Can't switch to other databases via ArangoDB Web interface when I am using ArangoDB Docker

Question

I started two containers via a bridge as follows:

docker network create -d bridge my-net
docker run --name arangodb -p 8529:8529 -e ARANGO_ROOT_PASSWORD=openSesame --network=my-net -d arangodb/arangodb:3.6.5
docker run --name arangodb-client --network=my-net -it --rm arangodb-client-image 

to build arangodb-client-image, I used the following Dockerfile

FROM python:3
ADD init.py /
RUN pip install pyArango
CMD [ "python3", "./init.py" ]

and init.py

from pyArango.connection import *
conn = Connection(arangoURL="http://arangodb:8529", username="root", password="openSesame")

#Creating and Opening Databases
db = conn.createDatabase(name="school")

# Creating Collections Documents
studentsCollection = db.createCollection(name="Students")

students = [('Oscar', 'Wilde', 3.5), ('Thomas', 'Hobbes', 3.2), 
    ('Mark', 'Twain', 3.0), ('Kate', 'Chopin', 3.8), ('Fyodor', 'Dostoevsky', 3.1), 
    ('Jane', 'Austen',3.4), ('Mary', 'Wollstonecraft', 3.7), ('Percy', 'Shelley', 3.5), 
    ('William', 'Faulkner', 3.8), ('Charlotte', 'Bronte', 3.0)]
for (first, last, gpa) in students:
    doc = studentsCollection.createDocument()
    doc['name'] = "%s %s" % (first, last)
    doc['gpa'] = gpa 
    doc['year'] = 2017
    doc._key = ''.join([first, last]).lower() 
    doc.save()

But when I open http://localhost:8529 in my machine, I can't select school database in the pull-down menu. but if use

docker exec -it arangodb arangosh --server.database school

I can see all the collections in school database.