Spark BigQuery Connector: BaseEncoding$DecodingException: Unrecognized character: 0xa - apache-spark

Question

I am trying to save a spark dataframe to a BigQuery table from an AWS EMR cluster. I am using the spark-bigquery-connector to do this. I have encoded my gcloud credentials service json file to Base64 from the command-line and am simply pasting the string for the credentials options. This does not work however, and causes the encoding error below. I know my json file is correct because I use it while running my script locally. What is causing this issue?
GCLOUD Service Credentials JSON File Structure
{
"type": "service_account",
"project_id": "<MY_PROJECT_NAME>",
"private_key_id": "<PRIVATE_KEY_ID>",
"private_key": "-----BEGIN PRIVATE KEY-----<LONG LIST OF CHARS>-----END PRIVATE KEY-----\n",
"client_email": "service#project.iam.gserviceaccount.com",
"client_id": "<CLIENT_ID>",
"auth_uri": "https://accounts.google.com/o/oauth2/auth",
"token_uri": "https://oauth2.googleapis.com/token",
"auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
"client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/<service>%40<project>.iam.gserviceaccount.com"
}
Spark Code
df \
.drop(*cols_to_drop) \
.write \
.format("bigquery") \
.option("temporaryGcsBucket", "emr_spark") \
.option("credentials", "<LONG_BASE64_STRING>") \
.option("project", "<MY_PROJECT_NAME>") \
.option("parentProject", "<MY_PROJECT_NAME>") \
.option("table", "<MY_PROJECT_NAME>:dataset.table") \
.mode("overwrite") \
.save()
Error:
py4j.protocol.Py4JJavaError: An error occurred while calling o137.save.
: java.lang.IllegalArgumentException: com.google.cloud.spark.bigquery.repackaged.com.google.common.io.BaseEncoding$DecodingException: Unrecognized character: 0xa
at com.google.cloud.spark.bigquery.repackaged.com.google.common.io.BaseEncoding.decode(BaseEncoding.java:219)
at com.google.cloud.spark.bigquery.repackaged.com.google.api.client.util.Base64.decodeBase64(Base64.java:104)
at com.google.cloud.spark.bigquery.SparkBigQueryOptions.createCredentials(SparkBigQueryOptions.scala:47)
at com.google.cloud.spark.bigquery.BigQueryRelationProvider$.createBigQuery(BigQueryRelationProvider.scala:125)
at com.google.cloud.spark.bigquery.BigQueryRelationProvider$$anonfun$getOrCreateBigQuery$1.apply(BigQueryRelationProvider.scala:107)
at com.google.cloud.spark.bigquery.BigQueryRelationProvider$$anonfun$getOrCreateBigQuery$1.apply(BigQueryRelationProvider.scala:107)
at scala.Option.getOrElse(Option.scala:121)
at com.google.cloud.spark.bigquery.BigQueryRelationProvider.getOrCreateBigQuery(BigQueryRelationProvider.scala:107)
at com.google.cloud.spark.bigquery.BigQueryRelationProvider.createRelation(BigQueryRelationProvider.scala:79)
at org.apache.spark.sql.execution.datasources.SaveIntoDataSourceCommand.run(SaveIntoDataSourceCommand.scala:45)
at org.apache.spark.sql.execution.command.ExecutedCommandExec.sideEffectResult$lzycompute(commands.scala:70)
at org.apache.spark.sql.execution.command.ExecutedCommandExec.sideEffectResult(commands.scala:68)
at org.apache.spark.sql.execution.command.ExecutedCommandExec.doExecute(commands.scala:86)
at org.apache.spark.sql.execution.SparkPlan$$anonfun$execute$1.apply(SparkPlan.scala:131)
at org.apache.spark.sql.execution.SparkPlan$$anonfun$execute$1.apply(SparkPlan.scala:127)
at org.apache.spark.sql.execution.SparkPlan$$anonfun$executeQuery$1.apply(SparkPlan.scala:155)
at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:151)
at org.apache.spark.sql.execution.SparkPlan.executeQuery(SparkPlan.scala:152)
at org.apache.spark.sql.execution.SparkPlan.execute(SparkPlan.scala:127)
at org.apache.spark.sql.execution.QueryExecution.toRdd$lzycompute(QueryExecution.scala:80)
at org.apache.spark.sql.execution.QueryExecution.toRdd(QueryExecution.scala:80)
at org.apache.spark.sql.DataFrameWriter$$anonfun$runCommand$1.apply(DataFrameWriter.scala:676)
at org.apache.spark.sql.DataFrameWriter$$anonfun$runCommand$1.apply(DataFrameWriter.scala:676)
at org.apache.spark.sql.execution.SQLExecution$$anonfun$withNewExecutionId$1.apply(SQLExecution.scala:78)
at org.apache.spark.sql.execution.SQLExecution$.withSQLConfPropagated(SQLExecution.scala:125)
at org.apache.spark.sql.execution.SQLExecution$.withNewExecutionId(SQLExecution.scala:73)
at org.apache.spark.sql.DataFrameWriter.runCommand(DataFrameWriter.scala:676)
at org.apache.spark.sql.DataFrameWriter.saveToV1Source(DataFrameWriter.scala:285)
at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:271)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
at py4j.Gateway.invoke(Gateway.java:282)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:238)
at java.lang.Thread.run(Thread.java:748)
Caused by: com.google.cloud.spark.bigquery.repackaged.com.google.common.io.BaseEncoding$DecodingException: Unrecognized character: 0xa
at com.google.cloud.spark.bigquery.repackaged.com.google.common.io.BaseEncoding$Alphabet.decode(BaseEncoding.java:490)
at com.google.cloud.spark.bigquery.repackaged.com.google.common.io.BaseEncoding$Base64Encoding.decodeTo(BaseEncoding.java:974)
at com.google.cloud.spark.bigquery.repackaged.com.google.common.io.BaseEncoding.decodeChecked(BaseEncoding.java:233)
at com.google.cloud.spark.bigquery.repackaged.com.google.common.io.BaseEncoding.decode(BaseEncoding.java:217)
... 39 more

Answer 1

I believe the issue arises because the connector expects string input, but the Base64 encoding generates a bytes object. So simply utf-8 decoding the Base64 encoded bytes solved my DecodingException.
import json
import base64
creds = JSON credentials
# Dump json to str. Encode to utf-8 to get bytes. Encode bytes to Base64 bytes.
# Decode bytes to get a string
creds64 = base64.b64encode(json.dumps(creds).encode('utf-8')).decode('utf-8')

Answer 2

The issue was how the string was represented in my python script.
Representing the string in multiple lines caused the encoding error:
credentials="""
ewogICJ0eXBlIjogInNlcnZpY2VfYWNjb3VudCIsCiAgInByb2plY3RfaWQiOiAiPE1ZX1BST0pFQ1RfTkFNRT4iL
AogICJwcml2YXRlX2tleV9pZCI6ICI8UFJJVkFURV9LRVlfSUQ+IiwKICAicHJpdmF0ZV9rZXkiOiAiLS0tLS1CRU
dJTiBQUklWQVRFIEtFWS0tLS0tPExPTkcgTElTVCBPRiBDSEFSUz4tLS0tLUVORCBQUklWQVRFIEtFWS0tLS0tXG4
iLAogICJjbGllbnRfZW1haWwiOiAic2VydmljZUBwcm9qZWN0LmlhbS5nc2VydmljZWFjY291bnQuY29tIiwKICAi
Y2xpZW50X2lkIjogIjxDTElFTlRfSUQ+IiwKICAiYXV0aF91cmkiOiAiaHR0cHM6Ly9hY2NvdW50cy5nb29nbGUuY
29tL28vb2F1dGgyL2F1dGgiLAogICJ0b2tlbl91cmkiOiAiaHR0cHM6Ly9vYXV0aDIuZ29vZ2xlYXBpcy5jb20vdG
9rZW4iLAogICJhdXRoX3Byb3ZpZGVyX3g1MDlfY2VydF91cmwiOiAiaHR0cHM6Ly93d3cuZ29vZ2xlYXBpcy5jb20
vb2F1dGgyL3YxL2NlcnRzIiwKICAiY2xpZW50X3g1MDlfY2VydF91cmwiOiAiaHR0cHM6Ly93d3cuZ29vZ2xlYXBp
cy5jb20vcm9ib3QvdjEvbWV0YWRhdGEveDUwOS88c2VydmljZT4lNDA8cHJvamVjdD4uaWFtLmdzZXJ2aWNlYWNjb
3VudC5jb20iCn0=
"""
Representing the string in one line fixed my issue:
credentials="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"
As mentioned in comments, you can also use the backslash at the end of each line as well