from pprint import pprint
import boto

# connect up parts of the Amazon infrastructure

ec2 = boto.connect_ec2()
cw = boto.connect_cloudwatch()
rds = boto.connect_rds()

def all_instances():
    reservations = ec2.get_all_instances()
    instances = [i for r in reservations for i in r.instances]
    return instances

def all_zones():
    print ec2.get_all_zones()
    
def all_rds():
    return rds.get_all_dbinstances()

def instance(tag_name):
    try:
        return ec2.get_all_instances(filters={'tag:Name' : tag_name})[0].instances[0]
    except Exception, e:
        return None

def console_output(instance):
    """returnn console output of instance"""
    try:
        return instance.get_console_output().output
    except Exception, e:
        return None

def instance_metrics(instance):
    """metrics that apply to given instance"""
    metrics = cw.list_metrics() 
    my_metrics = []
    
    for metric in metrics: 
        if 'InstanceId' in metric.dimensions:
            if instance.id in metric.dimensions['InstanceId']:
                my_metrics.append(metric)
    
    return my_metrics
    
# how to get average CPU utilization of web1?
# filter(lambda x: x.name == 'CPUUtilization', m)
# metric.query(start_time, end_time,'Average', period=6000)

def instance_metric(instance, metric_name):
    m = instance_metrics(instance)
    return filter(lambda x: x.name == metric_name, m)

def launch_time(instance):
    return boto.utils.parse_ts(instance.launch_time)
    
def max_cpu(instance):
    pass
    
    
def stats_for_instances(instances=None):
    """return basic stats for input instances"""
    if instances is None:
        instances = all_instances()
    stats = []
    for instance in instances:
        instance.update()  # to get latest update
        stats.append((instance.id, instance.key_name, instance.state, instance.ip_address, instance.dns_name))
    
    return stats  
    
if __name__ == '__main__':
    pprint (stats_for_instances(all_instances()))
    web1 = instance('web1')
    print instance_metrics(web1)