Retriever's configuration file

This is the file that stores all configuration information the retriever module needs to establish a connection to a HTTP server and submit a (properly authenticated) request(s) for products and updates. The file is normally named retriever.conf (although any other name would do): this file is passed to the retriever as the first command-line parameter.

The file adheres to the standard JMV config file format

SERVER_URL
The complete URL to a Metcast server (a CGI script on a HTTP server that can take a Metcast request and try to handle it). This is the same kind of information one types on the "Location:" line in Netscape.
Examples:
SERVER_URL = http://152.80.34.202/cgi-bin/server
SERVER_URL = HTTP://nites-2:80/
SERVER_URL = http://www.nlmoc.navy.mil
SERVER_URL = file:///users/oleg/HTTP-Retrieve/conus.mime

PROXY_NAME
The name (or an IP address) of a HTTP proxy. This is the same thing a user enters into Netscape's "Options:Network Preferences:Proxies:Manual Proxy Configuration:HTTP Proxy" field.
Examples:
PROXY_NAME = 192.16.167.45
PROXY_NAME = phobos.metnet.navy.mil

PROXY_PORT
The port on the HTTP proxy host for listening (and relaying) HTTP connections. This is the same value a user enters into Netscape's "Options:Network Preferences:Proxies:Manual Proxy Configuration:HTTP Proxy:Port" field. If this parameter is omitted, a default value of 80 is assumed.
Example:
PROXY_PORT = 80

PROXY_ENABLE
TRUE/FALSE: tells if the SERVER_URL is to be accessed through the proxy specified by PROXY_NAME and PROXY_PORT. If PROXY_ENABLE=FALSE the corresponding fields in the JMV net options panel ought to be grayed out. For what I care, I won't even look for PROXY_NAME if PROXY_ENABLE is FALSE.

AUTH_CREDENTIAL
A credential of a particular user or site to submit to a HTTP server for authentication. The retriever as a user agent sends this credential to the server in a Authorization: request header. The credential may be required by the server to access a (supposedly restricted) resource specified in SERVER_URL
Example:
AUTH_CREDENTIAL = Basic Y2xhbXM6Y2hvd2Rlcg==
See Authorization and Access Authentication for more details.

AUTH_ENABLE
TRUE/FALSE: tells if the client wants to go into trouble of authenticating itself. If the resource at SERVER_URL is publicly available (or a Metcast's Web server would grant access considering client's IP address), the authentication may not be necessary. Again, if AUTH_ENABLE = FALSE, USERNAME and PASSWORD fields on the JMV configuration panel ought to be grayed out; as far as the retriever is concerned, it won't even look for the AUTH_CREDENTIAL field in this configuration file if AUTH_ENABLE is FALSE or omitted.

REQ_IF_MODIFIED
TRUE/FALSE; FALSE means the client is asking a Metcast server for products no matter how old they are; TRUE means that the client asks for products updated/created within the last REQ_IF_MODIFIED_SINCE minutes.

REQ_IF_MODIFIED_SINCE
The number of minutes for the fresh-products request. This value only matters if REQ_IF_MODIFIED was set to TRUE. Example:
REQ_IF_MODIFIED_SINCE = 10

REQ_UPDATES
TRUE/FALSE: TRUE means that the client should not exit after submitting the request and processing server's reply. Rather, the retriever would sleep in the background, and with the period of REQ_UPDATES_INTERVAL minutes, repeatedly ask the Metcast server for product updates.

REQ_UPDATES_INTERVAL
The number of minutes for requesting product updates. Example:
REQ_UPDATES_INTERVAL = 15

RETRY_ON_ERROR
The number of times the retriever would try to repeat a request that failed because of a third-party error. A request may fail for a number of reasons, some of them are the client's fault (for example, a syntax error in the request message), but some of them are not (e.g., a network connection has timed out or unexpectedly terminated, the server is temporarily unavailable, etc). It is the latter errors that may be remedied by retrying the request, a specified number of times.

The field is not mandatory; if it is omitted, some reasonable default will be used (typically 5 times)

Example:
RETRY_ON_ERROR = 5

Example

# JMV HTTP transport configuration

SERVER_URL = http://152.80.34.202:80/cgi-bin/server
PROXY_ENABLE = TRUE
PROXY_NAME = 192.16.167.45
PROXY_PORT = 80
AUTH_CREDENTIAL = Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==
AUTH_ENABLE = true
REQ_IF_MODIFIED = true
REQ_IF_MODIFIED_SINCE = 120
REQ_UPDATES = FALSE
REQ_UPDATES_INTERVAL = 15
RETRY_ON_ERROR = 7

History

$Id: Retriever-conf.html,v 2.1 1998/04/25 01:53:32 oleg Exp oleg $