Locally reading S3 files through Spark (or better: pyspark) - authentication

I want to read an S3 file from my (local) machine, through Spark (pyspark, really). Now, I keep getting authentication errors like
java.lang.IllegalArgumentException: AWS Access Key ID and Secret
Access Key must be specified as the username or password
(respectively) of a s3n URL, or by setting the fs.s3n.awsAccessKeyId
or fs.s3n.awsSecretAccessKey properties (respectively).
I looked everywhere here and on the web, tried many things, but apparently S3 has been changing over the last year or months, and all methods failed but one:
pyspark.SparkContext().textFile("s3n://user:password#bucket/key")
(note the s3n [s3 did not work]). Now, I don't want to use a URL with the user and password because they can appear in logs, and I am also not sure how to get them from the ~/.aws/credentials file anyway.
So, how can I read locally from S3 through Spark (or, better, pyspark) using the AWS credentials from the now standard ~/.aws/credentials file (ideally, without copying the credentials there to yet another configuration file)?
PS: I tried os.environ["AWS_ACCESS_KEY_ID"] = … and os.environ["AWS_SECRET_ACCESS_KEY"] = …, it did not work.
PPS: I am not sure where to "set the fs.s3n.awsAccessKeyId or fs.s3n.awsSecretAccessKey properties" (Google did not come up with anything). However, I did try many ways of setting these: SparkContext.setSystemProperty(), sc.setLocalProperty(), and conf = SparkConf(); conf.set(…); conf.set(…); sc = SparkContext(conf=conf). Nothing worked.

Yes, you have to use s3n instead of s3. s3 is some weird abuse of S3 the benefits of which are unclear to me.
You can pass the credentials to the sc.hadoopFile or sc.newAPIHadoopFile calls:
rdd = sc.hadoopFile('s3n://my_bucket/my_file', conf = {
'fs.s3n.awsAccessKeyId': '...',
'fs.s3n.awsSecretAccessKey': '...',
})

The problem was actually a bug in the Amazon's boto Python module. The problem was related to the fact that MacPort's version is actually old: installing boto through pip solved the problem: ~/.aws/credentials was correctly read.
Now that I have more experience, I would say that in general (as of the end of 2015) Amazon Web Services tools and Spark/PySpark have a patchy documentation and can have some serious bugs that are very easy to run into. For the first problem, I would recommend to first update the aws command line interface, boto and Spark every time something strange happens: this has "magically" solved a few issues already for me.

Here is a solution on how to read the credentials from ~/.aws/credentials. It makes use of the fact that the credentials file is an INI file which can be parsed with Python's configparser.
import os
import configparser
config = configparser.ConfigParser()
config.read(os.path.expanduser("~/.aws/credentials"))
aws_profile = 'default' # your AWS profile to use
access_id = config.get(aws_profile, "aws_access_key_id")
access_key = config.get(aws_profile, "aws_secret_access_key")
See also my gist at https://gist.github.com/asmaier/5768c7cda3620901440a62248614bbd0 .

Environment variables setup could help.
Here in Spark FAQ under the question "How can I access data in S3?" they suggest to set AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables.

I cannot say much about the java objects you have to give to the hadoopFile function, only that this function already seems depricated for some "newAPIHadoopFile". The documentation on this is quite sketchy and I feel like you need to know Scala/Java to really get to the bottom of what everything means.
In the mean time, I figured out how to actually get some s3 data into pyspark and I thought I would share my findings.
This documentation: Spark API documentation says that it uses a dict that gets converted into a java configuration (XML). I found the configuration for java, this should probably reflect the values you should put into the dict: How to access S3/S3n from local hadoop installation
bucket = "mycompany-mydata-bucket"
prefix = "2015/04/04/mybiglogfile.log.gz"
filename = "s3n://{}/{}".format(bucket, prefix)
config_dict = {"fs.s3n.awsAccessKeyId":"FOOBAR",
"fs.s3n.awsSecretAccessKey":"BARFOO"}
rdd = sc.hadoopFile(filename,
'org.apache.hadoop.mapred.TextInputFormat',
'org.apache.hadoop.io.Text',
'org.apache.hadoop.io.LongWritable',
conf=config_dict)
This code snippet loads the file from the bucket and prefix (file path in the bucket) specified on the first two lines.

Related

Passing AWS role to the application that uses default boto3 configs

I have an aws setup that requires me to assume role and get corresponding credentials in order to write to s3. For example, to write with aws cli, I need to use --profile readwrite flag. If I write code myself with boot, I'd assume role via sts, get credentials, and create new session.
However, there is a bunch of applications and packages relying on boto3's configuration, e.g. internal code runs like this:
s3 = boto3.resource('s3')
result_s3 = s3.Object(bucket, s3_object_key)
result_s3.put(
Body=value.encode(content_encoding),
ContentEncoding=content_encoding,
ContentType=content_type,
)
From documentation, boto3 can be set to use default profile using (among others) AWS_PROFILE env variable, and it clearly "works" in terms that boto3.Session().profile_name does match the variable - but the applications still won't write to s3.
What would be the cleanest/correct way to set them properly? I tried to pull credentials from sts, and write them as AWS_SECRET_TOKEN etc, but that didn't work for me...
Have a look at the answer here:
How to choose an AWS profile when using boto3 to connect to CloudFront
You can get boto3 to use the other profile like so:
rw = boto3.session.Session(profile_name='readwrite')
s3 = rw.resource('s3')
I think the correct answer to my question is one shared by Nathan Williams in the comment.
In my specific case, given that I had to initiate code from python, and was a bit worried about setting AWS settings that might spill into other operations, I used
the fact that boto3 has DEFAULT_SESSION singleton, used each time, and just overwrote this with a session that assumed the proper role:
hook = S3Hook(aws_conn_id=aws_conn_id)
boto3.DEFAULT_SESSION = hook.get_session()
(here, S3Hook is airflow's s3 handling object). After that (in the same runtime) everything worked perfectly

Airflow S3Hook object has no attribute load_bytes

The goal of my operator is to communicate with s3, then write some string data to my s3 bucket.
I saw there is already an s3_hook to be used. I thought maybe this is a better way than using boto3.
The main logic looks like:
from airflow.hooks.S3_hook import S3Hook
hook = S3Hook('test_s3')
log.info(hook.load_bytes('some_data', 'some_key', 'a_bucket'))
Then I got some error like
'S3Hook' object has no attribute 'load_bytes'
I'm pretty sure that the S3Hook class has that function (see here).
After this, I switched to use the function load_string. However, the airflow throw me an error like:
'S3' object has no attribute 'upload_fileobj'
I'm using the airflow with s3 support. Not sure why I the error above. My test_s3 connection is fine since I have tested my test_s3 connection by using read_key to read some texts file from s3 without any issue.
Does anyone else have the similar situation? I'm very confused, where did I miss? Thanks!

Using boto (not boto3) with DigitalOcean Spaces

I'm hoping for sample code using boto (not boto3) for writing an object to DigitalOcean's Spaces system and then reading it back.
This StackOverflow question suggested one approach to get started, but the following code produces the result None:
import boto
s3 = boto.s3.S3RegionInfo(name='nyc3',
endpoint='https://nyc3.digitaloceanspaces.com',
aws_access_key_id=XXXX,
aws_secret_access_key=XXXX).connect()
print s3
Spaces has the same API as Amazon S3, so I'm hoping boto will work.
(Why do I want to use boto instead of boto3? Answer: I have boto3 code working perfectly in my test system, but it fails in what seems to be unpredictable ways when operating at scale, and the fail seems to be inside boto3. If I can get the code working in boto, it is not only a workaround, but would suggest there is a boto3 problem.)

How to configure cache folder for SourceDiskCache?

I understand from the documentation that the SourceDiskCache folder cannot be configured using the XML configuration file and is only available "through code installation". However I can't figure out how!
I need to configure a custom folder. I have tried a few different things, with different results (both in Application_Start):
This doesn't throw an error, but uses the default folder (/cache)
var sourceDiskCachePlugin = new SourceDiskCachePlugin {VirtualCacheDir = "~/App_Data/cache"};
Config.Current.Plugins.GetOrInstall(sourceDiskCachePlugin);
This (and most other variations I have tried) throws the error "SourceDiskCache settings may not be adjusted after it is started."
new SourceDiskCachePlugin().Install(Config.Current);
Config.Current.Plugins.Get<SourceDiskCachePlugin>().VirtualCacheDir = "~/App_Data/cache";
How can I configure this?
Also, the documentation states that SourceDiskCache is in beta - is this still the case, and will XML configuration ever be available?
This would be the normal way to configure and install it:
var plugin = new SourceDiskCachePlugin()
plugin.VirtualCacheDir = "~/App_Data/cache";
plugin.Install(Config.Current);
If your code is running more than once, use Config.Current.Plugins.GetOrInstall(plugin); It's best if you only install the plugin during Application_Start.
However, approach #1 from your question should work equally well, as long as you've set the right NTFS permissions on App_Data.

Get a file from IVirtualImageProvider

I have a custom plugin for serving images trought LDAP IPlugin
and IVirtualImageProvider now im doing a task of importing users from LDAP to our own system and as such i need to import those images, i was wondering if there is any way of using the plugin i previously created to import those images, perhaps something in the like of
ImageResizer.ImageJob i = new ImageResizer.ImageJob("http://host/ad/A68986", "~/uploads/<guid>.<ext>", new ImageResizer.ResizeSettings(
"width=2000;height=2000;format=jpg;mode=max"));
But the first parameter (source) would be "resolved" by my LDAP plugin, ImageResizer API
Edit: I figured out this is possible since source can be a IVirtualFile, that implies that i know in advance which one to create (for my case my own ldap) it would be nice to pass the url and somehow get the correct IVirtualFile
Yes, ImageJob resolves any 'app-relative virtual paths' using installed IVirtualImageProviders. Such paths must begin with "~/", and match the path prefix and syntax you've designed, of course.
In your case, this might look like
var i = new ImageResizer.ImageJob("~/ad/A68986", "~/uploads/<guid>.<ext>",
new ImageResizer.ResizeSettings("width=2000;height=2000;format=jpg;mode=max"));
You can also call Config.Current.Pipeline.GetFile to get an IVirtualFile reference based on a path, if you just want the original data.