Add upgrade feature

test.sh

@@ -21,7 +21,7 @@ cp ubernerd.sh /tmp/ubernerd-test/
 # Test ubernerd installation inside a container with systemd init enabled
 docker run -d --name ubernerd-test --privileged -v /tmp/ubernerd-test:/root/ubernerd-test -w /root/ubernerd-test --rm almalinux/9-init
 # Create the symlink, to test running from a different working directory
-docker exec -e CREATE_SYMLINK=1 ubernerd-test ./ubernerd.sh
+docker exec -e CREATE_SYMLINK=1 -e UBERNERD_UPGRADE=1 ubernerd-test ./ubernerd.sh
 
 # Use -w to run from a different working directory to test the symlink
 # Use --network=host because there is no iptables in this image

ubernerd.sh

@@ -5,6 +5,9 @@ set -euo pipefail
 # Set the CREATE_SYMLINK environment variable to 1 to make the nerdctl command available globally
 # This will modify the host rootfs
 CREATE_SYMLINK="${CREATE_SYMLINK:-0}"
+UBERNERD_UPGRADE="${UBERNERD_UPGRADE:-0}"
+# TODO: allow a configurable namespace (default ubernerd) to prevent possible clashes on the filesystem
+# with regards to the service file and socket path etc.
 
 absolute_script_path="$(realpath "${BASH_SOURCE[0]}")"
 script_name=$(basename "${absolute_script_path}")
@@ -101,13 +104,62 @@ for dir_name in "${dir_list[@]}"; do
  mkdir -p --verbose "$dir_name"
 done
 
-# Check if containerd and nerdctl inside nerdctl_full, else download and extract latest release
-# TODO: Update/upgrade logic: currently ubernerd only installs latest version once, and sticks to that version
+download_nerdctl(){
+ arch=$(uname -m)
 
+ if [[ $arch == "x86_64" ]]; then
+ arch=amd64
+ echo "Detected $arch architecture, downloading $arch version..."
+ else
+ arch=arm64
+ echo "Assuming $arch architecture, downloading $arch version..."
+ fi
+
+ download_url="$(download 'https://api.github.com/repos/containerd/nerdctl/releases/latest' | mygrep 'nerdctl-full-' | mygrep "-linux-$arch.tar.gz" | mygrep 'browser_download_url' | cut -d '"' -f 4)"
+
+ echo ''
+ echo "Downloading $download_url..."
+ download "$download_url" | tar -xz -C 'nerdctl_full'
+}
+
+
+# TODO: only download from api.github.com once...
+
+needs_download=0
+
+# Check if containerd and nerdctl inside nerdctl_full, else download and extract latest release
+# If UBERNERD_UPGRADE is enabled, check if upgrade is available too
 if [[ -f 'nerdctl_full/bin/containerd' && -f 'nerdctl_full/bin/nerdctl' ]]; then
  echo ''
- echo 'Found containerd and nerdctl inside nerdctl_full directory (no need to download).'
+ echo 'Found containerd and nerdctl inside nerdctl_full directory.'
+
+ if [[ "$UBERNERD_UPGRADE" -eq 1 ]]; then
+ echo "Check if upgrade is available..."
+ local_version="$(nerdctl_full/bin/nerdctl version -f '{{.Client.Version}}' 2>/dev/null)" || true
+
+ string="$(download 'https://api.github.com/repos/containerd/nerdctl/releases/latest' | mygrep '"tag_name":')"
+ pattern='v([0-9]+\.?)+'
+ [[ $string =~ $pattern ]]
+ remote_version="${BASH_REMATCH[0]}"
+
+ if [[ "$remote_version" != "$local_version" ]]; then
+ echo "Need to upgrade to: $remote_version".
+ needs_download=1
+ old_nerdctl_full="nerdctl_full_$local_version"
+
+ echo "Backing up current installation to $old_nerdctl_full"
+ mv nerdctl_full "$old_nerdctl_full"
+ mkdir nerdctl_full
+ else
+ echo "Already using the latest version: $remote_version".
+ fi
+ fi
+
 else
+ needs_download=1
+fi
+
+if [[ "$needs_download" -eq 1 ]]; then
  echo ''
  echo 'Need to download latest release of nerdctl...'
 
@@ -125,21 +177,7 @@ else
  fail "$manualy_download_extract_message"
  fi
 
- arch=$(uname -m)
-
- if [[ $arch == "x86_64" ]]; then
- arch=amd64
- echo "Detected $arch architecture, downloading $arch version..."
- else
- arch=arm64
- echo "Assuming $arch architecture, downloading $arch version..."
- fi
-
- download_url="$(download 'https://api.github.com/repos/containerd/nerdctl/releases/latest' | mygrep 'nerdctl-full-' | mygrep "-linux-$arch.tar.gz" | mygrep 'browser_download_url' | cut -d '"' -f 4)"
-
- echo ''
- echo "Downloading $download_url..."
- download "$download_url" | tar -xz -C 'nerdctl_full'
+ download_nerdctl
 fi
 
 # TODO: To support the opt plugin, the path variable needs to be dynamically set to a path