2014-09-04 22:46 GMT+04:00 Daniel Mikusa <dmik...@pivotal.io>: > On Thu, Sep 4, 2014 at 1:48 PM, David P. Caldwell < > da...@code.davidpcaldwell.com> wrote: > >> I have a small program that downloads and installs an arbitrary >> version of Tomcat, using the API provided by Apache to select the >> proper mirror, and so forth. >> >> The script currently takes the Tomcat version as an argument. My >> script provides a default (which in my case is the latest version of >> Tomcat 7), but I have to manually update that default whenever I >> notice a new version has been released. >> >> What would be the best way for the script itself to determine the >> latest available version? Obviously I would give points for "easy" and >> points for "robust," knowing that those two things might be in >> conflict. >> >> I can think of many horrifying ways to do it: >> >> * loop through integers starting with the last known version, >> attempting to download 7.0.x, until getting a 404 >> * scraping and parsing the HTML at >> http://archive.apache.org/dist/tomcat/tomcat-7/, which I expect is >> rather stable >> > > I did this recently for Tomcat 8. Here's the command I used, which works > on my Mac. > > LATEST_VERSION=$(curl -s http://tomcat.apache.org/download-80.cgi | grep > "<h3 id=\"8.0." | xpath '/h3/text()' 2>/dev/null) > > A slight variation works on Ubuntu if you install xpath. > > LATEST_VERSION=$(curl -s http://tomcat.apache.org/download-80.cgi | grep > "<h3 id=\"8.0." | xpath -e '/h3/text()' 2>/dev/null) > > I'm sure there are other ways to do it, this was just the first one I put > together that worked for me. >
There also exist the following XML file.and the following page http://tomcat.apache.org/doap_Tomcat.rdf http://tomcat.apache.org/whichversion.html >> So my challenge isn't coming up with *a* way to do it, but coming up >> with the best way. I would say that download-nn.cgi is the most reliable from the above ones. A version cannot be released without updating the download page. But there are the following concerns: - server generates the page dynamically, (but as a bonus it gives you a list of best mirrors for your IP address) - stability of markup. (I would prefer to parse a download link, instead of <h3> header tag) If those are of concern, then the doap_Tomcat.rdf XML file would be a better source of information. Regarding parsing the download page of a mirror (and archive,apache.org is one of those mirrors): - An announcement and tomcat.a.o site update are usually postponed by a day to let the mirrors sync. If you parse the page of a mirror, you may get version number that have already been released to mirrors, but have not yet announced. The version may be absent from other mirrors. - If you parse the page of a mirror and there are several Tomcat versions available (e.g. N and N-1), and your user chooses version "N-1". It allows you to download the version "N-1" from the mirror instead of archive.a.o site. By the way, do you verify md5 hash or PGP signature of the files downloaded from mirrors? > * loop through integers starting with the last known version, > attempting to download 7.0.x, until getting a 404 There have been several reports of mirrors that did not respond with proper 404, but instead produced a redirection to some advertisement page. Such behaviour is against ASF mirror policies, and those mirrors have been unlisted y ASF infrastructure team, but it may happen again. Sometimes a MiTM responds with a redirect (e.g. a mobile operator may do so when there are some problems with your account). Best regards, Konstantin Kolinko --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
