better logic

autodeploy/download.sh

@@ -20,6 +20,7 @@ Optional arguments:
 EOF
 }
 
+
 ARCHIVE=""
 BINARY=""
 POSITIONAL_ARGS=()
@@ -67,66 +68,75 @@ URL="${POSITIONAL_ARGS[0]}"
 #echo "binary:  $BINARY"
 
 
-function ensure_binary() {
+function download() {
     local url=$1
     local archive=$2
     local binary=$3
 
-    if [ -f "$binary" ]; then
-        echo "File $binary exists already"
+    if check_meta "$url" "$archive"; then
+        echo "Skipping download $url"
         return
     fi
 
-    update "$url" "$archive"
+    echo "Downloading $url ..."
+    rm "$archive" "$binary" || true
+    curl --location --silent --show-error --remote-time --output "$archive" "$url"
     tar xzf "$archive"
 }
 
-function update() {
-    local url=$1
-    local archive=$2
 
-    if ! check_file_sizes "$url" "$archive"; then
-        echo "Downloading $url (if remote is newer) ..."
-        curl --location --remote-time --time-cond "$archive" --output "$archive" "$url"
-    else
-        echo "Skipped download $url"
-    fi
-}
-
-function check_file_sizes() {
+function check_meta() {
     local url=$1
     local fn=$2
-    local local_size remote_size
+
+    local local_meta remote_meta
 
     if [ ! -f "$fn" ]; then
         echo "File $fn not found"
         return 1
     fi
 
-    local_size=$(get_local_file_size "$fn")
-    remote_size=$(get_remote_file_size "$url")
+    local_meta=$(get_local_meta "$fn")
+    remote_meta=$(get_remote_meta "$url")
 
-    if [ "$remote_size" -ne "$local_size" ]; then
-        echo "Remote and local size of file $fn differs (remote: $remote_size, local: $local_size)"
+    if [ "$remote_meta" != "$local_meta" ]; then
+        echo "Remote and local meta data of file $fn differ (remote: $remote_meta, local: $local_meta)"
         return 1
+    else
+        echo "Remote and local meta data of file $fn are identical ($remote_meta)"
+        return 0
     fi
-
-    echo "Remote and local size of file $fn is identical"
-    return 0
 }
 
-function get_local_file_size() {
+
+function get_local_meta() {
     local fn=$1
-    stat --format="%s" "$fn"
+    stat --format "s:%s|t:%Y" "$fn"
 }
 
-function get_remote_file_size() {
+function get_remote_meta() {
     local url=$1
-    curl --location --head --silent "$url" | grep -i "content-length" | tail -n 1 | cut -d ' ' -f 2 | tr -d '\r'
+    header=$(get_header "$url")
+    size=$(extract_from "$header" "content-length")
+    time=$(extract_from "$header" "last-modified")
+    time=$(date --date "$time" +%s)
+    echo "s:$size|t:$time"
+}
+
+function get_header() {
+    local url=$1
+    curl --head --location --silent --show-error "$url"
+}
+
+function extract_from() {
+    local header=$1
+    local entry=$2
+    echo "$header" | grep "^${entry}:" | tail -n 1 | cut -d ' ' -f 2- | tr -d "\r"
 }
 
 
-ensure_binary "$URL" "$ARCHIVE" "$BINARY"
+
+download "$URL" "$ARCHIVE" "$BINARY"