This code is already restricted to SMS and email, so this is only to make it obvious if there is a code refactor down the line. Perhaps this is overkill and we back out this commit.
Brings in:
- [x] https://github.com/alphagov/notifications-utils/pull/801
Formats the content of the template at the time of creating the event.
This means that any downstream code (eg Celery tasks) can assume the
content is already formatted correctly.
Also, these downstream tasks don’t know which template the broadcast
was created from, so if we support personalisation in the future this is
the most sensible place to bring together the template and the
personalisation.
---
I had to re-create some of the deleted code from utils for stuff like
formatting the timestamp to the CAP standard.
The CBC Proxy is essentially a lambda function which we invoke with
various arguments.
A way in which this can fail is that the notifications-api app invoking
the function may not be able, any longer, to invoke the function.
This could be caused by, for example:
* an egress restriction preventing access to eu-west-2.lambda.amazonaws.com
* a network partition preventing access to eu-west-2.lambda.amazonaws.com
* the app's credentials have been rotated or revoked
If we invoke a simple "canary" lambda function for which the app should
have access to invoke, and check it for failures, we will know quickly
if something is likely to be broken.
This is especially important for cell broadcasts compared to email/SMS
because we always have a baseline of traffic for email/SMS, and so any
failure is observed almost immediately. This is not true for CB where we
may expect to only see one CB message every week/month/quarter/year, as
opposed to every minute or second for email/SMS.
Signed-off-by: Toby Lorne <toby.lornewelch-richards@digital.cabinet-office.gov.uk>
Co-authored-by: Pea <pea.tyczynska@digital.cabinet-office.gov.uk>
"areas" and "simple_polygons" in "transmitted_areas" do not have the
same length
as an example, choosing the area "england" results in a single item in
"areas" but many polygons in "simple_polygons"
therefore zipping these two together gives a list of areas:
* of length 1
* containing only new grimsby
which is not what we want
as the CBC does not care about the areaDesc field within CAP, we should
omit it from the function invocation and delegate the contents of
areaDesc to the CBC Proxy implementation
Signed-off-by: Toby Lorne <toby.lornewelch-richards@digital.cabinet-office.gov.uk>
Co-authored-by: Richard <richard.baker@digital.cabinet-office.gov.uk>
Co-authored-by: David <david.mcdonald@digital.cabinet-office.gov.uk>
When we initially added a new task to persist the notifications for a high volume service we wanted to implement it as quickly as possible, so ignored SMS.
This will allow a high volume service to send SMS, the SMS will be sent to a queue to then persist and send the SMS, similar to emails.
At this point I haven't added a new application to consume the new save-api-sms-tasks. But we can add a separate application or be happy with how the app scales for both email and sms.
limit means we only return 50k letters, if there are more than that for
a service we'll skip them and they won't be picked up until the next
day.
If you remove the limit, sqlalchemy prefetches query results so it can
build up ORM results, for example collapsing joined rows into single
objects with chidren. SQLAlchemy streams the data into a buffer, and
normally will still prefetch the entire resultset so it can ensure
integrity of the session, (so that if you modify one result that is
duplicated further down in the results, both rows are updated in the
session for example). However, we don't care about that, but we do care
about preventing the result set taking up too much memory. We can use
`yield_per` to yield from sqlalchemy to the iterator (in this case the
`for letter in letters_awaiting_sending` loop in letters_pdf_tasks.py) -
this means every time we hit 10000 rows, we go back to the database to
get the next 10k. This way, we only ever need 10k rows in memory at a
time.
This has some caveats, mostly around how we handle the data the query
returns. They're a bit hard to parse but I'm pretty sure the notable
limitations are:
* It's dangerous to modify ORM objects returned by yield_per queries
* It's dangerous to join in a yield_per query if you think there will be
more than one row per item (for example, if you join from notification
to service, there'll be multiple result rows containing the same
service, and if these are split over different yield chunks, then we
may experience undefined behaviour.
These two limitations are focused around there being no guarantee of
having one unique row per item.
For more reading:
https://docs.sqlalchemy.org/en/13/orm/query.html?highlight=yield_per#sqlalchemy.orm.query.Query.yield_perhttps://www.mail-archive.com/sqlalchemy@googlegroups.com/msg12443.html
We are phasing out our cbc-proxy stub which displayed CAP XML messages
We are in the process of testing with real CBCs, so maintaining our own
stub is not useful
This commit
* removes the HTTP POST requests to the CBC proxy
* writes up the update/cancel methods of the cbc_client (not impl)
Signed-off-by: Toby Lorne <toby.lornewelch-richards@digital.cabinet-office.gov.uk>
previously we were returning the entire ORM object. Returning columns
has a couple of benefits:
* Means we can join on to services there and then, avoiding second
queries to get the crown status of the service later in the collate
flow.
* Massively reduces the amount of data we return - particularly free
text fields like personalisation that could be potentially quite big.
5 columns rather than 26 columns.
* Minor thing, but will skip some CPU cycles as sqlalchemy will no
longer construct an ORM object and try and keep track of changes. We
know this function doesn't change any of the values to persist them
back, so this is an unnecessary step from sqlalchemy.
Disadvantages are:
* The dao_get_letters_to_be_printed return interface is now much more
tightly coupled to the get_key_and_size_of_letters_to_be_sent_to_print
function that calls it.
we've seen issues where tasks mysteriously hang and do not process
large volumes of letters - in this case >150k letters in created state.
to try and get at least some letters out of the door, limit the query to
only return 50k letters per postage type. We may need to run the task
multiple times, or letters may get delayed until the next day when
they'd be picked up (provided there's enough capacity then). The task
should only be re-run AFTER the ftp tasks have all finished, and updated
the letters to sending, or we run the risk of sending the same letters
twice.
For context, the largest ever letter day we've sent is ~65k in march of
this year.
we had issues where we had 150k 2nd class notifications, and the collate
task never ran properly, presumably because the volume of data being
returned was too big.
to try and help with this, we can switch to streaming rather than using
`.all` and building up lists of data. This should help, though the
initial query may be a problem still.
This is at request of DVLA. They would prefer to have zip files with the
same number of arguments in the name. After being offered a few
different options, such as including an org and service id for all zips,
they chose to just remove the 'INSOLVENCY' tag.
For more context see PR that added the tag
https://github.com/alphagov/notifications-api/pull/3006
When letters are sent to DVLA, we will now put them in a separate
ZIP file for each service, so that if there are printing issues
due to bad files from one service, other services will hopefully
not be affected by that.
When we create a broadcast message, we should invoke the cbc proxy to
send a cap message
Either a function will be invoked within AWS, or a noop function call
is made, depending on the environment
We have only implemented CB message creation in the CBC Proxy, without
polygons, therefore we:
* only invoke the CBC Proxy during message creation
* only send description, identifier, and hard-coded headline
Signed-off-by: Toby Lorne <toby.lornewelch-richards@digital.cabinet-office.gov.uk>
Co-authored-by: Pea <pea.tyczynska@digital.cabinet-office.gov.uk>
Co-authored-by: Katie <katie.smith@digital.cabinet-office.gov.uk>
We are going to invoke a lambda to send a message to the CBC
We need a CBC Proxy Client to do this
The Client will be able to send/update/cancel broadcasts in the CBC
Unless we have configured the app with AWS credentials for the
CBCProxyClient, we just want to use a client that does nothing: the noop
client
The AWS access keys are separate for the CBC Proxy vs other Notify AWS
things because the CBC Proxy lives in another AWS account
Signed-off-by: Toby Lorne <toby.lornewelch-richards@digital.cabinet-office.gov.uk>
Co-authored-by: Pea <pea.tyczynska@digital.cabinet-office.gov.uk>
Co-authored-by: Katie <katie.smith@digital.cabinet-office.gov.uk>
