Add semaphore support to web UI

This updates the OpenAPI docs to include the semaphores endpoint,
and adds a Semaphores tab to the web UI to show information about
semaphores within a tenant.

Change-Id: If78b27131ac76aff93c47a986fce6eae3e068668

11 files changed, 580 insertions, 0 deletions

diff --git a/releasenotes/notes/semaphore-webui-66c41b6aa6c6cfb6.yaml b/releasenotes/notes/semaphore-webui-66c41b6aa6c6cfb6.yaml
new file mode 100644
index 000000000..ffbcce9a9
--- /dev/null
+++ b/releasenotes/notes/semaphore-webui-66c41b6aa6c6cfb6.yaml
@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Details about the configuration and current usage of semaphores
+    are now available in the web UI under the "Semaphores" tab.
diff --git a/web/public/openapi.yaml b/web/public/openapi.yaml
index b101c66e0..d69111cf8 100644
--- a/web/public/openapi.yaml
+++ b/web/public/openapi.yaml
@@ -283,6 +283,31 @@ paths:
       summary: Get a project public key
       tags:
       - tenant
+  /api/tenant/{tenant}/semaphores:
+    get:
+      operationId: list-semaphores
+      parameters:
+      - description: The tenant name
+        in: path
+        name: tenant
+        required: true
+        schema:
+          type: string
+      responses:
+        '200':
+          content:
+            application/json:
+              schema:
+                description: The list of semaphores
+                items:
+                  $ref: '#/components/schemas/semaphore'
+                type: array
+          description: Returns the list of semaphores
+        '404':
+          description: Tenant not found
+      summary: List available semaphores
+      tags:
+      - tenant
   /api/tenant/{tenant}/status:
     get:
       operationId: get-status
@@ -520,6 +545,46 @@ components:
           description: The pipeline name
           type: string
       type: object
+    semaphore:
+      description: A semaphore
+      properties:
+        name:
+          description: The semaphore name
+          type: string
+        global:
+          description: Whether the semaphore is global
+          type: boolean
+        max:
+          description: The maximum number of holders
+          type: integer
+        holders:
+          $ref: '#/components/schemas/semaphoreHolders'
+      type: object
+    semaphoreHolders:
+      description: Information about the holders of a semaphore
+      properties:
+        count:
+          description: The number of jobs currently holding this semaphore
+          type: integer
+        this_tenant:
+          description: Holders within this tenant
+          items:
+            $ref: '#/components/schemas/semaphoreHolder'
+          type: array
+        other_tenants:
+          description: The number of jobs in other tenants currently holding this semaphore
+          type: integer
+      type: object
+    semaphoreHolder:
+      description: Information about a holder of a semaphore
+      properties:
+        buildset_uuid:
+          description: The UUID of the job's buildset
+          type: string
+        job_name:
+          description: The name of the job
+          type: string
+      type: object
     statusJob:
       description: A job status
       properties:
diff --git a/web/src/actions/semaphores.js b/web/src/actions/semaphores.js
new file mode 100644
index 000000000..885a488e2
--- /dev/null
+++ b/web/src/actions/semaphores.js
@@ -0,0 +1,61 @@
+// Copyright 2018 Red Hat, Inc
+// Copyright 2022 Acme Gating, LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+import * as API from '../api'
+
+export const SEMAPHORES_FETCH_REQUEST = 'SEMAPHORES_FETCH_REQUEST'
+export const SEMAPHORES_FETCH_SUCCESS = 'SEMAPHORES_FETCH_SUCCESS'
+export const SEMAPHORES_FETCH_FAIL = 'SEMAPHORES_FETCH_FAIL'
+
+export const requestSemaphores = () => ({
+  type: SEMAPHORES_FETCH_REQUEST
+})
+
+export const receiveSemaphores = (tenant, json) => ({
+  type: SEMAPHORES_FETCH_SUCCESS,
+  tenant: tenant,
+  semaphores: json,
+  receivedAt: Date.now()
+})
+
+const failedSemaphores = error => ({
+  type: SEMAPHORES_FETCH_FAIL,
+  error
+})
+
+const fetchSemaphores = (tenant) => dispatch => {
+  dispatch(requestSemaphores())
+  return API.fetchSemaphores(tenant.apiPrefix)
+    .then(response => dispatch(receiveSemaphores(tenant.name, response.data)))
+    .catch(error => dispatch(failedSemaphores(error)))
+}
+
+const shouldFetchSemaphores = (tenant, state) => {
+  const semaphores = state.semaphores.semaphores[tenant.name]
+  if (!semaphores || semaphores.length === 0) {
+    return true
+  }
+  if (semaphores.isFetching) {
+    return false
+  }
+  return false
+}
+
+export const fetchSemaphoresIfNeeded = (tenant, force) => (dispatch, getState) => {
+  if (force || shouldFetchSemaphores(tenant, getState())) {
+    return dispatch(fetchSemaphores(tenant))
+  }
+  return Promise.resolve()
+}
diff --git a/web/src/api.js b/web/src/api.js
index 1ba39998c..f429411d0 100644
--- a/web/src/api.js
+++ b/web/src/api.js
@@ -185,6 +185,9 @@ function fetchLabels(apiPrefix) {
 function fetchNodes(apiPrefix) {
   return Axios.get(apiUrl + apiPrefix + 'nodes')
 }
+function fetchSemaphores(apiPrefix) {
+  return Axios.get(apiUrl + apiPrefix + 'semaphores')
+}
 function fetchAutoholds(apiPrefix) {
   return Axios.get(apiUrl + apiPrefix + 'autohold')
 }
@@ -332,6 +335,7 @@ export {
   fetchLabels,
   fetchNodes,
   fetchOpenApi,
+  fetchSemaphores,
   fetchTenants,
   fetchInfo,
   fetchComponents,
diff --git a/web/src/containers/semaphore/Semaphore.jsx b/web/src/containers/semaphore/Semaphore.jsx
new file mode 100644
index 000000000..831669c13
--- /dev/null
+++ b/web/src/containers/semaphore/Semaphore.jsx
@@ -0,0 +1,88 @@
+// Copyright 2018 Red Hat, Inc
+// Copyright 2022 Acme Gating, LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+import React from 'react'
+import PropTypes from 'prop-types'
+import { connect } from 'react-redux'
+import { Link } from 'react-router-dom'
+import {
+  DescriptionList,
+  DescriptionListTerm,
+  DescriptionListGroup,
+  DescriptionListDescription,
+  Spinner,
+} from '@patternfly/react-core'
+
+function Semaphore({ semaphore, tenant, fetching }) {
+  if (fetching && !semaphore) {
+    return (
+      <center>
+        <Spinner size="xl" />
+      </center>
+    )
+  }
+  if (!semaphore) {
+    return (
+      <div>
+        No semaphore found
+      </div>
+    )
+  }
+  const rows = []
+  rows.push({label: 'Name', value: semaphore.name})
+  rows.push({label: 'Current Holders', value: semaphore.holders.count})
+  rows.push({label: 'Max', value: semaphore.max})
+  rows.push({label: 'Global', value: semaphore.global ? 'Yes' : 'No'})
+  if (semaphore.global) {
+    rows.push({label: 'Holders in Other Tenants',
+               value: semaphore.holders.other_tenants})
+  }
+  semaphore.holders.this_tenant.forEach(holder => {
+    rows.push({label: 'Held By',
+               value: <Link to={`${tenant.linkPrefix}/buildset/${holder.buildset_uuid}`}>
+                        {holder.job_name}
+                      </Link>})
+  })
+  return (
+    <DescriptionList isHorizontal
+                     style={{'--pf-c-description-list--RowGap': '0.5rem'}}
+                     className='pf-u-m-xl'>
+      {rows.map((item, idx) => (
+        <DescriptionListGroup key={idx}>
+          <DescriptionListTerm>
+            {item.label}
+          </DescriptionListTerm>
+          <DescriptionListDescription>
+            {item.value}
+          </DescriptionListDescription>
+        </DescriptionListGroup>
+      ))}
+    </DescriptionList>
+  )
+}
+
+Semaphore.propTypes = {
+  semaphore: PropTypes.object.isRequired,
+  fetching: PropTypes.bool.isRequired,
+  tenant: PropTypes.object.isRequired,
+}
+
+function mapStateToProps(state) {
+  return {
+    tenant: state.tenant,
+  }
+}
+
+export default connect(mapStateToProps)(Semaphore)
diff --git a/web/src/containers/semaphore/SemaphoreTable.jsx b/web/src/containers/semaphore/SemaphoreTable.jsx
new file mode 100644
index 000000000..6f400d7b4
--- /dev/null
+++ b/web/src/containers/semaphore/SemaphoreTable.jsx
@@ -0,0 +1,166 @@
+// Copyright 2020 Red Hat, Inc
+// Copyright 2022 Acme Gating, LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+import React from 'react'
+import PropTypes from 'prop-types'
+import { connect } from 'react-redux'
+import {
+  EmptyState,
+  EmptyStateBody,
+  EmptyStateIcon,
+  Spinner,
+  Title,
+  Label,
+} from '@patternfly/react-core'
+import {
+  ResourcesFullIcon,
+  TachometerAltIcon,
+  LockIcon,
+  TenantIcon,
+  FingerprintIcon,
+} from '@patternfly/react-icons'
+import {
+  Table,
+  TableHeader,
+  TableBody,
+  TableVariant,
+} from '@patternfly/react-table'
+import { Link } from 'react-router-dom'
+
+import { IconProperty } from '../../Misc'
+
+function SemaphoreTable(props) {
+  const { semaphores, fetching, tenant } = props
+  const columns = [
+    {
+      title: <IconProperty icon={<FingerprintIcon />} value="Name" />,
+      dataLabel: 'Name',
+    },
+    {
+      title: <IconProperty icon={<TachometerAltIcon />} value="Current" />,
+      dataLabel: 'Current',
+    },
+    {
+      title: <IconProperty icon={<ResourcesFullIcon />} value="Max" />,
+      dataLabel: 'Max',
+    },
+    {
+      title: <IconProperty icon={<TenantIcon />} value="Global" />,
+      dataLabel: 'Global',
+    },
+  ]
+
+  function createSemaphoreRow(semaphore) {
+
+    return {
+      cells: [
+        {
+          title: (
+            <Link to={`${tenant.linkPrefix}/semaphore/${semaphore.name}`}>{semaphore.name}</Link>
+          ),
+        },
+        {
+          title: semaphore.holders.count,
+        },
+        {
+          title: semaphore.max,
+        },
+        {
+          title: semaphore.global ? (
+            <Label
+              style={{
+                marginLeft: 'var(--pf-global--spacer--sm)',
+                verticalAlign: '0.15em',
+              }}
+            >
+              Global
+            </Label>
+          ) : ''
+        },
+      ]
+    }
+  }
+
+  function createFetchingRow() {
+    const rows = [
+      {
+        heightAuto: true,
+        cells: [
+          {
+            props: { colSpan: 8 },
+            title: (
+              <center>
+                <Spinner size="xl" />
+              </center>
+            ),
+          },
+        ],
+      },
+    ]
+    return rows
+  }
+
+  const haveSemaphores = semaphores && semaphores.length > 0
+
+  let rows = []
+  if (fetching) {
+    rows = createFetchingRow()
+    columns[0].dataLabel = ''
+  } else {
+    if (haveSemaphores) {
+      rows = semaphores.map((semaphore) => createSemaphoreRow(semaphore))
+    }
+  }
+
+  return (
+    <>
+      <Table
+        aria-label="Semaphore Table"
+        variant={TableVariant.compact}
+        cells={columns}
+        rows={rows}
+        className="zuul-table"
+      >
+        <TableHeader />
+        <TableBody />
+      </Table>
+
+      {/* Show an empty state in case we don't have any semaphores but are also not
+          fetching */}
+      {!fetching && !haveSemaphores && (
+        <EmptyState>
+          <EmptyStateIcon icon={LockIcon} />
+          <Title headingLevel="h1">No semaphores found</Title>
+          <EmptyStateBody>
+            Nothing to display.
+          </EmptyStateBody>
+        </EmptyState>
+      )}
+    </>
+  )
+}
+
+SemaphoreTable.propTypes = {
+  semaphores: PropTypes.array,
+  fetching: PropTypes.bool.isRequired,
+  tenant: PropTypes.object,
+  user: PropTypes.object,
+  dispatch: PropTypes.func,
+}
+
+export default connect((state) => ({
+  tenant: state.tenant,
+  user: state.user,
+}))(SemaphoreTable)
diff --git a/web/src/pages/Semaphore.jsx b/web/src/pages/Semaphore.jsx
new file mode 100644
index 000000000..a0ae8ddca
--- /dev/null
+++ b/web/src/pages/Semaphore.jsx
@@ -0,0 +1,69 @@
+// Copyright 2018 Red Hat, Inc
+// Copyright 2022 Acme Gating, LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+import React, { useEffect } from 'react'
+import PropTypes from 'prop-types'
+import { connect } from 'react-redux'
+
+import {
+  Title,
+} from '@patternfly/react-core'
+import { PageSection, PageSectionVariants } from '@patternfly/react-core'
+
+import { fetchSemaphoresIfNeeded } from '../actions/semaphores'
+import Semaphore from '../containers/semaphore/Semaphore'
+
+function SemaphorePage({ match, semaphores, tenant, fetchSemaphoresIfNeeded, isFetching }) {
+
+  const semaphoreName = match.params.semaphoreName
+
+  useEffect(() => {
+    document.title = `Zuul Semaphore | ${semaphoreName}`
+    fetchSemaphoresIfNeeded(tenant, true)
+  }, [fetchSemaphoresIfNeeded, tenant, semaphoreName])
+
+  const semaphore = semaphores[tenant.name] ? semaphores[tenant.name].find(
+    e => e.name === semaphoreName) : undefined
+
+  return (
+    <PageSection variant={PageSectionVariants.light}>
+      <Title headingLevel="h2">
+        Details for Semaphore <span style={{color: 'var(--pf-global--primary-color--100)'}}>{semaphoreName}</span>
+      </Title>
+
+      <Semaphore semaphore={semaphore}
+                 fetching={isFetching} />
+    </PageSection>
+  )
+}
+
+SemaphorePage.propTypes = {
+  match: PropTypes.object.isRequired,
+  semaphores: PropTypes.object.isRequired,
+  tenant: PropTypes.object.isRequired,
+  isFetching: PropTypes.bool.isRequired,
+  fetchSemaphoresIfNeeded: PropTypes.func.isRequired,
+}
+const mapDispatchToProps = { fetchSemaphoresIfNeeded }
+
+function mapStateToProps(state) {
+  return {
+    tenant: state.tenant,
+    semaphores: state.semaphores.semaphores,
+    isFetching: state.semaphores.isFetching,
+  }
+}
+
+export default connect(mapStateToProps, mapDispatchToProps)(SemaphorePage)
diff --git a/web/src/pages/Semaphores.jsx b/web/src/pages/Semaphores.jsx
new file mode 100644
index 000000000..0ad0040c0
--- /dev/null
+++ b/web/src/pages/Semaphores.jsx
@@ -0,0 +1,61 @@
+// Copyright 2021 BMW Group
+// Copyright 2022 Acme Gating, LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+import React, { useEffect } from 'react'
+import PropTypes from 'prop-types'
+import { connect } from 'react-redux'
+import {
+  PageSection,
+  PageSectionVariants,
+} from '@patternfly/react-core'
+
+import { fetchSemaphoresIfNeeded } from '../actions/semaphores'
+import SemaphoreTable from '../containers/semaphore/SemaphoreTable'
+
+function SemaphoresPage({ tenant, semaphores, isFetching, fetchSemaphoresIfNeeded }) {
+  useEffect(() => {
+    document.title = 'Zuul Semaphores'
+    fetchSemaphoresIfNeeded(tenant, true)
+  }, [fetchSemaphoresIfNeeded, tenant])
+
+  return (
+    <>
+      <PageSection variant={PageSectionVariants.light}>
+        <SemaphoreTable
+          semaphores={semaphores[tenant.name]}
+          fetching={isFetching} />
+      </PageSection>
+    </>
+  )
+}
+
+SemaphoresPage.propTypes = {
+  tenant: PropTypes.object.isRequired,
+  semaphores: PropTypes.object.isRequired,
+  isFetching: PropTypes.bool.isRequired,
+  fetchSemaphoresIfNeeded: PropTypes.func.isRequired,
+}
+
+function mapStateToProps(state) {
+  return {
+    tenant: state.tenant,
+    semaphores: state.semaphores.semaphores,
+    isFetching: state.semaphores.isFetching,
+  }
+}
+
+const mapDispatchToProps = { fetchSemaphoresIfNeeded }
+
+export default connect(mapStateToProps, mapDispatchToProps)(SemaphoresPage)
diff --git a/web/src/reducers/index.js b/web/src/reducers/index.js
index 83c86c105..9a76049dc 100644
--- a/web/src/reducers/index.js
+++ b/web/src/reducers/index.js
@@ -34,6 +34,7 @@ import project from './project'
 import pipelines from './pipelines'
 import projects from './projects'
 import preferences from './preferences'
+import semaphores from './semaphores'
 import status from './status'
 import tenant from './tenant'
 import tenants from './tenants'
@@ -60,6 +61,7 @@ const reducers = {
   pipelines,
   project,
   projects,
+  semaphores,
   status,
   tenant,
   tenants,
diff --git a/web/src/reducers/semaphores.js b/web/src/reducers/semaphores.js
new file mode 100644
index 000000000..5e98bcab7
--- /dev/null
+++ b/web/src/reducers/semaphores.js
@@ -0,0 +1,48 @@
+// Copyright 2018 Red Hat, Inc
+// Copyright 2022 Acme Gating, LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations
+// under the License.
+
+import {
+  SEMAPHORES_FETCH_FAIL,
+  SEMAPHORES_FETCH_REQUEST,
+  SEMAPHORES_FETCH_SUCCESS
+} from '../actions/semaphores'
+
+export default (state = {
+  isFetching: false,
+  semaphores: {},
+}, action) => {
+  switch (action.type) {
+    case SEMAPHORES_FETCH_REQUEST:
+      return {
+        isFetching: true,
+        semaphores: state.semaphores,
+      }
+    case SEMAPHORES_FETCH_SUCCESS:
+      return {
+        isFetching: false,
+        semaphores: {
+          ...state.semaphores,
+          [action.tenant]: action.semaphores
+        }
+      }
+    case SEMAPHORES_FETCH_FAIL:
+      return {
+        isFetching: false,
+        semaphores: state.semaphores,
+      }
+    default:
+      return state
+  }
+}
diff --git a/web/src/routes.js b/web/src/routes.js
index e1bfdae16..a60216a97 100644
--- a/web/src/routes.js
+++ b/web/src/routes.js
@@ -22,6 +22,8 @@ import JobPage from './pages/Job'
 import JobsPage from './pages/Jobs'
 import LabelsPage from './pages/Labels'
 import NodesPage from './pages/Nodes'
+import SemaphorePage from './pages/Semaphore'
+import SemaphoresPage from './pages/Semaphores'
 import AutoholdsPage from './pages/Autoholds'
 import AutoholdPage from './pages/Autohold'
 import BuildPage from './pages/Build'
@@ -70,6 +72,11 @@ const routes = () => [
     component: AutoholdsPage
   },
   {
+    title: 'Semaphores',
+    to: '/semaphores',
+    component: SemaphoresPage
+  },
+  {
     title: 'Builds',
     to: '/builds',
     component: BuildsPage
@@ -133,6 +140,10 @@ const routes = () => [
     component: AutoholdPage
   },
   {
+    to: '/semaphore/:semaphoreName',
+    component: SemaphorePage
+  },
+  {
     to: '/config-errors',
     component: ConfigErrorsPage,
   },