def origin_access_identity(
self) -> cloudfront.CloudFrontOriginAccessIdentity:
"""Return cloudformation access identity.
It is needed to be used as principal for s3 bucket access policy.
"""
if self._origin_access_identity is None:
cf_oai_config = cloudfront.CloudFrontOriginAccessIdentityConfig(
Comment=f"{self.name} Cloudfront origin access identity")
self._origin_access_identity = cloudfront.CloudFrontOriginAccessIdentity(
name_to_id(f"{self.name}-cloudfront-oai"),
CloudFrontOriginAccessIdentityConfig=cf_oai_config,
)
return self._origin_access_identity
def add_origin_access_identity(self):
# type: () -> cloudfront.CloudFrontOriginAccessIdentity
"""Add the origin access identity resource to the template.
Returns:
The OAI resource
"""
return self.template.add_resource(
cloudfront.CloudFrontOriginAccessIdentity(
"OAI",
CloudFrontOriginAccessIdentityConfig=cloudfront.CloudFrontOriginAccessIdentityConfig( # noqa
Comment="CF access to website"
),
)
)
def create_template(self):
"""Create template (main function called by Stacker)."""
template = self.template
variables = self.get_variables()
template.set_version('2010-09-09')
template.set_description('Static Website - Bucket and Distribution')
# Conditions
template.add_condition(
'AcmCertSpecified',
And(Not(Equals(variables['AcmCertificateArn'].ref, '')),
Not(Equals(variables['AcmCertificateArn'].ref, 'undefined')))
)
template.add_condition(
'AliasesSpecified',
And(Not(Equals(Select(0, variables['Aliases'].ref), '')),
Not(Equals(Select(0, variables['Aliases'].ref), 'undefined')))
)
template.add_condition(
'CFLoggingEnabled',
And(Not(Equals(variables['LogBucketName'].ref, '')),
Not(Equals(variables['LogBucketName'].ref, 'undefined')))
)
template.add_condition(
'DirectoryIndexSpecified',
And(Not(Equals(variables['RewriteDirectoryIndex'].ref, '')),
Not(Equals(variables['RewriteDirectoryIndex'].ref, 'undefined'))) # noqa
)
template.add_condition(
'WAFNameSpecified',
And(Not(Equals(variables['WAFWebACL'].ref, '')),
Not(Equals(variables['WAFWebACL'].ref, 'undefined')))
)
# Resources
oai = template.add_resource(
cloudfront.CloudFrontOriginAccessIdentity(
'OAI',
CloudFrontOriginAccessIdentityConfig=cloudfront.CloudFrontOriginAccessIdentityConfig( # noqa pylint: disable=line-too-long
Comment='CF access to website'
)
)
)
bucket = template.add_resource(
s3.Bucket(
'Bucket',
AccessControl=s3.Private,
LifecycleConfiguration=s3.LifecycleConfiguration(
Rules=[
s3.LifecycleRule(
NoncurrentVersionExpirationInDays=90,
Status='Enabled'
)
]
),
VersioningConfiguration=s3.VersioningConfiguration(
Status='Enabled'
),
WebsiteConfiguration=s3.WebsiteConfiguration(
IndexDocument='index.html',
ErrorDocument='error.html'
)
)
)
template.add_output(Output(
'BucketName',
Description='Name of website bucket',
Value=bucket.ref()
))
allowcfaccess = template.add_resource(
s3.BucketPolicy(
'AllowCFAccess',
Bucket=bucket.ref(),
PolicyDocument=PolicyDocument(
Version='2012-10-17',
Statement=[
Statement(
Action=[awacs.s3.GetObject],
Effect=Allow,
Principal=Principal(
'CanonicalUser',
oai.get_att('S3CanonicalUserId')
),
Resource=[
Join('', [bucket.get_att('Arn'),
'/*'])
]
)
]
)
)
)
cfdirectoryindexrewriterole = template.add_resource(
iam.Role(
'CFDirectoryIndexRewriteRole',
Condition='DirectoryIndexSpecified',
AssumeRolePolicyDocument=PolicyDocument(
Version='2012-10-17',
Statement=[
Statement(
Effect=Allow,
Action=[awacs.sts.AssumeRole],
Principal=Principal('Service',
['lambda.amazonaws.com',
'edgelambda.amazonaws.com'])
)
]
),
ManagedPolicyArns=[
IAM_ARN_PREFIX + 'AWSLambdaBasicExecutionRole'
]
)
)
cfdirectoryindexrewrite = template.add_resource(
awslambda.Function(
'CFDirectoryIndexRewrite',
Condition='DirectoryIndexSpecified',
Code=awslambda.Code(
ZipFile=Join(
'',
["'use strict';\n",
"exports.handler = (event, context, callback) => {\n",
"\n",
" // Extract the request from the CloudFront event that is sent to Lambda@Edge\n", # noqa pylint: disable=line-too-long
" var request = event.Records[0].cf.request;\n",
" // Extract the URI from the request\n",
" var olduri = request.uri;\n",
" // Match any '/' that occurs at the end of a URI. Replace it with a default index\n", # noqa pylint: disable=line-too-long
" var newuri = olduri.replace(/\\/$/, '\\/",
variables['RewriteDirectoryIndex'].ref,
"');\n", # noqa
" // Log the URI as received by CloudFront and the new URI to be used to fetch from origin\n", # noqa pylint: disable=line-too-long
" console.log(\"Old URI: \" + olduri);\n",
" console.log(\"New URI: \" + newuri);\n",
" // Replace the received URI with the URI that includes the index page\n", # noqa pylint: disable=line-too-long
" request.uri = newuri;\n",
" // Return to CloudFront\n",
" return callback(null, request);\n",
"\n",
"};\n"]
)
),
Description='Rewrites CF directory HTTP requests to default page', # noqa
Handler='index.handler',
Role=cfdirectoryindexrewriterole.get_att('Arn'),
Runtime='nodejs8.10'
)
)
# Generating a unique resource name here for the Lambda version, so it
# updates automatically if the lambda code changes
code_hash = hashlib.md5(
str(cfdirectoryindexrewrite.properties['Code'].properties['ZipFile'].to_dict()).encode() # noqa pylint: disable=line-too-long
).hexdigest()
cfdirectoryindexrewritever = template.add_resource(
awslambda.Version(
'CFDirectoryIndexRewriteVer' + code_hash,
Condition='DirectoryIndexSpecified',
FunctionName=cfdirectoryindexrewrite.ref()
)
)
# If custom associations defined, use them
if variables['lambda_function_associations']:
lambda_function_associations = [
cloudfront.LambdaFunctionAssociation(
EventType=x['type'],
LambdaFunctionARN=x['arn']
) for x in variables['lambda_function_associations']
]
else: # otherwise fallback to pure CFN condition
lambda_function_associations = If(
'DirectoryIndexSpecified',
[cloudfront.LambdaFunctionAssociation(
EventType='origin-request',
LambdaFunctionARN=cfdirectoryindexrewritever.ref()
)],
NoValue
)
cfdistribution = template.add_resource(
get_cf_distribution_class()(
'CFDistribution',
DependsOn=allowcfaccess.title,
DistributionConfig=get_cf_distro_conf_class()(
Aliases=If(
'AliasesSpecified',
variables['Aliases'].ref,
NoValue
),
Origins=[
get_cf_origin_class()(
DomainName=Join(
'.',
[bucket.ref(),
's3.amazonaws.com']),
S3OriginConfig=get_s3_origin_conf_class()(
OriginAccessIdentity=Join(
'',
['origin-access-identity/cloudfront/',
oai.ref()])
),
Id='S3Origin'
)
],
DefaultCacheBehavior=cloudfront.DefaultCacheBehavior(
AllowedMethods=['GET', 'HEAD'],
Compress=False,
DefaultTTL='86400',
ForwardedValues=cloudfront.ForwardedValues(
Cookies=cloudfront.Cookies(Forward='none'),
QueryString=False,
),
LambdaFunctionAssociations=lambda_function_associations, # noqa
TargetOriginId='S3Origin',
ViewerProtocolPolicy='redirect-to-https'
),
DefaultRootObject='index.html',
Logging=If(
'CFLoggingEnabled',
cloudfront.Logging(
Bucket=Join('.',
[variables['LogBucketName'].ref,
's3.amazonaws.com'])
),
NoValue
),
PriceClass=variables['PriceClass'].ref,
Enabled=True,
WebACLId=If(
'WAFNameSpecified',
variables['WAFWebACL'].ref,
NoValue
),
ViewerCertificate=If(
'AcmCertSpecified',
cloudfront.ViewerCertificate(
AcmCertificateArn=variables['AcmCertificateArn'].ref, # noqa
SslSupportMethod='sni-only'
),
NoValue
)
)
)
)
template.add_output(Output(
'CFDistributionId',
Description='CloudFront distribution ID',
Value=cfdistribution.ref()
))
template.add_output(
Output(
'CFDistributionDomainName',
Description='CloudFront distribution domain name',
Value=cfdistribution.get_att('DomainName')
)
)
def __init__(self, title, comment, **kwargs):
super().__init__(title, **kwargs)
self.CloudFrontOriginAccessIdentityConfig = (
clf.CloudFrontOriginAccessIdentityConfig(Comment=comment)
)