new: [docker-updater] new charm.

precise/docker-updater/README

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+
+
+Unfinished because untested. But, the script docker-updater is
+tested and used.
+
+
+This LXC requires a kernel >3.8 at least. (to be able to run docker in
+LXC) It requires also "aufs" capabilities (apparmor.d permission, but
+also available in kernel)
+
+XXXvlab: we could run docker in LXC via a socket towards an host's
+install of docker and remove this constraint.
+
+
+It is meant to build image of applications based on a single git-sub
+code.
+
+It provides an IMAGE that does not requires 'git' tool, and won't
+contain any git history.
+
+Then, it'll be able to update this image by small "docker commits"
+quite efficiently.
+
+
+Currently the image produced can only be run on docker host that
+support running aufs in the containers (this implies, that the docker
+fs driver IS NOT aufs, that the host kernel support aufs, and that
+permissions are set so that container can mount an aufs filesystem).

precise/docker-updater/config

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+lxc.aa_profile = unconfined

precise/docker-updater/hooks/install

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+#!/bin/bash
+
+set -eux # -x for verbose logging to juju debug-log
+
+##
+## Init.d and defaults running options
+##
+
+cp src/usr/local/sbin/* src/usr/local/sbin/
+

precise/docker-updater/hooks/start

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+#!/bin/bash
+
+juju-log "Nothing to Start for base."

precise/docker-updater/hooks/stop

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+#!/bin/bash
+
+juju-log "Nothing to stop for base."

precise/docker-updater/metadata.yaml

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+name: docker-updater
+summary: "Docker Updater"
+maintainer: "Valentin Lab <valentin.lab@kalysto.org>"
+inherit: docker
+description: |
+    Docker Updater
+data-resources:
+  - /var/lib/docker
+  - /srv/docker-updates

precise/docker-updater/revision

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+0

precise/docker-updater/src/usr/local/bin/docker-update

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+#!/bin/bash
+
+
+#!-
+. /etc/shlib
+#!-
+
+
+DOCKER_UPDATE_PATH=${DOCKER_UPDATE_PATH:-/srv/docker-updates}
+
+
+include common
+include pretty
+
+usage="$exname COMPONENT MASTER_IMAGE_NAME BRANCH UPDATED_IMAGE_NAME"
+
+
+COMPONENT_NAME="$1"
+MASTER_IMAGE_NAME="$2"
+BRANCH="$3"
+UPDATED_IMAGE_NAME="$4"
+
+## Note: we will need in the DOCKER_UPDATE_HOST:
+##  - git-sub
+
+## should we check for aufs ?
+
+mkdir -p "$DOCKER_UPDATE_PATH"
+cd "$DOCKER_UPDATE_PATH"
+if ! [ -d "$COMPONENT_NAME" ]; then
+   echo "ERROR: repository $DOCKER_UPDATE_PATH//$COMPONENT_NAME is not existent."
+   echo "You should build it on this host prior to run this hook."
+   echo "As a remainder: this host is supposed to keep the reference git that"
+   echo "was used to built the master image."
+   exit 1
+fi
+
+if [ -e "$COMPONENT_NAME.locked" ]; then
+   echo "Master is being updated."
+   echo "Or '$COMPONENT_NAME.locked' file was left dangling over."
+   exit 1
+fi
+
+
+clean_all() {
+   cd /
+   mountpoint "$tmpdir_root" 2>/dev/null && umount "$tmpdir_root"
+   [ -d "$tmpdir_root" ] && rmdir "$tmpdir_root"
+   [ -d "$tmpdir_changes" ] && rm -rf "$tmpdir_changes"
+}
+
+tmpdir_changes=$(mktemp -d /tmp/$COMPONENT_NAME.changes.XXXXXX)
+tmpdir_root=$(mktemp -d /tmp/$COMPONENT_NAME.root.XXXXXX)
+
+trap "clean_all" EXIT
+mount -t aufs -o br=$tmpdir_changes:$DOCKER_UPDATE_PATH/$COMPONENT_NAME -o udba=none  none "$tmpdir_root"
+cd "$tmpdir_root"
+
+## XXXvlab: We probably would need to:
+##   - fetch only the module concerned
+##   - fetch only the ref concerned
+git fetch origin "$BRANCH"
+git checkout "$BRANCH"
+git sub update
+
+cd / &&
+umount "$tmpdir_root" &&
+rmdir "$tmpdir_root"
+if [ "$?" != 0 ]; then
+    echo "Uh oh... could not umount aufs $tmpdir_root or delete it."
+    exit 1
+fi
+cd "$tmpdir_changes"
+
+echo "Cleaning the change layer."
+find  . -name .git -type d -exec  rm -rf {} \; -prune
+
+## XXXvlab: if we produced it we shouldn't have to pull it
+echo "Pulling $MASTER_IMAGE_NAME"
+docker pull "$MASTER_IMAGE_NAME" >/dev/null 2>&1
+
+container_id=$(docker run -d \
+    -v $tmpdir_changes:/mnt/changes \
+    "$MASTER_IMAGE_NAME" \
+    /bin/bash -c "
+        mkdir -p /srv/app/{root,changes}
+        cp -a /mnt/changes /srv/app/changes/0000
+        ls /srv/app/changes/0000
+    ")
+
+if [ "$(docker wait "$container_id")" != "0" ]; then
+    echo "Copy of changes to docker images failed !"
+    echo "Log of container:"
+    docker logs $container_id
+    exit 1
+fi
+
+docker commit --author "$exname" \
+    --message "Automatic Updater" \
+    "$container_id" \
+    "$UPDATED_IMAGE_NAME"
+
+docker push "$UPDATED_IMAGE_NAME"