Dashboard Backup Makefile

############################################################ IDENT(1)
#
# $Title: Script to make backup of Grafana dashboards $
# $Copyright: 2019-2022 Devin Teske. All rights reserved. $
# $FrauBSD$
#
############################################################ INFORMATION
#
# Accesses a remote Grafana instance via HTTPS using an API key (created by an
# administrator of said Grafana instance) to download the JSON models of all
# dashboards, saved to the current working directory (CWD).
#
# Each time `make' is run, each Grafana dashboard is downloaded and compared to
# the existing JSON model (if previously downloaded) in CWD. If the model has
# changed, the message is printed:
#
#   U dashboard.json
#   U dashboard.meta.json
#
# NB: The `U' stands for `updated' (familiar to users of sccs/rcs/cvs)
#
# Where `dashboard' is the name of the dashboard (specifically its internal
# ``slug'' name) and dashboard.meta contains the metadata properties.
#
# This backup script requires (sorted alphabetically):
#   cat [coreutils]
#   cmp [diffutils]
#   curl
#   jq
#   make
#   mv [coreutils]
#   rm [coreutils]
#   sh (any flavor)
#   xargs [findutils]
#
# NB: RedHat/CentOS package listed in brackets if different than utility name.
#
############################################################ CONFIGURATION

#
# Grafana to backup
# NB: HOST must be fully qualified
# NB: Access is via HTTPS on configured PORT
#
HOST = ip_or_hostname
PORT = 3000

#
# API Key for accessing the above Grafana
# NB: Required
#
API_KEY = unquoted_api_key_here

############################################################ FUNCTIONS

DIE = sh -c 'fmt="$$1"; \
    if [ "$$fmt" ]; then \
        shift 1; \
        printf "$$fmt\n" "$$@" >&2; \
    fi; \
    exit 1; \
' sh

API_GET = sh -c 'uri="$$1" output="$${2:-/dev/stdout}"; \
    curl -sLo- -H "Authorization: Bearer $(API_KEY)" \
        "https://$(HOST):$(PORT)/api/$$uri" > "$$output"; \
' sh

JSON_PUT = sh -c 'input="$$1"; \
    json=$$( cat "$$input" ); \
    slug=$$( echo "$$json" | jq -r .meta.slug ); \
    output1=".$$slug.json"; \
    output2=".$$slug.meta.json"; \
    echo "$$json" | jq .dashboard > "$$output1"; \
    echo "$$json" | jq .meta > "$$output2"; \
    rm -f "$$input"; \
    echo "$$slug"; \
' sh

############################################################ TARGETS

all:
    @set -e; \
    json=$$( $(API_GET) search ); \
    case "$$json" in \
    "") $(DIE) "API search failed" ;; \
    {*}) msgtype=$$( echo "$$json" | jq -r '.message|type' ); \
        [ "$$msgtype" = "null" ] || $(DIE) "%s: %s" \
            "$(HOST)" "$$( echo "$$json" | jq -r .message )"; \
    esac; \
    uids=$$( echo "$$json" | \
        jq -r 'map(select(.type=="dash-db"))|.[].uid' ); \
    [ "$$uids" ] || $(DIE) "No dashboards found"; \
    echo "$$uids" | \
        xargs -P99 -rn1 -I%%% $(API_GET) dashboards/uid/%%% .%%%.tmp; \
    trap "rm -f .*.tmp" EXIT; \
    slugs=$$( echo "$$uids" | \
        xargs -P99 -rn1 -I%%% $(JSON_PUT) .%%%.tmp ); \
    trap "rm -f .*.json" EXIT; \
    for slug in $$slugs; do \
        ! cmp -s ".$$slug.json" "$$slug.json" 2> /dev/null || \
            continue; \
        echo "U $$slug.json"; \
        mv -f ".$$slug.json" "$$slug.json"; \
        echo "U $$slug.meta.json"; \
        mv -f ".$$slug.meta.json" "$$slug.meta.json"; \
    done

################################################################################
# END
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