Now let's build from the previous chapter and add the missing parts to have a complete security flow.

## Get the `username` and `password` { #get-the-username-and-password }

We are going to use **FastAPI** security utilities to get the `username` and `password`.

OAuth2 specifies that when using the "password flow" (that we are using) the client/user must send a `username` and `password` fields as form data.

ERROR: This pool is not scheduled for decommissioning currently.
```

## Canceling a decommission

Stop an on-going decommission in progress, mainly used in situations when the load may be too high and you may want to schedule the decommission at a later point in time.

`mc admin decommission cancel` without an argument, lists out any on-going decommission in progress.

```
λ mc admin decommission cancel alias/

/**
 * A test which demonstrates maven's recursive inheritance where
 * a distinct value is taken from each parent contributing to
 * the final model of the project being assembled. There is no
 * overriding going on amongst the models being used in this test:
 * each model in the lineage is providing a value that is not present
 * anywhere else in the lineage. We are just making sure that values

/**
 * A test which demonstrates maven's recursive inheritance where
 * a distinct value is taken from each parent contributing to
 * the final model of the project being assembled. There is no
 * overriding going on amongst the models being used in this test:
 * each model in the lineage is providing a value that is not present
 * anywhere else in the lineage. We are just making sure that values

her face brightened up at the thought that she was now the right
size for going through the little door into that lovely garden.
First, however, she waited for a few minutes to see if she was
going to shrink any further:  she felt a little nervous about
this; `for it might end, you know,' said Alice to herself, `in my
going out altogether, like a candle.  I wonder what I should be

          // reset state in case of an error so that later dispatch calls will actually do something
          synchronized (this) {
            isThreadScheduled = false;
          }
          // Log it and keep going.
          logger
              .get()
              .log(
                  Level.SEVERE,
                  "Exception while running callbacks for " + listener + " on " + executor,
                  e);

          // reset state in case of an error so that later dispatch calls will actually do something
          synchronized (this) {
            isThreadScheduled = false;
          }
          // Log it and keep going.
          logger
              .get()
              .log(
                  Level.SEVERE,
                  "Exception while running callbacks for " + listener + " on " + executor,
                  e);

              },
              "waiting": {
                "delay": 2628000,
                "message": "As this PR has been waiting for the original user for a while but seems to be inactive, it's now going to be closed. But if there's anyone interested, feel free to create a new PR.",
                "reminder": {
                    "before": "P3D",

```

But possibly the most important part of the callback is making sure that your API user (the external developer) implements the *external API* correctly, according to the data that *your API* is going to send in the request body of the callback, etc.

So, what we will do next is add the code to document how that *external API* should look like to receive the callback from *your API*.

# Download specific version of libstdc++ shared library based on the value of
# the `VERSION` parameter
case "${VERSION}" in
devtoolset-7)
  # Download binary libstdc++ 4.4 release we are going to link against.
  # We only need the shared library, as we're going to develop against the
  # libstdc++ provided by devtoolset.
  wget "http://old-releases.ubuntu.com/ubuntu/pool/main/g/gcc-4.4/libstdc++6_4.4.3-4ubuntu5_amd64.deb" && \