Summary

Scanning a YAML Specs file in Bamboo fails with the following error: 

Bamboo YAML import failed: Invalid format of the YAML file: Number of aliases for non-scalar nodes exceeds the specified max=1500

Environment

All supported versions of Bamboo using YAML Specs.

Diagnosis

When scanning a YAML Repository-stored Specs in Bamboo, the following error is shown in the logs of the failed Specs execution:

02-Mar-2023 16:18:58	Bamboo YAML import failed: Invalid format of the YAML file: Number of aliases for non-scalar nodes exceeds the specified max=1500

The following stack trace can be found in the BAMBOO_HOME/logs/atlassian-bamboo.log file:

2023-03-02 16:18:58,466 INFO [15-BAM::SpecsDetection:pool-18-thread-4] [YamlSpecsImportServiceImpl] Bamboo YAML import failed on incorrect YAML
com.atlassian.bamboo.specs.yaml.YamlSpecsValidationException: Invalid format of the YAML file: Number of aliases for non-scalar nodes exceeds the specified max=1500
	at com.atlassian.bamboo.configuration.external.yaml.BambooYamlSpecsServiceImpl.splitDocuments(BambooYamlSpecsServiceImpl.java:54)
	at com.atlassian.bamboo.configuration.external.rss.YamlSpecsImportServiceImpl.processSimplifiedYaml(YamlSpecsImportServiceImpl.java:106)
	at com.atlassian.bamboo.configuration.external.RepositoryStoredSpecsServiceImpl.tryProcessYaml(RepositoryStoredSpecsServiceImpl.java:338)
	at com.atlassian.bamboo.configuration.external.RepositoryStoredSpecsServiceImpl.runBambooSpecs(RepositoryStoredSpecsServiceImpl.java:184)
	at com.atlassian.bamboo.configuration.external.RssDetectionServiceImpl.runRssDetection(RssDetectionServiceImpl.java:374)
	at com.atlassian.bamboo.configuration.external.detection.RssDetectionRunnable.run(RssDetectionRunnable.java:42)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at com.atlassian.bamboo.utils.BambooRunnables$1.run(BambooRunnables.java:48)
	at com.atlassian.bamboo.security.ImpersonationHelper.runWith(ImpersonationHelper.java:26)
	at com.atlassian.bamboo.security.ImpersonationHelper.runWithSystemAuthority(ImpersonationHelper.java:17)
	at com.atlassian.bamboo.security.ImpersonationHelper$1.run(ImpersonationHelper.java:41)
	at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: org.yaml.snakeyaml.error.YAMLException: Number of aliases for non-scalar nodes exceeds the specified max=1500
[...]

Cause

When using Specs, Bamboo has a default limit of 1500 aliases for non-scalar nodes in a YAML file. For versions older than 7.0.6, 7.2.0, and 7.1.3, the limit was 50, as described in the following bug:

• BAM-21037 - Getting issue details... STATUS

Solution

Bamboo versions 7.0.6, 7.1.3, 7.2.0 or newer

For these newer versions, a system property has been introduced to allow increasing the maximum number of aliases that can be read from a YAML Specs file. Please follow the steps below:

1. Backup and edit the BAMBOO_INSTALL/bin/setenv file.

2. Add the following property to the JVM_SUPPORT_RECOMMENDED_ARGS line int the setenv file, replacing NEW_LIMIT with a value higher than 1500 that meets your YAML Specs file needs:

   -Dbamboo.specs.max.aliases.for.collections=NEW_LIMIT

3. For example: 

   setenv.sh

   #  Occasionally Atlassian Support may recommend that you set some specific JVM arguments.  You can use this variable below to do that.
   #
   : ${JVM_SUPPORT_RECOMMENDED_ARGS:="-Dbamboo.setup.remote.agent.authentication.enabled=false"}
   JVM_SUPPORT_RECOMMENDED_ARGS="-Dbamboo.specs.max.aliases.for.collections=2000"
   
   #
   #  Uncomment the line below to enable the Byteman agent.

4. Restart Bamboo so the changes are reflected.
5. You can double-check if the property has been picked up by Bambo by going to Bamboo Administration > Overview > System information and looking for it in the Environment variables section:
6. Run your Specs again and it should now succeed (as long as you've set a new value that covers the number of anchor aliases you are using). 

Bamboo versions older than 7.0.6, 7.1.3, 7.2.0

If you're running an older version of Bamboo (< 7.0.6, 7.2.0, 7.1.3), please upgrade to a more recent version to benefit from the aliases limit increase (now 1500) and for the possibility to increase that value (as described above).