new: [vps] add ``upgrade postgres`` action

bin/vps

@@ -2380,6 +2380,110 @@ cmdline.spec:mongo:cmd:upgrade:run() {
 }
 
 
+cmdline.spec.gnu postgres
+
+cmdline.spec::cmd:postgres:run() {
+    :
+}
+
+cmdline.spec.gnu upgrade
+cmdline.spec:postgres:cmd:upgrade:run() {
+
+    : :posarg: [TARGET_VERSION]  "Target version to migrate to"
+    : :optval: --service,-s      "The postgre service name (defaults to 'postgres')"
+    : :optfla: --debug,-d        "Display debugging information"
+
+    local URL
+
+    depends yq
+
+    postgres_service="${opt_service:-postgres}"
+    available_actions=$(compose --get-available-actions) || exit 1
+    available_actionable_services=($(e "$available_actions" | yq 'keys().[]'))
+    if [[ " ${available_actionable_services[*]} " != *" $postgres_service "* ]]; then
+        err "Service '$postgres_service' was not found in current 'compose.yml'."
+        exit 1
+    fi
+    opts_compose=()
+    if [ -n "$opt_debug" ]; then
+        opts_compose+=("--debug")
+    else
+        opts_compose+=("-q")
+    fi
+
+    project_name=$(compose:project_name) || exit 1
+    containers=($(compose:service:containers "${project_name}" "${postgres_service}")) || exit 1
+
+    ## XXXvlab: quick hack, to make more beautiful later
+    cron_container=$(compose:service:containers "${project_name}" "cron")
+    containers+=("$cron_container")
+    docker stop "$cron_container" >/dev/null 2>&1 || true
+
+    before_version=
+    uptodate=
+    upgraded=
+    msgerr=()
+    while read-0a-err errlvl line; do
+        echo "$line"
+        rline=$(printf "%s" "$line" | sed_compat "s/$__color_sequence_regex//g")
+        case "$rline" in
+            "II Current postgres version: "*)
+                before_version="${rline#II Current postgres version: }"
+                ;;
+            "II ${postgres_service} is already up-to-date.")
+                if [ -z "$before_version" ]; then
+                    msgerr+=("expected a 'current version' line before the 'up-to-date' one.")
+                    continue
+                fi
+                after_version="$before_version"
+                uptodate=1
+                ;;
+            "II Successfully upgraded from ${before_version} to "*)
+                after_version="${rline#II Successfully upgraded from ${before_version} to }"
+                upgraded=1
+                ;;
+            *)
+                :
+                ;;
+        esac
+    done < <(
+        ## -q to remove the display of ``compose`` related information
+        ##    like relation resolution.
+        ## -c on the upgrade action to force color
+        ansi_color=yes p-0a-err compose -q -c "${opts_compose[@]}" upgrade "$postgres_service" --no-hint -c "$TARGET_VERSION" 2>&1
+    )
+
+    if [ "$errlvl" != 0 ]; then
+        exit "$errlvl"
+    fi
+    if [ -n "$uptodate" ]; then
+        for container in "${containers[@]}"; do
+            [ -n "$container" ] || continue
+            Wrap -d "start ${DARKYELLOW}${postgres_service}${NORMAL}'s container" -- \
+                 docker start "$container" || {
+                err "Failed to start container '$container'."
+                exit 1
+            }
+        done
+        exit 0
+    fi
+    if [ -z "$upgraded" ]; then
+        err "Unexpected output of 'upgrade' action with errorlevel 0 and without success"
+        exit 1
+    fi
+
+    desc="update \`compose.yml\` to set ${DARKYELLOW}$postgres_service${NORMAL}'s "
+    desc+="docker image to actual code version ${WHITE}${after_version}${NORMAL}"
+    Wrap -d "$desc" -- \
+         compose:file:value-change \
+         "${postgres_service}.docker-compose.image" \
+         "docker.0k.io/postgres:${after_version}-myc" || exit 1
+
+    echo "${WHITE}Launching final compose${NORMAL}"
+    compose up || exit 1
+}
+
+
 
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