Yannis Zarkadas
367d485407
Implementation of the cassandra sidecar logic. This sidecar helps us inject our custom values during startup and provides HTTP liveness and readiness checks. In the future it will also be used for: - Shutting Down / Decommissioning a cassandra instance - Backups - Restores Signed-off-by: Yannis Zarkadas <yanniszarkadas@gmail.com>
96 lines
2.8 KiB
Go
96 lines
2.8 KiB
Go
/*
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Copyright 2018 The Rook Authors. All rights reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package sidecar
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import (
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"fmt"
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"github.com/rook/rook/pkg/operator/cassandra/constants"
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"github.com/yanniszark/go-nodetool/nodetool"
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"net/http"
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)
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// setupHTTPChecks brings up the liveness and readiness probes
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func (m *MemberController) setupHTTPChecks() error {
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http.HandleFunc(constants.LivenessProbePath, livenessCheck(m))
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http.HandleFunc(constants.ReadinessProbePath, readinessCheck(m))
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err := http.ListenAndServe(fmt.Sprintf("0.0.0.0:%d", constants.ProbePort), nil)
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// If ListenAndServe returns, something went wrong
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m.logger.Fatalf("Error in HTTP checks: %s", err.Error())
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return err
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}
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func livenessCheck(m *MemberController) func(http.ResponseWriter, *http.Request) {
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return func(w http.ResponseWriter, req *http.Request) {
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status := http.StatusOK
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// Check if JMX is reachable
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_, err := m.nodetool.Status()
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if err != nil {
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m.logger.Errorf("Liveness check failed with error: %s", err.Error())
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status = http.StatusServiceUnavailable
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}
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w.WriteHeader(status)
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}
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}
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func readinessCheck(m *MemberController) func(http.ResponseWriter, *http.Request) {
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return func(w http.ResponseWriter, req *http.Request) {
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status := http.StatusOK
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err := func() error {
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// Contact Cassandra to learn about the status of the member
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HostIDMap, err := m.nodetool.Status()
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if err != nil {
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return fmt.Errorf("Error while executing nodetool status in readiness check: %s", err.Error())
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}
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// Get local node through static ip
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localNode, ok := HostIDMap[m.ip]
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if !ok {
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return fmt.Errorf("Couldn't find node with ip %s in nodetool status.", m.ip)
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}
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// Check local node status
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// Up means the member is alive
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if localNode.Status != nodetool.NodeStatusUp {
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return fmt.Errorf("Unexpected local node status: %s", localNode.Status)
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}
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// Check local node state
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// Normal means that the member has completed bootstrap and joined the cluster
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if localNode.State != nodetool.NodeStateNormal {
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return fmt.Errorf("Unexpected local node state: %s", localNode.State)
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}
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return nil
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}()
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if err != nil {
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m.logger.Errorf("Readiness check failed with error: %s", err.Error())
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status = http.StatusServiceUnavailable
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}
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w.WriteHeader(status)
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}
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}
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