snap: use adopt-info to set grade and version

adopt-info is a snapcraft feature that allows us to specify the snap grade and
version at runtime. Depending on the environment the master or the latest
stable branch can be used to build the Kata Containers snap, for the kata
CI and launchpad snap-master branch, the master branch are used, otherwise
the latest stable branch.

Signed-off-by: Julio Montes <julio.montes@intel.com>

snap/snapcraft.yaml

@@ -1,16 +1,39 @@
 name: kata-containers
-version: "master"
 summary: Build lightweight VMs that seamlessly plug into the containers ecosystem
 description: |
   Kata Containers is an open source project and community working to build a
   standard implementation of lightweight Virtual Machines (VMs) that feel and
   perform like containers, but provide the workload isolation and security
   advantages of VMs
-grade: stable
 confinement: classic
+adopt-info: metadata
 
 parts:
+  metadata:
+    plugin: nil
+    prime:
+      - -*
+    build-packages:
+      - git
+      - git-extras
+    override-pull: |
+      branch="master"
+
+      # kata CI or launchpad snap-master
+      if [ "${CI}" = "true" ] || echo "${SNAPCRAFT_IMAGE_INFO}" | egrep -o "build_url.*" | grep  -q "${branch}"; then
+        snapcraftctl set-grade "devel"
+      else
+        # Get the latest stable version
+        runtime_url="https://github.com/kata-containers/runtime"
+        branch=$(git ls-remote --tags ${runtime_url}  | egrep -o "refs.*" | egrep -v "\-alpha|\-rc|{}" | cut -d/ -f3 | sort -r | head -1)
+        snapcraftctl set-grade "stable"
+      fi
+
+      snapcraftctl set-version "${branch}"
+      echo "${branch}" | tee ${SNAPCRAFT_STAGE}/kata_version
+
   yq:
+    after: [metadata]
     plugin: nil
     prime:
       - -*
@@ -41,8 +64,9 @@ parts:
   go:
     after: [yq]
     override-build: |
+      kata_version=$(cat ${SNAPCRAFT_STAGE}/kata_version)
       yq=$(realpath ../../yq/build/yq)
-      versions_url=https://raw.githubusercontent.com/kata-containers/runtime/${SNAPCRAFT_PROJECT_VERSION}/versions.yaml
+      versions_url=https://raw.githubusercontent.com/kata-containers/runtime/${kata_version}/versions.yaml
       version="$(curl -sSL ${versions_url} | ${yq} r - languages.golang.version)"
       curl -LO https://dl.google.com/go/go${version}.src.tar.gz
       tar -xf go${version}.src.tar.gz --strip-components=1
@@ -60,6 +84,7 @@ parts:
     plugin: nil
     build-attributes: [no-patchelf]
     override-build: |
+      kata_version=$(cat ${SNAPCRAFT_STAGE}/kata_version)
       pkg_name=runtime
 
       # set GOPATH
@@ -71,7 +96,7 @@ parts:
       mkdir -p ${pkg_gopath}
 
       # download source
-      git clone -b ${SNAPCRAFT_PROJECT_VERSION} https://github.com/kata-containers/${pkg_name} ${pkg_gopath}
+      git clone -b ${kata_version} https://github.com/kata-containers/${pkg_name} ${pkg_gopath}
       cd ${pkg_gopath}
 
       # build and install
@@ -98,6 +123,7 @@ parts:
     plugin: nil
     build-attributes: [no-patchelf]
     override-build: |
+      kata_version=$(cat ${SNAPCRAFT_STAGE}/kata_version)
       pkg_name=proxy
 
       # set GOPATH
@@ -109,7 +135,7 @@ parts:
       mkdir -p ${pkg_gopath}
 
       # download source
-      git clone -b ${SNAPCRAFT_PROJECT_VERSION} https://github.com/kata-containers/${pkg_name} ${pkg_gopath}
+      git clone -b ${kata_version} https://github.com/kata-containers/${pkg_name} ${pkg_gopath}
       cd ${pkg_gopath}
 
       # build and install
@@ -121,6 +147,7 @@ parts:
     plugin: nil
     build-attributes: [no-patchelf]
     override-build: |
+      kata_version=$(cat ${SNAPCRAFT_STAGE}/kata_version)
       pkg_name=shim
 
       # set GOPATH
@@ -132,7 +159,7 @@ parts:
       mkdir -p ${pkg_gopath}
 
       # download source
-      git clone -b ${SNAPCRAFT_PROJECT_VERSION} https://github.com/kata-containers/${pkg_name} ${pkg_gopath}
+      git clone -b ${kata_version} https://github.com/kata-containers/${pkg_name} ${pkg_gopath}
       cd ${pkg_gopath}
 
       # build and install
@@ -192,6 +219,7 @@ parts:
     plugin: nil
     build-attributes: [no-patchelf]
     override-build: |
+      kata_version=$(cat ${SNAPCRAFT_STAGE}/kata_version)
       pkg_name=ksm-throttler
 
       # set GOPATH
@@ -203,7 +231,7 @@ parts:
       mkdir -p ${pkg_gopath}
 
       # download source
-      git clone -b ${SNAPCRAFT_PROJECT_VERSION} https://github.com/kata-containers/${pkg_name} ${pkg_gopath}
+      git clone -b ${kata_version} https://github.com/kata-containers/${pkg_name} ${pkg_gopath}
       cd ${pkg_gopath}
 
       # build and install
@@ -280,11 +308,12 @@ parts:
       - libcapstone-dev
       - bc
     override-build: |
+      kata_version=$(cat ${SNAPCRAFT_STAGE}/kata_version)
       yq=$(realpath ../../yq/build/yq)
       pkg_name="qemu"
       configs_dir="${SNAPCRAFT_STAGE}/qemu/default-configs"
 
-      versions_url=https://raw.githubusercontent.com/kata-containers/runtime/${SNAPCRAFT_PROJECT_VERSION}/versions.yaml
+      versions_url=https://raw.githubusercontent.com/kata-containers/runtime/${kata_version}/versions.yaml
       # arch-specific definition
       case "$(uname -m)" in
         "aarch64")