monfront - add basic interface to create some entities

cmd/monfront/create.go

@@ -0,0 +1,148 @@
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"log"
+	"net/http"
+	"strings"
+)
+
+func showCreate(con *Context) {
+	if con.r.Method == "POST" {
+		addCreate(con)
+		return
+	}
+	if con.r.Method != "GET" {
+		con.w.WriteHeader(http.StatusMethodNotAllowed)
+		con.w.Write([]byte("method is not supported"))
+		return
+	}
+	if !con.CanEdit {
+		con.w.WriteHeader(http.StatusForbidden)
+		con.w.Write([]byte("no permission to change data"))
+		return
+	}
+	con.Content = map[string]any{}
+
+	primitives := []struct {
+		name  string
+		query string
+	}{
+		{"commands", "select id, name, updated, command, message from commands order by name"},
+		{"checkers", "select id, name, description from checkers order by name"},
+		{"notifier", "select id, name, settings from notifier order by name"},
+		{"nodes", "select id, name, updated, message from nodes order by name"},
+	}
+	for _, prim := range primitives {
+		rows, err := DB.Query(prim.query)
+		defer rows.Close()
+		if err != nil {
+			log.Printf("could not get commands: %s", err)
+			con.Error = "could not get commands"
+			returnError(http.StatusInternalServerError, con, con.w)
+			return
+		}
+		result, err := rowsToResult(rows)
+		if err != nil {
+			log.Printf("could not get %s: %s", prim.name, err)
+			con.Error = "could not get " + prim.name
+			returnError(http.StatusInternalServerError, con, con.w)
+			return
+		}
+		con.Content[prim.name] = result
+	}
+
+	con.w.Header()["Content-Type"] = []string{"text/html"}
+	con.Render("create_index")
+	return
+}
+
+type (
+	sqlResult struct {
+		Columns []string
+		Rows    [][]sql.NullString
+	}
+)
+
+func rowsToResult(rows *sql.Rows) (*sqlResult, error) {
+	res := &sqlResult{}
+	cols, err := rows.Columns()
+	if err != nil {
+		return res, fmt.Errorf("could not get columns: %w", err)
+	}
+	res.Columns = cols
+	res.Rows = [][]sql.NullString{}
+	colNum := len(cols)
+
+	for rows.Next() {
+		line := make([]sql.NullString, colNum)
+		lineMap := make([]any, colNum)
+		for i := 0; i < colNum; i++ {
+			lineMap[i] = &(line[i])
+		}
+		if err := rows.Scan(lineMap...); err != nil {
+			return res, fmt.Errorf("could not scan values: %w", err)
+		}
+		res.Rows = append(res.Rows, line)
+	}
+
+	return res, nil
+}
+
+func addCreate(con *Context) {
+	if !con.CanEdit {
+		con.w.WriteHeader(http.StatusForbidden)
+		con.w.Write([]byte("no permission to change data"))
+		return
+	}
+
+	if err := con.r.ParseForm(); err != nil {
+		con.w.WriteHeader(http.StatusBadRequest)
+		fmt.Fprintf(con.w, "could not parse parameters: %s", err)
+		return
+	}
+
+	con.w.Header()["Location"] = []string{"/create"}
+
+	addType := con.r.PostForm.Get("type")
+	types := map[string]struct {
+		Fields []string
+		Table  string
+	}{
+		"command":  {[]string{"name", "command", "message"}, "commands"},
+		"node":     {[]string{"name", "message"}, "nodes"},
+		"checker":  {[]string{"name", "description"}, "checkers"},
+		"notifier": {[]string{"name", "settings"}, "notifier"},
+		"check":    {[]string{"name", "message", "options", "intval", "node_id", "command_id", "checker_id"}, "checks"},
+	}
+	t, found := types[addType]
+	if !found {
+		con.Error = "undefined type '" + addType + "'"
+		returnError(http.StatusBadRequest, con, con.w)
+		return
+	}
+
+	fields := make([]any, len(t.Fields))
+	vals := make([]string, len(t.Fields))
+	for i := 0; i < len(fields); i++ {
+		vals[i] = fmt.Sprintf(`$%d`, i+1)
+		fields[i] = con.r.PostForm.Get(t.Fields[i])
+		if fields[i] == "" {
+			con.Error = "field " + t.Fields[i] + " must not be empty"
+			returnError(http.StatusBadRequest, con, con.w)
+			return
+		}
+	}
+	stmt := `insert into ` + t.Table + `(` + strings.Join(t.Fields, ",") + `) values (` + strings.Join(vals, ",") + `)`
+	_, err := DB.Exec(stmt, fields...)
+	if err != nil {
+		log.Printf("could not insert new %s: %s", addType, err)
+		con.Error = "could not insert new " + addType
+		returnError(http.StatusInternalServerError, con, con.w)
+		return
+	}
+
+	con.w.WriteHeader(http.StatusSeeOther)
+	return
+}

cmd/monfront/main.go

@@ -170,6 +170,7 @@ func main() {
 
 	s := newServer(l, db, tmpl, auth, autho)
 	s.Handle("/", showChecks)
+	s.Handle("/create", showCreate)
 	s.Handle("/check", showCheck)
 	s.Handle("/checks", showChecks)
 	s.Handle("/groups", showGroups)

cmd/monfront/server.go

@@ -46,6 +46,8 @@ type (
 		CheckDetails *checkDetails            `json:"check_details,omitempty"`
 		Groups       []group                  `json:"groups,omitempty"`
 		Unhandled    bool                     `json:"-"` // set this flag when unhandled was called
+
+		Content map[string]any `json:"-"` // used for the configuration dashboard
 	}
 )
 

cmd/monfront/templates/create_index.html

@@ -0,0 +1,84 @@
+{{ template "header" . }}
+<section id="content">
+  <h1>create entries</h1>
+  <details>
+    <summary>checks</summary>
+      <form action="/create" method="POST">
+      <p><label>name</label><input name="name" /></p>
+      <p><label>node</label>
+        <select name="node_id">
+          {{ range $node := .Content.nodes.Rows }}
+            <option value="{{ (index . 0).String }}">{{ (index . 1).String }}</option>
+          {{ end }}
+        </select>
+      </p>
+      <p><label>command</label><select name="command_id">
+          {{ range $node := .Content.commands.Rows }}
+            <option value="{{ (index . 0).String }}">{{ (index . 1).String }}</option>
+          {{ end }}
+      </select></p>
+      <p><label>checker</label><select name="checker_id">
+          {{ range $node := .Content.checkers.Rows }}
+            <option value="{{ (index . 0).String }}">{{ (index . 1).String }}</option>
+          {{ end }}
+      </select></p>
+      <p><label>interval</label><input type="integer" name="interval" value="300" /></p>
+      <fieldset>
+        <legend>options</legend>
+        <!-- TODO implement setting options -->
+      </fieldset>
+      <p><label>message</label><textarea name="message"></textarea></p>
+      <p><button type="submit" name="type" value="check">create</button></p>
+    </form>
+  </details>
+  <details>
+    <summary>nodes</summary>
+    <details>
+      <summary>create new node</summary>
+      <form action="/create" method="POST">
+        <p><label>name</label><input name="name" /></p>
+        <p><label>message</label><textarea name="message"></textarea></p>
+        <p><button type="submit" name="type" value="node">create</button></p>
+      </form>
+    </details>
+    {{ template "rows_to_table" .Content.nodes }}
+  </details>
+  <details>
+    <summary>commands</summary>
+    <details>
+      <summary>create new command</summary>
+      <form action="/create" method="POST">
+        <p><label>name</label><input name="name" /></p>
+        <p><label>command</label><textarea name="command"></textarea></p>
+        <p><label>message</label><textarea name="message"></textarea></p>
+        <p><button type="submit" name="type" value="command">create</button></p>
+      </form>
+    </details>
+    {{ template "rows_to_table" .Content.commands }}
+  </details>
+  <details>
+    <summary>checkers</summary>
+    <details>
+      <summary>create new checker instance</summary>
+      <form action="/create" method="POST">
+        <p><label>name</label><input name="name" /></p>
+        <p><label>description</label><textarea name="description"></textarea></p>
+        <p><button type="submit" name="type" value="checker">create</button></p>
+      </form>
+    </details>
+    {{ template "rows_to_table" .Content.checkers }}
+  </details>
+  <details>
+    <summary>notifier</summary>
+    <details>
+      <summary>create new notifier</summary>
+      <form action="/create" method="POST">
+        <p><label>name</label><input name="name" /></p>
+        <p><label>settings</label><textarea name="settings">{}</textarea></p>
+        <p><button type="submit" name="type" value="notifier">create</button></p>
+      </form>
+    </details>
+    {{ template "rows_to_table" .Content.notifier }}
+  </details>
+</section>
+{{ template "footer" . }}

cmd/monfront/templates/header.html

@@ -92,6 +92,7 @@
         <li><a href="/">home</a></li>
         <li><a href="/checks?filter-state=1&filter-ack=false">checks</a></li>
         <li><a href="/groups">groups</a></li>
+        <li><a href="/create">create</a></li>
       </ul>
     </nav>
 		{{ if .Error }}<div class="error">{{ .Error }}</div>{{ end }}

cmd/monfront/templates/rows_to_table.html

@@ -0,0 +1,19 @@
+    <table>
+      <tr>
+        {{ range $col := .Columns }}
+          <th>{{ $col }}</th>
+        {{ end }}
+        <th></th>
+      </tr>
+      {{ range $row := .Rows }}
+        <tr>
+          {{ range $col := $row }}
+          <td>{{ if $col.Valid }}{{ $col.String }}{{ end }}</td>
+          {{ end }}
+          <td>
+            <button name="update" value="{{ (index $row 0).String }}">update</button>
+            <button name="delete" value="{{ (index $row 0).String }}">delete</button>
+          </td>
+        </tr>
+      {{ end }}
+    </table>