github: check downgrade to v4

To downgrade correctly you must:

* Disable td-agent.service alias beforehand.
  * It conflict with v4 td-agent.service
  * If you didn't disable it, it causes broken symlink from
    td-agent.service to /lib/systemd/system/fluentd.service.
* Purge v5 apt-line in fluent-lts-apt-source or fluent-apt-source.

Signed-off-by: Kentaro Hayashi <[email protected]>

fluent-package/apt/systemd-test/downgrade-to-v4.sh

@@ -0,0 +1,72 @@
+#!/bin/bash
+
+set -exu
+
+. $(dirname $0)/../commonvar.sh
+
+sudo apt install -y curl ca-certificates
+curl -O https://packages.treasuredata.com/4/${distribution}/${code_name}/pool/contrib/f/fluentd-apt-source/fluentd-apt-source_2020.8.25-1_all.deb
+sudo apt install -y ./fluentd-apt-source_2020.8.25-1_all.deb
+
+# Install v4
+sudo apt clean all
+sudo apt update
+sudo apt install -V -y td-agent=${td_agent_version}-1
+
+systemctl status --no-pager td-agent
+
+# fluent-package 5 (LTS)
+curl -fsSL https://toolbelt.treasuredata.com/sh/install-${distribution}-${code_name}-fluent-package5-lts.sh | sh
+
+# Install the current
+sudo apt install -V -y \
+    /vagrant/${distribution}/pool/${code_name}/${channel}/*/*/fluent-package_*_${architecture}.deb
+
+# Skip test because it covers with upgrade-from-v4.sh
+sudo apt purge fluent-lts-apt-source
+
+# Remove td-agent.service alias not to conflict with v4
+sudo systemctl disable td-agent
+
+# Downgrade to v4
+curl -fsSL https://toolbelt.treasuredata.com/sh/install-debian-bullseye-td-agent4.sh | sh
+
+# Test: service status
+(!systemctl status --no-pager fluentd)
+(systemctl status --no-pager td-agent)
+
+# Test: config migration
+test -d /etc/td-agent
+(! test -h /etc/fluent/fluentd.conf)
+test -e /etc/td-agent/td-agent.conf
+
+# Test: log file migration
+test -d /var/log/td-agent
+test -e /var/log/td-agent/td-agent.log
+
+# Test: bin file migration
+test -x /usr/sbin/td-agent
+test -x /usr/sbin/td-agent-gem
+
+# Test: environmental variables
+pid=$(systemctl show td-agent --property=MainPID --value)
+env_vars=$(sudo sed -e 's/\x0/\n/g' /proc/$pid/environ)
+test $(eval $env_vars && echo $HOME) = "/var/lib/td-agent"
+test $(eval $env_vars && echo $LOGNAME) = "td-agent"
+test $(eval $env_vars && echo $USER) = "td-agent"
+test $(eval $env_vars && echo $FLUENT_CONF) = "/etc/td-agent/td-agent.conf"
+test $(eval $env_vars && echo $TD_AGENT_LOG_FILE) = "/var/log/td-agent/td-agent.log"
+test $(eval $env_vars && echo $FLUENT_PLUGIN) = "/etc/td-agent/plugin"
+test $(eval $env_vars && echo $FLUENT_SOCKET) = "/var/run/td-agent/td-agent.sock"
+
+# Test: No error logs
+# (v4 default config outputs 'warn' log, so we should check only 'error' and 'fatal' logs)
+sleep 3
+test -e /var/log/td-agent/td-agent.log
+(! grep -e '\[error\]' -e '\[fatal\]' /var/log/td-agent/td-agent.log)
+
+# Uninstall
+sudo apt remove -y td-agent
+(! systemctl status --no-pager td-agent)
+
+(! test -h /etc/systemd/system/td-agent.service)

fluent-package/apt/systemd-test/test.sh

@@ -27,6 +27,7 @@ if [ ! $vm = "debian-bookworm" ]; then
     test_filenames+=(
         update-from-v4.sh
         update-to-next-version-with-backward-compat-for-v4.sh
+        downgrade-to-v4.sh
     )
 fi
 

fluent-package/yum/systemd-test/downgrade-to-v4.sh

@@ -0,0 +1,74 @@
+#!/bin/bash
+
+set -exu
+
+. $(dirname $0)/../commonvar.sh
+
+# Install v4
+case ${distribution} in
+    amazon)
+	curl -fsSL https://toolbelt.treasuredata.com/sh/install-amazon2-td-agent.sh | sh
+	;;
+    *)
+	curl -fsSL https://toolbelt.treasuredata.com/sh/install-redhat-td-agent4.sh | sh
+	;;
+esac
+
+systemctl status --no-pager td-agent
+
+# Install the current
+sudo $DNF install -y \
+    /vagrant/${distribution}/pool/${code_name}/${channel}/*/*/fluent-package_*_${architecture}.deb
+
+# Remove td-agent.service alias not to conflict with v4
+sudo systemctl disable td-agent
+
+# Downgrade to v4
+case ${distribution} in
+    amazon)
+	curl -fsSL https://toolbelt.treasuredata.com/sh/install-amazon2-td-agent.sh | sh
+	;;
+    *)
+	curl -fsSL https://toolbelt.treasuredata.com/sh/install-redhat-td-agent4.sh | sh
+	;;
+esac
+
+# Test: service status
+(!systemctl status --no-pager fluentd)
+(systemctl status --no-pager td-agent)
+
+# Test: config migration
+test -d /etc/td-agent
+(! test -h /etc/fluent/fluentd.conf)
+test -e /etc/td-agent/td-agent.conf
+
+# Test: log file migration
+test -d /var/log/td-agent
+test -e /var/log/td-agent/td-agent.log
+
+# Test: bin file migration
+test -x /usr/sbin/td-agent
+test -x /usr/sbin/td-agent-gem
+
+# Test: environmental variables
+pid=$(systemctl show td-agent --property=MainPID --value)
+env_vars=$(sudo sed -e 's/\x0/\n/g' /proc/$pid/environ)
+test $(eval $env_vars && echo $HOME) = "/var/lib/td-agent"
+test $(eval $env_vars && echo $LOGNAME) = "td-agent"
+test $(eval $env_vars && echo $USER) = "td-agent"
+test $(eval $env_vars && echo $FLUENT_CONF) = "/etc/td-agent/td-agent.conf"
+test $(eval $env_vars && echo $TD_AGENT_LOG_FILE) = "/var/log/td-agent/td-agent.log"
+test $(eval $env_vars && echo $FLUENT_PLUGIN) = "/etc/td-agent/plugin"
+test $(eval $env_vars && echo $FLUENT_SOCKET) = "/var/run/td-agent/td-agent.sock"
+
+# Test: No error logs
+# (v4 default config outputs 'warn' log, so we should check only 'error' and 'fatal' logs)
+sleep 3
+test -e /var/log/td-agent/td-agent.log
+(! grep -e '\[error\]' -e '\[fatal\]' /var/log/td-agent/td-agent.log)
+
+# Uninstall
+sudo $DNF remove -y td-agent
+(! systemctl status --no-pager td-agent)
+
+(! test -h /etc/systemd/system/td-agent.service)

fluent-package/yum/systemd-test/test.sh

@@ -22,6 +22,7 @@ test_filenames=(
     update-from-v4.sh
     update-to-next-version.sh
     update-to-next-version-with-backward-compat-for-v4.sh
+    downgrade-to-v4.sh
 )
 
 for yum_repo_type in local v5 lts; do