NoCredentials class for accessing publicly available data

src/GoogleCloud.jl

@@ -4,7 +4,7 @@ Google Cloud APIs
 module GoogleCloud
 
 export
-    JSONCredentials, MetadataCredentials, GoogleSession, authorize,
+    JSONCredentials, MetadataCredentials, NoCredentials, GoogleSession, authorize,
     set_session!, get_session
 export
     iam, storage, compute, container, pubsub, logging, datastore

src/api/api.jl

@@ -239,9 +239,13 @@ function execute(session::GoogleSession, resource::APIResource, method::APIMetho
 
     # obtain and use access token
     auth = authorize(session)
-    headers = Dict{String, String}(
-        "Authorization" => "$(auth[:token_type]) $(auth[:access_token])"
-    )
+    headers = if isnothing(auth)
+        Dict{String, String}()
+    else
+        Dict{String, String}(
+            "Authorization" => "$(auth[:token_type]) $(auth[:access_token])"
+        )
+    end
     params = Dict(params)
 
     # check if data provided when not expected
@@ -273,7 +277,7 @@ function execute(session::GoogleSession, resource::APIResource, method::APIMetho
 
     # merge in default parameters and evaluate any expressions
     params = merge!(copy(method.default_params), Dict(params))
-    extra = Dict(:project_id => session.credentials.project_id)
+    extra = hasproperty(session.credentials, :project_id) ? Dict(:project_id => session.credentials.project_id) : Dict()
     for (key, val) in params
         if isa(val, Symbol)
             params[key] = extra[val]

src/credentials.jl

@@ -3,7 +3,7 @@ Google Cloud Platform service-account API credentials.
 """
 module credentials
 
-export Credentials, JSONCredentials, MetadataCredentials
+export Credentials, JSONCredentials, MetadataCredentials, NoCredentials
 
 import Base: show, print
 import JSON
@@ -126,4 +126,8 @@ function print(io::IO, x::Credentials)
 end
 show(io::IO, x::JSONCredentials) = print(io, x)
 
+struct NoCredentials <: Credentials
 end
+
+end
+

src/session.jl

@@ -195,4 +195,6 @@ function authorize(session::GoogleSession; cache::Bool=true)
     authorization
 end
 
+authorize(session::GoogleSession{T}) where {T <: NoCredentials} = nothing
+
 end

test/nocredentials.jl

@@ -0,0 +1,31 @@
+using Test
+
+using GoogleCloud
+using JSON
+
+creds = NoCredentials()
+
+session = GoogleSession(creds, ["devstorage.full_control"])
+
+## Test download of JSON data from Pong dataset
+bucketName = "atari-replay-datasets"
+prefix="dqn/Pong/1/replay_logs/\$store\$_action"
+
+fileList = GoogleCloud.storage(:Object, :list, bucketName; prefix, session)
+
+parities = map(fileList) do item
+    reduce(⊻, GoogleCloud.storage(:Object, :get, bucketName, item[:name]; session))
+end
+
+EXPECTED_PARITY = 0xf1
+
+## Test download of binary data from sentinel dataset
+sentinelbucket = "gcp-public-data-sentinel-2"
+sentinelpath = "L2/tiles/32/T/NS/S2A_MSIL2A_20210506T102021_N0300_R065_T32TNS_20210506T132458.SAFE/GRANULE/L2A_T32TNS_A030664_20210506T102022/IMG_DATA/R20m/T32TNS_20210506T102021_B07_20m.jp2"
+sentinelimage = GoogleCloud.storage(:Object, :get, sentinelbucket, sentinelpath; session)
+EXPECTED_PARITY_SENTINEL = 0x6e
+
+@testset "storage access and NoCredentials" begin
+    @test reduce(⊻, fetch.(parities)) == EXPECTED_PARITY
+    @test reduce(⊻, sentinelimage) == EXPECTED_PARITY_SENTINEL
+end

test/runtests.jl

@@ -2,4 +2,5 @@ using GoogleCloud
 using Test 
 
 include("api.jl")
+include("nocredentials.jl")
 #include("storage.jl")