From 5bbe6dba95de0fe91398d74f189801c62b3ecc85 Mon Sep 17 00:00:00 2001
From: Carl Csaposs <carl.csaposs@canonical.com>
Date: Tue, 29 Jul 2025 11:53:51 +0200
Subject: [PATCH 01/12] Add s390x integration tests

---
 .github/workflows/integration_test.yaml | 11 ++++++++--
 spread.yaml                             | 28 +++++++++++++++++++++----
 tests/integration/markers.py            |  3 +++
 tests/integration/test_architecture.py  | 23 +++++++++++++++++++-
 4 files changed, 58 insertions(+), 7 deletions(-)

diff --git a/.github/workflows/integration_test.yaml b/.github/workflows/integration_test.yaml
index b7d035f37..9b668a63a 100644
--- a/.github/workflows/integration_test.yaml
+++ b/.github/workflows/integration_test.yaml
@@ -42,7 +42,9 @@ jobs:
               _, runner, task, variant = job.split(":")
               # Example: "test_charm.py"
               task = task.removeprefix("tests/spread/")
-              if runner.endswith("-arm"):
+              if "s390x" in runner:
+                  architecture = "s390x"
+              elif runner.endswith("-arm"):
                   architecture = "arm64"
               else:
                   architecture = "amd64"
@@ -86,8 +88,9 @@ jobs:
     runs-on: ${{ matrix.job.runner }}
     timeout-minutes: 217  # Sum of steps `timeout-minutes` + 5
     steps:
-      - name: Free up disk space
+      - name: (GitHub hosted) Free up disk space
         timeout-minutes: 1
+        if: ${{ !contains(matrix.job.runner, 'self-hosted') }}
         run: |
           printf '\nDisk usage before cleanup\n'
           df --human-readable
@@ -95,6 +98,10 @@ jobs:
           rm -r /opt/hostedtoolcache/
           printf '\nDisk usage after cleanup\n'
           df --human-readable
+      - name: (IS hosted) Disk usage
+        timeout-minutes: 1
+        if: ${{ contains(matrix.job.runner, 'self-hosted') }}
+        run: df --human-readable
       - name: Checkout
         timeout-minutes: 3
         uses: actions/checkout@v4
diff --git a/spread.yaml b/spread.yaml
index 7cd6e1a52..72ba391d3 100644
--- a/spread.yaml
+++ b/spread.yaml
@@ -93,6 +93,18 @@ backends:
           username: runner
           variants:
             - -juju29
+      - self-hosted-linux-s390x-noble-edge:
+          username: ubuntu
+          environment:
+            # Several python packages (e.g. cryptography, bcrypt) do not have s390x builds on PyPI,
+            # so they must be built from source. pkg-config & rust toolchain needed
+            # (These packages are being built when installing poetry or integration test Python
+            # dependencies)
+            CONCIERGE_EXTRA_DEBS: pipx,pkg-config,rustup
+            # s390x only available on edge
+            CONCIERGE_MICROK8S_CHANNEL: 1.32-strict/edge
+          variants:
+            - -juju29
 
 suites:
   tests/spread/:
@@ -109,10 +121,18 @@ prepare: |
   snap refresh --hold
   chown -R root:root "$SPREAD_PATH"
   cd "$SPREAD_PATH"
-  snap install --classic concierge
+  # Install via snap after https://github.com/canonical/concierge/pull/81 released
+  go install github.com/canonical/concierge@latest
+
+  # Install charmcraft & pipx on lxd-vm backend and install pipx on IS-hosted runners
+  ~/go/bin/concierge prepare --trace
 
-  # Install charmcraft & pipx (on lxd-vm backend)
-  concierge prepare --trace
+  if [[ $SPREAD_SYSTEM == *"s390x"* ]]
+  then
+    rustup set profile minimal
+    # TODO add renovate comment for rust version
+    rustup default 1.88.0
+  fi
 
   pipx install tox poetry
 prepare-each: |
@@ -124,7 +144,7 @@ prepare-each: |
     poetry add --lock --group integration juju@^2
   fi
   # `concierge prepare` needs to be run for each spread job in case Juju version changed
-  concierge prepare --trace
+  ~/go/bin/concierge prepare --trace
 
   # Unable to set constraint on all models because of Juju bug:
   # https://bugs.launchpad.net/juju/+bug/2065050
diff --git a/tests/integration/markers.py b/tests/integration/markers.py
index 46d84271d..d38ea4a4c 100644
--- a/tests/integration/markers.py
+++ b/tests/integration/markers.py
@@ -15,3 +15,6 @@
 arm64_only = pytest.mark.skipif(
     architecture.architecture != "arm64", reason="Requires arm64 architecture"
 )
+s390x_only = pytest.mark.skipif(
+    architecture.architecture != "s390x", reason="Requires s390x architecture"
+)
diff --git a/tests/integration/test_architecture.py b/tests/integration/test_architecture.py
index b7044c8c5..fee7850a9 100644
--- a/tests/integration/test_architecture.py
+++ b/tests/integration/test_architecture.py
@@ -61,4 +61,25 @@ async def test_amd_charm_on_arm_host(ops_test: OpsTest) -> None:
     )
 
 
-# TODO: add s390x test
+@markers.arm64_only
+async def test_amd_charm_on_s390x_host(ops_test: OpsTest) -> None:
+    """Tries deploying an amd64 charm on s390x host."""
+    charm = "./mysql-router-k8s_ubuntu@22.04-amd64.charm"
+
+    resources = {
+        "mysql-router-image": METADATA["resources"]["mysql-router-image"]["upstream-source"]
+    }
+
+    await ops_test.model.deploy(
+        charm,
+        application_name=MYSQL_ROUTER_APP_NAME,
+        num_units=1,
+        resources=resources,
+        base="ubuntu@22.04",
+    )
+
+    await ops_test.model.wait_for_idle(
+        apps=[MYSQL_ROUTER_APP_NAME],
+        status="error",
+        raise_on_error=False,
+    )

From e940b6e99801feb5140efbbfc2875aad66385951 Mon Sep 17 00:00:00 2001
From: Carl Csaposs <carl.csaposs@canonical.com>
Date: Tue, 29 Jul 2025 12:22:38 +0200
Subject: [PATCH 02/12] Docker hub mirror

---
 spread.yaml | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/spread.yaml b/spread.yaml
index 72ba391d3..322d1a055 100644
--- a/spread.yaml
+++ b/spread.yaml
@@ -86,6 +86,7 @@ backends:
     # Manually pass specific environment variables
     environment:
       CI: '$(HOST: echo $CI)'
+      DOCKERHUB_MIRROR: '$(HOST: echo $DOCKERHUB_MIRROR)'
     systems:
       - ubuntu-24.04:
           username: runner
@@ -123,6 +124,26 @@ prepare: |
   cd "$SPREAD_PATH"
   # Install via snap after https://github.com/canonical/concierge/pull/81 released
   go install github.com/canonical/concierge@latest
+  
+  if [[ -n "$DOCKERHUB_MIRROR" ]]
+  then
+    # Running on IS-hosted runner; configure microk8s to use Docker Hub mirror
+    # Run before concierge prepare because of https://github.com/canonical/concierge/issues/75
+
+    snap install microk8s --channel "$CONCIERGE_MICROK8S_CHANNEL"
+  
+    # Wait for microk8s to populate iptables
+    # https://chat.canonical.com/canonical/pl/jo5cg6wqjjrudqd5ybj6hhttee
+    microk8s status --wait-ready
+
+    tee /var/snap/microk8s/current/args/certs.d/docker.io/hosts.toml << EOF
+    server = "$DOCKERHUB_MIRROR"
+    [host."${DOCKERHUB_MIRROR#'https://'}"]
+    capabilities = ["pull", "resolve"]
+  EOF
+    microk8s stop
+    microk8s start
+  fi
 
   # Install charmcraft & pipx on lxd-vm backend and install pipx on IS-hosted runners
   ~/go/bin/concierge prepare --trace

From 6c97d9012065dd86e5582535f24b7893559b459d Mon Sep 17 00:00:00 2001
From: Carl Csaposs <carl.csaposs@canonical.com>
Date: Thu, 31 Jul 2025 11:57:58 +0200
Subject: [PATCH 03/12] Use non-strict microk8s on IS-hosted runners

---
 spread.yaml | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/spread.yaml b/spread.yaml
index 322d1a055..bc3017225 100644
--- a/spread.yaml
+++ b/spread.yaml
@@ -102,8 +102,11 @@ backends:
             # (These packages are being built when installing poetry or integration test Python
             # dependencies)
             CONCIERGE_EXTRA_DEBS: pipx,pkg-config,rustup
-            # s390x only available on edge
-            CONCIERGE_MICROK8S_CHANNEL: 1.32-strict/edge
+            # s390x only available on edge risk of microk8s snap
+            # IS-hosted GitHub runners do not work with the strictly confined microk8s snap:
+            # https://github.com/canonical/microk8s/issues/5082
+            # https://chat.canonical.com/canonical/pl/i6yydsx5ifrepp56khq5fq5dke
+            CONCIERGE_MICROK8S_CHANNEL: latest/edge
           variants:
             - -juju29
 
@@ -130,7 +133,7 @@ prepare: |
     # Running on IS-hosted runner; configure microk8s to use Docker Hub mirror
     # Run before concierge prepare because of https://github.com/canonical/concierge/issues/75
 
-    snap install microk8s --channel "$CONCIERGE_MICROK8S_CHANNEL"
+    snap install microk8s --channel "$CONCIERGE_MICROK8S_CHANNEL" --classic
   
     # Wait for microk8s to populate iptables
     # https://chat.canonical.com/canonical/pl/jo5cg6wqjjrudqd5ybj6hhttee

From 004847872f8121129d57c46a225d8106ea6333e1 Mon Sep 17 00:00:00 2001
From: Carl Csaposs <carl.csaposs@canonical.com>
Date: Thu, 31 Jul 2025 12:30:51 +0200
Subject: [PATCH 04/12] temp disable unit needs

---
 .github/workflows/ci.yaml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index c6b88a70d..ffe1cbcee 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -59,7 +59,6 @@ jobs:
     name: Integration test charm
     needs:
       - lint
-      - unit-test
       - build
     uses: ./.github/workflows/integration_test.yaml
     with:

From d4d1ba7d3d02f004765aceedfad7d4fb25f20eb8 Mon Sep 17 00:00:00 2001
From: Carl Csaposs <carl.csaposs@canonical.com>
Date: Thu, 31 Jul 2025 13:52:08 +0200
Subject: [PATCH 05/12] try bootstrap with add-k8s & without concierge to use
 classic microk8s snap

---
 concierge.yaml | 2 +-
 spread.yaml    | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/concierge.yaml b/concierge.yaml
index 361973cb8..95ee838d4 100644
--- a/concierge.yaml
+++ b/concierge.yaml
@@ -4,7 +4,7 @@ juju:
 providers:
   microk8s:
     enable: true
-    bootstrap: true
+    bootstrap: false
     addons:
       - dns
       - hostpath-storage
diff --git a/spread.yaml b/spread.yaml
index bc3017225..aee72049b 100644
--- a/spread.yaml
+++ b/spread.yaml
@@ -151,6 +151,9 @@ prepare: |
   # Install charmcraft & pipx on lxd-vm backend and install pipx on IS-hosted runners
   ~/go/bin/concierge prepare --trace
 
+  microk8s config | juju add-k8s my-k8s --client
+  juju bootstrap my-k8s concierge-microk8s
+
   if [[ $SPREAD_SYSTEM == *"s390x"* ]]
   then
     rustup set profile minimal

From 8982ba285ad475d5c5bf97f2a4df955b2fb37f2c Mon Sep 17 00:00:00 2001
From: Carl Csaposs <carl.csaposs@canonical.com>
Date: Thu, 31 Jul 2025 14:20:27 +0200
Subject: [PATCH 06/12] add model

---
 spread.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/spread.yaml b/spread.yaml
index aee72049b..ac72e8599 100644
--- a/spread.yaml
+++ b/spread.yaml
@@ -153,6 +153,7 @@ prepare: |
 
   microk8s config | juju add-k8s my-k8s --client
   juju bootstrap my-k8s concierge-microk8s
+  juju add-model testing
 
   if [[ $SPREAD_SYSTEM == *"s390x"* ]]
   then

From d76fdea23c557c3b8d100322d84c696a5bf54ecf Mon Sep 17 00:00:00 2001
From: Carl Csaposs <carl.csaposs@canonical.com>
Date: Thu, 31 Jul 2025 15:11:48 +0200
Subject: [PATCH 07/12] fix marker

---
 tests/integration/test_architecture.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/integration/test_architecture.py b/tests/integration/test_architecture.py
index fee7850a9..b8dd06f70 100644
--- a/tests/integration/test_architecture.py
+++ b/tests/integration/test_architecture.py
@@ -61,7 +61,7 @@ async def test_amd_charm_on_arm_host(ops_test: OpsTest) -> None:
     )
 
 
-@markers.arm64_only
+@markers.s390x_only
 async def test_amd_charm_on_s390x_host(ops_test: OpsTest) -> None:
     """Tries deploying an amd64 charm on s390x host."""
     charm = "./mysql-router-k8s_ubuntu@22.04-amd64.charm"

From 859843437675a6c462e706b543536a0c28f475dd Mon Sep 17 00:00:00 2001
From: Carl Csaposs <carl.csaposs@canonical.com>
Date: Thu, 31 Jul 2025 15:23:17 +0200
Subject: [PATCH 08/12] fix tasks

---
 tests/spread/test_exporter.py/task.yaml          | 1 +
 tests/spread/test_exporter_with_tls.py/task.yaml | 1 +
 2 files changed, 2 insertions(+)

diff --git a/tests/spread/test_exporter.py/task.yaml b/tests/spread/test_exporter.py/task.yaml
index 800f0c4a2..e2f7ff6c2 100644
--- a/tests/spread/test_exporter.py/task.yaml
+++ b/tests/spread/test_exporter.py/task.yaml
@@ -7,3 +7,4 @@ artifacts:
   - allure-results
 systems:
   - -ubuntu-24.04-arm
+  - -self-hosted-linux-s390x-noble-edge
diff --git a/tests/spread/test_exporter_with_tls.py/task.yaml b/tests/spread/test_exporter_with_tls.py/task.yaml
index 4d7dce7fc..70d2c33b9 100644
--- a/tests/spread/test_exporter_with_tls.py/task.yaml
+++ b/tests/spread/test_exporter_with_tls.py/task.yaml
@@ -7,3 +7,4 @@ artifacts:
   - allure-results
 systems:
   - -ubuntu-24.04-arm
+  - -self-hosted-linux-s390x-noble-edge

From c65200a489d605efc6cd9b4c2af9744bd06ffef0 Mon Sep 17 00:00:00 2001
From: Carl Csaposs <carl.csaposs@canonical.com>
Date: Thu, 31 Jul 2025 15:24:07 +0200
Subject: [PATCH 09/12] temp remove already completed tests

---
 tests/spread/test_charm.py/task.yaml        | 7 -------
 tests/spread/test_log_rotation.py/task.yaml | 7 -------
 tests/spread/test_tls.py/task.yaml          | 7 -------
 tests/spread/test_upgrade.py/task.yaml      | 7 -------
 4 files changed, 28 deletions(-)
 delete mode 100644 tests/spread/test_charm.py/task.yaml
 delete mode 100644 tests/spread/test_log_rotation.py/task.yaml
 delete mode 100644 tests/spread/test_tls.py/task.yaml
 delete mode 100644 tests/spread/test_upgrade.py/task.yaml

diff --git a/tests/spread/test_charm.py/task.yaml b/tests/spread/test_charm.py/task.yaml
deleted file mode 100644
index 96450bdc3..000000000
--- a/tests/spread/test_charm.py/task.yaml
+++ /dev/null
@@ -1,7 +0,0 @@
-summary: test_charm.py
-environment:
-  TEST_MODULE: test_charm.py
-execute: |
-  tox run -e integration -- "tests/integration/$TEST_MODULE" --model testing --alluredir="$SPREAD_TASK/allure-results"
-artifacts:
-  - allure-results
diff --git a/tests/spread/test_log_rotation.py/task.yaml b/tests/spread/test_log_rotation.py/task.yaml
deleted file mode 100644
index 8e8900110..000000000
--- a/tests/spread/test_log_rotation.py/task.yaml
+++ /dev/null
@@ -1,7 +0,0 @@
-summary: test_log_rotation.py
-environment:
-  TEST_MODULE: test_log_rotation.py
-execute: |
-  tox run -e integration -- "tests/integration/$TEST_MODULE" --model testing --alluredir="$SPREAD_TASK/allure-results"
-artifacts:
-  - allure-results
diff --git a/tests/spread/test_tls.py/task.yaml b/tests/spread/test_tls.py/task.yaml
deleted file mode 100644
index a60574491..000000000
--- a/tests/spread/test_tls.py/task.yaml
+++ /dev/null
@@ -1,7 +0,0 @@
-summary: test_tls.py
-environment:
-  TEST_MODULE: test_tls.py
-execute: |
-  tox run -e integration -- "tests/integration/$TEST_MODULE" --model testing --alluredir="$SPREAD_TASK/allure-results"
-artifacts:
-  - allure-results
diff --git a/tests/spread/test_upgrade.py/task.yaml b/tests/spread/test_upgrade.py/task.yaml
deleted file mode 100644
index a53e8a4ee..000000000
--- a/tests/spread/test_upgrade.py/task.yaml
+++ /dev/null
@@ -1,7 +0,0 @@
-summary: test_upgrade.py
-environment:
-  TEST_MODULE: test_upgrade.py
-execute: |
-  tox run -e integration -- "tests/integration/$TEST_MODULE" --model testing --alluredir="$SPREAD_TASK/allure-results"
-artifacts:
-  - allure-results

From 14991c105c8e71cfe2c7f03d8aa73b282d2bdb98 Mon Sep 17 00:00:00 2001
From: Carl Csaposs <carl.csaposs@canonical.com>
Date: Fri, 1 Aug 2025 11:47:46 +0200
Subject: [PATCH 10/12] self-signed-certificates channel s390x

---
 tests/integration/test_exporter_with_tls.py | 4 ++--
 tests/integration/test_expose_external.py   | 4 ++--
 tests/integration/test_tls.py               | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/tests/integration/test_exporter_with_tls.py b/tests/integration/test_exporter_with_tls.py
index b872bb8c1..2667e8963 100644
--- a/tests/integration/test_exporter_with_tls.py
+++ b/tests/integration/test_exporter_with_tls.py
@@ -34,8 +34,8 @@
 
 if juju_.is_3_or_higher:
     tls_app_name = "self-signed-certificates"
-    if architecture.architecture == "arm64":
-        tls_channel = "latest/edge"
+    if architecture.architecture == "s390x":
+        tls_channel = "1/edge"
     else:
         tls_channel = "latest/stable"
     tls_config = {"ca-common-name": "Test CA"}
diff --git a/tests/integration/test_expose_external.py b/tests/integration/test_expose_external.py
index 92f1348cc..39945c9c7 100644
--- a/tests/integration/test_expose_external.py
+++ b/tests/integration/test_expose_external.py
@@ -36,8 +36,8 @@
 TLS_SETUP_SLEEP_TIME = 30
 if juju_.is_3_or_higher:
     TLS_APP_NAME = "self-signed-certificates"
-    if architecture.architecture == "arm64":
-        TLS_CHANNEL = "latest/edge"
+    if architecture.architecture == "s390x":
+        TLS_CHANNEL = "1/edge"
     else:
         TLS_CHANNEL = "latest/stable"
     TLS_CONFIG = {"ca-common-name": "Test CA"}
diff --git a/tests/integration/test_tls.py b/tests/integration/test_tls.py
index 00fb17f95..6e687fb26 100644
--- a/tests/integration/test_tls.py
+++ b/tests/integration/test_tls.py
@@ -30,8 +30,8 @@
 
 if juju_.is_3_or_higher:
     tls_app_name = "self-signed-certificates"
-    if architecture.architecture == "arm64":
-        tls_channel = "latest/edge"
+    if architecture.architecture == "s390x":
+        tls_channel = "1/edge"
     else:
         tls_channel = "latest/stable"
     tls_config = {"ca-common-name": "Test CA"}

From a06735d7b96d338bfc3060072ed15930b5eec9b7 Mon Sep 17 00:00:00 2001
From: Carl Csaposs <carl.csaposs@canonical.com>
Date: Fri, 1 Aug 2025 11:48:37 +0200
Subject: [PATCH 11/12] temp remove already completed tests

---
 tests/spread/test_architecture.py/task.yaml            |  9 ---------
 tests/spread/test_exporter_with_tls.py/task.yaml       | 10 ----------
 .../spread/{test_exporter.py => test_tls.py}/task.yaml |  7 ++-----
 3 files changed, 2 insertions(+), 24 deletions(-)
 delete mode 100644 tests/spread/test_architecture.py/task.yaml
 delete mode 100644 tests/spread/test_exporter_with_tls.py/task.yaml
 rename tests/spread/{test_exporter.py => test_tls.py}/task.yaml (57%)

diff --git a/tests/spread/test_architecture.py/task.yaml b/tests/spread/test_architecture.py/task.yaml
deleted file mode 100644
index cad863364..000000000
--- a/tests/spread/test_architecture.py/task.yaml
+++ /dev/null
@@ -1,9 +0,0 @@
-summary: test_architecture.py
-environment:
-  TEST_MODULE: test_architecture.py
-execute: |
-  tox run -e integration -- "tests/integration/$TEST_MODULE" --model testing --alluredir="$SPREAD_TASK/allure-results"
-artifacts:
-  - allure-results
-backends:
-  - -lxd-vm  # This task requires charm built on different architecture from host
diff --git a/tests/spread/test_exporter_with_tls.py/task.yaml b/tests/spread/test_exporter_with_tls.py/task.yaml
deleted file mode 100644
index 70d2c33b9..000000000
--- a/tests/spread/test_exporter_with_tls.py/task.yaml
+++ /dev/null
@@ -1,10 +0,0 @@
-summary: test_exporter_with_tls.py
-environment:
-  TEST_MODULE: test_exporter_with_tls.py
-execute: |
-  tox run -e integration -- "tests/integration/$TEST_MODULE" --model testing --alluredir="$SPREAD_TASK/allure-results"
-artifacts:
-  - allure-results
-systems:
-  - -ubuntu-24.04-arm
-  - -self-hosted-linux-s390x-noble-edge
diff --git a/tests/spread/test_exporter.py/task.yaml b/tests/spread/test_tls.py/task.yaml
similarity index 57%
rename from tests/spread/test_exporter.py/task.yaml
rename to tests/spread/test_tls.py/task.yaml
index e2f7ff6c2..a60574491 100644
--- a/tests/spread/test_exporter.py/task.yaml
+++ b/tests/spread/test_tls.py/task.yaml
@@ -1,10 +1,7 @@
-summary: test_exporter.py
+summary: test_tls.py
 environment:
-  TEST_MODULE: test_exporter.py
+  TEST_MODULE: test_tls.py
 execute: |
   tox run -e integration -- "tests/integration/$TEST_MODULE" --model testing --alluredir="$SPREAD_TASK/allure-results"
 artifacts:
   - allure-results
-systems:
-  - -ubuntu-24.04-arm
-  - -self-hosted-linux-s390x-noble-edge

From d75243071e9a98e5de4fe105b33404a7efff51d9 Mon Sep 17 00:00:00 2001
From: Carl Csaposs <carl.csaposs@canonical.com>
Date: Fri, 1 Aug 2025 12:24:45 +0200
Subject: [PATCH 12/12] fix base

---
 tests/integration/test_exporter_with_tls.py | 1 -
 tests/integration/test_expose_external.py   | 1 -
 tests/integration/test_tls.py               | 1 -
 3 files changed, 3 deletions(-)

diff --git a/tests/integration/test_exporter_with_tls.py b/tests/integration/test_exporter_with_tls.py
index 2667e8963..bbc7601e1 100644
--- a/tests/integration/test_exporter_with_tls.py
+++ b/tests/integration/test_exporter_with_tls.py
@@ -138,7 +138,6 @@ async def test_exporter_endpoint(ops_test: OpsTest, charm) -> None:
         application_name=tls_app_name,
         channel=tls_channel,
         config=tls_config,
-        base="ubuntu@22.04",
     )
 
     await ops_test.model.wait_for_idle([tls_app_name], status="active", timeout=SLOW_TIMEOUT)
diff --git a/tests/integration/test_expose_external.py b/tests/integration/test_expose_external.py
index 39945c9c7..32b2f93c4 100644
--- a/tests/integration/test_expose_external.py
+++ b/tests/integration/test_expose_external.py
@@ -197,7 +197,6 @@ async def test_expose_external_with_tls(ops_test: OpsTest) -> None:
         TLS_APP_NAME,
         channel=TLS_CHANNEL,
         config=TLS_CONFIG,
-        base="ubuntu@22.04",
     )
     async with ops_test.fast_forward("60s"):
         await ops_test.model.wait_for_idle(
diff --git a/tests/integration/test_tls.py b/tests/integration/test_tls.py
index 6e687fb26..e21a434ba 100644
--- a/tests/integration/test_tls.py
+++ b/tests/integration/test_tls.py
@@ -79,7 +79,6 @@ async def test_deploy_and_relate(ops_test: OpsTest, charm) -> None:
                 application_name=tls_app_name,
                 channel=tls_channel,
                 config=tls_config,
-                base="ubuntu@22.04",
             ),
             ops_test.model.deploy(
                 TEST_APP_NAME,