Multi-line search and inject new variable into helm templates.

multiline-mutator-v1.awk

#
# Multi-line search and inject new variable into helm templates.
#
# n.b. Works somewhat dynamically.
#

BEGIN {
    insertion = "{{- include \"bots.k8s-envvars\" . | indent 8 }}"
    expr_seq[0] = " +envFrom: *$"
    expr_seq[1] = "^{prefix1}(  )?- configMapRef: *$"
    expr_seq[2] = "^{prefix1}(  )?    name: bots-envvars *$"
    expr_seq[3] = "^{prefix1}env: *$"
    expr_idx = -1
    prefix1 = ""
    prefix2 = ""
}

# Skip empty and / or comment lines.
/^ *$/ || /^ *#/ {
    print $0
    next
}

expr_idx == length(expr_seq) {
    # Isolate any additional requisite leading spaces.
    prefix2 = gensub(/^( *).*$/, "\\1", "g", $0)
    print prefix2 insertion
    expr_idx = -1
}

{ print $0 }

# First line match.
expr_idx == -1 && $0 ~ expr_seq[0] {
    expr_idx = 1

    # Match subsequent expr_seq against any leading spaces.
    prefix1 = gensub(/^( *)[^ ]+.*$/, "\\1", "g", $0)

    # Replace template parameters in expressions.
    for (x in expr_seq) {
        expr_seq[x] = gensub(/[{]prefix1[}]/, prefix1, "g", expr_seq[x])
    }
    next
}

# Match next expression.
expr_idx != -1 && $0 ~ expr_seq[expr_idx] {
    expr_idx += 1
    next
}

# If this bock is reached, reset the state machine.
{
    expr_idx = -1
    next
}

multiline-mutator-v2.awk

#
# Multi-line search and inject new variable into helm templates.
#
# n.b. Works somewhat dynamically.
#

BEGIN {
    # n.b. valid values: "before" or "after".
    match_indent = "before"

    #insertion = "{{- include \"bots.k8s-envvars\" . | indent 8 }}"
    insertion = "{{- include \"bots.jfr-volume-mount\" . | indent 8 }}"
    insertion = "{{- include \"bots.jfr-volume\" . | indent 6 }}"
    #expr_seq[0] = " +envFrom: *$"
    #expr_seq[1] = "^{prefix1}(  )?- configMapRef: *$"
    #expr_seq[2] = "^{prefix1}(  )?    name: bots-envvars *$"
    #expr_seq[3] = "^{prefix1}env: *$"
    expr_seq[0] = "^ +[{][{]- include \"bots\\.log-volume-mount\""
    expr_seq[0] = "^ +[{][{]- include \"bots\\.log-volume\""
    expr_idx = -1
    prefix1 = ""
    prefix2 = ""
    done = 0
}

function do_insert() {
    if (expr_idx == length(expr_seq)) {
        # Isolate any additional requisite leading spaces.
        prefix2 = gensub(/^( *).*$/, "\\1", "g", $0)
        if (match_indent == "after") {
            printf prefix2
        } else {
            printf prefix1
        }
        print insertion
        expr_idx = -1
    }
}

# Skip empty and / or comment lines.
/^ *$/ || /^ *#/ {
    print $0
    next
}

do_insert()

{ print $0 }

# First line match.
expr_idx == -1 && $0 ~ expr_seq[0] {
    expr_idx = 1

    # Match subsequent expr_seq against any leading spaces.
    prefix1 = gensub(/^( *)[^ ]+.*$/, "\\1", "g", $0)

    # Replace template parameters in expressions.
    for (x in expr_seq) {
        expr_seq[x] = gensub(/[{]prefix1[}]/, prefix1, "g", expr_seq[x])
    }
    next
}

# Match next expression.
expr_idx != -1 && $0 ~ expr_seq[expr_idx] {
    expr_idx += 1
    next
}

# If this bock is reached, reset the state machine.
{
    expr_idx = -1
    next
}

function f() {
    print "HI"
    }

END {
    if (done == 0) {
        do_insert()
    }
}