introduce skywalking-eye to check license header (#79)

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 3ec6629..e551ac7 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -38,6 +38,11 @@
         run: |
           git submodule sync --recursive
           git -c protocol.version=2 submodule update --init --force --recursive --depth=1
+      - name: Check License Header
+        if: env.SKIP_CI != 'true'
+        uses: apache/skywalking-eyes@main
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       - name: 'Install Lua'
         shell: bash
         run: |
diff --git a/.licenserc.yaml b/.licenserc.yaml
new file mode 100644
index 0000000..71c6a16
--- /dev/null
+++ b/.licenserc.yaml
@@ -0,0 +1,35 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+
+header:
+  license:
+    spdx-id: Apache-2.0
+    copyright-owner: Apache Software Foundation
+
+  paths-ignore:
+    - 'dist'
+    - 'licenses'
+    - '**/*.md'
+    - 'LICENSE'
+    - 'NOTICE'
+    - 'rockspec'
+    - '.gitignore'
+    - '.luacheckrc'
+    - '.mvn'
+    - 'lib/resty'
+    - 'lib/skywalking/dependencies'
+
+  comment: on-failure
\ No newline at end of file
diff --git a/t/client.t b/t/client.t
index 172d16d..5149d31 100644
--- a/t/client.t
+++ b/t/client.t
@@ -1,3 +1,19 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You 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.
+#
 use Test::Nginx::Socket 'no_plan';
 
 use Cwd qw(cwd);
diff --git a/t/segment_ref.t b/t/segment_ref.t
index 307b751..fc966db 100644
--- a/t/segment_ref.t
+++ b/t/segment_ref.t
@@ -1,3 +1,19 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You 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.
+#
 use Test::Nginx::Socket 'no_plan';
 
 use Cwd qw(cwd);
diff --git a/t/util.t b/t/util.t
index 0b5a027..71e6827 100644
--- a/t/util.t
+++ b/t/util.t
@@ -1,3 +1,19 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You 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.
+#
 use Test::Nginx::Socket 'no_plan';
 
 use Cwd qw(cwd);