diff --git a/poetry.lock b/poetry.lock
index c976c42d2..8380e1b89 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -982,16 +982,6 @@ files = [
{file = "MarkupSafe-2.1.3-cp311-cp311-musllinux_1_1_x86_64.whl", hash = "sha256:5bbe06f8eeafd38e5d0a4894ffec89378b6c6a625ff57e3028921f8ff59318ac"},
{file = "MarkupSafe-2.1.3-cp311-cp311-win32.whl", hash = "sha256:dd15ff04ffd7e05ffcb7fe79f1b98041b8ea30ae9234aed2a9168b5797c3effb"},
{file = "MarkupSafe-2.1.3-cp311-cp311-win_amd64.whl", hash = "sha256:134da1eca9ec0ae528110ccc9e48041e0828d79f24121a1a146161103c76e686"},
- {file = "MarkupSafe-2.1.3-cp312-cp312-macosx_10_9_universal2.whl", hash = "sha256:f698de3fd0c4e6972b92290a45bd9b1536bffe8c6759c62471efaa8acb4c37bc"},
- {file = "MarkupSafe-2.1.3-cp312-cp312-macosx_10_9_x86_64.whl", hash = "sha256:aa57bd9cf8ae831a362185ee444e15a93ecb2e344c8e52e4d721ea3ab6ef1823"},
- {file = "MarkupSafe-2.1.3-cp312-cp312-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:ffcc3f7c66b5f5b7931a5aa68fc9cecc51e685ef90282f4a82f0f5e9b704ad11"},
- {file = "MarkupSafe-2.1.3-cp312-cp312-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:47d4f1c5f80fc62fdd7777d0d40a2e9dda0a05883ab11374334f6c4de38adffd"},
- {file = "MarkupSafe-2.1.3-cp312-cp312-manylinux_2_5_i686.manylinux1_i686.manylinux_2_17_i686.manylinux2014_i686.whl", hash = "sha256:1f67c7038d560d92149c060157d623c542173016c4babc0c1913cca0564b9939"},
- {file = "MarkupSafe-2.1.3-cp312-cp312-musllinux_1_1_aarch64.whl", hash = "sha256:9aad3c1755095ce347e26488214ef77e0485a3c34a50c5a5e2471dff60b9dd9c"},
- {file = "MarkupSafe-2.1.3-cp312-cp312-musllinux_1_1_i686.whl", hash = "sha256:14ff806850827afd6b07a5f32bd917fb7f45b046ba40c57abdb636674a8b559c"},
- {file = "MarkupSafe-2.1.3-cp312-cp312-musllinux_1_1_x86_64.whl", hash = "sha256:8f9293864fe09b8149f0cc42ce56e3f0e54de883a9de90cd427f191c346eb2e1"},
- {file = "MarkupSafe-2.1.3-cp312-cp312-win32.whl", hash = "sha256:715d3562f79d540f251b99ebd6d8baa547118974341db04f5ad06d5ea3eb8007"},
- {file = "MarkupSafe-2.1.3-cp312-cp312-win_amd64.whl", hash = "sha256:1b8dd8c3fd14349433c79fa8abeb573a55fc0fdd769133baac1f5e07abf54aeb"},
{file = "MarkupSafe-2.1.3-cp37-cp37m-macosx_10_9_x86_64.whl", hash = "sha256:8e254ae696c88d98da6555f5ace2279cf7cd5b3f52be2b5cf97feafe883b58d2"},
{file = "MarkupSafe-2.1.3-cp37-cp37m-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:cb0932dc158471523c9637e807d9bfb93e06a95cbf010f1a38b98623b929ef2b"},
{file = "MarkupSafe-2.1.3-cp37-cp37m-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:9402b03f1a1b4dc4c19845e5c749e3ab82d5078d16a2a4c2cd2df62d57bb0707"},
@@ -1761,6 +1751,17 @@ files = [
[package.dependencies]
six = ">=1.5"
+[[package]]
+name = "python-hosts"
+version = "1.0.6"
+description = "A hosts file manager library written in python"
+optional = false
+python-versions = "*"
+files = [
+ {file = "python-hosts-1.0.6.tar.gz", hash = "sha256:2df59f07327753202b707c6b2140ec21af2922bd569148a47fa17abfe2152c6e"},
+ {file = "python_hosts-1.0.6-py3-none-any.whl", hash = "sha256:f902433664cad0f1bc50ef09be7906ac2a06df40945d0515c3e3f4ef39578762"},
+]
+
[[package]]
name = "pytz"
version = "2023.3"
@@ -1784,7 +1785,6 @@ files = [
{file = "PyYAML-6.0.1-cp310-cp310-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:69b023b2b4daa7548bcfbd4aa3da05b3a74b772db9e23b982788168117739938"},
{file = "PyYAML-6.0.1-cp310-cp310-manylinux_2_17_s390x.manylinux2014_s390x.whl", hash = "sha256:81e0b275a9ecc9c0c0c07b4b90ba548307583c125f54d5b6946cfee6360c733d"},
{file = "PyYAML-6.0.1-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:ba336e390cd8e4d1739f42dfe9bb83a3cc2e80f567d8805e11b46f4a943f5515"},
- {file = "PyYAML-6.0.1-cp310-cp310-musllinux_1_1_x86_64.whl", hash = "sha256:326c013efe8048858a6d312ddd31d56e468118ad4cdeda36c719bf5bb6192290"},
{file = "PyYAML-6.0.1-cp310-cp310-win32.whl", hash = "sha256:bd4af7373a854424dabd882decdc5579653d7868b8fb26dc7d0e99f823aa5924"},
{file = "PyYAML-6.0.1-cp310-cp310-win_amd64.whl", hash = "sha256:fd1592b3fdf65fff2ad0004b5e363300ef59ced41c2e6b3a99d4089fa8c5435d"},
{file = "PyYAML-6.0.1-cp311-cp311-macosx_10_9_x86_64.whl", hash = "sha256:6965a7bc3cf88e5a1c3bd2e0b5c22f8d677dc88a455344035f03399034eb3007"},
@@ -1792,16 +1792,8 @@ files = [
{file = "PyYAML-6.0.1-cp311-cp311-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:42f8152b8dbc4fe7d96729ec2b99c7097d656dc1213a3229ca5383f973a5ed6d"},
{file = "PyYAML-6.0.1-cp311-cp311-manylinux_2_17_s390x.manylinux2014_s390x.whl", hash = "sha256:062582fca9fabdd2c8b54a3ef1c978d786e0f6b3a1510e0ac93ef59e0ddae2bc"},
{file = "PyYAML-6.0.1-cp311-cp311-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:d2b04aac4d386b172d5b9692e2d2da8de7bfb6c387fa4f801fbf6fb2e6ba4673"},
- {file = "PyYAML-6.0.1-cp311-cp311-musllinux_1_1_x86_64.whl", hash = "sha256:e7d73685e87afe9f3b36c799222440d6cf362062f78be1013661b00c5c6f678b"},
{file = "PyYAML-6.0.1-cp311-cp311-win32.whl", hash = "sha256:1635fd110e8d85d55237ab316b5b011de701ea0f29d07611174a1b42f1444741"},
{file = "PyYAML-6.0.1-cp311-cp311-win_amd64.whl", hash = "sha256:bf07ee2fef7014951eeb99f56f39c9bb4af143d8aa3c21b1677805985307da34"},
- {file = "PyYAML-6.0.1-cp312-cp312-macosx_10_9_x86_64.whl", hash = "sha256:855fb52b0dc35af121542a76b9a84f8d1cd886ea97c84703eaa6d88e37a2ad28"},
- {file = "PyYAML-6.0.1-cp312-cp312-macosx_11_0_arm64.whl", hash = "sha256:40df9b996c2b73138957fe23a16a4f0ba614f4c0efce1e9406a184b6d07fa3a9"},
- {file = "PyYAML-6.0.1-cp312-cp312-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:a08c6f0fe150303c1c6b71ebcd7213c2858041a7e01975da3a99aed1e7a378ef"},
- {file = "PyYAML-6.0.1-cp312-cp312-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:6c22bec3fbe2524cde73d7ada88f6566758a8f7227bfbf93a408a9d86bcc12a0"},
- {file = "PyYAML-6.0.1-cp312-cp312-musllinux_1_1_x86_64.whl", hash = "sha256:8d4e9c88387b0f5c7d5f281e55304de64cf7f9c0021a3525bd3b1c542da3b0e4"},
- {file = "PyYAML-6.0.1-cp312-cp312-win32.whl", hash = "sha256:d483d2cdf104e7c9fa60c544d92981f12ad66a457afae824d146093b8c294c54"},
- {file = "PyYAML-6.0.1-cp312-cp312-win_amd64.whl", hash = "sha256:0d3304d8c0adc42be59c5f8a4d9e3d7379e6955ad754aa9d6ab7a398b59dd1df"},
{file = "PyYAML-6.0.1-cp36-cp36m-macosx_10_9_x86_64.whl", hash = "sha256:50550eb667afee136e9a77d6dc71ae76a44df8b3e51e41b77f6de2932bfe0f47"},
{file = "PyYAML-6.0.1-cp36-cp36m-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:1fe35611261b29bd1de0070f0b2f47cb6ff71fa6595c077e42bd0c419fa27b98"},
{file = "PyYAML-6.0.1-cp36-cp36m-manylinux_2_17_s390x.manylinux2014_s390x.whl", hash = "sha256:704219a11b772aea0d8ecd7058d0082713c3562b4e271b849ad7dc4a5c90c13c"},
@@ -1818,7 +1810,6 @@ files = [
{file = "PyYAML-6.0.1-cp38-cp38-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:a0cd17c15d3bb3fa06978b4e8958dcdc6e0174ccea823003a106c7d4d7899ac5"},
{file = "PyYAML-6.0.1-cp38-cp38-manylinux_2_17_s390x.manylinux2014_s390x.whl", hash = "sha256:28c119d996beec18c05208a8bd78cbe4007878c6dd15091efb73a30e90539696"},
{file = "PyYAML-6.0.1-cp38-cp38-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:7e07cbde391ba96ab58e532ff4803f79c4129397514e1413a7dc761ccd755735"},
- {file = "PyYAML-6.0.1-cp38-cp38-musllinux_1_1_x86_64.whl", hash = "sha256:49a183be227561de579b4a36efbb21b3eab9651dd81b1858589f796549873dd6"},
{file = "PyYAML-6.0.1-cp38-cp38-win32.whl", hash = "sha256:184c5108a2aca3c5b3d3bf9395d50893a7ab82a38004c8f61c258d4428e80206"},
{file = "PyYAML-6.0.1-cp38-cp38-win_amd64.whl", hash = "sha256:1e2722cc9fbb45d9b87631ac70924c11d3a401b2d7f410cc0e3bbf249f2dca62"},
{file = "PyYAML-6.0.1-cp39-cp39-macosx_10_9_x86_64.whl", hash = "sha256:9eb6caa9a297fc2c2fb8862bc5370d0303ddba53ba97e71f08023b6cd73d16a8"},
@@ -1826,7 +1817,6 @@ files = [
{file = "PyYAML-6.0.1-cp39-cp39-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:5773183b6446b2c99bb77e77595dd486303b4faab2b086e7b17bc6bef28865f6"},
{file = "PyYAML-6.0.1-cp39-cp39-manylinux_2_17_s390x.manylinux2014_s390x.whl", hash = "sha256:b786eecbdf8499b9ca1d697215862083bd6d2a99965554781d0d8d1ad31e13a0"},
{file = "PyYAML-6.0.1-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:bc1bf2925a1ecd43da378f4db9e4f799775d6367bdb94671027b73b393a7c42c"},
- {file = "PyYAML-6.0.1-cp39-cp39-musllinux_1_1_x86_64.whl", hash = "sha256:04ac92ad1925b2cff1db0cfebffb6ffc43457495c9b3c39d3fcae417d7125dc5"},
{file = "PyYAML-6.0.1-cp39-cp39-win32.whl", hash = "sha256:faca3bdcf85b2fc05d06ff3fbc1f83e1391b3e724afa3feba7d13eeab355484c"},
{file = "PyYAML-6.0.1-cp39-cp39-win_amd64.whl", hash = "sha256:510c9deebc5c0225e8c96813043e62b680ba2f9c50a08d3724c7f28a747d1486"},
{file = "PyYAML-6.0.1.tar.gz", hash = "sha256:bfdf460b1736c775f2ba9f6a92bca30bc2095067b8a9d77876d1fad6cc3b4a43"},
@@ -2295,4 +2285,4 @@ files = [
[metadata]
lock-version = "2.0"
python-versions = "^3.10"
-content-hash = "2a5086863d1db642d6476bba5aba299aa1b494f0df8abb54574c567e778b06fe"
+content-hash = "099499829dacf52d7a1bb57bb08d1c85204c062c1536e319a5319d7e797b6962"
diff --git a/pyproject.toml b/pyproject.toml
index 783d3d083..8253e17f1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,6 +17,7 @@ boto3 = "^1.28.23"
pyopenssl = "^24.0.0"
typing_extensions = "^4.7.1"
jinja2 = "^3.1.2"
+python_hosts = "^1.0.6"
[tool.poetry.group.charm-libs.dependencies]
# data_platform_libs/v0/data_interfaces.py
diff --git a/src/charm.py b/src/charm.py
index c014748c9..2acf766bb 100755
--- a/src/charm.py
+++ b/src/charm.py
@@ -620,6 +620,9 @@ def workload_initialise(self) -> None:
self._mysql.reset_root_password_and_start_mysqld()
self._mysql.configure_mysql_users()
+ # ensure hostname can be resolved
+ self.hostname_resolution.update_etc_hosts(None)
+
current_mysqld_pid = self._mysql.get_pid_of_port_3306()
self._mysql.configure_instance()
diff --git a/src/hostname_resolution.py b/src/hostname_resolution.py
index 30fafd794..471a971e2 100644
--- a/src/hostname_resolution.py
+++ b/src/hostname_resolution.py
@@ -3,15 +3,14 @@
"""Library containing logic pertaining to hostname resolutions in the VM charm."""
-import io
import json
import logging
import socket
import typing
-from ops.charm import RelationDepartedEvent
from ops.framework import Object
-from ops.model import BlockedStatus, Unit
+from ops.model import Unit
+from python_hosts import Hosts, HostsEntry
from constants import HOSTNAME_DETAILS, PEER
from ip_address_observer import IPAddressChangeCharmEvents, IPAddressObserver
@@ -22,11 +21,15 @@
if typing.TYPE_CHECKING:
from charm import MySQLOperatorCharm
+COMMENT = "Managed by mysql charm"
+
class MySQLMachineHostnameResolution(Object):
"""Encapsulation of the the machine hostname resolution."""
- on = IPAddressChangeCharmEvents()
+ on = ( # pyright: ignore [reportIncompatibleMethodOverride, reportAssignmentType
+ IPAddressChangeCharmEvents()
+ )
def __init__(self, charm: "MySQLOperatorCharm"):
super().__init__(charm, "hostname-resolution")
@@ -38,12 +41,8 @@ def __init__(self, charm: "MySQLOperatorCharm"):
self.framework.observe(self.charm.on.config_changed, self._update_host_details_in_databag)
self.framework.observe(self.on.ip_address_change, self._update_host_details_in_databag)
- self.framework.observe(
- self.charm.on[PEER].relation_changed, self._potentially_update_etc_hosts
- )
- self.framework.observe(
- self.charm.on[PEER].relation_departed, self._remove_host_from_etc_hosts
- )
+ self.framework.observe(self.charm.on[PEER].relation_changed, self.update_etc_hosts)
+ self.framework.observe(self.charm.on[PEER].relation_departed, self.update_etc_hosts)
self.ip_address_observer.start_observer()
@@ -60,111 +59,58 @@ def _update_host_details_in_databag(self, _) -> None:
logger.exception("Unable to get local IP address")
ip = "127.0.0.1"
- host_details = {
- "hostname": hostname,
- "fqdn": fqdn,
- "ip": ip,
- }
+ host_details = {"names": [hostname, fqdn], "address": ip}
self.charm.unit_peer_data[HOSTNAME_DETAILS] = json.dumps(host_details)
- def _get_host_details(self) -> dict[str, str]:
- host_details = {}
+ def _get_host_details(self) -> list[HostsEntry]:
+ host_details = list()
+
+ if not self.charm.peers:
+ return []
for key, data in self.charm.peers.data.items():
if isinstance(key, Unit) and data.get(HOSTNAME_DETAILS):
unit_details = json.loads(data[HOSTNAME_DETAILS])
- unit_details["unit"] = key.name
- host_details[unit_details["hostname"]] = unit_details
-
- return host_details
-
- def _does_etc_hosts_need_update(self, host_details: dict[str, str]) -> bool:
- outdated_hosts = host_details.copy()
- with open("/etc/hosts", "r") as hosts_file:
- for line in hosts_file:
- if "# unit=" not in line:
- continue
+ if unit_details.get("address"):
+ entry = HostsEntry(comment=COMMENT, entry_type="ipv4", **unit_details)
+ else:
+ # case when migrating from old format
+ entry = HostsEntry(
+ address=unit_details["ip"],
+ names=[unit_details["hostname"], unit_details["fqdn"]],
+ comment=COMMENT,
+ entry_type="ipv4",
+ )
- ip, fqdn, hostname = line.split("#")[0].strip().split()
- if outdated_hosts.get(hostname).get("ip") == ip:
- outdated_hosts.pop(hostname)
+ host_details.append(entry)
- return bool(outdated_hosts)
+ return host_details
- def _potentially_update_etc_hosts(self, _) -> None:
+ def update_etc_hosts(self, _) -> None:
"""Potentially update the /etc/hosts file with new hostname to IP for units."""
if not self.charm._is_peer_data_set:
return
- host_details = self._get_host_details()
- if not host_details:
+ host_entries = self._get_host_details()
+ if not host_entries:
logger.debug("No hostnames in the peer databag. Skipping update of /etc/hosts")
return
- if not self._does_etc_hosts_need_update(host_details):
- logger.debug("No hostnames in /etc/hosts changed. Skipping update to /etc/hosts")
- return
-
- hosts_in_file = []
-
- with io.StringIO() as updated_hosts_file:
- with open("/etc/hosts", "r") as hosts_file:
- for line in hosts_file:
- if "# unit=" not in line:
- updated_hosts_file.write(line)
- continue
-
- for hostname, details in host_details.items():
- if hostname == line.split()[2]:
- hosts_in_file.append(hostname)
-
- fqdn, ip, unit = details["fqdn"], details["ip"], details["unit"]
-
- logger.debug(
- f"Overwriting {hostname} ({unit=}) with {ip=}, {fqdn=} in /etc/hosts"
- )
- updated_hosts_file.write(f"{ip} {fqdn} {hostname} # unit={unit}\n")
- break
-
- for hostname, details in host_details.items():
- if hostname not in hosts_in_file:
- fqdn, ip, unit = details["fqdn"], details["ip"], details["unit"]
-
- logger.debug(f"Adding {hostname} ({unit=} with {ip=}, {fqdn=} in /etc/hosts")
- updated_hosts_file.write(f"{ip} {fqdn} {hostname} # unit={unit}\n")
-
- with open("/etc/hosts", "w") as hosts_file:
- hosts_file.write(updated_hosts_file.getvalue())
-
- try:
- self.charm._mysql.flush_host_cache()
- except MySQLFlushHostCacheError:
- self.charm.unit.status = BlockedStatus("Unable to flush MySQL host cache")
-
- def _remove_host_from_etc_hosts(self, event: RelationDepartedEvent) -> None:
- departing_unit_name = event.unit.name
-
- logger.debug(f"Checking if an entry for {departing_unit_name} is in /etc/hosts")
- with open("/etc/hosts", "r") as hosts_file:
- for line in hosts_file:
- if f"# unit={departing_unit_name}" in line:
- break
- else:
- return
+ logger.debug("Updating /etc/hosts with new hostname to IP mappings")
+ hosts = Hosts()
- logger.debug(f"Removing entry for {departing_unit_name} from /etc/hosts")
- with io.StringIO() as updated_hosts_file:
- with open("/etc/hosts", "r") as hosts_file:
- for line in hosts_file:
- if f"# unit={departing_unit_name}" not in line:
- updated_hosts_file.write(line)
+ if hosts.exists(address="127.0.1.1", names=[socket.getfqdn()]):
+ # remove MAAS injected entry
+ logger.debug("Removing MAAS injected entry from /etc/hosts")
+ hosts.remove_all_matching(address="127.0.1.1")
- with open("/etc/hosts", "w") as hosts_file:
- hosts_file.write(updated_hosts_file.getvalue())
+ hosts.remove_all_matching(comment=COMMENT)
+ hosts.add(host_entries)
+ hosts.write()
try:
self.charm._mysql.flush_host_cache()
except MySQLFlushHostCacheError:
- self.charm.unit.status = BlockedStatus("Unable to flush MySQL host cache")
+ logger.warning("Unable to flush MySQL host cache")
diff --git a/tests/unit/test_backups.py b/tests/unit/test_backups.py
index 86b171b6f..02e0bdfb3 100644
--- a/tests/unit/test_backups.py
+++ b/tests/unit/test_backups.py
@@ -329,7 +329,7 @@ def test_can_unit_perform_backup(
@patch_network_get(private_address="1.1.1.1")
@patch("mysql_vm_helpers.MySQL.offline_mode_and_hidden_instance_exists", return_value=False)
@patch("mysql_vm_helpers.MySQL.get_member_state")
- @patch("hostname_resolution.MySQLMachineHostnameResolution._remove_host_from_etc_hosts")
+ @patch("python_hosts.Hosts.write")
def test_can_unit_perform_backup_failure(
self,
_,
@@ -381,7 +381,7 @@ def test_can_unit_perform_backup_failure(
@patch_network_get(private_address="1.1.1.1")
@patch("mysql_vm_helpers.MySQL.set_instance_option")
@patch("mysql_vm_helpers.MySQL.set_instance_offline_mode")
- @patch("hostname_resolution.MySQLMachineHostnameResolution._remove_host_from_etc_hosts")
+ @patch("python_hosts.Hosts.write")
def test_pre_backup(
self,
_,
@@ -551,7 +551,7 @@ def test_pre_restore_checks(
@patch_network_get(private_address="1.1.1.1")
@patch("mysql_vm_helpers.MySQL.is_server_connectable", return_value=True)
@patch("charm.MySQLOperatorCharm.is_unit_busy", return_value=False)
- @patch("hostname_resolution.MySQLMachineHostnameResolution._remove_host_from_etc_hosts")
+ @patch("python_hosts.Hosts.write")
def test_pre_restore_checks_failure(
self,
_,
diff --git a/tests/unit/test_charm.py b/tests/unit/test_charm.py
index 247d1a29d..e91b721b9 100644
--- a/tests/unit/test_charm.py
+++ b/tests/unit/test_charm.py
@@ -290,7 +290,7 @@ def test_on_start_exceptions(
@patch("charm.is_volume_mounted", return_value=True)
@patch("mysql_vm_helpers.MySQL.reboot_from_complete_outage")
@patch("charm.snap_service_operation")
- @patch("hostname_resolution.MySQLMachineHostnameResolution._remove_host_from_etc_hosts")
+ @patch("python_hosts.Hosts.write")
def test_on_update(
self,
_,
diff --git a/tests/unit/test_hostname_resolution.py b/tests/unit/test_hostname_resolution.py
new file mode 100644
index 000000000..3e32f8879
--- /dev/null
+++ b/tests/unit/test_hostname_resolution.py
@@ -0,0 +1,62 @@
+# Copyright 2024 Canonical Ltd.
+# See LICENSE file for licensing details.
+
+import json
+import unittest
+from unittest.mock import patch
+
+from ops.testing import Harness
+
+from charm import MySQLOperatorCharm
+from constants import HOSTNAME_DETAILS, PEER
+
+APP_NAME = "mysql"
+
+
+class TestHostnameResolution(unittest.TestCase):
+ def setUp(self):
+ self.harness = Harness(MySQLOperatorCharm)
+ self.addCleanup(self.harness.cleanup)
+ self.harness.begin()
+ self.charm = self.harness.charm
+ self.hostname_resolution = self.charm.hostname_resolution
+
+ def test_get_host_details(self):
+ """Test get_peer_host_details method."""
+ host_entries = self.hostname_resolution._get_host_details()
+
+ # before relation
+ self.assertEqual(host_entries, [])
+
+ # Add relation
+ id = self.harness.add_relation(PEER, APP_NAME)
+
+ host_entries = self.hostname_resolution._get_host_details()
+ self.assertEqual(host_entries, [])
+
+ # Add unit
+ self.harness.add_relation_unit(id, f"{APP_NAME}/0")
+ self.harness.update_relation_data(
+ id,
+ f"{APP_NAME}/0",
+ {
+ HOSTNAME_DETAILS: json.dumps(
+ {"address": "1.1.1.1", "names": ["name1", "name2", "name3"]}
+ )
+ },
+ )
+
+ host_entries = self.hostname_resolution._get_host_details()
+ self.assertEqual(len(host_entries), 1)
+ self.assertEqual(host_entries[0].address, "1.1.1.1")
+
+ @patch("socket.gethostname", return_value="mysql-0")
+ def test_update_host_details_in_databag(self, _gethostname_mock):
+ """Test update_host_details_in_databag method."""
+ # Add relation
+ self.harness.add_relation(PEER, APP_NAME)
+ self.assertEqual(self.charm.unit_peer_data.get(HOSTNAME_DETAILS), None)
+ self.hostname_resolution._update_host_details_in_databag(None)
+ _gethostname_mock.assert_called()
+
+ self.assertTrue("mysql-0" in self.charm.unit_peer_data[HOSTNAME_DETAILS])