Unable to change read write permissions to hdfs directory

Question

I am trying to copy text file into hdfs location.
I'm facing Access issue, so I tried changing permissions.
But I'm unable to change the same facing below error:

chaithu@localhost:~$ hadoop fs -put test.txt /user
put: Permission denied: user=chaithu, access=WRITE, inode="/user":hdfs:supergroup:drwxr-xr-x

chaithu@localhost:~$ hadoop fs -chmod 777 /user
chmod: changing permissions of '/user': Permission denied. user=chaithu is not the owner of inode=user

chaithu@localhost:~$ hadoop fs -ls /
Found 2 items
drwxrwxrwt   - hdfs supergroup          0 2017-12-20 00:23 /tmp
drwxr-xr-x   - hdfs supergroup          0 2017-12-20 10:24 /user

Kindly help me how can I change the rights to full read and write for all users to access the HDFS folder.

Answer 1

First off, you shouldn't be writing into the /user folder directly nor set 777 on it

You're going to need a user directory for your current user to even run a mapreduce job, so you need to sudo su - hdfs first to become an HDFS superuser.

Then run these to create HDFS directories for your user account

 hdfs dfs -mkdir -p /user/chaithu
 hdfs dfs -chown -R chaithu /user/chaithu
 hdfs dfs -chmod -R 770 /user/chaithu

Then exit from the hdfs user, and chaithu can now write to its own HDFS directory.

hadoop fs -put test.txt

That alone will put the file in the current user's folder.

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Or, if that's too much work for you write to /tmp instead

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A lazy option is to rewrite your user account to the super user.

export HADOOP_USER_NAME=hdfs 
hadoop fs -put test.txt /user

And this is why hadoop is not secure or enforce user account access by default (i.e. never do this in production)

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And finally, you can always just turn permissions completely off in hdfs-site.xml (again, only useful in development phases)

 <property>
    <name>dfs.permissions</name>
    <value>false</value>
  </property>