Update to the cookbook syncer (#244)

Summary:
The syncer would silently overwrite your cli or env options
with a config file in a way that was confusing.

This properly handles an expected hierarchy of:
default -> config -> env -> cli

Also, the vim modeline was set to 2-space indentation, but the code
was 4-space, so update the code to match the vim modeline.

Signed-off-by: Phil Dibowitz <phil@ipom.com>

Pull Request resolved: #244

Test Plan:
Imported from GitHub, without a `Test Plan:` line.

Note: we don't use this script internally, it's for the benefit of our downstream open-source users (like Phil)

Differential Revision: D65949355

fbshipit-source-id: e49c3f519bdc0e80dfd3fa0c492139775ac86ed1

scripts/sync_fb_cookbooks.sh

@@ -21,44 +21,50 @@
 
 set -u
 
-# constants
-CONF="$HOME/.config/sync_fb_cookbooks.conf"
-
 # defaults
-upstreamdir="$HOME/src/chef-cookbooks"
-internaldir="$HOME/src/chef"
+config="$HOME/.config/sync_fb_cookbooks.conf"
+default_upstreamdir="$HOME/src/chef-cookbooks"
+default_internaldir="$HOME/src/chef"
 
 # methods
 error() {
-    echo "ERROR: $*"
+  echo "ERROR: $*"
 }
 
 warn() {
-    echo "WARNING: $*"
+  echo "WARNING: $*"
+}
+
+info() {
+  echo "INFO: $*"
 }
 
 die() {
-    error "$@"
-    exit 1
+  error "$@"
+  exit 1
 }
 
 ourhelp() {
-    cat <<EOF
+  cat <<EOF
 Usage: $0 [<options>]
 
 OPTIONS
     -c <cookbook>
         Compare just <cookbook>
 
+    -C <config_file>
+        Path to config file
+        Default: $config
+
     -d
-        Diff mode.
+        Diff mode
 
     -h
-        This.
+        This
 
     -i <dir>
-        Where your clone of the INTERNAL repo is.
-        Default: $internaldir
+        Where your clone of the INTERNAL repo is
+        Default: $default_internaldir
 
     -p
         Push changes internal -> upstream
@@ -67,11 +73,11 @@ OPTIONS
         Sync changes upstream -> internal
 
     -u <dir>
-        Where your clone of the UPSTREAM repo is.
-        Default: $internaldir
+        Where your clone of the UPSTREAM repo is
+        Default: $default_internaldir
 
 CONFIG FILE
-You can also tell this script where your repos are by creating $CONF
+You can also tell this script where your repos are by creating $config
 in shell format and defining 'upstreamdir' and 'internaldir', like so:
 
     upstreamdir="\$HOME/mycheckouts/chef-cookbooks"
@@ -94,75 +100,102 @@ GENERAL USAGE
 
     # OR.... push out internal changes
     $ $0 -c fb_sysfs -p
-
 EOF
 }
 
-# people put repos in different places, don't make them pass in
-# -u and -i every time.
-if [ -e "$CONF" ]; then
-    # shellcheck disable=SC1090
-    source "$CONF" || die "Configuration file $CONF malformed"
-fi
-
 mode=''
 cookbook=''
-while getopts c:dhi:psu: opt; do
-    case $opt in
-        c)
-            cookbook="$OPTARG"
-            ;;
-        d)
-            mode='diff'
-            ;;
-        h)
-            ourhelp
-            exit
-            ;;
-        i)
-            internaldir="$OPTARG"
-            ;;
-        p)
-            mode='push'
-            ;;
-        s)
-            mode='sync'
-            ;;
-        u)
-            upstreamdir="$OPTARG"
-            ;;
-        ?)
-            ourhelp
-            exit 1
-            ;;
-    esac
+while getopts 'c:C:dhi:psu:' opt; do
+  case $opt in
+    c)
+      cookbook="$OPTARG"
+      ;;
+    C)
+      config="$OPTARG"
+      ;;
+    d)
+      mode='diff'
+      ;;
+    h)
+      ourhelp
+      exit
+      ;;
+    i)
+      internaldir="$OPTARG"
+      ;;
+    p)
+      mode='push'
+      ;;
+    s)
+      mode='sync'
+      ;;
+    u)
+      upstreamdir="$OPTARG"
+      ;;
+    ?)
+      ourhelp
+      exit 1
+      ;;
+  esac
 done
 
+# save what was passed in either through env
+# or command-line...
+save_internaldir=""
+save_upstreamdir=""
+if [ -n "$internaldir" ]; then
+  save_internaldir="$internaldir"
+fi
+if [ -n "$upstreamdir" ]; then
+  save_upstreamdir="$upstreamdir"
+fi
+
+# initialize with defaults
+internaldir="$default_internaldir"
+upstreamdir="$default_upstreamdir"
+
+# now read the config file, if we have one
+if [ -e "$config" ]; then
+  # shellcheck disable=SC1090
+  info "Loading config from $config"
+  source "$config" || die "Configuration file $config malformed"
+fi
+
+# Now merge in passed-in config
+if [ -n "$save_internaldir" ]; then
+  internaldir="$save_internaldir"
+fi
+if [ -n "$save_upstreamdir" ]; then
+  upstreamdir="$save_upstreamdir"
+fi
+
+info "Using upstream: $upstreamdir | internal: $internaldir"
+
 if [ -z "$mode" ]; then
-    if [ -n "$cookbook" ]; then
-        mode='diff'
-    else
-        mode='status'
-    fi
+  if [ -n "$cookbook" ]; then
+    mode='diff'
+  else
+    mode='status'
+  fi
 fi
 
 cd "$internaldir/cookbooks" || die "where am I?"
 [ -z "$cookbook" ] && cookbook="$(ls -d fb_*)"
 for cb in $cookbook; do
-    ours="$cb/"
-    upstream="$upstreamdir/cookbooks/$cb/"
-    if [ "$cb" = 'fb_init' ]; then
-        upstream="$upstreamdir/cookbooks/fb_init_sample/"
-    fi
-    if [ "$mode" = 'status' ]; then
-        diff -Nru "$ours" "$upstream" &>/dev/null || echo "$cb does not match"
-    elif [ "$mode" = 'diff' ]; then
-        diff -Nru "$ours" "$upstream"
-    elif [ "$mode" = 'push' ]; then
-        rsync -avz "$ours" "$upstream"
-    elif [ "$mode" = 'sync' ]; then
-        rsync -avz "$upstream" "$ours"
-    else
-        die "wut? wut mode is '$mode'"
-    fi
+  ours="$cb/"
+  upstream="$upstreamdir/cookbooks/$cb/"
+  if [ "$cb" = 'fb_init' ]; then
+    upstream="$upstreamdir/cookbooks/fb_init_sample/"
+  fi
+  if [ "$mode" = 'status' ]; then
+    diff -Nru "$ours" "$upstream" &>/dev/null || echo "$cb does not match"
+  elif [ "$mode" = 'diff' ]; then
+    diff -Nru "$ours" "$upstream"
+  elif [ "$mode" = 'push' ]; then
+    rsync -avz "$ours" "$upstream"
+  elif [ "$mode" = 'sync' ]; then
+    rsync -avz "$upstream" "$ours"
+  else
+    die "wut? wut mode is '$mode'"
+  fi
 done