发出编写python脚本以打开另一台AWS EC2计算机的问题

Question

I am trying to set up a process on my jenkins EC2 that turns on another EC2 machine at a given time.

I started by writing a simple python script as follows to turn on the other EC2 machine:

import boto.ec2
conn = boto.ec2.connect_to_region("us-east-1")
conn.run_instances(
    'ami-...',
    key_name='my_key_name',
    instance_type='my_instance_type',
    security_groups=['my_security_group']
)

But this errors with:

[SSH] Exception:java.net.NoRouteToHostException: No route to host
com.jcraft.jsch.JSchException: java.net.NoRouteToHostException: No route to host
        at com.jcraft.jsch.Util.createSocket(Util.java:341)
        at com.jcraft.jsch.Session.connect(Session.java:182)
        at com.jcraft.jsch.Session.connect(Session.java:150)
        at org.jvnet.hudson.plugins.SSHSite.createSession(SSHSite.java:141)
        at org.jvnet.hudson.plugins.SSHSite.executeCommand(SSHSite.java:151)
        at org.jvnet.hudson.plugins.SSHBuildWrapper.executePreBuildScript(SSHBuildWrapper.java:75)
        at org.jvnet.hudson.plugins.SSHBuildWrapper.setUp(SSHBuildWrapper.java:59)
        at hudson.model.Build$BuildExecution.doRun(Build.java:156)
        at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:537)
        at hudson.model.Run.execute(Run.java:1741)
        at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
        at hudson.model.ResourceController.execute(ResourceController.java:98)
        at hudson.model.Executor.run(Executor.java:408)
Caused by: java.net.NoRouteToHostException: No route to host
        at java.net.PlainSocketImpl.socketConnect(Native Method)
        at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
        at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
        at java.net.Socket.connect(Socket.java:579)
        at java.net.Socket.connect(Socket.java:528)
        at java.net.Socket.<init>(Socket.java:425)
        at java.net.Socket.<init>(Socket.java:208)
        at com.jcraft.jsch.Util.createSocket(Util.java:335)
        ... 12 more

If I'm reading the error correctly it is saying that it can't connect to the other EC2 machine, most likely because it is switched off :)

This is where I'm getting stuck and I'm hoping that someone can help to narrow down the issue - am I using a wrong approach to turn on another EC2 machine? / any suggestions to help narrow down the issue would be appreciated?

I have checked the security groups of both EC2 machines, and have checked that when the other EC2 machine is on I am able to ping it from the jenkins machine.

Answer 1

Are you trying to connect to the new instance immediately after launching it? It will take a few minutes for the new instance to boot and be ready for network connections. You could have the Python code that launches the instance loop and poll for the state of the instance to become running .