How To

How to use `ccptaskid` to separate output of different replicas to different files in `execute-script`.

    mkdir -p /ccp_data/output && echo $RANDOM >> /ccp_data/output/`printenv ccptaskid`.txt

ccpiamurl is the URL of the Identity management service.
ccpclientid is the client_id to be used for requesting token renewal.
ccprefreshtoken is a refresh token by which new access tokens can be requested.
ccpcontext represents the context (VO or VRE) in which the Method execution has been requested.

As an example the following Python code shows how to use the variables to request a token renewal.

How to request a login token and an UMA token for accessing D4Science service from inside Method code

#Get auth info from env variables
refreshtoken = os.environ["ccprefreshtoken"]
context = os.environ["ccpcontext"]
clientid = os.environ["ccpclientid"]
iam = os.environ["ccpiamurl"]

#Auth related functions
logindata = { 'grant_type' : 'refresh_token', 'client_id' : clientid, 'refresh_token' : refreshtoken}
loginheaders = { "Accept" : "application/json", "Content-Type" : "application/x-www-form-urlencoded"}

umadata = { 'grant_type' : 'urn:ietf:params:oauth:grant-type:uma-ticket', 'audience' : context}
umaheaders = { "Accept" : "application/json", "Content-Type" : "application/x-www-form-urlencoded"}

def getToken():
    # login with offline_token
    resp1 = requests.post(iam, data=logindata, headers=loginheaders)
    jwt = resp1.json()
    #get UMA token for context
    umaheaders["Authorization"] = "Bearer " + jwt["access_token"]
    resp2 = requests.post(iam, data=umadata, headers=umaheaders)
    return resp2.json()["access_token"]

# Get valid token for context
tok = getToken()

# List VRE fodler content
vrefolder = requests.get(workspace + "/vrefolder", headers={"Accept" : "application/json", "Authorization" : "Bearer " + tok}).json()s

A similar example in bash could have the following form:

How to download a file from the D4Science workspace from a private URL passed as input parameter

echo "Getting token"
TOKEN=$(curl -X POST $ccpiamurl -d grant_type=refresh_token -d client_id=$ccpclientid -d refresh_token=$ccprefreshtoken -H "X-D4Science-Context: $ccpcontext" | jq -r '."access_token"')

echo Downloading $wslink to $inputfile
curl -L $wslink -o $inputfile -H "Authorization: Bearer $TOKEN"

echo "Downloaded"

A special folder is provided in the Runtime to a Method execution for storing output files. Files are currently the only way for a Method to output results by value. The folder is named /ccp_data and all the files written to this folder are returned in the context of the Execution as a zip archive.