Cluster Install Walk-through
This is a step-by-step sequence of API calls that simulate a typical zero-to-cluster installation workflow scenario.
-
Create a Repository.
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Create Machine Credentials with appropriate settings for your cluster. You may need to create multiple if you have disparate credentials across your cluster.
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Create a Config Profile with appropriate configuration settings where you wish to override the defaults. If you wish to vary your configs for each datacenter or even at the node-level, you need to create multiple.
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Create a Cluster model, including datacenters and nodes (see Datacenter and Node). Assign repository, machine credentials, and config profiles to the appropriate cluster model objects.
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Create an Node job.
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Watch the job (see Jobs) for status.
Example:
#!/usr/bin/env python
# (C) DataStax, 2015. All Rights Reserved
#
# Demonstrates installation of DataStax Community on existing empty servers
# using the LCM API
#
# Example Usage:
# node-install-demo.py (target node ip one) (target node ip two) (...)
import sys
import os
import requests
import json
import threading
# CONFIGURABLE GLOBAL VARIABLES
server_ip = "127.0.0.1"
base_url = 'http://%s:8888/api/v2/lcm/' % server_ip
homedir = os.getenv("HOME")
# private_key_path = os.path.join(homedir, ".ssh/id_rsa")
# private_key = open(private_key_path).read()
# HELPER FUNCTIONS
def do_post(url, post_data):
"""Convenience function to simplify posting data to the LCM api."""
print "Posting to:", url
result = requests.post(base_url + url,
data=json.dumps(post_data),
headers={'Content-Type': 'application/json'})
result_data = json.loads(result.text)
print "Response is:", result.text
return result_data
# CLUSTER SETUP
# Credentials to log-in to the DSE nodes over SSH and obtain root privileges
#
# Log in over SSH as root authenticating with a password
# Run commands directly, without su or sudo
# machine_credential = do_post("machine_credentials/",
# {"name": "mc11",
# "login-user": "root",
# "login-password": "root",
# "become-mode": "direct"})
# Log in over SSH as vagrant, authenticating with an ssh-key
# Run commands through su when root privileges are necessary
# machine_credential = do_post("provisioning/machine_credentials/",
# {"name": "mc11",
# "login-user": "vagrant",
# "ssh-private-key": private_key,
# "become-mode": "su",
# "become-user": "root",
# "become-password": "password"})
# Log in over SSH as ubuntu, authenticating with a password
# Run commands through sudo when root privileges are necessary
machine_credential = do_post("machine_credentials/",
{"name": "mc11",
"login-user": "johndoe",
"login-password": "foobie",
"become-mode": "sudo",
"become-password": "foobie"})
# Describes many DSE settings and LCM options to the LCM api.
# Other than the name and datastax-version, all attributes are optional
# and have sensible defaults.
cluster_profile = do_post(
"config_profiles/",
{"name": "cp1",
"datastax-version": "4.8.1",
"json": {'cassandra-yaml': {"start-native-transport": True},
'logback-xml': {'file-appender-min-index': 2,
'loggers': [{'name': 'com.thinkaurelius.thrift',
'level': 'ERROR'}]},
'java-setup': {'major-version': "1.8.0"
# 'update-version': "77",
# 'build-version': '02'
},
'package-proxy': {
'enabled': False
# 'protocol': 'http',
# 'host': 'proxy.lan',
# 'port': '3128'
# 'authentication-required': False,
# 'username': 'user',
# 'password': 'pw'
}},
"comment": "no comment"})
repository = do_post(
"repositories/",
{"name": "my-repo-credentials",
"username": "johndoe",
"password": "foobie"
})
# Describes a cluster to the LCM api.
cluster = do_post("clusters/",
{"name": "cluster01",
"machine-credential-id": machine_credential["id"],
"repository-id": repository["id"],
"config-profile-id": cluster_profile["id"]})
# Describes a data-center to the LCM api.
# Machine-credentials, repository-credentials, and config-profiles can also be
# assigned to datacenters, or will be inherited from the cluster if unset.
datacenter = do_post("datacenters/",
{"name": "datacenter01",
"cluster-id": cluster["id"]})
# Describes a list of nodes to the LCM api using ip-addresses specified as
# command-line arguments to this script, ie:
# node-install-demo.py 10.0.1.10 10.0.1.11
ip_addresses = sys.argv[1:]
nodes = [do_post("nodes/",
{"name": ip,
"ssh-management-address": ip,
"datacenter-id": datacenter["id"]})
for ip in ip_addresses]
# Request an install job to execute the installation and configuration of the
# cluster. Until this point, we've been describing future state. Now LCM will
# execute the changes necessary to achieve that state.
install_job = do_post("actions/install",
{"job-scope": "cluster",
"resource-id": cluster["id"]})
# Poll the LCM api for updates on the status of the job and progress events
displayed_events = {}
def check_job_status(job_id, displayed_events):
# Fetch the most recent 200 job-events
url = "job_events/?job-id=%s&per-page=200" % job_id
result = requests.get(base_url + url)
# Display events if we haven't seen them before
search_results = json.loads(result.text)
for search_result in search_results['results']:
job_event_result = requests.get(search_result['href'])
job_event = json.loads(job_event_result.text)
if job_event['id'] not in displayed_events:
displayed_events[job_event['id']] = True
# Job events are extremely detailed, select some of the more
# human-friendly fields for display
print "Node %s: %s %s (%s): %s" % (job_event['node-id'],
job_event['event-type'],
job_event['event-subtype'],
job_event['message'],
job_event['event-resource'])
# Check if the entire job has been completed
job_url = "jobs/%s" % job_id
job_response = requests.get(base_url + job_url)
job_results = json.loads(job_response.text)
# Poll every 5 seconds, displaying status until the job is complete
if job_results['status'] == 'RUNNING':
t = threading.Timer(5.0,
check_job_status,
[job_id, displayed_events])
t.start()
elif job_results['status'] == 'COMPLETE':
print "Job completed successfully."
# Initiate status polling
t = threading.Timer(5.0,
check_job_status,
[install_job["id"], displayed_events])
t.start()
