There are several Built in subroutines in VCL ;
vcl_recv,vcl_pipe,vcl_pass,vcl_hit,vcl_miss and so on;
ref. https://varnish-cache.org/docs/4.1/users-guide/vcl-built-in-subs.html
Can anyone tell me
which built-in objects are accessible from which subroutine. ?
(perhaps in tabular format)
You can find this information here, e.g.:
bereq.backend
Type: BACKEND
Readable from: vcl_pipe, backend
Writable from: vcl_pipe, backend
This is the backend or director we attempt to fetch from.
Related
https://github.com/DefinitelyTyped/DefinitelyTyped/blob/bb1cc0e143f40f52a8d771e93036fc211df85cfb/types/nano/index.d.ts#L160
i am new to couch db and i know, i can use "fetch" if i want doc in result but i want doc in result based on some conditions when called with start_key and end_key. any help would be appreciated.
fetchRevs(
docnames: BulkFetchDocsWrapper,
params: DocumentFetchParams,
callback?: Callback<DocumentFetchRevsResponse>
): Request;
The fetchRevs endpoint is probably not what you want. I would take a look at the CouchDB API Overview and use:
PUT /mydb to create a database
PUT /mydb/docid to create a document in a database
GET /mydb/_all_docs?include_docs=true to retrieve all the documents
POST /mydb/_find to query the database
These API endpoints are modelled in the Typescript definition file you reference together with URLs that reference the API equivalents.
I am deploying FIWARE security GEs (i.e., Wilma, AuthzForce, Keyrock) in my computer. Security level 2 (Basic Authorization) is working well, but now I need security level 3 (Advanced Authorization) using XACML.
Long story short, I want a tutorial of implementation security level 3. However, as far as I know, any tutorial or document about security level 3 does not exist.
For now, I create my policy with PAP's API, and change 'custom_policy' option in config.js from 'undefined' to 'policy.js'. And then I create 'policy.js' file into 'PEP/policies', but don't change anything compared with its template file because I don't know what this code does exactly. I think I should make XACML Request form using 'xml' variable. But in my case, PEP gives me the error when I make the XACML Request using 'xml' variable, and return this variable. Here is my error of PEP:
Error: Root - Error in AZF communication <?xml version="1.0" encoding="UTF-8" standalone="yes"?><error xmlns="http://authzforce.github.io/rest-api-model/xmlns/authz/S" xmlns:ns2="http://www.w3.org/2005/Atom" xmlns:ns3="http://authzforce.github.io/core/xmlns/pdp/5.0" xmlns:ns4="http://authzforce.github.io/pap-dao-flat-file/xmlns/properties/3.6"><message>Invalid parameters: cvc-elt.1: Cannot find the declaration of element 'Request'.</message></error>
And here is my 'getPolicy' code (XACML Request) in policy.js. I just made very simple request whether response is permit or not because I'm not sure what I'm doing at that time.:
exports.getPolicy = function (roles, req, app_id) {
var xml = xmlBuilder.create('Request', {
'xmlns': 'urn:oasis:names:tc:xacml:3.0:core:schema:wd-17',
'CombinedDecision': 'false',
'ReturnPolicyIdList': 'false'})
.ele('Attributes', {
'Category': 'urn:oasis:names:tc:xacml:1.0:subject-category:access-subject'});
So, anyone can give me any information about implementation of security level 3?
Upgrade to Wilma 6.2 (bug fixing).
Reuse the code from lib/azf.js which is known to work, and adapt the Request content to your needs. The variable is wrongly called XACMLPolicy there, but don't be mistaken, this is an actual XACML Request. This is using xml2json package to convert the JSON to XML, whereas in your code you seem to use a different one, xmlbuilder maybe? You didn't paste the full code - where does this xmlBuilder variable come from? - so I'm just guessing.
If you are indeed using xmlbuilder package and want to stick with it, I notice that in the example using namespaces, the xmlns attribute is put in a different way:
var xmlBuilder = require('xmlbuilder');
var xml = xmlBuilder.create('Request', { encoding: 'utf-8' })
.att('xmlns', 'urn:oasis:names:tc:xacml:3.0:core:schema:wd-17')
.att('CombinedDecision': 'false')
.att('ReturnPolicyIdList': 'false')
.ele('Attributes', {'Category': 'urn:oasis:names:tc:xacml:1.0:subject-category:access-subject'});
Maybe this makes a difference, I didn't check.
Also feel free to create an issue with your question on Wilma's github to get help from the dev team. (I am not one of them but we've worked together for AuthzForce integration.)
The error you are getting is really
Invalid parameters: cvc-elt.1: Cannot find the declaration of element
'Request'.
This is a simple XML validation issue. You need to make sure that the XACML request you send contains the right namespace declaration.
You'll see there is another question on this topic here.
Can you paste your XACML request so we can tell whether it is valid?
Since, I can get parameters from both the methods using a code similar to the one below:
req.params.<PARAM NAME> in single/many separate app.METHOD function(s)
(think this may result in code repetition)
&
app.params(<ARRAY>,<CALLBACK>) function, independent of the app.METHOD functions, and called if the URL contains any parameter (:id, :name .etc)
What are the use-cases to apply one over the other?
My best guess would be is using app.params for parameter validation or some sort of preprocessing. For example the express docs provide and example where you attach req.user information to the request using app.params and after that you can work directly with the user information instead of processing the parameter again. Using req.params would be more specific in terms of processing the specific query. For example I'd use req.params for a REST endpoint which should perform an operation by id (update/delete) as in general there shouldn't be any additional preprocessing involder.
I'm writing a REST api in node js that will execute a sql query and send the results;
in the request I need to send the WHERE conditions; ex:
GET 127.0.0.1:5007/users //gets the list of users
GET 127.0.0.1:5007/users
id = 1 //gets the user with id 1
Right now the conditions are passed from the client to the rest api in the request's headers.
In the API I'm using sequelize, an ORM that needs to receive WHERE conditions in a particular form (an object); ex: having the condition:
(x=1 AND (y=2 OR z=3)) OR (x=3 AND y=1)
this needs to be formatted as a nested object:
-- x=1
-- AND -| -- y=2
| -- OR ----|
| -- z=3
-- OR -|
|
| -- x=3
-- AND -|
-- y=1
so the object would be:
Sequelize.or (
Sequelize.and (
{x=1},
Sequelize.or(
{y=2},
{z=3}
)
),
Sequelize.and (
{x=3},
{y=1}
)
)
Now I'm trying to pass a simple string (like "(x=1 AND (y=2 OR z=3)) OR (x=3 AND y=1)"), but then I will need a function on the server that can convert the string in the needed object (this method in my opinion has the advantage that the developer writing the client, can pass the where conditions in a simple way, like using sql, and this method is also indipendent from the used ORM, with no need to change the client if we need to change the server or use a different ORM);
The function to read and convert the conditions' string into an object is giving me headache (I'm trying to write one without success, so if you have some examples about how to do something like this...)
What I would like to get is a route capable of executing almost any kind of sql query and give the results:
now I have a different route for everything:
127.0.0.1:5007/users //to get all users
127.0.0.1:5007/users/1 //to get a single user
127.0.0.1:5007/lastusers //to get user registered in the last month
and so on for the other tables i need to query (one route for every kind of request I need in the client);
instead I would like to have only one route, something like:
127.0.0.1:5007/request
(when calling this route I will pass the table name and the conditions' string)
Do you think this solution would be a good solution or you generally use other ways to handle this kind of things?
Do you have any idea on how to write a function to convert the conditions' string into the desired object?
Any suggestion would be appreciated ;)
I would strongly advise you not to expose any part of your database model to your clients. Doing so means you can't change anything you expose without the risk of breaking the clients. One suggestion as far as what you've supplied is that you can and should use query parameters to cut down on the number of endpoints you've got.
GET /users //to get all users
GET /users?registeredInPastDays=30 //to get user registered in the last month
GET /users/1 //to get a single user
Obviously "registeredInPastDays" should be renamed to something less clumsy .. it's just an example.
As far as the conditions string, there ought to be plenty of parsers available online. The grammar looks very straightforward.
IMHO the main disadvantage of your solution is that you are creating just another API for quering data. Why create sthm from scratch if it is already created? You should use existing mature query API and focus on your business logic rather then inventing sthm new.
For example, you can take query syntax from Odata. Many people have been developing that standard for a long time. They have already considered different use cases and obstacles for query API.
Resources are located with a URI. You can use or mix three ways to address them:
Hierarchically with a sequence of path segments:
/users/john/posts/4711
Non hierarchically with query parameters:
/users/john/posts?minVotes=10&minViews=1000&tags=java
With matrix parameters which affect only one path segment:
/users;country=ukraine/posts
This is normally sufficient enough but it has limitations like the maximum length. In your case a problem is that you can't easily describe and and or conjunctions with query parameters. But you can use a custom or standard query syntax. For instance if you want to find all cars or vehicles from Ford except the Capri with a price between $10000 and $20000 Google uses the search parameter
q=cars+OR+vehicles+%22ford%22+-capri+%2410000..%2420000
(the %22 is a escaped ", the %24 a escaped $).
If this does not work for your case and you want to pass data outside of the URI the format is just a matter of your taste. Adding a custom header like X-Filter may be a valid approach. I would tend to use a POST. Although you just want to query data this is still RESTful if you treat your request as the creation of a search result resource:
POST /search HTTP/1.1
your query-data
Your server should return the newly created resource in the Location header:
HTTP/1.1 201 Created
Location: /search/3
The result can still be cached and you can bookmark it or send the link. The downside is that you need an additional POST.
Given the following code:
listView.ItemsSource =
App.azureClient.GetTable<SomeTable>().ToIncrementalLoadingCollection();
We get incremental loading without further changes.
But what if we modify the read.js server side script to e.g. use mssql to query another table instead. What happens to the incremental loading? I'm assuming it breaks; if so, what's needed to support it again?
And what if the query used the untyped version instead, e.g.
App.azureClient.GetTable("SomeTable").ReadAsync(...)
Could incremental loading be somehow supported in this case, or must it be done "by hand" somehow?
Bonus points for insights on how Azure Mobile Services implements incremental loading between the server and the client.
The incremental loading collection works by sending the $top and $skip query parameters (those are also sent when you do a query by using the .Take and .Skip methods in the table). So if you want to modify the read script to do something other than the default behavior, while still maintaining the ability to use that table with an incremental loading collection, you need to take those values into account.
To do that, you can ask for the query components, which will contain the values, as shown below:
function read(query, user, request) {
var queryComponents = query.getComponents();
console.log('query components: ', queryComponents); // useful to see all information
var top = queryComponents.take;
var skip = queryComponents.skip;
// do whatever you want with those values, then call request.respond(...)
}
The way it's implemented at the client is by using a class which implements the ISupportIncrementalLoading interface. You can see it (and the full source code for the client SDKs) in the GitHub repository, or more specifically the MobileServiceIncrementalLoadingCollection class (the method is added as an extension in the MobileServiceIncrementalLoadingCollectionExtensions class).
And the untyped table does not have that method - as you can see in the extension class, it's only added to the typed version of the table.