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| 1 | +// Copyright 2019 the Kilo authors |
| 2 | +// |
| 3 | +// Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | +// you may not use this file except in compliance with the License. |
| 5 | +// You may obtain a copy of the License at |
| 6 | +// |
| 7 | +// http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | +// |
| 9 | +// Unless required by applicable law or agreed to in writing, software |
| 10 | +// distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | +// See the License for the specific language governing permissions and |
| 13 | +// limitations under the License. |
| 14 | + |
| 15 | +package main |
| 16 | + |
| 17 | +import ( |
| 18 | + "bytes" |
| 19 | + "fmt" |
| 20 | + "io" |
| 21 | + "mime" |
| 22 | + "net" |
| 23 | + "net/http" |
| 24 | + "os" |
| 25 | + "os/exec" |
| 26 | + |
| 27 | + "github.com/squat/kilo/pkg/mesh" |
| 28 | +) |
| 29 | + |
| 30 | +type graphHandler struct { |
| 31 | + mesh *mesh.Mesh |
| 32 | + granularity mesh.Granularity |
| 33 | + hostname *string |
| 34 | + subnet *net.IPNet |
| 35 | +} |
| 36 | + |
| 37 | +func (h *graphHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { |
| 38 | + ns, err := h.mesh.Nodes().List() |
| 39 | + if err != nil { |
| 40 | + http.Error(w, fmt.Sprintf("failed to list nodes: %v", err), http.StatusInternalServerError) |
| 41 | + return |
| 42 | + } |
| 43 | + ps, err := h.mesh.Peers().List() |
| 44 | + if err != nil { |
| 45 | + http.Error(w, fmt.Sprintf("failed to list peers: %v", err), http.StatusInternalServerError) |
| 46 | + return |
| 47 | + } |
| 48 | + |
| 49 | + nodes := make(map[string]*mesh.Node) |
| 50 | + for _, n := range ns { |
| 51 | + if n.Ready() { |
| 52 | + nodes[n.Name] = n |
| 53 | + } |
| 54 | + } |
| 55 | + if len(nodes) == 0 { |
| 56 | + http.Error(w, "did not find any valid Kilo nodes in the cluster", http.StatusInternalServerError) |
| 57 | + return |
| 58 | + } |
| 59 | + peers := make(map[string]*mesh.Peer) |
| 60 | + for _, p := range ps { |
| 61 | + if p.Ready() { |
| 62 | + peers[p.Name] = p |
| 63 | + } |
| 64 | + } |
| 65 | + topo, err := mesh.NewTopology(nodes, peers, h.granularity, *h.hostname, 0, []byte{}, h.subnet, nodes[*h.hostname].PersistentKeepalive, nil) |
| 66 | + if err != nil { |
| 67 | + http.Error(w, fmt.Sprintf("failed to create topology: %v", err), http.StatusInternalServerError) |
| 68 | + return |
| 69 | + } |
| 70 | + |
| 71 | + dot, err := topo.Dot() |
| 72 | + if err != nil { |
| 73 | + http.Error(w, fmt.Sprintf("failed to generate graph: %v", err), http.StatusInternalServerError) |
| 74 | + } |
| 75 | + |
| 76 | + buf := bytes.NewBufferString(dot) |
| 77 | + |
| 78 | + format := r.URL.Query().Get("format") |
| 79 | + switch format { |
| 80 | + case "": |
| 81 | + format = "svg" |
| 82 | + case "dot", "gv": |
| 83 | + // If the raw dot data is requested, return it as string. |
| 84 | + // This allows client-side rendering rather than server-side. |
| 85 | + w.Write(buf.Bytes()) |
| 86 | + return |
| 87 | + |
| 88 | + case "svg", "png", "bmp", "fig", "gif", "json", "ps": |
| 89 | + // Accepted format |
| 90 | + |
| 91 | + default: |
| 92 | + http.Error(w, "unsupported format", http.StatusInternalServerError) |
| 93 | + return |
| 94 | + } |
| 95 | + |
| 96 | + layout := r.URL.Query().Get("layout") |
| 97 | + switch layout { |
| 98 | + case "": |
| 99 | + layout = "circo" |
| 100 | + |
| 101 | + case "circo", "dot", "neato", "twopi", "fdp": |
| 102 | + // Accepted layout |
| 103 | + |
| 104 | + default: |
| 105 | + http.Error(w, "unsupported layout", http.StatusInternalServerError) |
| 106 | + return |
| 107 | + } |
| 108 | + |
| 109 | + command := exec.Command("dot", "-K"+layout, "-T"+format) |
| 110 | + command.Stderr = os.Stderr |
| 111 | + |
| 112 | + stdin, err := command.StdinPipe() |
| 113 | + if err != nil { |
| 114 | + http.Error(w, err.Error(), http.StatusInternalServerError) |
| 115 | + return |
| 116 | + } |
| 117 | + |
| 118 | + if _, err = io.Copy(stdin, buf); err != nil { |
| 119 | + http.Error(w, err.Error(), http.StatusInternalServerError) |
| 120 | + return |
| 121 | + } |
| 122 | + |
| 123 | + if err = stdin.Close(); err != nil { |
| 124 | + http.Error(w, err.Error(), http.StatusInternalServerError) |
| 125 | + return |
| 126 | + } |
| 127 | + |
| 128 | + output, err := command.Output() |
| 129 | + if err != nil { |
| 130 | + http.Error(w, "unable to render graph", http.StatusInternalServerError) |
| 131 | + return |
| 132 | + } |
| 133 | + |
| 134 | + mimeType := mime.TypeByExtension("." + format) |
| 135 | + if mimeType == "" { |
| 136 | + mimeType = "application/octet-stream" |
| 137 | + } |
| 138 | + |
| 139 | + w.Header().Add("content-type", mimeType) |
| 140 | + w.Write(output) |
| 141 | +} |
| 142 | + |
| 143 | +func healthHandler(w http.ResponseWriter, _ *http.Request) { |
| 144 | + w.WriteHeader(http.StatusOK) |
| 145 | +} |
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