|
| 1 | +import yaml |
| 2 | +from logger import getJSONLogger |
| 3 | +from kubernetes import client, config |
| 4 | +from kubernetes.client.rest import ApiException |
| 5 | +import base64 |
| 6 | +import OpenSSL |
| 7 | +from OpenSSL import crypto |
| 8 | +import boto3 |
| 9 | + |
| 10 | +CERT_BEGIN = "-----BEGIN CERTIFICATE-----" |
| 11 | +CERT_END = "-----END CERTIFICATE-----" |
| 12 | +CRD_GROUP = 'cert-manager.io' |
| 13 | +CRD_CERT_NAME = 'certificate' |
| 14 | +CRD_CERT_PLURAL = 'certificates' |
| 15 | + |
| 16 | +logger = getJSONLogger('kube-cert-acm.helpers') |
| 17 | + |
| 18 | + |
| 19 | +# Discover in cluster kubernetes configuration |
| 20 | +config.load_incluster_config() |
| 21 | +api_instance = client.CoreV1Api() |
| 22 | +custom_api_instance = client.CustomObjectsApi() |
| 23 | + |
| 24 | +session = boto3.Session() |
| 25 | +aws_client = session.client('acm') |
| 26 | + |
| 27 | + |
| 28 | +def read_conf_file(config_file: str) -> list: |
| 29 | + """Read config file and return a list of valid entries.""" |
| 30 | + certificates = [] |
| 31 | + with open(config_file, 'r') as f: |
| 32 | + try: |
| 33 | + confs = yaml.safe_load(f) |
| 34 | + except yaml.YAMLError as yerr: |
| 35 | + logger.error(f'Error parsing config file. Err: {yerr}') |
| 36 | + raise Exception |
| 37 | + for cert in confs: |
| 38 | + if all(key in cert for key in ('cert', 'namespace', 'domain_name')): |
| 39 | + logger.debug(f'Required keys are present in {cert}') |
| 40 | + certificates.append(cert) |
| 41 | + else: |
| 42 | + logger.error(f'A required key is missing in {cert}') |
| 43 | + |
| 44 | + return certificates |
| 45 | + |
| 46 | + |
| 47 | +def get_certificate_secret_name(certificate: str, namespace: str) -> str: |
| 48 | + """Get the secret name of the provided certificate / namespace.""" |
| 49 | + try: |
| 50 | + api_resp = custom_api_instance.get_namespaced_custom_object( |
| 51 | + group=CRD_GROUP, version='v1', namespace=namespace, name=certificate, plural=CRD_CERT_PLURAL) |
| 52 | + except ApiException as e: |
| 53 | + logger.error( |
| 54 | + f'Exception getting Certificate: {certificate}. Status: {e.status}. Reason: {e.reason}', exc_info=False) |
| 55 | + raise Exception |
| 56 | + try: |
| 57 | + cert_secret_name = api_resp['spec']['secretName'] |
| 58 | + except Exception as e: |
| 59 | + logger.error( |
| 60 | + f'Exception extracting secretName from certificate object. Error: {e}') |
| 61 | + return None |
| 62 | + return cert_secret_name |
| 63 | + |
| 64 | + |
| 65 | +def get_cert_and_key_from_secret(secret: str, namespace: str): |
| 66 | + """Get the certificate and its private key from the provided secret / namespace.""" |
| 67 | + try: |
| 68 | + resp = api_instance.read_namespaced_secret(secret, namespace) |
| 69 | + except ApiException as e: |
| 70 | + logger.exception( |
| 71 | + f"Exception reading secret {secret} from namesapce {namespace}). Status: {e.status}, Reason: {e.reason}", exc_info=False) |
| 72 | + return None, None |
| 73 | + try: |
| 74 | + certificate = base64.b64decode(resp.data.get('tls.crt')) |
| 75 | + key = base64.b64decode(resp.data.get('tls.key')) |
| 76 | + except Exception as e: |
| 77 | + logger.error('Failed to extract data from returned secret') |
| 78 | + return None, None |
| 79 | + return certificate, key |
| 80 | + |
| 81 | + |
| 82 | +def get_certificate_and_chain(kube_certificate: str): |
| 83 | + """Separate certificate from the chain.""" |
| 84 | + try: |
| 85 | + crypto.load_certificate(crypto.FILETYPE_PEM, kube_certificate) |
| 86 | + except OpenSSL.crypto.Error as e: |
| 87 | + logger.error(f"OpenSSL error while loading certificate. Error: {e}") |
| 88 | + return None, None |
| 89 | + certs = kube_certificate.decode().split(CERT_BEGIN)[1:] |
| 90 | + certificate, chain = '', '' |
| 91 | + for chunk in certs: |
| 92 | + if CERT_BEGIN not in certificate or CERT_END not in certificate: |
| 93 | + certificate = CERT_BEGIN + chunk |
| 94 | + else: |
| 95 | + chain = chain + CERT_BEGIN + chunk |
| 96 | + return certificate, chain |
| 97 | + |
| 98 | + |
| 99 | +def certificate_exists(domain_name: str) -> bool: |
| 100 | + """Check if a certificate for this domain is already in ACM""" |
| 101 | + logger.info( |
| 102 | + f'Check if there is any certificate in ACM for the domain: {domain_name}') |
| 103 | + try: |
| 104 | + resp = aws_client.list_certificates() |
| 105 | + except Exception as e: |
| 106 | + logger.error(f'Error listing certificates. Error: {e}') |
| 107 | + raise Exception |
| 108 | + for cert in resp['CertificateSummaryList']: |
| 109 | + if domain_name == cert.get('DomainName'): |
| 110 | + return True |
| 111 | + return False |
| 112 | + |
| 113 | + |
| 114 | +def get_acm_certificate(domain_name: str): |
| 115 | + """Get ACM certificate for the provided domain name""" |
| 116 | + try: |
| 117 | + resp = aws_client.list_certificates() |
| 118 | + except Exception as e: |
| 119 | + logger.error(f'Error listing certificates. Error: {e}') |
| 120 | + return None, None |
| 121 | + for cert in resp['CertificateSummaryList']: |
| 122 | + if domain_name == cert.get('DomainName'): |
| 123 | + certificate_arn = cert.get('CertificateArn') |
| 124 | + acm_cert = aws_client.get_certificate( |
| 125 | + CertificateArn=certificate_arn)['Certificate'] |
| 126 | + return acm_cert, certificate_arn |
| 127 | + |
| 128 | + |
| 129 | +def compare_certificates(kube_certificate: str, acm_certificate: str) -> bool: |
| 130 | + """Compare a kubernetes and ACM certificates to check if they are the same""" |
| 131 | + try: |
| 132 | + kube_cert_sn = crypto.load_certificate( |
| 133 | + crypto.FILETYPE_PEM, kube_certificate).get_serial_number() |
| 134 | + acm_cert_sn = crypto.load_certificate( |
| 135 | + crypto.FILETYPE_PEM, acm_certificate).get_serial_number() |
| 136 | + except OpenSSL.crypto.Error as e: |
| 137 | + logger.error(f"OpenSSL error while getting certificate SN. Error: {e}") |
| 138 | + return False |
| 139 | + logger.debug(f"Cluster cert SN: {kube_cert_sn}") |
| 140 | + logger.debug(f"ACM cert SN: {acm_cert_sn}") |
| 141 | + if kube_cert_sn == acm_cert_sn: |
| 142 | + logger.info('These 2 certificates are the same') |
| 143 | + return True |
| 144 | + else: |
| 145 | + logger.info('These 2 certificates are different') |
| 146 | + return False |
| 147 | + |
| 148 | + |
| 149 | +def import_certificate(certificate: str, chain: str, kube_private_key: str, certificate_arn: str = None) -> bool: |
| 150 | + """Improt provided certificate to ACM""" |
| 151 | + try: |
| 152 | + if certificate_arn: |
| 153 | + resp = aws_client.import_certificate( |
| 154 | + Certificate=certificate, |
| 155 | + CertificateArn=certificate_arn, |
| 156 | + CertificateChain=chain, |
| 157 | + PrivateKey=kube_private_key) |
| 158 | + else: |
| 159 | + resp = aws_client.import_certificate( |
| 160 | + Certificate=certificate, |
| 161 | + CertificateChain=chain, |
| 162 | + PrivateKey=kube_private_key) |
| 163 | + if resp['CertificateArn']: |
| 164 | + logger.info( |
| 165 | + f"Certificate imported with the ARN: {resp['CertificateArn']}") |
| 166 | + return True |
| 167 | + else: |
| 168 | + logger.error("Failed to import certificate to ACM") |
| 169 | + except Exception as e: |
| 170 | + logger.error(f'Exception during certificate import to ACM. Error: {e}') |
| 171 | + return False |
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