From 91d40e453c3456b7ad9fa239104d626d0f5fd767 Mon Sep 17 00:00:00 2001
From: "d.kovalenko" <dmitry.lipetsk@gmail.com>
Date: Tue, 14 Jul 2026 14:09:03 +0300
Subject: [PATCH 1/2] CI: Ubuntu 26.04 is added to test

---
 .github/workflows/ci.yml      |  2 +
 Dockerfile--ubuntu_26_04.tmpl | 90 +++++++++++++++++++++++++++++++++++
 2 files changed, 92 insertions(+)
 create mode 100644 Dockerfile--ubuntu_26_04.tmpl

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 39fa220..117d6e4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -92,6 +92,8 @@ jobs:
             python: "3.14"
           - platform: "ubuntu_24_04"
             python: "3"
+          - platform: "ubuntu_26_04"
+            python: "3"
           - platform: "altlinux_10"
             python: "3"
           - platform: "altlinux_11"
diff --git a/Dockerfile--ubuntu_26_04.tmpl b/Dockerfile--ubuntu_26_04.tmpl
new file mode 100644
index 0000000..828561f
--- /dev/null
+++ b/Dockerfile--ubuntu_26_04.tmpl
@@ -0,0 +1,90 @@
+ARG PYTHON_VERSION=3
+
+# --------------------------------------------- base1
+FROM ubuntu:26.04 AS base1
+
+# Disable interactive apt questions so that the build doesn't hang when setting time zones
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    sudo \
+    curl \
+    ca-certificates \
+    openssh-server \
+    sshpass \
+    time \
+    netcat-traditional \
+    iproute2 \
+    git \
+    && rm -rf /var/lib/apt/lists/*
+
+# --------------------------------------------- base2_with_python-3
+FROM base1 AS base2_with_python-3
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    python3 \
+    python3-dev \
+    python3-venv \
+    && rm -rf /var/lib/apt/lists/*
+
+ENV PYTHON_BINARY=python3
+
+# --------------------------------------------- final
+FROM base2_with_python-${PYTHON_VERSION} AS final
+
+EXPOSE 22
+RUN ssh-keygen -A
+
+RUN useradd -m test
+
+# It enables execution of "sudo service ssh start" without password
+RUN echo "test ALL=(ALL:ALL) NOPASSWD:ALL" >> /etc/sudoers
+
+COPY --chown=test:test . /home/test/testgres
+WORKDIR /home/test/testgres
+
+ENV LANG=C.UTF-8
+
+RUN chmod 700 /home/test/ && \
+    mkdir -p /home/test/.ssh && \
+    chown -R test:test /home/test/.ssh
+
+#
+# \"$@\"
+#   - quote is important!
+#   - "DUMMY-DUMMY-DUMMY" will be ignored. Do not ask me "why?". AXEZ.
+#
+ENTRYPOINT ["sh", "-c", " \
+    set -eux; \
+    echo 'SYSTEM START: PREPARING SSH'; \
+    service ssh start; \
+    ls -la /home/test/.ssh/; \
+    \"$@\" \
+", "DUMMY-DUMMY-DUMMY"]
+
+# Run tests by default (master machine role)
+CMD ["bash", "-c", " \
+set -eux; \
+echo \"HOME DIR IS [`realpath ~/`]\"; \
+echo \"WORK DIR IS [$(pwd)]\"; \
+if [ ! -f /home/test/.ssh/id_rsa ]; then \
+    su test -c \"ssh-keygen -t rsa -f /home/test/.ssh/id_rsa -q -N ''\"; \
+    su test -c \"cat /home/test/.ssh/id_rsa.pub >> /home/test/.ssh/authorized_keys\"; \
+    chmod 600 /home/test/.ssh/authorized_keys; \
+fi; \
+ls -la /home/test/.ssh/; \
+su test -c \"ssh-keyscan -H localhost >> /home/test/.ssh/known_hosts\"; \
+su test -c \"ssh-keyscan -H 127.0.0.1 >> /home/test/.ssh/known_hosts\"; \
+if [ -n \"${TEST_CFG__REMOTE_HOST:-}\" ]; then \
+    su test -c \"ssh-keyscan -H ${TEST_CFG__REMOTE_HOST} >> /home/test/.ssh/known_hosts\"; \
+fi; \
+if [ -n \"${TEST_CFG__REMOTE_SSH_KEY:-}\" ]; then \
+    cp \"${TEST_CFG__REMOTE_SSH_KEY}\" \"${TEST_CFG__REMOTE_SSH_KEY}_ci\"; \
+    export TEST_CFG__REMOTE_SSH_KEY=\"${TEST_CFG__REMOTE_SSH_KEY}_ci\"; \
+    chown test:test \"${TEST_CFG__REMOTE_SSH_KEY}\"; \
+    chmod 600 \"${TEST_CFG__REMOTE_SSH_KEY}\"; \
+    ls -la /home/test/.ssh/; \
+fi; \
+ls -la ./; \
+su test -c \"bash ./run_tests3.sh\"; \
+"]

From e28b74f4e99840b17fcaba509ad43dc5aa40e0b7 Mon Sep 17 00:00:00 2001
From: "d.kovalenko" <dmitry.lipetsk@gmail.com>
Date: Tue, 14 Jul 2026 15:42:01 +0300
Subject: [PATCH 2/2] CI: Fix for TestOsOpsCommon::test_mkdir__mt[remote_ops]
 on ubuntu 26.04

Returning classic GNU coreutils instead of the default Rust/uutils.
---
 Dockerfile--ubuntu_26_04.tmpl | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Dockerfile--ubuntu_26_04.tmpl b/Dockerfile--ubuntu_26_04.tmpl
index 828561f..ddfaa9d 100644
--- a/Dockerfile--ubuntu_26_04.tmpl
+++ b/Dockerfile--ubuntu_26_04.tmpl
@@ -16,6 +16,11 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     netcat-traditional \
     iproute2 \
     git \
+    # FIX FOR TestOsOpsCommon::test_mkdir__mt[remote_ops] \
+    #   INFO [2026-07-14 11:12:31] [Worker #3] Number 0 is reserved! \
+    #   INFO [2026-07-14 11:12:31] [Worker #0] Number 0 is reserved! \
+    # Returning classic GNU coreutils instead of the default Rust/uutils \
+    && apt-get install -y --allow-remove-essential coreutils-from-gnu coreutils-from-uutils- \
     && rm -rf /var/lib/apt/lists/*
 
 # --------------------------------------------- base2_with_python-3