#+TITLE: Mongo Charm

* Quick information

** Upgrade


Since 4.0.6 based on alpine 3.9, alpine is not packaging mongo
anymore. So we use the official version (that is huge). We still
must change entrypoint to enforce proper directory paths.

A ``Dockerfile`` is provided for this mean.

You can fetch latest official tags:
#+begin_quote
docker-tags-fetch mongo -l 10 -f '^[0-9]+\.[0-9]+\.[0-9]+$'
#+end_quote

change it in docker file, then

#+begin_quote
docker build . -t docker.0k.io/mongo:"$TAG"-myc
#+end_quote


** General Access

You can access mondo db, if running, through


#+begin_src sh
SERVICENAME=mongo
compose exec "$SERVICENAME" /usr/bin/mongo --quiet --eval "some js code"
#+end_src

if not running, you might want to run it.


The following could be added to actions

*** list databases


#+begin_src sh
SERVICENAME=mongo
compose exec -T mongo /usr/bin/mongo --quiet \
    --eval "JSON.stringify(db.adminCommand({listDatabases: 1}))" | \
    jq -r '.databases[] | .name'
#+end_src


*** Dump database

This one will use the probably already builded image from your project on your
host to run a competing mongo with a host directory to store the dump.

#+begin_src sh
PROJECTNAME=myc
SERVICENAME=mongo
docker run --rm --name mongo_client -ti \
     -v /tmp/mongo:/tmp/mongo --network "${PROJECTNAME}_default" \
     -u root \
     --entrypoint /bin/sh "${PROJECTNAME}_$SERVICENAME"
#+end_src

Then inside docker:

#+begin_src sh
apk add mongodb-tools
#+end_src

Then for each databases:

#+begin_src sh
DBNAME="xxx"
cd /tmp/mongo
mongodump -h mongo -d "$DBNAME" -o mdump/
#+end_src


*** Drop database


#+begin_src sh
DBNAME=xxx
PROJECTNAME=myc
SERVICENAME=mongo
docker exec -i "${PROJECTNAME}_${SERVICE}_1" /usr/bin/mongo --quiet < \
    <(echo "
use $DBNAME;
db.dropDatabase();
")
#+end_src

Note: if some connection are active to the database, it might not be
deleted, you should check by relisting the database.



*** Restore database


#+begin_src sh
SOURCE_DIR=/tmp/gogocarto
docker run --rm -ti \
    -v "$SOURCE_DIR":/tmp/backups/gogocarto \
    -w /tmp/backups \
    --entrypoint mongorestore \
    --network myc_default \
    myc_mongo \
    --host rs01/mongo /tmp/backups/
#+end_src

There should not have any errors.

Please note that '/tmp/backups' in the last example should contain
one directory per database.

Note also that you should drop database (see previous section) prior
to restore them.