSTORE_DIR}/73713_yoshi-automation-github-key)
+
+# Setup git credentials
+echo "https://${GITHUB_TOKEN}:@github.com" >> ~/.git-credentials
+git config --global credential.helper 'store --file ~/.git-credentials'
+
+python3.6 -m pip install git+https://github.com/googleapis/synthtool.git#egg=gcp-synthtool
+python3.6 -m autosynth.synth \
+    --repository=googleapis/java-shared-dependencies \
+    --synth-file-name=.github/readme/synth.py \
+    --metadata-path=.github/readme/synth.metadata \
+    --pr-title="chore: regenerate README" \
+    --branch-suffix="readme"

synth.metadata

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-shared-dependencies.git",
-        "sha": "65fb72633254d79d47be4fb621856bc0b7a6a87a"
+        "sha": "8fef296c1db88cc3dc5f50ef21ae8015f4c5883f"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "da29da32b3a988457b49ae290112b74f14b713cc"
+        "sha": "0762e8ee2ec21cdfc4d82020b985a104feb0453b"
       }
     }
   ],
@@ -21,6 +21,7 @@
     ".github/ISSUE_TEMPLATE/feature_request.md",
     ".github/ISSUE_TEMPLATE/support_request.md",
     ".github/PULL_REQUEST_TEMPLATE.md",
+    ".github/readme/synth.py",
     ".github/trusted-contribution.yml",
     ".github/workflows/auto-release.yaml",
     ".github/workflows/ci.yaml",
@@ -31,6 +32,7 @@
     ".kokoro/common.sh",
     ".kokoro/continuous/common.cfg",
     ".kokoro/continuous/java8.cfg",
+    ".kokoro/continuous/readme.cfg",
     ".kokoro/dependencies.sh",
     ".kokoro/linkage-monitor.sh",
     ".kokoro/nightly/common.cfg",
@@ -54,6 +56,7 @@
     ".kokoro/presubmit/linkage-monitor.cfg",
     ".kokoro/presubmit/lint.cfg",
     ".kokoro/presubmit/samples.cfg",
+    ".kokoro/readme.sh",
     ".kokoro/release/bump_snapshot.cfg",
     ".kokoro/release/common.cfg",
     ".kokoro/release/common.sh",