def wizard_iam(global_config):
terminal.print_header("IAM Configuration")
terminal.write_str("""\
An IAM role must be created for this lambda function giving it access to CloudFront, Route53, S3,
SNS(notifications), IAM(certificates), and CloudWatch(logs/alarms).""")
print()
terminal.write_str(
"If you do not let the wizard create this role you will be asked to select an existing role to use."
)
create_iam_role = terminal.get_yn(
"Do you want to automatically create this role", True)
if not create_iam_role:
role_list = iam.list_roles()
options = []
for i, role in enumerate(role_list):
options.append({'selector': i, 'prompt': role, 'return': role})
iam_role_name = terminal.get_selection("Select the IAM Role:",
options,
prompt_after="Which IAM Role?",
allow_empty=False)
else:
iam_role_name = "lambda-letsencrypt-{}".format(
global_config['namespace'])
global_config['create_iam_role'] = create_iam_role
global_config['iam_role_name'] = iam_role_name
def wizard_region(global_config):
terminal.print_header("AWS Region")
terminal.write_str(
"""Choose the region you want ot use for new resources""")
aws_region = choose_aws_region()
global_config['aws_region'] = aws_region
def wizard_summary(global_config):
gc = global_config
terminal.print_header("**Summary**")
print("Namespace: {}".format(
gc['namespace']))
print("AWS region: {}".format(
gc['aws_region']))
print("Notification Email: {}".format(
gc['sns_email'] or "(notifications disabled)"))
print("S3 Config Bucket: {}".format(
gc['s3_cfg_bucket']),
end="")
if gc['create_s3_cfg_bucket']:
print(" (to be created)")
else:
print(" (existing)")
if gc['create_iam_role']:
print(
"IAM Role Name: {} (to be created)"
.format(gc['iam_role_name']))
else:
print("IAM Role Name: {} (existing)".
format(gc['iam_role_name']))
print("Support HTTP Challenges: {}".format(
gc['use_http_challenges']))
if gc['use_http_challenges']:
print("S3 HTTP Challenge Bucket: {}".format(
gc['s3_challenge_bucket']),
end="")
if gc['create_s3_challenge_bucket']:
print(" (to be created)")
else:
print(" (existing)")
print("Domains To Manage With Lets-Encrypt")
for d in gc['cf_domains']:
print(" {} - [{}]".format(d['DOMAIN'],
",".join(d['VALIDATION_METHODS'])))
for d in gc['elb_domains']:
print(" {} - [{}]".format(d['DOMAIN'],
",".join(d['VALIDATION_METHODS'])))
print("CloudFront Distributions To Manage:")
for cf in gc['cf_sites']:
print(" {} - [{}]".format(cf['CLOUDFRONT_ID'],
",".join(cf['DOMAINS'])))
print("Elastic Load Balancers to Manage:")
for lb in gc['elb_sites']:
print(" {}:{} - [{}]".format(lb['ELB_NAME'], lb['ELB_PORT'],
",".join(lb['DOMAINS'])))
print("Create daily Lambda function trigger: {}".format(
gc['create_cloudwatch_rule']))
def update_lambda():
terminal.print_header("Updating Lambda function")
if not create_lambda_zip():
return
fn = choose_lambda_function_for_update()
updated = awslambda.update_function_code(fn, zip_file_name)
if updated:
print(terminal.Colors.OKGREEN + u'\u2713' + terminal.Colors.ENDC)
else:
print(terminal.Colors.FAIL + u'\u2717' + terminal.Colors.ENDC)
return
def wizard_namespace(global_config):
namespace = None
terminal.print_header("Namespace")
terminal.write_str("""\
It is necessary to provide unique names when creating configuration and
challenge S3 buckets; provided value will be appended to default names.
In other cases uniqueness is not necessary although helpful if you need to
distinguish among resources.""")
namespace = terminal.get_input(
"Enter value to append to resource names (eg: foobar): ",
allow_empty=False)
global_config['namespace'] = namespace
def wizard_challenges(global_config):
create_s3_challenge_bucket = False
s3_challenge_bucket = None
terminal.print_header("Lets-Encrypt Challenge Validation Settings")
terminal.write_str("""\
This tool will handle validation of your domains automatically. There are two possible validation methods: HTTP
and DNS.""")
print()
terminal.write_str("""\
HTTP validation is only available for CloudFront sites. It requires an S3 bucket to store the challenge
responses in. This bucket needs to be publicly accessible. Your CloudFront Distribution(s) will be reconfigured
to use this bucket as an origin for challenge responses.""")
terminal.write_str(
"If you do not configure a bucket for this you will only be able to use DNS validation."
)
print()
terminal.write_str("""\
DNS validation requires your domain to be managed with Route53. This validation method is always available and
requires no additional configuration.""")
terminal.write_str(
terminal.Colors.WARNING +
"Note: DNS validation is currently only supported by the staging server."
+ terminal.Colors.ENDC)
print()
terminal.write_str(
"Each domain you want to manage can be configured to validate using either of these methods."
)
print()
use_http_challenges = terminal.get_yn(
"Do you want to configure HTTP validation", True)
if use_http_challenges:
create_s3_challenge_bucket = terminal.get_yn(
"Do you want to create a bucket for these challenges(Choose No to select an existing bucket)",
True)
if create_s3_challenge_bucket:
s3_challenge_bucket = "lambda-letsencrypt-challenges-{}".format(
global_config['namespace'])
else:
s3_challenge_bucket = choose_s3_bucket()
else:
# only dns challenge support is available
pass
global_config['use_http_challenges'] = use_http_challenges
global_config['create_s3_challenge_bucket'] = create_s3_challenge_bucket
global_config['s3_challenge_bucket'] = s3_challenge_bucket
def wizard_s3_cfg_bucket(global_config):
terminal.print_header("S3 Configuration Bucket")
terminal.write_str("""\
An S3 Bucket is required to store configuration. If you already have a bucket you want to use for this choose no
and select it from the list. Otherwise let the wizard create one for you."""
)
create_s3_cfg_bucket = terminal.get_yn("Create a bucket for configuration",
True)
if create_s3_cfg_bucket:
s3_cfg_bucket = "lambda-letsencrypt-config-{}".format(
global_config['namespace'])
else:
s3_cfg_bucket = choose_s3_bucket()
global_config['create_s3_cfg_bucket'] = create_s3_cfg_bucket
global_config['s3_cfg_bucket'] = s3_cfg_bucket
def wizard_sns(global_config):
sns_email = None
terminal.print_header("Notifications")
terminal.write_str("""\
The lambda function can send notifications when a certificate is issued,
errors occur, or other things that may need your attention.
Notifications are optional.""")
use_sns = True
sns_email = terminal.get_input(
"Enter the email address for notifications(blank to disable): ",
allow_empty=True)
if len(sns_email) == 0:
use_sns = False
global_config['use_sns'] = use_sns
global_config['sns_email'] = sns_email
def wizard_trigger(global_config):
terminal.print_header("Lets-Encrypt certificate check trigger")
terminal.write_str("""\
To set up certificate and later update it, it is necessary to invoke
generated AWS Lambda function regularly. Lambda function will make sure
certificate is issued (might take 2-3 invocations), will check its expiry,
will update it before it expires.""")
print()
terminal.write_str("""\
Trigger is created as a AWS CloudWatch Event rule with target
pointing to Lambda function.""")
print()
terminal.write_str("""\
If you skip set up of this trigger, you will need to either invoke
function yourself or set up trigger which does it.""")
print()
create_cloudwatch_rule = terminal.get_yn("Set up AWS Lambda trigger?",
default=True)
global_config['create_cloudwatch_rule'] = create_cloudwatch_rule
def wizard_elb(global_config):
terminal.print_header("ELB Configuration")
terminal.write_str("""\
Now we'll detect your existing Elastic Load Balancers and allow you
to configure them to use SSL. You must select the domain names
you want on the certificate for each ELB.""")
terminal.write_str("""\
Note that only DNS validation(via Route53) is supported for ELBs""")
print()
global_config['elb_sites'] = []
global_config['elb_domains'] = []
# Get the list of all Cloudfront Distributions
elb_list = elb.list_elbs()
elb_list_opts = []
for i, elb_name in enumerate(elb_list):
elb_list_opts.append({
'selector': i,
'prompt': elb_name,
'return': elb_name
})
route53_list = route53.list_zones()
route53_list_opts = []
for i, zone in enumerate(route53_list):
route53_list_opts.append({
'selector':
i,
'prompt':
"{} - {}".format(zone['Name'], zone['Id']),
'return':
zone
})
while True:
lb = terminal.get_selection(
"Choose an ELB to configure SSL for(Leave blank for none)",
elb_list_opts,
prompt_after="Which ELB?",
allow_empty=True)
if lb is None:
break
lb_port = terminal.get_input(
"What port number will this certificate be for(HTTPS is 443) [443]?",
allow_empty=True)
if len(lb_port) == 0:
lb_port = 443
domains = []
while True:
if len(domains) > 0:
print("Already selected: {}".format(",".join(domains)))
zone = terminal.get_selection(
"Choose a Route53 Zone that points to this load balancer: ",
route53_list_opts,
prompt_after="Which zone?",
allow_empty=True)
# stop when they don't enter anything
if zone is None:
break
# Only allow adding each domain once
if zone['Name'] in domains:
continue
domains.append(zone['Name'])
global_config['elb_domains'].append({
'DOMAIN':
zone['Name'],
'ROUTE53_ZONE_ID':
zone['Id'],
'VALIDATION_METHODS': ['dns-01']
})
site = {
'ELB_NAME': lb,
'ELB_PORT': lb_port,
'DOMAINS': domains,
}
global_config['elb_sites'].append(site)
def wizard():
terminal.print_header("Lambda Lets-Encrypt Wizard")
terminal.write_str("""\
This wizard will guide you through the process of setting up your existing
CloudFront Distributions to use SSL certificates provided by Lets-Encrypt
and automatically issued/maintained by an AWS Lambda function.
These certificates are free of charge, and valid for 90 days. This wizard
will also set up a Lambda function that is responsible for issuing and
renewing these certificates automatically as they near their expiration
date.
The cost of the AWS services used to make this work are typically less
than a penny per month. For full pricing details please refer to the
docs.
""")
print()
print(terminal.Colors.WARNING + "WARNING: ")
terminal.write_str("""\
Manual configuration is required at this time to configure the Lambda
function to run on a daily basis to keep your certificate updated. If
you do not follow the steps provided at the end of this wizard your
Lambda function will *NOT* run.
""")
print(terminal.Colors.ENDC)
global_config = {}
wizard_namespace(global_config)
wizard_region(global_config)
wizard_sns(global_config)
wizard_iam(global_config)
wizard_s3_cfg_bucket(global_config)
wizard_challenges(global_config)
wizard_cf(global_config)
wizard_elb(global_config)
wizard_trigger(global_config)
cfg_menu = [{
'selector': 0,
'prompt': 'Namespace',
'return': wizard_namespace
}, {
'selector': 1,
'prompt': 'AWS Region',
'return': wizard_region
}, {
'selector': 2,
'prompt': 'SNS',
'return': wizard_sns
}, {
'selector': 3,
'prompt': 'IAM',
'return': wizard_iam
}, {
'selector': 4,
'prompt': 'S3 Config',
'return': wizard_s3_cfg_bucket
}, {
'selector': 5,
'prompt': 'Challenges',
'return': wizard_challenges
}, {
'selector': 6,
'prompt': 'CloudFront',
'return': wizard_cf
}, {
'selector': 7,
'prompt': 'Elastic Load Balancers',
'return': wizard_cf
}, {
'selector': 8,
'prompt': 'Lambda function trigger',
'return': wizard_trigger
}, {
'selector': 9,
'prompt': 'Done',
'return': None
}]
finished = False
while not finished:
wizard_summary(global_config)
finished = terminal.get_yn("Are these settings correct", True)
if not finished:
selection = terminal.get_selection(
"Which section do you want to change",
cfg_menu,
prompt_after="Which section to modify?",
allow_empty=False)
if selection:
selection(global_config)
wizard_save_config(global_config)
def wizard_save_config(global_config):
terminal.print_header("Making Requested Changes")
templatevars = {}
with open(config_file_template_name, 'r') as template:
configfile = Template(template.read())
templatevars['SNS_ARN'] = None
templatevars['NOTIFY_EMAIL'] = None
templatevars['AWS_REGION'] = global_config['aws_region']
# Configure SNS if appropriate
sns_arn = None
if len(global_config['sns_email']) > 0:
# Create SNS Topic if necessary
print("Creating SNS Topic for Notifications ", end='')
sns_arn = sns.get_or_create_topic(global_config['sns_email'])
if sns_arn is False or sns_arn is None:
print(terminal.Colors.FAIL + u'\u2717' + terminal.Colors.ENDC)
else:
print(terminal.Colors.OKGREEN + u'\u2713' + terminal.Colors.ENDC)
templatevars['SNS_ARN'] = sns_arn
templatevars['NOTIFY_EMAIL'] = global_config['sns_email']
# create config bucket if necessary
if global_config['create_s3_cfg_bucket']:
print("Creating S3 Configuration Bucket ", end='')
s3.create_bucket(global_config['aws_region'],
global_config['s3_cfg_bucket'])
print(terminal.Colors.OKGREEN + u'\u2713' + terminal.Colors.ENDC)
# create challenge bucket if necessary(needs to be configured as static website)
if global_config['create_s3_challenge_bucket']:
print("Creating S3 Challenge Bucket ", end='')
s3.create_web_bucket(global_config['aws_region'],
global_config['s3_challenge_bucket'])
print(terminal.Colors.OKGREEN + u'\u2713' + terminal.Colors.ENDC)
# create IAM role if required
if global_config['create_iam_role']:
policy_document = iam.generate_policy_document(s3buckets=[
global_config['s3_cfg_bucket'],
global_config['s3_challenge_bucket']
],
snstopicarn=sns_arn)
iam_arn = iam.configure(global_config['iam_role_name'],
policy_document)
# attempt to avoid error: The role defined for the function cannot be assumed by Lambda.
print("Wait for IAM role")
time.sleep(5)
print("Still waiting..")
time.sleep(5)
print("Still waiting...")
time.sleep(5)
templatevars['S3_CONFIG_BUCKET'] = global_config['s3_cfg_bucket']
templatevars['S3_CHALLENGE_BUCKET'] = global_config['s3_challenge_bucket']
domains = global_config['cf_domains'] + global_config['elb_domains']
sites = global_config['cf_sites'] + global_config['elb_sites']
templatevars['DOMAINS'] = json.dumps(domains, indent=4)
templatevars['SITES'] = json.dumps(sites, indent=4)
# write out the config file
config = configfile.substitute(templatevars)
with open(generated_config_file_name, 'w') as configfinal:
print("Writing Configuration File ", end='')
configfinal.write(config)
print(terminal.Colors.OKGREEN + u'\u2713' + terminal.Colors.ENDC)
if not create_lambda_zip():
return
print("Configuring Lambda Function:")
iam_arn = iam.get_arn(global_config['iam_role_name'])
print(" IAM ARN: {}".format(iam_arn))
print(" Uploading Function ", end='')
lambda_function_name = "lambda-letsencrypt-{}".format(
global_config['namespace'])
lambda_function = awslambda.create_function(lambda_function_name, iam_arn,
zip_file_name)
if lambda_function:
print(terminal.Colors.OKGREEN + u'\u2713' + terminal.Colors.ENDC)
else:
print(terminal.Colors.FAIL + u'\u2717' + terminal.Colors.ENDC)
return
if global_config['create_cloudwatch_rule']:
print(" Setting daily Lambda function trigger ", end='')
lambda_execution_rule = cloud_watch_events.cloudwatch_create_daily_rule_for_function(
lambda_function['FunctionName'], lambda_function['FunctionArn'],
iam_arn)
if lambda_execution_rule:
print(terminal.Colors.OKGREEN + u'\u2713' + terminal.Colors.ENDC)
else:
print(terminal.Colors.FAIL + u'\u2717' + terminal.Colors.ENDC)
return
terminal.print_header("Testing")
terminal.write_str("""\
You may want to test this before you set it to be recurring. Click on
the 'Test' button in the AWS Console for the lambda-letsencrypt function.
The data you provide to this function does not matter. Make sure to review
the logs after it finishes and check for anything out of the ordinary.
""")
print()
terminal.write_str("""\
It will take at least 2 runs before your certificates are issued,
maybe 3 depending on how fast cloudfront responds. This is because it
needs one try to configure cloudfront, one to submit the challenge and
have it verified, and one final run to issue the certificate and configure
the cloudfront distribution
""")
def wizard_cf(global_config):
terminal.print_header("CloudFront Configuration")
global_config['cf_sites'] = []
global_config['cf_domains'] = []
# Get the list of all Cloudfront Distributions
cf_dist_list = cloudfront.list_distributions()
cf_dist_opts = []
for i, d in enumerate(cf_dist_list):
cf_dist_opts.append({
'selector':
i,
'prompt':
"{} - {} ({}) ".format(d['Id'], d['Comment'],
", ".join(d['Aliases'])),
'return':
d
})
terminal.write_str("""\
Now we'll detect your existing CloudFront Distributions and allow you
to configure them to use SSL. Domain names will be automatically
detected from the 'Aliases/CNAMEs' configuration section of each
Distribution.""")
print()
terminal.write_str("""\
You will configure each Distribution fully before being presented with
the list of Distributions again. You can configure as many Distributions
as you like.""")
while True:
print()
dist = terminal.get_selection(
"Select a CloudFront Distribution to configure with Lets-Encrypt(leave blank to finish)",
cf_dist_opts,
prompt_after="Which CloudFront Distribution?",
allow_empty=True)
if dist is None:
break
cnames = dist['Aliases']
terminal.write_str(
"The following domain names exist for the selected CloudFront Distribution:"
)
terminal.write_str(" " + ", ".join(cnames))
terminal.write_str("""\
Each domain in this list will be validated with Lets-Encrypt and added to the certificate assigned to this
Distribution.""")
print()
for dns_name in cnames:
domain = {'DOMAIN': dns_name, 'VALIDATION_METHODS': []}
print("Choose validation methods for the domain '{}'".format(
dns_name))
route53_id = route53.get_zone_id(dns_name)
if route53_id:
terminal.write_str(terminal.Colors.OKGREEN +
"Route53 zone detected!" +
terminal.Colors.ENDC)
validate_via_dns = terminal.get_yn("Validate using DNS",
default=False)
if validate_via_dns:
domain['ROUTE53_ZONE_ID'] = route53_id
domain['VALIDATION_METHODS'].append('dns-01')
else:
terminal.write_str(
terminal.Colors.WARNING +
"No Route53 zone detected, DNS validation not possible." +
terminal.Colors.ENDC)
validate_via_http = terminal.get_yn("Validate using HTTP",
default=True)
if validate_via_http:
domain['CLOUDFRONT_ID'] = dist['Id']
domain['VALIDATION_METHODS'].append('http-01')
global_config['cf_domains'].append(domain)
site = {'CLOUDFRONT_ID': dist['Id'], 'DOMAINS': cnames}
global_config['cf_sites'].append(site)