amazon-web-services - docker 错误 - "jq: error: Cannot iterate over null"

Question

所以我试图在 Elastic Beanstalk 上部署一个 dockerfile，但我无法克服这个错误 - “jq: error: Cannot iterate over null”。

Successfully built [myContainerId]
Successfully built aws_beanstalk/staging-app
[2015-01-29T10:35:59.494Z] INFO  [16343] - [CMD-AppDeploy/AppDeployStage0/AppDeployPreHook/04run.sh] : Starting activity...
[2015-01-29T10:36:05.507Z] INFO  [16343] - [CMD-AppDeploy/AppDeployStage0/AppDeployPreHook/04run.sh] : Activity execution failed, because: command failed with error code 1: /opt/elasticbeanstalk/hooks/appdeploy/pre/04run.sh
jq: error: Cannot iterate over null
Docker container quit unexpectedly after launch: Docker container quit unexpectedly on Thu Jan 29 10:36:05 UTC 2015:. Check snapshot logs for details. (Executor::NonZeroExitStatus)
at /opt/elasticbeanstalk/lib/ruby/lib/ruby/gems/2.1.0/gems/executor-1.0/lib/executor/exec.rb:81:in `sh'
from /opt/elasticbeanstalk/lib/ruby/lib/ruby/gems/2.1.0/gems/executor-1.0/lib/executor.rb:15:in `sh'
from /opt/elasticbeanstalk/lib/ruby/lib/ruby/gems/2.1.0/gems/beanstalk-core-1.1/lib/elasticbeanstalk/executable.rb:63:in `execute!'
from /opt/elasticbeanstalk/lib/ruby/lib/ruby/gems/2.1.0/gems/beanstalk-core-1.1/lib/elasticbeanstalk/hook-directory-executor.rb:29:in `block (2 levels) in run!'
from /opt/elasticbeanstalk/lib/ruby/lib/ruby/gems/2.1.0/gems/beanstalk-core-1.1/lib/elasticbeanstalk/activity.rb:169:in `call'
from /opt/elasticbeanstalk/lib/ruby/lib/ruby/gems/2.1.0/gems/beanstalk-core-1.1/lib/elasticbeanstalk/activity.rb:169:in `exec'

日志中没有任何其他错误。我的 Docker 容器已成功构建，因此错误似乎不太可能来自那里。

我的 Dockerrun.aws.json 看起来像:

   {
  "AWSEBDockerrunVersion": "1",
  "Image": {
    "Name": "blah",
    "Update": "false"
  },
  "Ports": [
    {
      "ContainerPort": "8080"
    }
  ]
}

我正用这个把头撞到墙上，我所做的任何改变似乎都不会影响它，谷歌搜索也没有任何帮助。

有什么想法吗？

Answer 1

如果其他人正在寻找如何避免在他们自己的 jq 命令中出现 Cannot iterate over null 错误，请在 [] 之后添加一个问号。例如

echo '{
  "AWSEBDockerrunVersion": "1",
  "Image": {
    "Name": "blah",
    "Update": "false"
  },
  "Ports": [
    {
      "ContainerPort": "8080"
    }
  ]
}'|jq -c '.Volumes[]?|[.HostDirectory,.ContainerDirectory]'

其中 [] 被替换为 []? 不显示错误。

来自手册:

.[]?
    Like .[], but no errors will be output if . is not an array or object.