[DPE-6345] LDAP II: Include charm libs (#824)

Author: sinclert-canonical

lib/charms/certificate_transfer_interface/v0/certificate_transfer.py

@@ -6,8 +6,9 @@
 This class handles certificate request and renewal through
 the interaction with the TLS Certificates Operator.
 
-This library needs that https://charmhub.io/tls-certificates-interface/libraries/tls_certificates
-library is imported to work.
+This library needs that the following libraries are imported to work:
+- https://charmhub.io/certificate-transfer-interface/libraries/certificate_transfer
+- https://charmhub.io/tls-certificates-interface/libraries/tls_certificates
 
 It also needs the following methods in the charm class:
 — get_hostname_by_unit: to retrieve the DNS hostname of the unit.
@@ -24,6 +25,15 @@
 import socket
 from typing import List, Optional
 
+from charms.certificate_transfer_interface.v0.certificate_transfer import (
+    CertificateAvailableEvent as CertificateAddedEvent,
+)
+from charms.certificate_transfer_interface.v0.certificate_transfer import (
+    CertificateRemovedEvent as CertificateRemovedEvent,
+)
+from charms.certificate_transfer_interface.v0.certificate_transfer import (
+    CertificateTransferRequires,
+)
 from charms.tls_certificates_interface.v2.tls_certificates import (
     CertificateAvailableEvent,
     CertificateExpiringEvent,
@@ -45,11 +55,12 @@
 
 # Increment this PATCH version before using `charmcraft publish-lib` or reset
 # to 0 if you are raising the major API version.
-LIBPATCH = 13
+LIBPATCH = 14
 
 logger = logging.getLogger(__name__)
 SCOPE = "unit"
-TLS_RELATION = "certificates"
+TLS_CREATION_RELATION = "certificates"
+TLS_TRANSFER_RELATION = "receive-ca-cert"
 
 
 class PostgreSQLTLS(Object):
@@ -63,18 +74,29 @@ def __init__(
         self.charm = charm
         self.peer_relation = peer_relation
         self.additional_dns_names = additional_dns_names or []
-        self.certs = TLSCertificatesRequiresV2(self.charm, TLS_RELATION)
+        self.certs_creation = TLSCertificatesRequiresV2(self.charm, TLS_CREATION_RELATION)
+        self.certs_transfer = CertificateTransferRequires(self.charm, TLS_TRANSFER_RELATION)
         self.framework.observe(
             self.charm.on.set_tls_private_key_action, self._on_set_tls_private_key
         )
         self.framework.observe(
-            self.charm.on[TLS_RELATION].relation_joined, self._on_tls_relation_joined
+            self.charm.on[TLS_CREATION_RELATION].relation_joined, self._on_tls_relation_joined
+        )
+        self.framework.observe(
+            self.charm.on[TLS_CREATION_RELATION].relation_broken, self._on_tls_relation_broken
+        )
+        self.framework.observe(
+            self.certs_creation.on.certificate_available, self._on_certificate_available
+        )
+        self.framework.observe(
+            self.certs_creation.on.certificate_expiring, self._on_certificate_expiring
         )
         self.framework.observe(
-            self.charm.on[TLS_RELATION].relation_broken, self._on_tls_relation_broken
+            self.certs_transfer.on.certificate_available, self._on_certificate_added
+        )
+        self.framework.observe(
+            self.certs_transfer.on.certificate_removed, self._on_certificate_removed
         )
-        self.framework.observe(self.certs.on.certificate_available, self._on_certificate_available)
-        self.framework.observe(self.certs.on.certificate_expiring, self._on_certificate_expiring)
 
     def _on_set_tls_private_key(self, event: ActionEvent) -> None:
         """Set the TLS private key, which will be used for requesting the certificate."""
@@ -93,8 +115,8 @@ def _request_certificate(self, param: Optional[str]):
         self.charm.set_secret(SCOPE, "key", key.decode("utf-8"))
         self.charm.set_secret(SCOPE, "csr", csr.decode("utf-8"))
 
-        if self.charm.model.get_relation(TLS_RELATION):
-            self.certs.request_certificate_creation(certificate_signing_request=csr)
+        if self.charm.model.get_relation(TLS_CREATION_RELATION):
+            self.certs_creation.request_certificate_creation(certificate_signing_request=csr)
 
     @staticmethod
     def _parse_tls_file(raw_content: str) -> bytes:
@@ -117,6 +139,7 @@ def _on_tls_relation_broken(self, event: RelationBrokenEvent) -> None:
         self.charm.set_secret(SCOPE, "ca", None)
         self.charm.set_secret(SCOPE, "cert", None)
         self.charm.set_secret(SCOPE, "chain", None)
+
         if not self.charm.update_config():
             logger.debug("Cannot update config at this moment")
             event.defer()
@@ -163,12 +186,52 @@ def _on_certificate_expiring(self, event: CertificateExpiringEvent) -> None:
             subject=self.charm.get_hostname_by_unit(self.charm.unit.name),
             **self._get_sans(),
         )
-        self.certs.request_certificate_renewal(
+        self.certs_creation.request_certificate_renewal(
             old_certificate_signing_request=old_csr,
             new_certificate_signing_request=new_csr,
         )
         self.charm.set_secret(SCOPE, "csr", new_csr.decode("utf-8"))
 
+    def _on_certificate_added(self, event: CertificateAddedEvent) -> None:
+        """Enable TLS when TLS certificate is added."""
+        relation = self.charm.model.get_relation(TLS_TRANSFER_RELATION, event.relation_id)
+        if relation is None:
+            logger.error("Relationship not established anymore.")
+            return
+
+        secret_name = f"ca-{relation.app.name}"
+        self.charm.set_secret(SCOPE, secret_name, event.ca)
+
+        try:
+            if not self.charm.push_ca_file_into_workload(secret_name):
+                logger.debug("Cannot push TLS certificates at this moment")
+                event.defer()
+                return
+        except (PebbleConnectionError, PathError, ProtocolError, RetryError) as e:
+            logger.error("Cannot push TLS certificates: %r", e)
+            event.defer()
+            return
+
+    def _on_certificate_removed(self, event: CertificateRemovedEvent) -> None:
+        """Disable TLS when TLS certificate is removed."""
+        relation = self.charm.model.get_relation(TLS_TRANSFER_RELATION, event.relation_id)
+        if relation is None:
+            logger.error("Relationship not established anymore.")
+            return
+
+        secret_name = f"ca-{relation.app.name}"
+        self.charm.set_secret(SCOPE, secret_name, None)
+
+        try:
+            if not self.charm.clean_ca_file_from_workload(secret_name):
+                logger.debug("Cannot clean CA certificates at this moment")
+                event.defer()
+                return
+        except (PebbleConnectionError, PathError, ProtocolError, RetryError) as e:
+            logger.error("Cannot clean CA certificates: %r", e)
+            event.defer()
+            return
+
     def _get_sans(self) -> dict:
         """Create a list of Subject Alternative Names for a PostgreSQL unit.
 

lib/charms/glauth_k8s/v0/ldap.py

@@ -49,10 +49,17 @@ requires:
     interface: tls-certificates
     limit: 1
     optional: true
+  receive-ca-cert:
+    interface: certificate_transfer
+    optional: true
   s3-parameters:
     interface: s3
     limit: 1
     optional: true
+  ldap:
+    interface: ldap
+    limit: 1
+    optional: true
   tracing:
     interface: tracing
     limit: 1

lib/charms/postgresql_k8s/v0/postgresql_tls.py

@@ -30,6 +30,8 @@ pydantic = "^1.10"
 cosl = ">=0.0.50"
 # tls_certificates_interface/v2/tls_certificates.py
 cryptography = "*"
+# certificate_transfer_interface/v0/certificate_transfer.py
+# tls_certificates_interface/v2/tls_certificates.py
 jsonschema = "*"
 # tempo_coordinator_k8s/v0/charm_tracing.py
 opentelemetry-exporter-otlp-proto-http = "1.21.0"

metadata.yaml

@@ -96,6 +96,7 @@
     TLS_KEY_FILE,
     TRACING_PROTOCOL,
     UNIT_SCOPE,
+    UPDATE_CERTS_BIN_PATH,
     USER,
     USER_PASSWORD_KEY,
 )
@@ -191,6 +192,8 @@ def __init__(self, *args):
         self.framework.observe(self.on.update_status, self._on_update_status)
         self.cluster_name = self.app.name
         self._member_name = self.unit.name.replace("/", "-")
+
+        self._certs_path = "/usr/local/share/ca-certificates"
         self._storage_path = self.meta.storages["pgdata"].location
 
         self.upgrade = PostgreSQLUpgrade(
@@ -1803,6 +1806,33 @@ def push_tls_files_to_workload(self) -> bool:
             logger.exception("TLS files failed to push. Error in config update")
             return False
 
+    def push_ca_file_into_workload(self, secret_name: str) -> bool:
+        """Move CA certificates file into the PostgreSQL storage path."""
+        certs = self.get_secret(UNIT_SCOPE, secret_name)
+        if certs is not None:
+            certs_file = Path(self._certs_path, f"{secret_name}.crt")
+            certs_file.write_text(certs)
+            subprocess.check_call([UPDATE_CERTS_BIN_PATH])  # noqa: S603
+
+        try:
+            return self.update_config()
+        except Exception:
+            logger.exception("CA file failed to push. Error in config update")
+            return False
+
+    def clean_ca_file_from_workload(self, secret_name: str) -> bool:
+        """Cleans up CA certificates from the PostgreSQL storage path."""
+        certs_file = Path(self._certs_path, f"{secret_name}.crt")
+        certs_file.unlink()
+
+        subprocess.check_call([UPDATE_CERTS_BIN_PATH])  # noqa: S603
+
+        try:
+            return self.update_config()
+        except Exception:
+            logger.exception("CA file failed to clean. Error in config update")
+            return False
+
     def _reboot_on_detached_storage(self, event: EventBase) -> None:
         """Reboot on detached storage.
 

pyproject.toml

@@ -56,6 +56,8 @@
 POSTGRESQL_DATA_PATH = f"{SNAP_DATA_PATH}/postgresql"
 POSTGRESQL_LOGS_PATH = f"{SNAP_LOGS_PATH}/postgresql"
 
+UPDATE_CERTS_BIN_PATH = "/usr/sbin/update-ca-certificates"
+
 PGBACKREST_CONFIGURATION_FILE = f"--config={PGBACKREST_CONF_PATH}/pgbackrest.conf"
 
 METRICS_PORT = "9187"

src/charm.py

@@ -1131,7 +1131,9 @@ async def backup_operations(
         config={"profile": "testing"},
     )
 
-    await ops_test.model.relate(database_app_name, tls_certificates_app_name)
+    await ops_test.model.relate(
+        f"{database_app_name}:certificates", f"{tls_certificates_app_name}:certificates"
+    )
     async with ops_test.fast_forward(fast_interval="60s"):
         await ops_test.model.wait_for_idle(apps=[database_app_name], status="active", timeout=1000)
 

src/constants.py

@@ -68,7 +68,9 @@ async def pitr_backup_operations(
     logger.info(
         "integrating self-signed-certificates with postgresql and waiting them to stabilize"
     )
-    await ops_test.model.relate(database_app_name, tls_certificates_app_name)
+    await ops_test.model.relate(
+        f"{database_app_name}:certificates", f"{tls_certificates_app_name}:certificates"
+    )
     async with ops_test.fast_forward(fast_interval="60s"):
         await ops_test.model.wait_for_idle(
             apps=[database_app_name, tls_certificates_app_name], status="active", timeout=1000

tests/integration/helpers.py

@@ -68,7 +68,9 @@ async def pitr_backup_operations(
     logger.info(
         "integrating self-signed-certificates with postgresql and waiting them to stabilize"
     )
-    await ops_test.model.relate(database_app_name, tls_certificates_app_name)
+    await ops_test.model.relate(
+        f"{database_app_name}:certificates", f"{tls_certificates_app_name}:certificates"
+    )
     async with ops_test.fast_forward(fast_interval="60s"):
         await ops_test.model.wait_for_idle(
             apps=[database_app_name, tls_certificates_app_name], status="active", timeout=1000