api: update/correct add_external_repo and rm_external_repo to fol…

…low debian spec and pi-apps api use

api

@@ -369,27 +369,28 @@ app_to_pkgname() { #given an app-name, convert it to a unique, valid package-nam
   echo "pi-apps-$(echo "$app" | md5sum | cut -c1-8 | awk '{print $1}')"
 }
 
-add_external_repo() { # add an external apt repo and its gpg key
-  repopath="$1"
-  reponame="$2"
-  pubkeyurl="$3"
+add_external_repo() { # add an external apt repo and its gpg key. follows https://wiki.debian.org/DebianRepository/UseThirdParty specification
+  local reponame="$1"
+  # "URI SUITE COMPONENT"
+  local repopath="$2"
+  local pubkeyurl="$5"
 
   # check if all needed vars are set
-  [ -z "$repopath" ] && error "add_external_packages: repopath not set"
-  [ -z "$reponame" ] && error "add_external_packages: reponame not set"
-  [ -z "$pubkeyurl" ] && error "add_external_packages: pubkeyurl not set"
+  [ -z "$repopath" ] && error "add_external_repo: repopath not set"
+  [ -z "$reponame" ] && error "add_external_repo: reponame not set"
+  [ -z "$pubkeyurl" ] && error "add_external_repo: pubkeyurl not set"
 
   # exit if reponame contains space, since apt doesn't accept .list files with spaces in filename or keyname.
   if [[ $reponame = *" "* ]]; then
     error "add_external_repo: provided reponame contains a space."
   fi
 
   # check if links are valid
-  wget -q --spider "$pubkeyurl" || error "add_external_packages: pubkeyurl isn't a valid link"
+  wget -q --spider "$pubkeyurl" || error "add_external_repo: pubkeyurl isn't a valid link"
 
-  # make pi-apps key storage dir if it doesn't exist
+  # make apt keyring directory if it doesn't exist
   if [ ! -d /usr/share/keyrings ]; then
-    sudo mkdir -p /usr/share/keyrings || error "add_external_repo: failed to create pi-apps key storage dir."
+    sudo mkdir -p /usr/share/keyrings || error "add_external_repo: failed to create apt keyring directory."
   fi
 
   # check if .list file already exists
@@ -398,32 +399,31 @@ add_external_repo() { # add an external apt repo and its gpg key
   fi
 
   # download gpg key from specified url
-  if [ -f /usr/share/keyrings/${reponame-keyring.gpg} ]; then
-    sudo rm -f /usr/share/keyrings/${reponame}-keyring.gpg
+  if [ -f /usr/share/keyrings/${reponame}-archive-keyring.gpg ]; then
+    sudo rm -f /usr/share/keyrings/${reponame}-archive-keyring.gpg
   fi 
-  curl -fsSL "$pubkeyurl" | sudo gpg --dearmor -o /usr/share/keyrings/${reponame}-keyring.gpg
+  curl -fsSL "$pubkeyurl" | sudo gpg --dearmor -o /usr/share/keyrings/${reponame}-archive-keyring.gpg
 
   if [ $? != 0 ];then
     sudo rm -f /etc/apt/sources.list.d/${reponame}.list
-    sudo rm -f /usr/share/keyrings/${reponame}-keyring.gpg
+    sudo rm -f /usr/share/keyrings/${reponame}-archive-keyring.gpg
     error "add_external_repo: download from specified pubkeyurl failed."
   fi
 
   # create .list file
-  echo "deb $repopath" | sudo tee /etc/apt/sources.list.d/${reponame}.list >/dev/null
+  echo "deb [signed-by=/usr/share/keyrings/${reponame}-archive-keyring.gpg] $repopath" | sudo tee /etc/apt/sources.list.d/${reponame}.list >/dev/null
 
   if [ $? != 0 ];then
     sudo rm -f /etc/apt/sources.list.d/${reponame}.list
-    sudo rm -f /usr/share/keyrings/${reponame}-keyring.gpg
+    sudo rm -f /usr/share/keyrings/${reponame}-archive-keyring.gpg
     error "add_external_repo: failed to create .list file"
   fi
 }
 
 rm_external_repo() { # remove an external apt repo and its gpg key, if the repo is no longer in use. (force-remove the repo with force argument)
-  # part of this function is modified from the`remove_repofile_if_unused` function.
 
-  reponame="$1"
-  force="$2"
+  local reponame="$1"
+  local force="$2"
 
   [ -z "$reponame" ] && error "rm_external_repo: reponame not provided"
 
@@ -436,29 +436,12 @@ rm_external_repo() { # remove an external apt repo and its gpg key, if the repo
   [ -f "/etc/apt/sources.list.d/$reponame.list" ] || exit 0
 
   if [ "$force" == force ]; then
-    rm -f /usr/share/keyrings/${reponame}-keyring.gpg || error "rm_external_repo: removal of ${reponame}-keyring.gpg failed"
+    rm -f /usr/share/keyrings/${reponame}-archive-keyring.gpg || error "rm_external_repo: removal of ${reponame}-archive-keyring.gpg failed"
     sudo rm -f /etc/apt/sources.list.d/${reponame}.list || error "rm_external_repo: removal of ${reponame}.list failed"
     exit 0
   fi
 
-  # determine what repo-urls are in the file
-  local urls="$(cat "/etc/apt/sources.list.d/$reponame.list" | grep -v '^#' | tr ' ' '\n' | grep '://')"
-
-  # there could be multiple urls in one file. Check each url and set the in_use variable to 1 if any packages are found
-  local IFS=$'\n'
-  local in_use=0
-  local url
-  for url in $urls ; do
-    if anything_installed_from_repo "$url" >/dev/null; then
-      in_use=1
-      break
-    fi
-  done
-
-  if [ "$in_use" == 0 ]; then
-    status "Removing the $reponame repo as it is not being used"
-    sudo rm -f "/etc/apt/sources.list.d/$reponame.list"
-  fi
+  remove_repofile_if_unused /etc/apt/sources.list.d/${reponame}.list "" /usr/share/keyrings/${reponame}-archive-keyring.gpg
 }
 
 install_packages() { #Make some packages dependencies of the $app app. Package-names, regex, filenames, and urls are supported.