Sewer

Sewer is a Let's Encrypt(ACME) client.
It's name is derived from Kenyan hip hop artiste, Kitu Sewer.
It allows you to obtain ssl/tls certificates from Let's Encrypt.

Let’s Encrypt is a free, automated, and open Certificate Authority. - https://letsencrypt.org

Sewer currently only supports the DNS mode of validation, I have no plans of supporting other modes of validation.
The currently supported DNS providers are:

1. Cloudflare
2. Aurora
3. acme-dns
4. Aliyun
5. He DNS, Hurricane Electric DNS
6. Rackspace
7. DNSPod
8. Bring your own dns provider ...

Sewer can be used very easliy programmatically as a library from code.
Sewer also comes with a command-line(cli) interface(app) that you can use from your favourite terminal

For a changelog(release notes), see: https://github.com/komuw/sewer/releases

Installation

pip3 install sewer
# with All DNS Provider support, include aliyun, Hurricane Electric, Aurora, ACME ...# pip3 install sewer[alldns]# with Cloudflare support# pip3 install sewer[cloudflare]# with Aliyun support# pip3 install sewer[aliyun]# with HE DNS(Hurricane Electric DNS) support# pip3 install sewer[hurricane]# with Aurora DNS Support# pip3 install sewer[aurora]# with ACME DNS Support# pip3 install sewer[acmedns]# with Rackspace DNS Support# pip3 install sewer[rackspace]# with DNSPod DNS Support# pip3 install sewer[dnspod]

sewer(since version 0.5.0) is now python3 only. To install the (now unsupported) python2 version, run;

pip install sewer==0.3.0

Sewer is in active development and it's API may change in backward incompatible ways.
https://pypi.python.org/pypi/sewer

Usage

importsewerdns_class=sewer.CloudFlareDns(CLOUDFLARE_EMAIL='example@example.com',
CLOUDFLARE_API_KEY='nsa-grade-api-key')
# 1. to create a new certificate:client=sewer.Client(domain_name='example.com',
dns_class=dns_class)
certificate=client.cert()
certificate_key=client.certificate_keyaccount_key=client.account_keyprint("your certificate is:", certificate)
print("your certificate's key is:", certificate_key)
print("your letsencrypt.org account key is:", account_key)
# NB: your certificate_key and account_key should be SECRET.# keep them very safe.# you can write these out to individual files, eg::withopen('certificate.crt', 'w') ascertificate_file:
certificate_file.write(certificate)
withopen('certificate.key', 'w') ascertificate_key_file:
certificate_key_file.write(certificate_key)
withopen('account_key.key', 'w') asaccount_key_file:
account_key_file.write(account_key)
# 2. to renew a certificate:importsewerdns_class=sewer.CloudFlareDns(CLOUDFLARE_EMAIL='example@example.com',
CLOUDFLARE_API_KEY='nsa-grade-api-key')
withopen('account_key.key', 'r') asaccount_key_file:
account_key=account_key_file.read()
client=sewer.Client(domain_name='example.com',
dns_class=dns_class,
account_key=account_key)
certificate=client.renew()
certificate_key=client.certificate_keywithopen('certificate.crt', 'w') ascertificate_file:
certificate_file.write(certificate)
withopen('certificate.key', 'w') ascertificate_key_file:
certificate_key_file.write(certificate_key)
# 3. You can also request/renew wildcard certificates:importsewerdns_class=sewer.CloudFlareDns(CLOUDFLARE_EMAIL='example@example.com',
CLOUDFLARE_API_KEY='nsa-grade-api-key')
client=sewer.Client(domain_name='*.example.com',
dns_class=dns_class)
certificate=client.cert()
certificate_key=client.certificate_keyaccount_key=client.account_key

CLI

Sewer also ships with a commandline interface(called sewer or sewer-cli) that you can use to get/renew certificates.
Your dns providers credentials need to be supplied as environment variables.

To get certificate, run:

CLOUDFLARE_EMAIL=example@example.com \
CLOUDFLARE_API_KEY=api-key \
sewer \
--dns cloudflare \
--domain example.com \
--action run

To renew a certificate, run:

CLOUDFLARE_EMAIL=example@example.com \
CLOUDFLARE_API_KEY=api-key \
sewer \
--account_key /path/to/your/account.key \
--dns cloudflare \
--domain example.com \
--action renew

To see help:

sewer --help usage: sewer [-h] [--version] [--account_key ACCOUNT_KEY]
[--certificate_key CERTIFICATE_KEY] --dns
{cloudflare,aurora,acmedns,aliyun,hurricane} --domain DOMAIN
[--alt_domains [ALT_DOMAINS [ALT_DOMAINS ...]]]
[--bundle_name BUNDLE_NAME] [--endpoint {production,staging}]
[--email EMAIL] --action {run,renew} [--out_dir OUT_DIR]
[--loglevel {DEBUG,INFO,WARNING,ERROR,CRITICAL}]
Sewer is a Let's Encrypt(ACME) client.optional arguments: -h, --help show this help message and exit --version The currently installed sewer version. --account_key ACCOUNT_KEY The path to your letsencrypt/acme account key. eg: --account_key /home/myaccount.key --certificate_key CERTIFICATE_KEY The path to your certificate key. eg: --certificate_key /home/mycertificate.key --dns {cloudflare,aurora,acmedns,aliyun,hurricane} The name of the dns provider that you want to use. --domain DOMAIN The domain/subdomain name for which you want to get/renew certificate for. wildcards are also supported eg: --domain example.com --alt_domains [ALT_DOMAINS [ALT_DOMAINS ...]] A list of alternative domain/subdomain name/s(if any) for which you want to get/renew certificate for. eg: --alt_domains www.example.com blog.example.com --bundle_name BUNDLE_NAME The name to use for certificate certificate key and account key. Default is name of domain. --endpoint {production,staging} Whether to use letsencrypt/acme production/live endpoints or staging endpoints. production endpoints are used by default. eg: --endpoint staging --email EMAIL Email to be used for registration and recovery. eg: --email me@example.com --action {run,renew} The action that you want to perform. Either run (get a new certificate) or renew (renew a certificate). eg: --action run --out_dir OUT_DIR The dir where the certificate and keys file will be stored. default: The directory you run sewer command. eg: --out_dir /data/ssl/ --loglevel {DEBUG,INFO,WARNING,ERROR,CRITICAL} The log level to output log messages at. eg: --loglevel DEBUG

The cerrtificate, certificate key and account key will be saved in the directory that you run sewer from.

The commandline interface(app) is called sewer or alternatively you could use, sewer-cli.

Features

• Obtain certificates.
• Renew certificates.
• Supports multiple DNS providers.
• Supports wildcard certificates
• Supports acme version 2 only.
• Bring your own dns provider
• Support for SAN certificates.
• Can be used as a python library as well as a command line(CLI) application.
• Bundling certificates.
• Well written(if I have to say so myself):
  • Good test coverage
  • Passing continous integration
  • High grade statically analyzed code

Bring your own DNS provider

It is very easy to use any dns provider with sewer.
All you have to do is create your own dns class that is a child class of sewer.BaseDns and then implement the
create_dns_record and delete_dns_record methods.
As an example, if you wanted to use AWS route53 as your dns provider with sewer, you
would do something like;

importsewerimportboto3classAWSroute53Dns(sewer.BaseDns):
def__init__(self,
HostedZoneId,
AWS_ACCESS_KEY_ID,
AWS_SECRET_ACCESS_KEY):
self.dns_provider_name='AWS_route53'self.HostedZoneId=HostedZoneIdself.boto_client=boto3.client(
'route53', aws_access_key_id=AWS_ACCESS_KEY_ID,
aws_secret_access_key=AWS_SECRET_ACCESS_KEY)
super(AWSroute53Dns, self).__init__()
defcreate_dns_record(self,
domain_name,
domain_dns_value):
""" AWS route53 with boto3 documentation; https://boto3.readthedocs.io/en/latest/reference/services/route53.html#Route53.Client.change_resource_record_sets """# do whatever is necessary for your particular DNS provider to create a TXT DNS record# eg for AWS route53, it will be something like::self.boto_client.change_resource_record_sets(
HostedZoneId=self.HostedZoneId,
ChangeBatch={
'Changes': [
{
'Action': 'CREATE',
'ResourceRecordSet': {
'Name': '_acme-challenge'+'.'+domain_name+'.',
'Type': 'TXT',
'TTL': 123,
'ResourceRecords': [
{
'Value': "{0}".format(domain_dns_value)},
]}},
]})
defdelete_dns_record(self,
domain_name,
domain_dns_value):
# do whatever is necessary for your particular DNS provider to delete a TXT DNS record# eg for AWS route53, it will be something like::self.boto_client.change_resource_record_sets(
HostedZoneId=self.HostedZoneId,
ChangeBatch={
'Changes': [
{
'Action': 'DELETE',
'ResourceRecordSet': {
'Name': '_acme-challenge'+'.'+domain_name+'.',
'Type': 'TXT',
'TTL': 123,
'ResourceRecords': [
{
'Value': "{0}".format(domain_dns_value)},
]}},
]})
custom_route53_dns_class=AWSroute53Dns(
HostedZoneId='my-zone', AWS_ACCESS_KEY_ID='access-key',
AWS_SECRET_ACCESS_KEY='secret-access-key')
# create a new certificate:client=sewer.Client(domain_name='example.com',
dns_class=custom_route53_dns_class)
certificate=client.cert()
certificate_key=client.certificate_keyaccount_key=client.account_keyprint("certificate::", certificate)
print("certificate's key::", certificate_key)

Development setup

see the how to contribute documentation

TODO

• support more DNS providers
• https://github.com/komuw/sewer/milestone/1

FAQ

• Why another ACME client?
  I wanted an ACME client that I could use to programmatically(as a library) acquire/get certificates. However I could not find anything satisfactory for use in Python code.
• Why is it called Sewer? I really like the Kenyan hip hop artiste going by the name of Kitu Sewer.

Here's the ouput of running sewer using the cli app:

CLOUDFLARE_EMAIL=example@example.com \
CLOUDFLARE_API_KEY=nsa-grade-api-key \
sewer \
--endpoint staging \
--dns cloudflare \
--domain subdomain.example.com \
--action run 2018-03-06 18:08.41 chosen_dns_provider message=Using cloudflare as dns provider.
2018-03-06 18:08.46 acme_register acme_server=https://acme-staging... domain_names=['subdomain.example.com'] sewer_version=0.5.0b
2018-03-06 18:08.52 acme_register_response acme_server=https://acme-staging... domain_names=['subdomain.example.com']
2018-03-06 18:08.52 apply_for_cert_issuance acme_server=https://acme-staging... domain_names=['subdomain.example.com'] sewer_version=0.5.0b
2018-03-06 18:09.01 apply_for_cert_issuance_response acme_server=https://acme-staging... domain_names=['subdomain.example.com']
2018-03-06 18:09.08 create_dns_record dns_provider_name=CloudFlareDns
2018-03-06 18:09.16 create_cloudflare_dns_record_response dns_provider_name=CloudFlareDns status_code=200
2018-03-06 18:09.36 send_csr acme_server=https://acme-staging... domain_names=['subdomain.example.com'] sewer_version=0.5.0b
2018-03-06 18:09.45 send_csr_response acme_server=https://acme-staging... domain_names=['subdomain.example.com']
2018-03-06 18:09.45 download_certificate acme_server=https://acme-staging... domain_names=['subdomain.example.com'] sewer_version=0.5.0b
2018-03-06 18:09.50 download_certificate_response acme_server=https://acme-staging... domain_names=['subdomain.example.com']
2018-03-06 18:09.54 the_end message=Certificate Succesfully issued. The certificate, certificate key and account key have been saved in the current directory