Changes between Version 1 and Version 2 of Hesiod

Timestamp:

02/23/12 10:20:54 (13 years ago)

Author:

jdreed

Comment:

--

Hesiod

@@ +1 @@
+=Hesiod=
+
+==Background==
+
 Hesiod 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.
 
 Hesiod is used in several places in Debathena:
  * Retrieving a user's entries in the passwd and group databases
+  * 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.
  * Determining which mail system they're using and if IMAP, which server to speak to
  * Translating a locker name to an AFS path, including the user's homedir
@@ -11 +16 @@
 Hesiod may, in some cases, be used to select a default printer for a specific workstation.  This information is ignored in the public cluster environment.
 
-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.
+==Examples==
 
+Hesiod can be queried with the `hesinfo` command.  
+
+{{{
+$ hesinfo jdreed passwd
+jdreed:*:7263:101:Jonathan D Reed,E17-110A,6172530657,:/mit/jdreed:/bin/athena/bash
+}}}
+
+Because [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).
+
+{{{
+$ getent passwd jdreed
+jdreed:*:7263:101:Jonathan D Reed,E17-110A,6172530657,:/mit/jdreed:/bin/athena/bash
+}}}
+
+The `hes` command in the `consult` locker takes a Hesiod name and iterates over all possible Hesiod types.
+
+{{{
+$ add consult
+$ hes jdreed
+    PASSWD: jdreed:*:7263:101:Jonathan D Reed,E17-110A,6172530657,:/mit/jdreed:/bin/athena/bash
+    FILSYS: AFS /afs/athena.mit.edu/user/j/d/jdreed w /mit/jdreed
+     POBOX: POP PO14.MIT.EDU jdreed
+   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:
+
+$ hes zephyr
+    FILSYS: AFS /afs/athena.mit.edu/astaff/project/zephyr w /mit/zephyr
+      SLOC: ARILINN.MIT.EDU
+      SLOC: NESKAYA.MIT.EDU
+   SERVICE: zephyr udp 2102
+}}}