0k-charms/rsync-backup/hooks/schedule_command-relation-joined

#!/bin/bash

## When writing relation script, remember:
##  - they should be idempotents
##  - they can be launched while the dockers is already up
##  - they are launched from the host
##  - the target of the link is launched first, and get a chance to ``relation-set``
##  - both side of the scripts get to use ``relation-get``.
##  - use actions of other side for other side's business logic

. lib/common

if [ -z "$RELATION_DATA_FILE" ]; then
    err "$FUNCNAME: relation does not seems to be correctly setup."
    exit 1
fi

if ! [ -r "$RELATION_DATA_FILE" ]; then
    err "$FUNCNAME: can't read relation's data." >&2
    exit 1
fi

if [ "$(cat "$RELATION_DATA_FILE" | shyaml get-type)" == "str" ]; then
    ## Cached version already there

    ## Note that we rely on the fact that when the relations
    ## options are changed in the `compose.yml` file, the relation
    ## data file is recreated from the values of the
    ## `compose.yml`.
    info "Previous relation data is still valid."
    exit 0
fi

set -e

private_key=$(options-get private-key) || exit 1
target=$(options-get target) || exit 1
ident=$(options-get ident) || exit 1

home=/var/lib/rsync
local_path_key=$home/.ssh
host_path_key="$SERVICE_CONFIGSTORE${local_path_key}"

echo "$private_key" | file_put "$host_path_key/id_rsa"
chmod 600 "$host_path_key/id_rsa"

schedule=$(relation-get schedule) || true

lock_opts=(-D -p 10 -k)

command=(
    docker run --rm
    -e LABEL_HOSTNAME="$ident"
    -v "$RSYNC_CONFIG_DIR:/etc/rsync"
    -v "$host_path_key:$local_path_key"
    -v "$HOST_DATASTORE:/mnt/source"
    -v "$HOST_COMPOSE_YML_FILE:/mnt/source/compose.yml"
    --network ${PROJECT_NAME}_default
    "$DOCKER_BASE_IMAGE"
    /mnt/source "$target"
)

quoted_command=()
for arg in "${command[@]}"; do
    quoted_command+=("$(printf "%q" "$arg")")
done

printf "(%s) {%s} %s\n" \
       "$schedule" \
       "${lock_opts[*]}" \
       "${quoted_command[*]}" > "$RELATION_DATA_FILE"