how to do local and remote file storage in a flutter app - flutter

I'm doing a flutter app that needs to open a binary file, display the content to a user and allow them to edit and save. File size would be between 10K and 10 MB. The file also needs to be in the cloud for sharing and accessing from other devices. To minimise remote network egress data charges and also local user mobile data charges, I'm envisaging that when the user saves the file it would be saved locally rather than written to the cloud and only written to the cloud when the user closes the file or maybe at regular intervals or no activity. To minimise network data charges I would like to keep a permanent local copy and the remote copy of the file would have a small supporting file that identified by who and when the remote file was last written. When the app starts, it checks if its local copy is up to date by reading the supporting file. The data does not need high security.
The app will run on Android, IOS, the web and preferably on the desktop - though I know that google firebase SDK for Windows is incomplete/ unavailable.
Is google firebase cloud storage the easiest and best way to do this. If not what is the easiest way.
Are there any cloud storage providers that don't charge for network egress data, just for storage.

Related

Firestore: Copy/Import data from local emulator to Cloud DB

I need to copy Firestore DB data from my local Firebase emulator to the cloud instance. I can move data from the Cloud DB to the local DB fine, using the EXPORT functionality in the Firebase admin console. We have been working on the local database instance for 3-4 months and now we need to move it back to the Cloud. I have tried to move the local "--export-on-exit" files back to my storage bucket and then IMPORT from there to the Cloud DB, but it fails everytime.
I have seen one comment by Doug at https://stackoverflow.com/a/71819566/20390759 that this is not possible, but the best solution is to write a program to copy from local to cloud. I've started working on that, but I can't find a way to have both projects/databases open at the same time, both local and cloud. They are all the same project ID, app-key, etc.
Attempted IMPORT: I copied the files created by "--export-on-exit" in the emulator to my cloud storage bucket. Then, I selected IMPORT and chose the file I copied up to the bucket. I get this error message:
Google Cloud Storage file does not exist: /xxxxxx.appspot.com/2022-12-05 from local/2022-12-05 from local.overall_export_metadata
So, I renamed the file metadata file to match the directory name from the local system, and the IMPORT claims to initiate successfully, but then fails with no error message.
I've been using Firestore for several years, but we just started using the emulator this year. Overall I like it, but if I can't easily move data back to the Cloud, I can't use it. Thanks for any ideas/help.

Offline folder access on server

on file server we have folder with user home folders..
i would like to ask, is it possible to access home folder offline (without using VPN and connect to companys network) and how?
Thanks
• Yes, you can access the ‘User\home folders’ directory through offline access also by enabling the option ‘Always available offline’ for that directory on the network file share and ensuring that ‘Sync center’ utility is enabled for managing offline files as below: -
Map the network drive on the system and access the file share for which you want to enable offline access. Then ‘Right click’ the share and select the option ‘Always available offline’ as below: -
Now, go to ‘ Control Panel --> Sync Center --> Manage offline files --> Enable offline files --> View offline files ‘ to check the shares on the network drive for which offline access is enabled. Also, ensure that network discovery, file and printer sharing, and password protected sharing is enabled as below: -
Once the above is done, go to Sync Center in Control Panel, select the offline task or folder displayed, right click it and select ‘Schedule for Offline files’ to select the specific directories or the whole content in the share to be scheduled to sync in the local disk storage reserved for offline access as below. Also, you can configure the offline accessible files disk usage limits through the sync center also by going to ‘Manage Offline files --> Disk Usage --> Change limits’: -
In this way, you can configure offline folders access through inbuilt Windows utility and access the desired folders offline after successful sync.

Is there a way to upload data from FTP server to Amazon S3? [duplicate]

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Is there a way to connect to an Amazon S3 bucket with FTP or SFTP rather than the built-in Amazon file transfer interface in the AWS console? Seems odd that this isn't a readily available option.
There are three options.
You can use a native Amazon Managed SFTP service (aka AWS Transfer for SFTP), which is easier to set up.
Or you can mount the bucket to a file system on a Linux server and access the files using the SFTP as any other files on the server (which gives you greater control).
Or you can just use a (GUI) client that natively supports S3 protocol (what is free).
Managed SFTP Service
In your Amazon AWS Console, go to AWS Transfer for SFTP and create a new server.
In SFTP server page, add a new SFTP user (or users).
Permissions of users are governed by an associated AWS role in IAM service (for a quick start, you can use AmazonS3FullAccess policy).
The role must have a trust relationship to transfer.amazonaws.com.
For details, see my guide Setting up an SFTP access to Amazon S3.
Mounting Bucket to Linux Server
Just mount the bucket using s3fs file system (or similar) to a Linux server (e.g. Amazon EC2) and use the server's built-in SFTP server to access the bucket.
Install the s3fs
Add your security credentials in a form access-key-id:secret-access-key to /etc/passwd-s3fs
Add a bucket mounting entry to fstab:
<bucket> /mnt/<bucket> fuse.s3fs rw,nosuid,nodev,allow_other 0 0
For details, see my guide Setting up an SFTP access to Amazon S3.
Use S3 Client
Or use any free "FTP/SFTP client", that's also an "S3 client", and you do not have setup anything on server-side. For example, my WinSCP or Cyberduck.
WinSCP has even scripting and .NET/PowerShell interface, if you need to automate the transfers.
Update
S3 now offers a fully-managed SFTP Gateway Service for S3 that integrates with IAM and can be administered using aws-cli.
There are theoretical and practical reasons why this isn't a perfect solution, but it does work...
You can install an FTP/SFTP service (such as proftpd) on a linux server, either in EC2 or in your own data center... then mount a bucket into the filesystem where the ftp server is configured to chroot, using s3fs.
I have a client that serves content out of S3, and the content is provided to them by a 3rd party who only supports ftp pushes... so, with some hesitation (due to the impedance mismatch between S3 and an actual filesystem) but lacking the time to write a proper FTP/S3 gateway server software package (which I still intend to do one of these days), I proposed and deployed this solution for them several months ago and they have not reported any problems with the system.
As a bonus, since proftpd can chroot each user into their own home directory and "pretend" (as far as the user can tell) that files owned by the proftpd user are actually owned by the logged in user, this segregates each ftp user into a "subdirectory" of the bucket, and makes the other users' files inaccessible.
There is a problem with the default configuration, however.
Once you start to get a few tens or hundreds of files, the problem will manifest itself when you pull a directory listing, because ProFTPd will attempt to read the .ftpaccess files over, and over, and over again, and for each file in the directory, .ftpaccess is checked to see if the user should be allowed to view it.
You can disable this behavior in ProFTPd, but I would suggest that the most correct configuration is to configure additional options -o enable_noobj_cache -o stat_cache_expire=30 in s3fs:
-o stat_cache_expire (default is no expire)
specify expire time(seconds) for entries in the stat cache
Without this option, you'll make fewer requests to S3, but you also will not always reliably discover changes made to objects if external processes or other instances of s3fs are also modifying the objects in the bucket. The value "30" in my system was selected somewhat arbitrarily.
-o enable_noobj_cache (default is disable)
enable cache entries for the object which does not exist. s3fs always has to check whether file(or sub directory) exists under object(path) when s3fs does some command, since s3fs has recognized a directory which does not exist and has files or subdirectories under itself. It increases ListBucket request and makes performance bad. You can specify this option for performance, s3fs memorizes in stat cache that the object (file or directory) does not exist.
This option allows s3fs to remember that .ftpaccess wasn't there.
Unrelated to the performance issues that can arise with ProFTPd, which are resolved by the above changes, you also need to enable -o enable_content_md5 in s3fs.
-o enable_content_md5 (default is disable)
verifying uploaded data without multipart by content-md5 header. Enable to send "Content-MD5" header when uploading a object without multipart posting. If this option is enabled, it has some influences on a performance of s3fs when uploading small object. Because s3fs always checks MD5 when uploading large object, this option does not affect on large object.
This is an option which never should have been an option -- it should always be enabled, because not doing this bypasses a critical integrity check for only a negligible performance benefit. When an object is uploaded to S3 with a Content-MD5: header, S3 will validate the checksum and reject the object if it's corrupted in transit. However unlikely that might be, it seems short-sighted to disable this safety check.
Quotes are from the man page of s3fs. Grammatical errors are in the original text.
Answer from 2014 for the people who are down-voting me:
Well, S3 isn't FTP. There are lots and lots of clients that support S3, however.
Pretty much every notable FTP client on OS X has support, including Transmit and Cyberduck.
If you're on Windows, take a look at Cyberduck or CloudBerry.
Updated answer for 2019:
AWS has recently released the AWS Transfer for SFTP service, which may do what you're looking for.
Or spin Linux instance for SFTP Gateway in your AWS infrastructure that saves uploaded files to your Amazon S3 bucket.
Supported by Thorntech
Amazon has released SFTP services for S3, but they only do SFTP (not FTP or FTPES) and they can be cost prohibitive depending on your circumstances.
I'm the Founder of DocEvent.io, and we provide FTP/S Gateways for your S3 bucket without having to spin up servers or worry about infrastructure.
There are also other companies that provide a standalone FTP server that you pay by the month that can connect to an S3 bucket through the software configuration, for example brickftp.com.
Lastly there are also some AWS Marketplace apps that can help, here is a search link. Many of these spin up instances in your own infrastructure - this means you'll have to manage and upgrade the instances yourself which can be difficult to maintain and configure over time.
WinSCp now supports S3 protocol
First, make sure your AWS user with S3 access permissions has an “Access key ID” created. You also have to know the “Secret access key”. Access keys are created and managed on Users page of IAM Management Console.
Make sure New site node is selected.
On the New site node, select Amazon S3 protocol.
Enter your AWS user Access key ID and Secret access key
Save your site settings using the Save button.
Login using the Login button.
Filezilla just released a Pro version of their FTP client. It connects to S3 buckets in a streamlined FTP like experience. I use it myself (no affiliation whatsoever) and it works great.
As other posters have pointed out, there are some limitations with the AWS Transfer for SFTP service. You need to closely align requirements. For example, there are no quotas, whitelists/blacklists, file type limits, and non key based access requires external services. There is also a certain overhead relating to user management and IAM, which can get to be a pain at scale.
We have been running an SFTP S3 Proxy Gateway for about 5 years now for our customers. The core solution is wrapped in a collection of Docker services and deployed in whatever context is needed, even on-premise or local development servers. The use case for us is a little different as our solution is focused data processing and pipelines vs a file share. In a Salesforce example, a customer will use SFTP as the transport method sending email, purchase...data to an SFTP/S3 enpoint. This is mapped an object key on S3. Upon arrival, the data is picked up, processed, routed and loaded to a warehouse. We also have fairly significant auditing requirements for each transfer, something the Cloudwatch logs for AWS do not directly provide.
As other have mentioned, rolling your own is an option too. Using AWS Lightsail you can setup a cluster, say 4, of $10 2GB instances using either Route 53 or an ELB.
In general, it is great to see AWS offer this service and I expect it to mature over time. However, depending on your use case, alternative solutions may be a better fit.

Best way to stage file from cloud storage to windows machine

I am wanting to store a data file for Quickbooks in the cloud. I understand that the data file is more of a database-in-a-file, so I know that I don't want to simply have the data file itself in a cloud directory.
When I say 'cloud', I'm meaning something like Google Drive or box.com.
What I see working is that I want to write a script (bat file, or do they have something new and improved for Windows XP, like some .net nonsense or something?)
The script would:
1) Download the latest copy of the data file from cloud storage and put it in a directory on the local machine
2) Launch Quickbooks with that data file
3) When the user exits Quickbooks, copy the data file back up into the cloud storage.
4) Rejoice.
So, my question(s)... Is there something that already does this? Is there an easily scriptable interface to work with the cloud storage options? In my ideal world, I'd be able to say 'scp google-drive://blah/blah.dat localdir' and have it copy the file down, and do the opposite after running QB. I'm guessing I'm not going to get that.
Intuit already provides a product to do this. It is called Intuit Data Protect and it backs up your Quickbooks company file to the cloud for you.
http://appcenter.intuit.com/intuitdataprotect
regards,
Jarred

How to send a video stream to a cloud?

I want to send a live video stream to a server and I want to perform facial recognition on that video and I would like to get the result back to the client program. Where do I get a server? Can I use Windows Azure here? If yes, can I also make a Python/C++ Server program listen on a particular port?
You haven't talked about the client-side piece. Assuming you're in control of a client app, you could push the video to a Blob, then drop a notification in an Azure queue for a background task to process the uploaded video fragment.
Instead of directly pushing to blobs, you could host a web service that lets you push uploads, and the web service could store the video fragment and then trigger a background processing task.
Running python should be very straightforward - just upload the python exe and any related modules, either with your Windows Azure deployment or in blob storage (then pull them down from blob storage and install them when the VM starts up). As far as port-listening, you can define up to 25 ports that are external-facing. You'd then have your python app listen on the port you defined (either tcp, http, or https).
More info on block and page blobs here. Steve Marx posted this example for installing python in your Web or Worker role.