new: [docker-host] add option to force upgrade of docker version

precise/host/hooks/install.d/60-docker.sh

@@ -1,8 +1,35 @@
 #!/bin/bash
 
+## Set NO_DOCKER_RESTART to prevent restarting docker after upgrade.
+## Set ALLOW_DOCKER_CHANGE to allow change your docker version.
+## Set TARGET_DOCKER_VERSION to force a version (use cautiously!)
+
+distro=$(lsb_release -is)
+release=$(lsb_release -rs)
+
+if [ -z "$TARGET_DOCKER_VERSION" ]; then
+    case "$distro" in
+        Debian)
+            case "$release" in
+                10|11|12) target_version=24;;
+                *) target_version=19;;
+            esac
+            ;;
+        Ubuntu)
+            case "$release" in
+                22.04) target_version=24;;
+                *) target_version=19;;
+            esac
+            ;;
+        *) target_version=17;;
+    esac
+else
+    target_version="$TARGET_DOCKER_VERSION"
+fi
+
 
 just_installed=
-if ! type -p docker; then
+if ! type -p docker >/dev/null; then
     echo "Installing docker..."
     type -p curl >/dev/null ||
         apt-get install -y curl </dev/null
@@ -11,37 +38,76 @@ if ! type -p docker; then
     just_installed=1
 fi
 
+read docker_client_version docker_server_version < <(
+    docker version --format '{{.Client.Version}} {{.Server.Version}}'
+)
 
-if [ -n "$just_installed" ]; then
-    need_restart=
-
-    case $(lsb_release -is) in
-        Debian)
-            case $(lsb_release -rs) in
-                10) docker_version=20.10;;
-                *) docker_version=17;;
-            esac
-            ;;
-        Ubuntu)
-            case $(lsb_release -rs) in
-                22.04) docker_version=20.10;;
-                *) docker_version=17;;
-            esac
-            ;;
-        *) docker_version=17;;
-    esac
+mismatch_client_server=
+## issue a warning if client and server versions are different
+if [ "$docker_client_version" != "$docker_server_version" ]; then
+    echo "WARNING: docker client and server versions differ!" >&2
+    echo "  client: $docker_client_version" >&2
+    echo "  server: $docker_server_version" >&2
+    mismatch_client_server=1
+fi
 
-    if ! [[ "$(docker --version)" == "Docker version $docker_version"* ]]; then
-        version="$(apt-cache madison docker-ce |
+distrib_available_version="$(apt-cache madison docker-ce |
                        cut -f 2 -d \| |
-                       grep "$docker_version" |
+                       grep "$target_version" |
                        head -n 1 | xargs echo)"
-        apt-get install -y --allow-downgrades docker-ce="$version"
-        need_restart=true
+
+cleaned_distrib_available_version="${distrib_available_version%%~*}"
+cleaned_distrib_available_version="${distrib_available_version%-*}"
+cleaned_distrib_available_version="${cleaned_distrib_available_version#*:}"
+if [ -z "$mismatch_client_server" ] &&
+       [[ "$docker_client_version" == "$cleaned_distrib_available_version" ]]; then
+    ## current and target versions match, no upgrade needed
+    echo "INFO: recommended target docker version $docker_client_version already installed" >&2
+    echo "  To set a different target version, set TARGET_DOCKER_VERSION" >&2
+    exit 0
+fi
+
+## Should we skip upgrade?
+if [ -z "$just_installed" ] && [ -z "$ALLOW_DOCKER_CHANGE" ]; then
+    if [ -n "$distrib_available_version" ]; then
+        if [ -z "$mismatch_client_server" ]; then
+            ## get current version for docker-ce debian package installed
+            current_debian_package_version="$(dpkg -s docker-ce | grep '^Version:' | cut -f 2 -d ' ')"
+            echo "INFO: docker recommended version available (current: $current_debian_package_version => recommended: $distrib_available_version)" >&2
+        else
+            current_docker_ce_package_version="$(dpkg -s docker-ce | grep '^Version:' | cut -f 2 -d ' ')"
+            current_docker_ce_cli_package_version="$(dpkg -s docker-ce-cli | grep '^Version:' | cut -f 2 -d ' ')"
+            echo "WARNING: docker recommended version available (recommended: $distrib_available_version)" >&2
+            echo "  And your client ($current_docker_ce_cli_package_version) and server ($current_docker_ce_package_version) versions differ." >&2
+        fi
+        echo "  To change version, run this script with ALLOW_DOCKER_CHANGE=1" >&2
+    else
+        echo "WARNING: your docker version does match target recommended version" >&2
+        echo "  And your distribution does not package target version." >&2
+        echo "  - Your distribution: $distro $release" >&2
+        echo "  - Current docker version: $docker_client_version" >&2
+        echo "  - Target recommended version: ${target_version}*" >&2
     fi
+    exit 0
+fi
 
-    if [ -n "$need_restart" ] && [ -z "$NO_DOCKER_RESTART" ]; then
+if [ -z "$distrib_available_version" ]; then
+    echo "ERROR: no docker version matching '${target_version}*' available for your distribution" >&2
+    echo "  Your distribution: $distro $release" >&2
+    echo "  Available versions:" >&2
+    apt-cache madison docker-ce | cut -f 2 -d \| | sed -r 's/^/  -/g' >&2
+    echo
+    echo "  1) You may need to contact your system administrator to upgrade this script." >&2
+    echo "  2) Meanwhile, if you know what you are doing, you can set yourself a target version" >&2
+    echo "     by setting TARGET_DOCKER_VERSION." >&2
+    exit 1
+fi
+
+apt-get install -y --allow-downgrades \
+        docker-ce="$distrib_available_version" \
+        docker-ce-cli="$distrib_available_version" </dev/null &&
+    if [ -z "$NO_DOCKER_RESTART" ]; then
         systemctl daemon-reload &&
             service docker restart
     fi
-fi
+