license: removes copyright year and uses SPDX ID

As a small project, we have to conserve resources and not sign up for
work that isn't required. I've recently realized many commerical and/or
CNCF projects both use SPDX IDs and also don't bother with copyright
year. If their legal team is ok with this, surely a volunteer team
without access to one, should be, too! Doing so accomplishes the
following:

* significantly increases readability of files, particularly small ones
* removes beginning of year maintenance, which cause a lot of FUD last
  year. IIRC some deployment failed and hours were spent in spite of docs.
* eliminates the need to do a full source check out, just to satisfy the
  license plugin. This means we can use actions/checkout defaults.

Signed-off-by: Adrian Cole <[email protected]>

.github/CONTRIBUTING.md

@@ -9,25 +9,16 @@ When submitting code, please apply [Square Code Style](https://github.com/square
 ## License
 
 By contributing your code, you agree to license your contribution under
-the terms of the [APLv2](LICENSE).
+the terms of the [APLv2](../LICENSE).
 
 All files are released with the Apache 2.0 license.
 
 If you are adding a new file it should have a header like below. This
 can be automatically added by running `./mvnw com.mycila:license-maven-plugin:format`.
 
 ```
-/**
- * Copyright 2019 The OpenZipkin Authors
- *
- * 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.
+/*
+ * Copyright The OpenZipkin Authors
+ * SPDX-License-Identifier: Apache-2.0
  */
  ```

.github/workflows/create_release.yml

@@ -19,7 +19,6 @@ jobs:
           # Prevent use of implicit GitHub Actions read-only token GITHUB_TOKEN. We don't deploy on
           # the tag MAJOR.MINOR.PATCH event, but we still need to deploy the maven-release-plugin master commit.
           token: ${{ secrets.GH_TOKEN }}
-          fetch-depth: 1  # only need the HEAD commit as license check isn't run
       - name: Setup java
         uses: actions/setup-java@v4
         with:

.github/workflows/deploy.yml

@@ -32,7 +32,6 @@ jobs:
           # Prevent use of implicit GitHub Actions read-only token GITHUB_TOKEN.
           # We push Javadocs to the gh-pages branch on commit.
           token: ${{ secrets.GH_TOKEN }}
-          fetch-depth: 0  # allow build-bin/idl_to_gh_pages to get the full history
       - name: Setup java
         uses: actions/setup-java@v4
         with:

.github/workflows/test.yml

@@ -22,8 +22,6 @@ jobs:
     steps:
       - name: Checkout Repository
         uses: actions/checkout@v4
-        with:
-          fetch-depth: 0 # full git history for license check
       - name: Setup java
         uses: actions/setup-java@v4
         with:
@@ -52,8 +50,6 @@ jobs:
     steps:
       - name: Checkout Repository
         uses: actions/checkout@v4
-        with:
-          fetch-depth: 0 # full git history for license check
       - name: Setup java
         uses: actions/setup-java@v4
         with:

.settings.xml

@@ -1,17 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
 
-    Copyright 2016-2020 The OpenZipkin Authors
-
-    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.
+    Copyright The OpenZipkin Authors
+    SPDX-License-Identifier: Apache-2.0
 
 -->
 <settings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

RELEASE.md

@@ -44,31 +44,6 @@ Here's an example of a snapshot deploy with specified credentials.
 $ export GPG_TTY=$(tty) && GPG_PASSPHRASE=whackamole SONATYPE_USER=adrianmole SONATYPE_PASSWORD=ed6f20bde9123bbb2312b221 build-bin/build-bin/maven/maven_deploy
 ```
 
-## First release of the year
-
-The license plugin verifies license headers of files include a copyright notice indicating the years a file was affected.
-This information is taken from git history. There's a once-a-year problem with files that include version numbers (pom.xml).
-When a release tag is made, it increments version numbers, then commits them to git. On the first release of the year,
-further commands will fail due to the version increments invalidating the copyright statement. The way to sort this out is
-the following:
-
-Before you do the first release of the year, move the SNAPSHOT version back and forth from whatever the current is.
-In-between, re-apply the licenses.
-
-Note: the command below is more complex than a normal project because this
-project has a bom.
-```bash
-$ mvn=$PWD/mvnw
-$ for p in ./bom .; do
- (cd $p
- $mvn versions:set -DnewVersion=3.0.1-SNAPSHOT -DgenerateBackupPoms=false
- $mvn -o clean install -DskipTests
- $mvn com.mycila:license-maven-plugin:format
- $mvn versions:set -DnewVersion=3.0.0-SNAPSHOT -DgenerateBackupPoms=false)
- done
-$ git commit -asm"Adjusts copyright headers for this year"
-```
-
 ## Manually releasing
 
 If for some reason, you lost access to CI or otherwise cannot get automation to work, bear in mind

activemq-client/pom.xml

@@ -1,17 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
 
-    Copyright 2016-2024 The OpenZipkin Authors
-
-    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.
+    Copyright The OpenZipkin Authors
+    SPDX-License-Identifier: Apache-2.0
 
 -->
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

activemq-client/src/main/java/zipkin2/reporter/activemq/ActiveMQConn.java

@@ -1,15 +1,6 @@
 /*
- * Copyright 2016-2024 The OpenZipkin Authors
- *
- * 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.
+ * Copyright The OpenZipkin Authors
+ * SPDX-License-Identifier: Apache-2.0
  */
 package zipkin2.reporter.activemq;
 

activemq-client/src/main/java/zipkin2/reporter/activemq/ActiveMQSender.java

@@ -1,15 +1,6 @@
 /*
- * Copyright 2016-2024 The OpenZipkin Authors
- *
- * 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.
+ * Copyright The OpenZipkin Authors
+ * SPDX-License-Identifier: Apache-2.0
  */
 package zipkin2.reporter.activemq;
 

activemq-client/src/main/java/zipkin2/reporter/activemq/LazyInit.java

@@ -1,15 +1,6 @@
 /*
- * Copyright 2016-2019 The OpenZipkin Authors
- *
- * 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.
+ * Copyright The OpenZipkin Authors
+ * SPDX-License-Identifier: Apache-2.0
  */
 package zipkin2.reporter.activemq;
 

activemq-client/src/test/java/zipkin2/reporter/activemq/ActiveMQContainer.java

@@ -1,15 +1,6 @@
 /*
- * Copyright 2016-2024 The OpenZipkin Authors
- *
- * 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.
+ * Copyright The OpenZipkin Authors
+ * SPDX-License-Identifier: Apache-2.0
  */
 package zipkin2.reporter.activemq;
 

activemq-client/src/test/java/zipkin2/reporter/activemq/ITActiveMQSender.java

@@ -1,15 +1,6 @@
 /*
- * Copyright 2016-2024 The OpenZipkin Authors
- *
- * 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.
+ * Copyright The OpenZipkin Authors
+ * SPDX-License-Identifier: Apache-2.0
  */
 package zipkin2.reporter.activemq;
 

amqp-client/pom.xml

@@ -1,17 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
 
-    Copyright 2016-2024 The OpenZipkin Authors
-
-    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.
+    Copyright The OpenZipkin Authors
+    SPDX-License-Identifier: Apache-2.0
 
 -->
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

amqp-client/src/it/amqp_v4/pom.xml

@@ -1,17 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
 
-    Copyright 2016-2024 The OpenZipkin Authors
-
-    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.
+    Copyright The OpenZipkin Authors
+    SPDX-License-Identifier: Apache-2.0
 
 -->
 <project xmlns="http://maven.apache.org/POM/4.0.0"

amqp-client/src/it/amqp_v4/src/test/java/zipkin2/reporter/amqp_v4/ITRabbitMQSender.java

@@ -1,15 +1,6 @@
 /*
- * Copyright 2016-2023 The OpenZipkin Authors
- *
- * 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.
+ * Copyright The OpenZipkin Authors
+ * SPDX-License-Identifier: Apache-2.0
  */
 package zipkin2.reporter.amqp_v4;
 

amqp-client/src/main/java/zipkin2/reporter/amqp/RabbitMQSender.java

@@ -1,15 +1,6 @@
 /*
- * Copyright 2016-2024 The OpenZipkin Authors
- *
- * 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.
+ * Copyright The OpenZipkin Authors
+ * SPDX-License-Identifier: Apache-2.0
  */
 package zipkin2.reporter.amqp;
 

amqp-client/src/test/java/zipkin2/reporter/amqp/ITRabbitMQSender.java

@@ -1,15 +1,6 @@
 /*
- * Copyright 2016-2024 The OpenZipkin Authors
- *
- * 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.
+ * Copyright The OpenZipkin Authors
+ * SPDX-License-Identifier: Apache-2.0
  */
 package zipkin2.reporter.amqp;
 

amqp-client/src/test/java/zipkin2/reporter/amqp/RabbitMQContainer.java

@@ -1,15 +1,6 @@
 /*
- * Copyright 2016-2024 The OpenZipkin Authors
- *
- * 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.
+ * Copyright The OpenZipkin Authors
+ * SPDX-License-Identifier: Apache-2.0
  */
 package zipkin2.reporter.amqp;
 

amqp-client/src/test/java/zipkin2/reporter/amqp/RabbitMQSenderTest.java

@@ -1,15 +1,6 @@
 /*
- * Copyright 2016-2024 The OpenZipkin Authors
- *
- * 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.
+ * Copyright The OpenZipkin Authors
+ * SPDX-License-Identifier: Apache-2.0
  */
 package zipkin2.reporter.amqp;
 

benchmarks/pom.xml

@@ -1,17 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
 
-    Copyright 2016-2024 The OpenZipkin Authors
-
-    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.
+    Copyright The OpenZipkin Authors
+    SPDX-License-Identifier: Apache-2.0
 
 -->
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

benchmarks/src/main/java/zipkin2/reporter/HttpSenderBenchmarks.java

@@ -1,15 +1,6 @@
 /*
- * Copyright 2016-2024 The OpenZipkin Authors
- *
- * 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.
+ * Copyright The OpenZipkin Authors
+ * SPDX-License-Identifier: Apache-2.0
  */
 package zipkin2.reporter;