new: timezone is fixed for containers

We prefer to create a file with the ``/etc/timezone`` information
in our own file directory to be shared read-only with containers.

Signed-off-by: Valentin Lab <valentin.lab@kalysto.org>

bin/compose

@@ -259,15 +259,26 @@ relink_subdirs() {
 
 mk_docker_run_options() {
 
-    docker_run_opts=("-v" "/var/run/docker.sock:/var/run/docker.sock")
+    ## Order matters, files get to override vars
+    compose_config_files=(
+        ## DEFAULT LINUX VARS
+        /etc/default/charm
+        /etc/default/datastore
+        /etc/default/compose
 
-    ## CACHE/DATA DIRS
-    docker_run_opts+=("-v" "$COMPOSE_VAR:/var/lib/compose")
-    docker_run_opts+=("-v" "$COMPOSE_CACHE:/var/cache/compose")
+        ## COMPOSE SYSTEM-WIDE FILES
+        /etc/compose.conf
+        /etc/compose.local.conf
+        /etc/compose/local.conf
 
-    docker_run_opts+=("-v" "$TZ_PATH:/etc/timezone:ro")
+        ## COMPOSE USER FILES
+        ~/.compose/etc/local.conf
+        ~/.compose.conf
+    )
 
 
+    docker_run_opts=("-v" "/var/run/docker.sock:/var/run/docker.sock")
+
     ## current dir
     if parent=$(while true; do
                     [ -e "./compose.yml" ] && {
@@ -301,6 +312,41 @@ mk_docker_run_options() {
     fi
 
 
+    COMPOSE_LOCAL_ROOT=${COMPOSE_LOCAL_ROOT:-"$HOME/.compose"}
+
+    case "$(get_os)" in
+        linux)
+            if [ "$UID" == 0 ]; then
+                COMPOSE_VAR=${COMPOSE_VAR:-/var/lib/compose}
+                COMPOSE_CACHE=${COMPOSE_CACHE:-/var/cache/compose}
+            else
+                COMPOSE_VAR="$COMPOSE_LOCAL_ROOT"/lib
+                COMPOSE_CACHE="$COMPOSE_LOCAL_ROOT"/cache
+            fi
+            ;;
+        mac)
+            COMPOSE_VAR=${COMPOSE_VAR:-"$COMPOSE_LOCAL_ROOT"/lib}
+            COMPOSE_CACHE=${COMPOSE_CACHE:-"$COMPOSE_LOCAL_ROOT"/cache}
+            ;;
+        *)
+            echo "System '$os' not supported yet." >&2
+            exit 1
+            ;;
+    esac
+
+
+    ## get TZ value and prepare TZ_PATH
+    TZ=$(get_tz) || exit 1
+    mkdir -p "${COMPOSE_VAR}/timezones"
+    TZ_PATH="${COMPOSE_VAR}/timezones/$(e "$TZ" | sha256sum | cut -c 1-8)" || exit 1
+    [ -e "$TZ_PATH" ] || e "$TZ" > "$TZ_PATH"
+
+    ## CACHE/DATA DIRS
+    docker_run_opts+=("-v" "$COMPOSE_VAR:/var/lib/compose")
+    docker_run_opts+=("-v" "$COMPOSE_CACHE:/var/cache/compose")
+
+    docker_run_opts+=("-v" "$TZ_PATH:/etc/timezone:ro")
+
     ##
     ## Checking vars
     ##
@@ -397,42 +443,47 @@ mk_docker_run_options() {
 }
 
 
-run() {
-    local os docker_run_opts
-
-    ## Order matters, files get to override vars
-    compose_config_files=(
-        /etc/default/charm
-        /etc/default/datastore
-        /etc/compose.conf
-        /etc/compose.local.conf
-        /etc/default/compose
-        ~/.compose/etc/local.conf
-        /etc/compose/local.conf
-    )
+get_tz() {
+    if [ -n "$TZ" ]; then
+        :
+    elif [ -n "$COMPOSE_LOCAL_ROOT" ] &&  ## previous compose run
+           [ -e "$COMPOSE_LOCAL_ROOT/etc/timezone" ]; then
+        read -r TZ < /etc/timezone
+    elif [ -e "/etc/timezone" ]; then  ## debian host system timezone
+        read -r TZ < /etc/timezone
+    elif [ -e "/etc/localtime" ]; then  ## redhat and macosx sys timezone
+        local fullpath dirname
+        fullpath="$(readlink -f /etc/localtime)"
+        dirname="${fullpath%/*}"
+        TZ=${TZ:-${fullpath##*/}/${dirname##*/}}
+    else
+        err "Timezone not found nor inferable !"
+        echo "   compose relies on '/etc/timezone' or '/etc/localtime' to be present " >&2
+        echo "   so as to ensure same timezone for all containers that need it." >&2
+        echo >&2
+        echo "   You can set a default value for compose by create issuing:" >&2
+        echo >&2
+        if [ -n "$COMPOSE_LOCAL_ROOT" ] && [ "$UID" != 0 ]; then
+            echo "      mkdir -p $COMPOSE_LOCAL_ROOT/etc &&" >&2
+            echo "      echo \"Europe/Paris\" > $COMPOSE_LOCAL_ROOT/etc/timezone" >&2
+        else
+            echo "      echo \"Europe/Paris\" > /etc/timezone" >&2
+        fi
+        echo >&2
+        echo "   Of course, you can change 'Europe/Paris' value by any other valid timezone." >&2
+        echo "   timezone." >&2
+        echo >&2
+        echo "   Notice you can also use \$TZ environment variable, but the value" >&2
+        echo "   will be necessary each time you launch compose." >&2
+        echo >&2
+        return 1
+    fi
+    e "$TZ"
+}
 
-    os=$(get_os)
-    case "$os" in
-        linux)
-            COMPOSE_VAR=/var/lib/compose
-            COMPOSE_CACHE=/var/cache/compose
-            TZ_PATH=/etc/timezone
-            ;;
-        mac)
-            if ! [ -e "$HOME/.compose/etc/timezone" ]; then
-                TZ=${TZ:-"Europe/Paris"}
-                echo "$TZ" > "$HOME"/.compose/etc/timezone
-            fi
-            TZ_PATH="$HOME"/.compose/etc/timezone
-            COMPOSE_VAR="$HOME"/.compose/lib
-            COMPOSE_CACHE="$HOME"/.compose/cache
-            ;;
-        *)
-            echo "System '$os' not supported yet." >&2
-            exit 1
-            ;;
-    esac
 
+run() {
+    local os docker_run_opts
 
     docker_run_opts=()
     if [ -z "$COMPOSE_LAUNCHER_OPTS" ]; then