create fluent-bit-plugin loki image (#2640)

Signed-off-by: Sam Singh Anantha <sam.singh@chainguard.dev>

images/fluent-bit-plugin-loki/README.md

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+<!--monopod:start-->
+# fluent-bit-plugin-loki
+| | |
+| - | - |
+| **OCI Reference** | `cgr.dev/chainguard/fluent-bit-plugin-loki` |
+
+
+* [View Image in Chainguard Academy](https://edu.chainguard.dev/chainguard/chainguard-images/reference/fluent-bit-plugin-loki/overview/)
+* [View Image Catalog](https://console.enforce.dev/images/catalog) for a full list of available tags.
+* [Contact Chainguard](https://www.chainguard.dev/chainguard-images) for enterprise support, SLAs, and access to older tags.*
+
+---
+<!--monopod:end-->
+
+<!--overview:start-->
+The Fluent Bit Loki plugin allows you to send your log or events to a Loki service.
+<!--overview:end-->
+
+<!--getting:start-->
+## Download this Image
+The image is available on `cgr.dev`:
+
+```
+docker pull cgr.dev/chainguard/fluent-bit-plugin-loki:latest
+```
+<!--getting:end-->
+
+<!--body:start-->
+## Usage
+
+### Docker
+
+You can run a Fluent Bit container with the Loki output plugin pre-installed using the following command:
+
+```bash
+docker run -v /var/log:/var/log \
+    -e LOG_PATH="/var/log/*.log" -e LOKI_URL="http://localhost:3100/loki/api/v1/push" \
+    cgr.dev/chainguard/fluent-bit-plugin-loki:latest
+```
+The [GitHub repository](https://github.com/grafana/loki/tree/main/clients/cmd/fluent-bit) has more details on running the fluent-bit plugin.  
+**Note:** The default loki plugin config can be found at `/fluent-bit/etc/fluent-bit-loki.conf`.
+
+### Helm
+The plugin can also be installed using the fluent-bit helm chart by configuring the image values:
+
+```yaml
+image:
+  repository: cgr.dev/chainguard/fluent-bit-plugin-loki
+  tag: latest
+```
+For detailed instructions on setting up the Fluent Bit Loki plugin, refer to the [Loki documentation](https://grafana.com/docs/loki/latest/send-data/fluentbit/).
+
+<!--body:end-->

images/fluent-bit-plugin-loki/config/main.tf

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+terraform {
+  required_providers {
+    apko = { source = "chainguard-dev/apko" }
+  }
+}
+
+variable "extra_packages" {
+  description = "The additional packages to install"
+  default = [
+    "fluent-bit",
+    "fluent-bit-compat",
+    "fluent-bit-plugin-loki"
+  ]
+}
+
+data "apko_config" "this" {
+  config_contents = file("${path.module}/template.apko.yaml")
+  extra_packages  = var.extra_packages
+}
+
+output "config" {
+  value = jsonencode(data.apko_config.this.config)
+}

images/fluent-bit-plugin-loki/config/template.apko.yaml

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+contents:
+  packages: []
+
+accounts:
+  groups:
+    - groupname: nonroot
+      gid: 65532
+  users:
+    - username: nonroot
+      uid: 65532
+      gid: 65532
+  run-as: 65532
+
+entrypoint:
+  command: "fluent-bit -e /fluent-bit/bin/out_grafana_loki.so -c /fluent-bit/etc/fluent-bit-loki.conf"

images/fluent-bit-plugin-loki/main.tf

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+terraform {
+  required_providers {
+    oci = { source = "chainguard-dev/oci" }
+  }
+}
+
+variable "target_repository" {
+  description = "The docker repo into which the image and attestations should be published."
+}
+
+module "config" { source = "./config" }
+
+module "fluent-bit-plugin-loki" {
+  source            = "../../tflib/publisher"
+  name              = basename(path.module)
+  target_repository = var.target_repository
+  config            = module.config.config
+
+  build-dev = true
+
+}
+
+module "test" {
+  source = "./tests"
+  digest = module.fluent-bit-plugin-loki.image_ref
+}
+
+resource "oci_tag" "latest" {
+  depends_on = [module.test]
+  digest_ref = module.fluent-bit-plugin-loki.image_ref
+  tag        = "latest"
+}
+
+resource "oci_tag" "latest-dev" {
+  depends_on = [module.test]
+  digest_ref = module.fluent-bit-plugin-loki.dev_ref
+  tag        = "latest-dev"
+}
+

images/fluent-bit-plugin-loki/metadata.yaml

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+name: fluent-bit-plugin-loki
+image: cgr.dev/chainguard/fluent-bit-plugin-loki
+logo: https://storage.googleapis.com/chainguard-academy/logos/fluent-bit-plugin-loki.svg
+endoflife: ""
+console_summary: ""
+short_description: "The Fluent Bit Loki plugin allows you to send your log or events to a Loki service."
+compatibility_notes: ""
+readme_file: README.md
+upstream_url: "https://github.com/grafana/loki"
+keywords:
+  - analytics
+  - application

images/fluent-bit-plugin-loki/tests/main.tf

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+terraform {
+  required_providers {
+    oci       = { source = "chainguard-dev/oci" }
+    imagetest = { source = "chainguard-dev/imagetest" }
+  }
+}
+
+variable "digest" {
+  description = "The image digest to run tests over."
+}
+
+data "oci_string" "ref" { input = var.digest }
+
+data "imagetest_inventory" "this" {}
+
+
+resource "imagetest_harness_k3s" "this" {
+  name      = "fluent-bit-plugin-loki"
+  inventory = data.imagetest_inventory.this
+
+  sandbox = {
+    mounts = [
+      {
+        source      = path.module
+        destination = "/tests"
+      }
+    ],
+  }
+}
+
+variable "loki_url" {
+  type    = string
+  default = "http://loki-gateway.loki.svc.cluster.local/loki/api/v1/push"
+}
+
+module "helm-fluent-bit" {
+  source = "../../../tflib/imagetest/helm"
+
+  name      = "fluent-bit"
+  namespace = "fluent-bit"
+  repo      = "https://fluent.github.io/helm-charts"
+  chart     = "fluent-bit"
+
+  values = {
+    image = {
+      repository = data.oci_string.ref.registry_repo
+      tag        = data.oci_string.ref.pseudo_tag
+    },
+    args = [
+      "-e",
+      "/fluent-bit/bin/out_grafana_loki.so",
+      "--workdir=/fluent-bit/etc",
+      "--config=/fluent-bit/etc/conf/fluent-bit.conf"
+    ],
+    env = [{
+      name  = "FLUENT_LOKI_URL",
+      value = var.loki_url
+    }],
+    daemonSetVolumes = [
+      {
+        name = "varlog",
+        hostPath = {
+          path = "/var/log"
+        }
+      },
+      {
+        name = "varlibdockercontainers",
+        hostPath = {
+          path = "/var/lib/docker/containers"
+        }
+      }
+    ],
+    daemonSetVolumeMounts = [
+      {
+        name      = "varlog",
+        mountPath = "/var/log"
+      },
+      {
+        name      = "varlibdockercontainers",
+        mountPath = "/var/lib/docker/containers",
+        readOnly  = true
+      }
+    ],
+    config = {
+      inputs  = "[INPUT]\n    Name tail\n    Tag kube.*\n    Path /var/log/containers/*.log\n    multiline.parser docker, cri\n    Mem_Buf_Limit 5MB\n    Skip_Long_Lines On\n",
+      outputs = "[Output]\n    Name grafana-loki\n    Match kube.*\n    Url ${var.loki_url}\n    Labels {job=\"fluent-bit\"}\n    LabelKeys level,app\n    BatchWait 1\n    BatchSize 1001024\n    LineFormat json\n    LogLevel info\n    AutoKubernetesLabels true\n"
+    },
+    podSecurityContext = {
+      fsGroup = 2000
+    },
+    securityContext = {
+      allowPrivilegeEscalation = false,
+      readOnlyRootFilesystem   = false,
+      runAsUser                = 0,
+      capabilities = {
+        drop = ["ALL"],
+        add  = ["DAC_READ_SEARCH"]
+      }
+    }
+  }
+}
+
+module "helm-loki" {
+  source = "../../../tflib/imagetest/helm"
+
+  name      = "loki"
+  namespace = "loki"
+  repo      = "https://grafana.github.io/helm-charts"
+  chart     = "loki"
+  values = {
+    deploymentMode = "SingleBinary",
+    loki = {
+      auth_enabled = false,
+      commonConfig = {
+        ring = {
+          instance_addr = "127.0.0.1",
+          kvstore = {
+            store = "inmemory"
+          }
+        },
+        replication_factor = 1,
+        path_prefix        = "/tmp/loki"
+      },
+      storage = {
+        type = "filesystem"
+      },
+      schemaConfig = {
+        configs = [
+          {
+            from  = "2024-01-01",
+            store = "tsdb",
+            index = {
+              prefix = "loki_index_",
+              period = "24h"
+            },
+            object_store = "filesystem",
+            schema       = "v13"
+          }
+        ]
+      },
+      storage_config = {
+        filesystem = {
+          directory = "/tmp/loki/chunks"
+        }
+      }
+    },
+    singleBinary = {
+      replicas = 1
+    },
+    read = {
+      replicas = 0
+    },
+    backend = {
+      replicas = 0
+    },
+    write = {
+      replicas = 0
+    },
+    chunksCache = {
+      enabled = false
+    },
+    resultsCache = {
+      enabled = false
+    }
+  }
+}
+
+
+resource "imagetest_feature" "basic" {
+  harness     = imagetest_harness_k3s.this
+  name        = "basic"
+  description = "Functionality test for fluent-bit-plugin-loki installed in a Kubernetes cluster"
+
+  steps = [
+    {
+      name = "Install loki"
+      cmd  = module.helm-loki.install_cmd
+    },
+
+    {
+      name = "Install fluent-bit"
+      cmd  = module.helm-fluent-bit.install_cmd
+    },
+    {
+      name    = "Query loki for fluent-bit logs"
+      workdir = "/tests"
+      cmd     = <<EOF
+        ./query_logs.sh
+      EOF
+    }
+  ]
+
+  labels = {
+    type = "k8s",
+  }
+}