Merge pull request #15 from matthiasbeyer/add-switch

Add switch

2 files changed, 113 insertions, 0 deletions

diff --git a/nix-script-switch.sh b/nix-script-switch.sh
new file mode 100755
index 0000000..ae1bd93
--- /dev/null
+++ b/nix-script-switch.sh
@@ -0,0 +1,108 @@
+#!/usr/bin/env bash
+
+source $(dirname ${BASH_SOURCE[0]})/nix-utils.sh
+
+CONFIG_DIR=
+
+COMMAND="switch"
+
+usage() {
+    cat <<EOS
+
+    $(help_synopsis "${BASH_SOURCE[0]}" "[-h] [-c <command>] [-g <git command>] -w <working directory> [-- args...]")
+
+        -c <command>    Command for nixos-rebuild. See 'man nixos-rebuild'
+        -g <git cmd>    Alternative git commit, defaults to 'tag -a'
+        -w <path>       Path to your configuration git directory
+        -h              Show this help and exit
+
+        Everything after a double dash (--) will be passed to nixos-rebuild as
+        additional parameters. For example:
+
+            nix-script switch -c switch -- -I nixpkgs=/home/user/pkgs
+
+$(help_end)
+EOS
+}
+
+COMMAND=
+ARGS=
+WD=
+TAG_NAME=
+GIT_COMMAND=
+
+while getopts "c:w:t:h" OPTION
+do
+    case $OPTION in
+        c)
+            COMMAND=$OPTARG
+            stdout "COMMAND = $COMMAND"
+            ;;
+        w)
+            WD=$OPTARG
+            stdout "WD = $WD"
+            ;;
+        t)
+            TAG_NAME=$OPTARG
+            stdout "TAG_NAME = $TAG_NAME"
+            ;;
+
+        g)
+            GIT_COMMAND=$OPTARG
+            stdout "GIT_COMMAND = $GIT_COMMAND"
+            ;;
+
+        h)
+            usage
+            exit 1
+            ;;
+    esac
+done
+
+ARGS=$(echo $* | sed -r 's/(.*)\-\-(.*)/\2/')
+stdout "ARGS = $ARGS"
+
+if [[ -z "$WD" ]]
+then
+    stderr "No configuration git directory."
+    stderr "Won't do anything"
+    exit 1
+fi
+
+if [[ ! -d "$WD" ]]
+then
+    stderr "No directory: $WD"
+    exit 1
+fi
+
+if [[ -z "$COMMAND" ]]
+then
+    COMMAND="switch"
+fi
+
+if [[ -z "$GIT_COMMAND" ]]
+then
+    GIT_COMMAND="tag -a"
+fi
+
+explain sudo nixos-rebuild $COMMAND $ARGS
+REBUILD_EXIT=$?
+
+if [[ $REBUILD_EXIT -eq 0 ]]
+then
+    LASTGEN=$(sudo nix-env -p /nix/var/nix/profiles/system --list-generations |\
+        grep current | cut -d " " -f 2)
+    sudo -k
+
+    if [[ -z "$TAG_NAME" ]]
+    then
+        TAG_NAME="nixos-$LASTGEN-$COMMAND"
+    fi
+
+    explain git --git-dir="$WD/.git" --work-tree="$WD" $GIT_COMMAND "'$TAG_NAME'"
+
+else
+    stderr "Switching failed. Won't executing any further commands."
+    exit $REBUILD_EXIT
+fi
+
diff --git a/nix-utils.sh b/nix-utils.sh
index 49b7b29..3ff20df 100644
--- a/nix-utils.sh
+++ b/nix-utils.sh
@@ -29,6 +29,11 @@ help_end() {
     echo ""
 }
 
+explain() {
+    stdout "$*"
+    $*
+}
+
 grep_generation() {
     $* | grep current | cut -d " " -f 2
 }