Changes between Version 1 and Version 2 of Hesiod


Ignore:
Timestamp:
02/23/12 10:20:54 (10 years ago)
Author:
jdreed
Comment:

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  • Hesiod

    v1 v2  
     1=Hesiod= 
     2 
     3==Background== 
     4 
    15Hesiod is a simple string lookup service built on top of the Domain Name System.  Conceptually, the service translates a pair of strings (the "name" and "type") into a set of result strings.  This lookup is done very simply; a DNS lookup is done for name.type.ns.athena.mit.edu and the strings in the resulting TXT records are returned. 
    26 
    37Hesiod is used in several places in Debathena: 
    48 * Retrieving a user's entries in the passwd and group databases 
     9  * Due to DNS limitations, the group list is often truncated.  A group must be marked as an "NFS Group" in order for group membership to be propagated to Hesiod. 
    510 * Determining which mail system they're using and if IMAP, which server to speak to 
    611 * Translating a locker name to an AFS path, including the user's homedir 
     
    1116Hesiod may, in some cases, be used to select a default printer for a specific workstation.  This information is ignored in the public cluster environment. 
    1217 
    13 Hesiod can be queried with the `hesinfo` command.  The `hes` command in the `consult` locker takes a Hesiod name and iterates over all possible Hesiod types. 
     18==Examples== 
    1419 
     20Hesiod can be queried with the `hesinfo` command.   
     21 
     22{{{ 
     23$ hesinfo jdreed passwd 
     24jdreed:*:7263:101:Jonathan D Reed,E17-110A,6172530657,:/mit/jdreed:/bin/athena/bash 
     25}}} 
     26 
     27Because [wiki:NSS] uses a Hesiod backend, you can accomplish the same thing with getent(1) (assuming there is not already a local user with the same name). 
     28 
     29{{{ 
     30$ getent passwd jdreed 
     31jdreed:*:7263:101:Jonathan D Reed,E17-110A,6172530657,:/mit/jdreed:/bin/athena/bash 
     32}}} 
     33 
     34The `hes` command in the `consult` locker takes a Hesiod name and iterates over all possible Hesiod types. 
     35 
     36{{{ 
     37$ add consult 
     38$ hes jdreed 
     39    PASSWD: jdreed:*:7263:101:Jonathan D Reed,E17-110A,6172530657,:/mit/jdreed:/bin/athena/bash 
     40    FILSYS: AFS /afs/athena.mit.edu/user/j/d/jdreed w /mit/jdreed 
     41     POBOX: POP PO14.MIT.EDU jdreed 
     42   GRPLIST: docsourc:2567:hdops:80547:bugs-acl:967:webmeet-adm:26990:ctug-admin:23752:facdev:14008:chd-home:27063:gsipb:15001:tooltime-acl:18546:cvs-users:18719:tooltime-team:26355:minidev:691:is-archive:29512:is-www:26481:olcdev:367:mcc-www:9235:helpstaff:16886: 
     43 
     44$ hes zephyr 
     45    FILSYS: AFS /afs/athena.mit.edu/astaff/project/zephyr w /mit/zephyr 
     46      SLOC: ARILINN.MIT.EDU 
     47      SLOC: NESKAYA.MIT.EDU 
     48   SERVICE: zephyr udp 2102 
     49}}}