From: Brian Warner Date: Thu, 5 Jul 2007 20:36:03 +0000 (-0700) Subject: add webapi.txt: explain our plans for the node's webserver X-Git-Url: https://git.rkrishnan.org/Site/Content/Exhibitors/nxhtml.html?a=commitdiff_plain;h=c15f37dc9be5d6c742d0c738f45b5b79288db1a0;p=tahoe-lafs%2Ftahoe-lafs.git add webapi.txt: explain our plans for the node's webserver --- diff --git a/docs/webapi.txt b/docs/webapi.txt new file mode 100644 index 00000000..ea1c9604 --- /dev/null +++ b/docs/webapi.txt @@ -0,0 +1,246 @@ + +Writing "8011" into CLIENTDIR/webport causes the client to run a webserver on +port 8011. Writing "tcp:8011:interface=127.0.0.1" into CLIENTDIR/webport does +the same but binds to the loopback interface, insuring that only the programs +on the local host can connect. Using +"ssl:8011:privateKey=mykey.pem:certKey=cert.pem" would run an SSL server. See +twisted.application.strports for more details. + +If CLIENTDIR/webpassword exists, it will be used (somehow) to require HTTP +Digest Authentication for all webserver connections. + + +The client provides some small number of "virtual drives". In the 0.4.0 +release, this number is two: the first is the global shared vdrive, the +second is the private non-shared vdrive. We will call these "global" and +"private" for now. + +For the purpose of this document, let us assume that the vdrives currently +contain the following directories and files: + + global/ + global/Documents/ + global/Documents/notes.txt + + private/ + private/Pictures/ + private/Pictures/tractors.jpg + + +== vdrive == + +Within the webserver, there is a tree of resources. The top-level "vdrive" +resource gives access to files and directories in all of the user's virtual +drives. For example, the URL that corresponds to notes.txt would be: + +FILEURL = http://localhost:8011/vdrive/global/Documents/notes.txt + +and the URL for tractors.jpg would be: + + http://localhost:8011/vdrive/private/Pictures/tractors.jpg + +In addition, each directory has a corresponding URL. The Pictures URL is: + +DIRURL = http://localhost:8011/vdrive/private/Pictures + +Now, what can we do with these URLs? By varying the HTTP "method" +(GET/PUT/POST/DELETE) and by appending a type-indicating query argument, we +control how what we want to do with the data and how it should be presented. + +In the following examples, FILEURL and DIRURL are abbreviations for the +previously listed examples. In addition. NEWFILEURL and NEWDIRURL are URLs +for files and directories which do not yet exist. + +=== Files === + + GET FILEURL + + This simply retrives the contents of the file at the given place in the + vdrive. The Content-Type is set according to the vdrive's metadata (if + available) or by using the usual filename-extension-magic built into most + webservers. The file's contents are provided in the body of the HTTP + response. + + (thought: we could conceivably provide some measure of gathering-peers + progress and pre-plaintext status information by emitting some extra + X-Tahoe-Status headers. Of course, once the headers are done and we start + sending plaintext, we have to stop sending such headers) + + PUT NEWFILEURL + + This uploads a file to the given place in the vdrive. It will create + intermediate directory nodes as necessary. The file's contents are taken + from the body of the HTTP request. For convenience, the HTTP response + contains the URI that results from uploading the file, although the client + is not obligated to do anything with the URI. According to the HTTP/1.1 + specification (rfc2068), this should return a 200 (OK) code when modifying + and existing file, and a 201 (Created) code when creating a new file. + + DELETE FILEURL + + This deletes the given file from the vdrive. Note that this *does not* + delete any parent directories, so a sequence of 'PUT NEWFILEURL' and + 'DELETE NEWFILEURL' does not return the vdrive to its original state (it + may leave some intermediate directory nodes). + + GET FILEURL?t=json + GET FILEURL?t=xml + + This returns machine-parseable information about the file in the HTTP + response body, including file size, metadata (like Content-Type), and URIs. + This information is also required to contain a flag that distinguishes + between files and directories. Programatic clients are expected to use this + query before actually downloading the file's contents. + + GET FILEURL?localfile=$FILENAME + + This instructs the client to download the given file and write its contents + into the local filesystem at $FILENAME. This request will only be accepted + from an HTTP client connection originating at 127.0.0.1 . This request is + most useful when the client node and the HTTP client are operated by the + same user. $FILENAME should be an absolute pathname. + + (thoughts: we could use either the response headers or the response body + to indicate download progress) + + PUT NEWFILEURL?localfile=$FILENAME + + This uploads file to the vdrive and gets the contents from a file in the + client's local filesystem. As with GET, this request will only be accepted + from an HTTP connection originating from 127.0.0.1. + + (we could indicate upload progress too. The response body could contain + the URI of the uploaded file) + + + GET FILEURL?t=uri + + This returns the URI of the given file in the HTTP response body. + +=== Directories === + + GET DIRURL + + This returns an HTML page, intended to be used by humans, which contains + HREF links to all files and directories reachable from this dirnode. These + HREF links do not have a t= argument, meaning that a human who follows them + will get pages also meant for a human. It also contains forms to upload new + files, and to delete files and directories. These forms use POST methods to + do their job. + + GET DIRURL?t=json + GET DIRURL?t=xml + + This returns machine-parseable information about this directory in the HTTP + response body. This information first contains a flag to indicate that + DIRURL referenced a directory (as opposed to a file). Then it contains a + flag to indicate whether this is a read-write dirnode or a read-only + dirnode. Finally it also contains information about the children of this + directory, probably as a mapping from child name to a set of metadata about + the child (basically the same data that would appear in a corresponding + GET?t=xml of the child itself). A programmatic client should be able to use + the information from this query to display filesystem navigation choices to + a human user. + + GET DIRURL?t=uri + GET DIRURL?t=readonly-uri + + Return a URI for this dirnode in the HTTP response body. If the dirnode is + read-only, the t=uri and t=readonly-uri responses will be the same. + + PUT NEWDIRURL?t=mkdir + + Create a new empty directory at the given path. The HTTP response contains + the URI of the given directory, although the client is not obligated to do + anything with it. + + GET DIRURL?localdir=$DIRNAME + + This instructs the client to perform a recursive download of the given + directory and all its descendant files and directories, writing the results + to the local filesystem starting at DIRNAME. + + (thoughts: we could use the response headers or the response body to + indicate download progress) + + PUT NEWDIRURL?localdir=$DIRNAME + + This instructs the client to perform a recursive upload of a directory on + the local filesystem into the vdrive at the given location. + + +== POST Forms == + + POST DIRURL?t=upload-form + + This instructs the client to upload a file into the given dirnode. We need + this because forms are the only way for a web browser to upload a file + (browsers do not know how to do PUT or DELETE). The file's contents and the + new child name will be included in the form's arguments. This can only be + used to upload a single file at a time. + + POST DIRURL?t=mkdir-form + + This instructs the client to create a new empty directory. The name of the + new child directory will be included in the form's arguments. + + POST DIRURL?t=put-uri-form + + This instructs the client to attach a child that is referenced by URI (just + like the PUT NEWFILEURL?t=uri method). The name and URI of the new child + will be included in the form's arguments. + + POST DIRURL?t=delete-form + + This instructs the client to delete a file from the given dirnode. The name + of the child to be deleted will be included in the form's arguments. + + +== URI == + + http://localhost:8011/uri/$URI + + A separate top-level resource namespace ("uri" instead of "vdrive") is used + to get access to files and dirnodes that are indexed directly by URI, + rather than by going through the vdrive. The resource thus referenced is + used the same way as if it were accessed through the vdrive, including + child-resource-traversal behavior. For example, if the URI corresponds to a + file, then + + GET http://localhost:8011/uri/$URI + + would retrieve the contents of the file. If the URI corresponds to a + directory, then: + + PUT http://localhost:8011/uri/$URI/subdir/newfile?localfile=$FILENAME + + would upload a file (with contents taken from the local filesystem) to a + new file in a subdirectory of the referenced dirnode. + + PUT NEWFILEURL?t=uri + + This attaches a child (either a file or a directory) to the vdrive at the + given location. The URI is provided in the body of the HTTP request. This + can be used to attach a shared directory to the vdrive. Intermediate + directories are created on-demand just like with the regular PUT command. + +== XMLRPC == + + http://localhost:8011/xmlrpc + + This resource provides an XMLRPC server on which all of the previous + operations can be expressed as function calls taking a "pathname" argument. + This is provided for applications that want to think of everything in terms + of XMLRPC. + + listdir(vdrivename, path) -> dict of (childname -> (stuff)) + put(vdrivename, path, contents) -> URI + get(vdrivename, path) -> contents + mkdir(vdrivename, path) -> URI + put_localfile(vdrivename, path, localfilename) -> URI + get_localfile(vdrivename, path, localfilename) + put_localdir(vdrivename, path, localdirname) # recursive + get_localdir(vdrivename, path, localdirname) # recursive + put_uri(vdrivename, path, URI) + + etc..