Use min.io-Server.md

HowTo: Use min.io-Server for Uploading Blobs and Store the URIs in Orion Context Broker/FROST-Server

This short description will help with first steps with min.io-Server and how to utilize the document-store together with Open Smart City-Sim.

Prerequisites

• An up and running min.io-Server (e.g. https://blob.myserver.com - referred as HOST later on)
• Credentials (ACCESS-KEY/SECRET-KEY) for that server.
• A configured bucket on that server where the Blobs can be stored (e.g. images referred as BUCKET later on)
  Note: For easy read-access (w/o authentication), this bucket can have a policy set to download.
• For browsing the blobs (at HOST/minio), the Admin-credentials are needed - except for public buckets (policy: download).

Prepare min.io-Client

1. Download the min-io-Client-binary:

   • Linux: https://dl.min.io/client/mc/release/linux-amd64/mc
   • Windows: https://dl.min.io/client/mc/release/windows-amd64/mc.exe
   • macOS (Install via Homebrew): $ brew install minio/stable/mc

   Note: Consider adding the binary to your PATH-Environment.

2. Configure an alias for the min.io-Server
   It's not possible to upload Blobs to the server directly. An alias is needed instead.
   Create an alias with the following command:

   $ mc alias set ALIAS HOST ACCESS-KEY SECRET-KEY
   

   Note: Subsequent access to the min.io-Server is now done with that alias (w/o further authentication).

Upload a Blob

A Blob is uploaded with the following command:

$ mc cp LOCAL_FILE ALIAS/BUCKET

The URI of that blob is: HOST/BUCKET/LOCAL_FILE

Note: Any prepending directory from LOCAL_FILE (e.g.: /subdir/filename) is cut, so the URI does only contain the filename.
Also note: Repeatedly uploads will overwrite an exiting file.

Store the URI in Orion Context Broker/FROST-Server

Afterwards, the URI can be sent to Orion Context Broker/FROST-Server via oscsim using a String-Attribute:

$ oscsim ... --attribute-string "Name of the attribute" "URI"

Example:

$ oscsim -s http://myserver.com -p SensorThings-HTTP -as Picture https://blob.myserver.com/images/1.jpg

Do Both, Upload and Store in One Step

Following bash-script lets you do both at once (assuming, the alias is already created, and the bucket exists):

#!/bin/bash

# min.io-Server specs
HOST=https://blob.myserver.com
ALIAS=mycloud
BUCKET=images

# The file to upload
LOCAL_FILE="my-images/test1.jpg"

# 1) Upload the file
echo Storing $LOCAL_FILE on $HOST
./mc cp $LOCAL_FILE $ALIAS/$BUCKET

# 2) Create the URI
# 2.1) Extract filename from path
REMOTE_FILE="${LOCAL_FILE##*/}"
# 2.2) Build up URI
URI=$HOST/$BUCKET/$REMOTE_FILE
echo The URI is: $URI

# 3) Store URI
oscsim -s http://myserver.com -p SensorThings-HTTP -as Picture $URI

Feel free to enhance this script to make use of parameters (e.g filename to upload/store) or even loop over a directory and store all contained files.

Further Readings

For a Quickstart on how to use min.io-Client, please refer to https://docs.min.io/docs/minio-client-quickstart-guide.html.