54 lines
1.6 KiB
Go
54 lines
1.6 KiB
Go
package client
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import (
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"context"
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"sort"
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"go.unistack.org/micro/v4/errors"
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"go.unistack.org/micro/v4/router"
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)
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// LookupFunc is used to lookup routes for a service
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type LookupFunc func(context.Context, Request, CallOptions) ([]string, error)
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// LookupRoute for a request using the router and then choose one using the selector
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func LookupRoute(_ context.Context, req Request, opts CallOptions) ([]string, error) {
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// check to see if an address was provided as a call option
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if len(opts.Address) > 0 {
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return opts.Address, nil
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}
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if opts.Router == nil {
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return nil, router.ErrRouteNotFound
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}
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// construct the router query
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query := []router.QueryOption{router.QueryService(req.Service())}
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// if a custom network was requested, pass this to the router. By default the router will use it's
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// own network, which is set during initialisation.
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if len(opts.Network) > 0 {
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query = append(query, router.QueryNetwork(opts.Network))
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}
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// lookup the routes which can be used to execute the request
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routes, err := opts.Router.Lookup(query...)
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if err == router.ErrRouteNotFound {
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return nil, errors.InternalServerError("go.micro.client", "service %s: %s", req.Service(), err.Error())
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} else if err != nil {
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return nil, errors.InternalServerError("go.micro.client", "error getting next %s node: %s", req.Service(), err.Error())
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}
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// sort by lowest metric first
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sort.Slice(routes, func(i, j int) bool {
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return routes[i].Metric < routes[j].Metric
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})
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addrs := make([]string, 0, len(routes))
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for _, route := range routes {
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addrs = append(addrs, route.Address)
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}
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return addrs, nil
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}
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