Download PG database as a file from Heroku - ruby-on-rails

Question

I'm trying to download a file (a copy) of our staging DB. I'm using pgbackups following these docs.
I created a backup, than got the public-url using heroku pgbackups:url b462 --app staging-appname, which worked.
Than I run the command curl -o latest.dump heroku pg:backups <public-url> b462 -a staging-appname and get curl: no URL specified!
Where it says <public-url> I've copied the actual long public-url, as in https://s3.amazonaws.com/reallly-long-url-with-acess-key-ect.
What am I missing here?

Answer 1

The following will create the backup:
heroku pg:backups capture --app name-of-the-app
Using the following information printed in terminal
---backup---> b001
In the following command
heroku pg:backups public-url b001 -a name-of-the-app
Will give you the url of the dump

Answer 2

Try just the following to get the latest file immediately after running heroku pgbackups:capture --app=staging-appname:
curl -o latest.dump `heroku pgbackups:url --app=staging-appname`
The b.. is required only if you are looking for a specific older file.

Answer 3

I was also struggling with this doc, and Prakash's suggestion didn't work for me (error complained about not being able to resolve 'heroku' which isn't part of the URL, so the syntax is seems to be bad, at least for the version of the pg or pgbackup gem I'm using.)
I also tried wget, as suggested in the heroku doc, to no avail.
When I'm stumped I try to think it down to the most simple elements, which led me to a far simpler solution than is provided by the doc...
I used the command in Rafael's answer to generate a temporary URL to retrieve the dump file:
heroku pg:backups public-url b001 -a name-of-the-app
Then, instead of plugging the resulting URL into the curl command, I just pasted that URL into Chrome's address bar and downloaded the file using my web browser.
The download was successful, the db file is valid.

Answer 4

With a little more sugar, here an example of shell script to download mysql dump from heroku and to restore it as a local database
backup_name=$1
if [ -z "$backup_name" ]
then
echo "You must supplied heroku backup name (ex: b001)"
return
fi
echo "Loading '$backup_name' database from heroku"
heroku pg:backups public-url $backup_name -a your-app-name > last_url.txt
curl -o latest.dump `cat last_url.txt`
dropdb local-db-name
createdb local-db-name
pg_restore -c -d local-db-name latest.dump
You need to give the heroku backup name as input.