Use systemctl replacement to generate documentation.

Containers are notoriously unfriendly to systemctl (really systemd) but we prefer to use systemctl to make our documentation as accurate as possible. This replacement performs all the functions of systemctl without requiring systemd, which great simplifies container configuration and allows the documentation build to work in more environments.

doc/xml/user-guide.xml

@@ -170,8 +170,6 @@
         <!-- Hosts -->
         <variable key="host-image">pgbackrest/doc:{[os-type]}</variable>
 
-        <variable key="host-option">-v /sys/fs/cgroup:/sys/fs/cgroup:rw -v /tmp/$(mktemp -d):/run</variable>
-
         <!-- Limit host memory to check for memory leaks. Some environments do not allow memory to be set so allow disabling. -->
         <variable key="host-mem-limit">y</variable>
         <variable key="host-mem" if="'{[host-mem-limit]}' eq 'y'">-m 512m</variable>
@@ -360,21 +358,8 @@
     </host-define>
 
     <host-define if="{[os-type-is-rhel]}" image="{[host-image]}" from="{[os-image]}">
-        ENV container docker
-
         {[copy-ca-cert]}
 
-        RUN mkdir -p /lib/systemd/system/sysinit.target.wants &amp;&amp; \
-            (cd /lib/systemd/system/sysinit.target.wants/; for i in *; do [ $i == \
-            systemd-tmpfiles-setup.service ] || rm -f $i; done); \
-            rm -f /lib/systemd/system/multi-user.target.wants/*;\
-            rm -f /etc/systemd/system/*.wants/*;\
-            rm -f /lib/systemd/system/local-fs.target.wants/*; \
-            rm -f /lib/systemd/system/sockets.target.wants/*udev*; \
-            rm -f /lib/systemd/system/sockets.target.wants/*initctl*; \
-            rm -f /lib/systemd/system/basic.target.wants/*;\
-            rm -f /lib/systemd/system/anaconda.target.wants/*;
-
         VOLUME [ "/sys/fs/cgroup" ]
 
         # Install packages
@@ -410,6 +395,14 @@
         RUN dnf install -y https://packages.microsoft.com/config/rhel/8/packages-microsoft-prod.rpm
         RUN dnf install -y azure-cli
 
+        # Install systemctl replacement that works without systemd running
+        ENV SYSCTL_REP_VER=1.5.8066
+        RUN wget -q -O - https://github.com/gdraheim/docker-systemctl-replacement/archive/refs/tags/v${SYSCTL_REP_VER?}.tar.gz | \
+            tar zx -C /root
+        RUN rm -f /usr/bin/systemctl
+        RUN cp /root/docker-systemctl-replacement-${SYSCTL_REP_VER?}/files/docker/systemctl3.py /usr/bin/systemctl
+        RUN rm -rf /root/docker-systemctl-replacement-${SYSCTL_REP_VER?}
+
         # Create an ssh key for root so all hosts can ssh to each other as root
         RUN \ {[ssh-key-install]}
 
@@ -420,14 +413,6 @@
         RUN adduser -n {[host-user]} &amp;&amp; \
             echo '{[host-user]}        ALL=(ALL)       NOPASSWD: ALL' > /etc/sudoers.d/{[host-user]}
 
-        # Enable the user session service so logons are allowed
-        RUN echo "[Install]" >> /usr/lib/systemd/system/systemd-user-sessions.service &amp;&amp; \
-            echo "[WantedBy=default.target]" >> /usr/lib/systemd/system/systemd-user-sessions.service &amp;&amp; \
-            systemctl enable systemd-user-sessions.service &amp;&amp; \
-            mkdir -p /etc/systemd/system/default.target.wants &amp;&amp; \
-            ln -s /usr/lib/systemd/system/systemd-user-sessions.service \
-                /etc/systemd/system/default.target.wants/systemd-user-sessions.service
-
         # Set locale
         RUN echo en_US.UTF-8 UTF-8 > /etc/locale.conf
 
@@ -435,7 +420,7 @@
         ENV PATH=/usr/pgsql-{[pg-version]}/bin:$PATH
         ENV PKG_CONFIG_PATH=/usr/pgsql-{[pg-version]}/lib/pkgconfig:$PKG_CONFIG_PATH
 
-        CMD ["/usr/sbin/init"]
+        ENTRYPOINT rm -rf /run/nologin &amp;&amp; /usr/sbin/sshd -D
     </host-define>
 
     <!-- ======================================================================================================================= -->
@@ -917,7 +902,7 @@
         <host-add if="'{[s3-local]}' eq 'y'" id="{[host-s3-id]}" name="{[host-s3]}" user="root" image="{[s3-image]}" os="{[os-type]}" option="-v {[fake-cert-path]}/s3-server.crt:/root/.minio/certs/public.crt:ro -v {[fake-cert-path]}/s3-server.key:/root/.minio/certs/private.key:ro -e MINIO_REGION={[s3-region]} -e MINIO_DOMAIN={[s3-endpoint]} -e MINIO_BROWSER=off -e MINIO_ACCESS_KEY={[s3-key]} -e MINIO_SECRET_KEY={[s3-key-secret]}" param="server /data --address :443" update-hosts="n"/>
 
         <!-- Create SFTP server first to allow it time to boot before being used -->
-        <host-add id="{[host-sftp-id]}" name="{[host-sftp]}" user="{[host-sftp-user]}" image="{[host-sftp-image]}" os="{[os-type]}" mount="{[host-sftp-mount]}" option="{[host-mem]} {[host-option]}"/>
+        <host-add id="{[host-sftp-id]}" name="{[host-sftp]}" user="{[host-sftp-user]}" image="{[host-sftp-image]}" os="{[os-type]}" mount="{[host-sftp-mount]}"/>
 
         <p>This user guide is intended to be followed sequentially from beginning to end &amp;mdash; each section depends on the last. For example, the <link section="/restore">Restore</link> section relies on setup that is performed in the <link section="/quickstart">Quick Start</link> section. Once <backrest/> is up and running then skipping around is possible but following the user guide in order is recommended the first time through.</p>
 
@@ -1017,7 +1002,7 @@
 
         <p>Installing <backrest/> from a package is preferable to building from source. See <link section="/installation">Installation</link> for more information about packages.</p>
 
-        <host-add id="{[host-build-id]}" name="{[host-build]}" user="{[host-build-user]}" image="{[host-build-image]}" os="{[os-type]}" mount="{[host-build-mount]}" option="{[host-option]}"/>
+        <host-add id="{[host-build-id]}" name="{[host-build]}" user="{[host-build-user]}" image="{[host-build-image]}" os="{[os-type]}" mount="{[host-build-mount]}"/>
 
         <p>When building from source it is best to use a build host rather than building on production. Many of the tools required for the build should generally not be installed in production. <backrest/> consists of a single executable so it is easy to copy to a new host once it is built.</p>
 
@@ -1104,7 +1089,7 @@
 
         <p>A new host named <host>{[host-pg1]}</host> is created to contain the demo cluster and run <backrest/> examples.</p>
 
-        <host-add id="{[host-pg1-id]}" name="{[host-pg1]}" user="{[host-pg1-user]}" image="{[host-pg1-image]}" os="{[os-type]}" mount="{[host-pg1-mount]}" option="{[host-mem]} {[host-option]}"/>
+        <host-add id="{[host-pg1-id]}" name="{[host-pg1]}" user="{[host-pg1-user]}" image="{[host-pg1-image]}" os="{[os-type]}" mount="{[host-pg1-mount]}" option="{[host-mem]}"/>
 
         <!-- <execute-list if="{[pg-version]} >= 11" host="{[host-pg1]}">
             <title>Create <user>{[br-user]}</user> user</title>
@@ -1583,7 +1568,7 @@
 
                 <execute if="{[os-type-is-rhel]}" user="root" output="y" err-expect="3">
                     <exe-cmd>{[pg-cluster-check]}</exe-cmd>
-                    <exe-highlight>Failed to start PostgreSQL</exe-highlight>
+                    <exe-highlight>failed</exe-highlight>
                 </execute>
             </execute-list>
 
@@ -2734,7 +2719,7 @@
 
             <admonition type="note">The <backrest/> version installed on the <host>repository</host> host must exactly match the version installed on the <postgres/> host.</admonition>
 
-            <host-add id="{[host-repo1-id]}" name="{[host-repo1]}" user="{[host-repo1-user]}" image="{[host-repo1-image]}" os="{[os-type]}" mount="{[host-repo1-mount]}" option="{[host-mem]} {[host-option]}"/>
+            <host-add id="{[host-repo1-id]}" name="{[host-repo1]}" user="{[host-repo1-user]}" image="{[host-repo1-image]}" os="{[os-type]}" mount="{[host-repo1-mount]}" option="{[host-mem]}"/>
 
             <p>The <user>{[br-user]}</user> user is created to own the <backrest/> repository. Any user can own the repository but it is best not to use <user>postgres</user> (if it exists) to avoid confusion.</p>
 
@@ -3158,7 +3143,7 @@
 
             <p>A new host named <host>{[host-pg2]}</host> is created to run the standby.</p>
 
-            <host-add id="{[host-pg2-id]}" name="{[host-pg2]}" user="{[host-pg2-user]}" image="{[host-pg2-image]}" os="{[os-type]}" mount="{[host-pg2-mount]}" option="{[host-mem]} {[host-option]}"/>
+            <host-add id="{[host-pg2-id]}" name="{[host-pg2]}" user="{[host-pg2-user]}" image="{[host-pg2-image]}" os="{[os-type]}" mount="{[host-pg2-mount]}" option="{[host-mem]}"/>
 
             <!-- <execute-list if="{[pg-version]} >= 11" host="{[host-pg2]}">
                 <title>Create <user>{[br-user]}</user> user</title>
@@ -3549,7 +3534,7 @@
 
             <p>A new host named <host>{[host-pgalt]}</host> is created to run the new primary.</p>
 
-            <host-add id="{[host-pgalt-id]}" name="{[host-pgalt]}" user="{[host-pgalt-user]}" image="{[host-pgalt-image]}" os="{[os-type]}" mount="{[host-pgalt-mount]}" option="{[host-mem]} {[host-option]}"/>
+            <host-add id="{[host-pgalt-id]}" name="{[host-pgalt]}" user="{[host-pgalt-user]}" image="{[host-pgalt-image]}" os="{[os-type]}" mount="{[host-pgalt-mount]}" option="{[host-mem]}"/>
 
             <block id="br-install">
                 <block-variable-replace key="br-install-host">{[host-pgalt]}</block-variable-replace>
@@ -4354,7 +4339,7 @@
         <execute-list host="{[host-pg1]}">
             <title>Check configuration</title>
 
-            <execute user="postgres" output="n" filter="n">
+            <execute user="root" output="n" filter="n">
                 <exe-cmd>{[pg-cluster-check-upgrade]}</exe-cmd>
             </execute>