// This is a jsonnet file, it generates kubernetes manifests. // To generate and apply, run "jsonnet k8s.jsonnet | kubectl apply -f -" // Note this file is only set up to generate manifests for a basic replication node, // for the sake of simplicity. { config: { // These are the important top-level settings. // Change these to configure the services. // Image tag (application version) to use. // Note: "latest" is not recommended in production, as you can't be sure what version // you're actually running, and must manually re-pull to get an updated copy. image_tag: "latest", // Twitch channels to capture. // Channels suffixed with a '!' are considered "important" and will be retried more aggressively // and warned about if they're not currently streaming. channels: ["desertbus!", "db_chief", "db_high", "db_audio", "db_bus"], // Stream qualities to capture qualities: ["source", "480p"], // The node selector and hostPath to use. All pods must be on the same host // and use this hostpath in order to share the disk. node_selector: {}, host_path: "/var/lib/wubloader", // The local port within each container to bind the backdoor server on. // You can exec into the container and telnet to this port to get a python shell. backdoor_port: 1234, // Other nodes to always backfill from. You should not include the local node. // If you are using the database to find peers, you should leave this empty. peers: [ ], // This node's name in the nodes table of the database localhost: "node_name", // The hostname to use in the Ingress ingress_host: "wubloader.example.com", // Connection args for the database. // If database is defined in this config, host and port should be postgres:5432. db_args: { user: "vst", password: "dbfh2019", // don't use default in production. Must not contain ' or \ as these are not escaped. host: "postgres", port: 5432, dbname: "wubloader", }, // The timestamp corresponding to 00:00 in bustime bustime_start: "1970-01-01T00:00:00Z", // Extra options to pass via environment variables, // eg. log level, disabling stack sampling. env: { // Uncomment this to set log level to debug // WUBLOADER_LOG_LEVEL: "DEBUG", // Uncomment this to disable stacksampling performance monitoring // WUBLOADER_DISABLE_STACKSAMPLER: "true", }, }, // A few derived values. // The connection string for the database. Constructed from db_args. db_connect: std.join(" ", [ "%s='%s'" % [key, $.config.db_args[key]] for key in std.objectFields($.config.db_args) ]), // Cleaned up version of $.channels without importance markers clean_channels: [std.split(c, '!')[0] for c in $.config.channels], // k8s-formatted version of env dict env_list: [ {name: key, value: $.config.env[key]} for key in std.objectFields($.config.env) ], // This function generates deployments for each service, since they only differ slightly, // with only a different image, CLI args and possibly env vars. // The image name is derived from the component name // (eg. "downloader" is quay.io/ekimekim/wubloader-downloader) // so we only pass in name, args and env vars (with the latter two optional). // Optional kwargs work just like python. deployment(name, args=[], env=[]):: { kind: "Deployment", apiVersion: "apps/v1", metadata: { name: "wubloader-%s" % name, labels: {app: "wubloader", component: name}, }, spec: { replicas: 1, selector: { matchLabels: {app: "wubloader", component: name}, }, template: { metadata: { labels: {app: "wubloader", component: name}, }, spec: { containers: [ { name: name, image: "quay.io/ekimekim/wubloader-%s:%s" % [name, $.config.image_tag], args: args, volumeMounts: [{name: "data", mountPath: "/mnt"}], env: $.env_list + env, // main env list combined with any deployment-specific ones }, ], volumes: [ { name: "data", hostPath: {path: $.config.host_path}, }, ], nodeSelector: $.config.node_selector, }, }, }, }, // This function generates a Service object for each service, since they're basically identical. service(name): { kind: "Service", apiVersion: "v1", metadata: { name: "wubloader-%s" % name, labels: {app: "wubloader", component: name}, }, spec: { selector: {app: "wubloader", component: name}, ports: [{name: "http", port: 80, targetPort: 80}], }, }, // The actual manifests. // These are all deployments. Note that all components work fine if multiple are running // (they may duplicate work, but not cause errors by stepping on each others' toes). manifests: [ // The downloader watches the twitch stream and writes the HLS segments to disk $.deployment("downloader", args=$.config.channels + [ "--base-dir", "/mnt", "--qualities", std.join(",", $.config.qualities), "--backdoor-port", std.toString($.config.backdoor_port), "--metrics-port", "80", ]), // The restreamer is a http server that fields requests for checking what segments exist // and allows HLS streaming of segments from any requested timestamp $.deployment("restreamer", args=[ "--base-dir", "/mnt", "--backdoor-port", std.toString($.config.backdoor_port), "--port", "80", ]), // The backfiller periodically compares what segments exist locally to what exists on // other nodes. If it finds ones it doesn't have, it downloads them. // It can talk to the database to discover other wubloader nodes, or be given a static list. $.deployment("backfiller", args=$.clean_channels + [ "--base-dir", "/mnt", "--qualities", std.join(",", $.config.qualities), "--static-nodes", std.join(",", $.config.peers), "--backdoor-port", std.toString($.config.backdoor_port), "--node-database", $.db_connect, "--localhost", $.config.localhost, "--metrics-port", "80", ]), // Segment coverage is a monitoring helper that periodically scans available segments // and reports stats. It also creates a "coverage map" image to represent this info. // It puts this in the segment directory where nginx will serve it. $.deployment("segment_coverage", args=$.clean_channels + [ "--base-dir", "/mnt", "--qualities", std.join(",", $.config.qualities), "--metrics-port", "80", ]), // Normally nginx would be responsible for proxying requests to different services, // but in k8s we can use Ingress to do that. However nginx is still needed to serve // static content - segments as well as thrimbletrimmer. $.deployment("nginx", env=[ {name: "THRIMBLETRIMMER", value: "true"}, {name: "SEGMENTS", value: "/mnt"}, ]), // Ingress to direct requests to the correct services. { kind: "Ingress", apiVersion: "v1", metadata: { name: "wubloader", labels: {app: "wubloader"}, }, spec: { rules: [ { host: $.config.ingress_host, http: { // Helper functions for defining the path rules below local rule(name, path, type) = { path: path, pathType: type, backend: { serviceName: "wubloader-%s" % name, servicePort: 80, }, }, local metric_rule(name) = rule(name, "/metrics/%s" % name, "Exact"), paths: [ // Map /metrics/NAME to each service (except restreamer) metric_rule("downloader"), metric_rule("backfiller"), metric_rule("segment_coverage"), // Map /segments and /thrimbletrimmer to the static content nginx rule("nginx", "/segments", "Prefix"), rule("nginx", "/thrimbletrimmer", "Prefix"), // Map everything else to restreamer rule("restreamer", "/", "Prefix"), ], }, }, ], }, }, ], }.manifests // final output is just the manifest list, none of the other fields